Adjunctive Surgery Is Often Without Oncological Benefit at Time of Postchemotherapy Retroperitoneal Lymph Node Dissection

PURPOSE

Postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) for advanced nonseminomatous germ cell tumors (GCTs) aims to resect all remaining metastatic tissue. Resection of adjacent visceral or vascular organs is commonly performed for complete resection. Resection of organs harboring only necrosis results in relevant overtreatment. The study aimed to describe the frequency of metastatic involvement of resected organs with teratoma or viable cancer and to analyze perioperative complications and relapse-free survival.

MATERIALS AND METHODS

In a 2-center study, we reviewed a cohort of 1204 patients who underwent PC-RPLND between 2008 and 2021 and identified 242 (20%) cases of adjunctive surgery during PC-RPLND. We analyzed the removed adjacent structures and the pathohistological presence of GCT elements in the resected organs: viable GCT, teratoma, or necrosis/fibrosis. Surgery-associated complications were reported according to the Clavien-Dindo classification.

RESULTS

Viable GCT, teratoma, and necrosis were present in 54 (22%), 94 (39%), and 94 (39%), respectively, of all patients with adjunctive resection of adjacent organs. Vascular resections or reconstructions (n = 112; viable: 23%, teratoma: 41%, necrosis: 36%) were performed most frequently, followed by nephrectomies (n = 77; viable: 29%, teratoma: 39%, necrosis: 33%). Perioperative complications of grade ≥ IIIa occurred in 6.6% of all patients, with no difference between the viable GCT and teratoma/necrosis groups (P = .1). A total of 76 patients have been followed without a relapse for at least 36 months. Median follow-up of the whole cohort was 22 months (quartile 7 and 48). Patients with viable GCT/teratoma in the resected specimens had a significantly increased risk of recurrence by 5 years compared to patients with only necrosis (19% vs 59% vs 81%, P < .001).

CONCLUSIONS

This study shows that 33% to 40% of all resections of adjacent organs do not harbor teratoma or viable GCT. This highlights the need for better patient selection for these complex patients.

MicroRNA-371a-3p-The Novel Serum Biomarker in Testicular Germ Cell Tumors

INTRODUCTION

Testicular germ cell tumors (TGCTs) are a paradigm for the use of serum tumor markers in clinical management. However, conventional markers such as alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (hCG), and lactate dehydrogenase (LDH) have quite limited sensitivities and specificities. Within the last decade, the microRNA-371a-3p (miR371) emerged as a possible new biomarker with promising features.

AREAS COVERED

This review covers the typical features as well as possible clinical applications of miR371 in TGCT patients, such as initial diagnosis, therapy monitoring, and follow-up. Additionally, technical issues are discussed.

EXPERT OPINION

With a sensitivity of around 90% and specificity >90%, miR371 clearly outperforms the classical serum tumor markers in TGCTs. The unique features of the test involve the potential of modifying recent standards of care in TGCT. In particular, miR371 is expected to aid clinical decision-making in scenarios such as discriminating small testicular TGCT masses from benign ones prior to surgery, assessing equivocal lymphadenopathies, and monitoring chemotherapy results. Likewise, it is expected to make follow-up easier by reducing the intensity of examinations and by sparing imaging procedures. Overall, the data presently available are promising, but further prospective studies are required before the test can be implemented in standard clinical care.

Urology during Afghanistan mission: lessons learned and implications for the future

PURPOSE

Battle-related trauma is common in modern warfare and can lead to genitourinary injuries. In Western countries, urogenital injuries are rare in the civilian environment. The main objective of this study was to assess urological workload for surgeons on deployment.

MATERIAL AND METHODS

Data were acquired over a period of five years of deployment in a U.S. facility in Afghanistan.

RESULTS

German urological surgeons treated on average one urologic outpatient per day and performed 314 surgical interventions overall. Surgical interventions were categorized as battle-related interventions (BRIs, n = 169, 53.8%) and nonbattle-related interventions (non-BRIs, n = 145, 46.2%). In the BRI group, interventions were mainly performed on the external genitalia (n = 67, 39.6%), while in the non-BRI group, endourological procedures predominated (n = 109). This is consistent with a higher rate of abdominal or pelvic procedures performed in the BRI group (n = 51, 30.2%). Furthermore, the types of interventions performed on the external genitalia differed significantly. In the BRI group, 58.2% (n = 39) of interventions were scrotal explorations, but none of those procedures were performed in the non-BRI group (p < 0.001). However, 50.0% (n = 13) of scrotal explorations in the non-BRI group were due to suspected torsions of the testes followed by orchidopexy (BRI: n = 1, 1.5%, p < 0.001). Concerning outpatients, the consultation was mainly due to complaints concerning the external genitalia (32.7%, n = 252) or kidney/ureteral stones (23.5%, n = 181).

CONCLUSION

While the treatment of urological outpatients in a deployment setting resembles the treatment of soldiers in Germany, BRIs requires abdominal/retroperitoneal urosurgical skills and basic skills in reconstructive surgery.

German specialists treating testicular cancer follow different guidelines with resulting inconsistency in assessment of retroperitoneal lymph-node metastasis: clinical implications and possible corrective measures

BACKGROUND

Testicular germ cell tumors (GCTs) are aggressive but highly curable tumors. To avoid over/undertreatment, reliable clinical staging of retroperitoneal lymph-node metastasis is necessary. Current clinical guidelines, in their different versions, lack specific recommendations on how to measure lymph-node metastasis.

OBJECTIVE

We aimed to assess the practice patterns of German institutions frequently treating testicular cancer for measuring retroperitoneal lymph-node size.

METHODS

An 8-item survey was distributed among German university hospitals and members of the German Testicular Cancer Study Group.

RESULTS

In the group of urologists, 54.7% assessed retroperitoneal lymph nodes depending on their short-axis diameter (SAD) (33.3% in any plane, 21.4% in the axial plane), while 45.3% used long-axis diameter (LAD) for the assessment (42.9% in any plane, 2.4% in the axial plane). Moreover, the oncologists mainly assessed lymph-node size based on the SAD (71.4%). Specifically, 42.9% of oncologists assessed the SAD in any plane, while 28.5% measured this dimension in the axial plane. Only 28.6% of oncologists considered the LAD (14.3% in any plane, 14.3% in the axial plane). None of the oncologists and 11.9% of the urologists (n = 5) always performed an MRI for the initial assessment, while for follow-up imaging, the use increased to 36.5% of oncologists and 31% of urologists. Furthermore, only 17% of the urologists, and no oncologists, calculated lymph-node volume in their assessment (p = 0.224).

CONCLUSION

Clear and consistent measurement instructions are urgently needed to be present in all guidelines across different specialistic fields involved in testicular cancer management.

Quantitative, Phenotypical, and Functional Characterization of Cellular Immunity in Children and Adolescents With Down Syndrome

Background

Infections and autoimmune disorders are more frequent in Down syndrome, suggesting abnormality of adaptive immunity. Although the role of B cells and antibodies is well characterized, knowledge regarding T cells is limited.

Methods

Lymphocyte subpopulations of 40 children and adolescents with Down syndrome and 51 controls were quantified, and phenotype and functionality of antigen-specific effector T cells were analyzed with flow cytometry after polyclonal and pathogen-specific stimulation (with varicella-zoster virus [VZV] and cytomegalovirus [CMV]). Results were correlated with immunoglobulin (Ig) G responses.

Results

Apart from general alterations in the percentage of lymphocytes, regulatory T cells, and T-helper 1 and 17 cells, all major T-cell subpopulations showed higher expression of the inhibitory receptor PD-1. Polyclonally stimulated effector CD4+ T-cell frequencies were significantly higher in subjects with Down syndrome, whereas their inhibitory receptor expression (programmed cell death 1 [PD-1] and cytotoxic T-lymphocyte antigen 4 [CTLA-4]) was similar to that of controls and cytokine expression profiles were only marginally altered. Pathogen-specific immunity showed age-appropriate levels of endemic infection, with correlation of CMV-specific cellular and humoral immunity in all subjects. Among VZV IgG-positive individuals, a higher percentage of VZV-specific T-cell-positive subjects was seen in those with Down syndrome.

Conclusions

Despite alterations in lymphocyte subpopulations, individuals with Down syndrome can mount effector T-cell responses with similar phenotype and functionality as controls but may require higher effector T-cell frequencies to ensure pathogen control.

Characterization of C3dg binding to a recess formed between short consensus repeats 1 and 2 of complement receptor type 2 (CR2; CD21)

To allow for a better characterization of the ligand binding structures of human complement receptor type 2 (CR2; CD21), we have established an IgG1 kappa mouse mAb, FE8, that interferes efficiently with binding of C3dg and EBV to CR2. In contrast to mAb OKB7, the only well-characterized mAb with similar specificity, mAb FE8 blocked binding of soluble C3dg or particles carrying multiple copies of surface-bound C3dg to CR2 or induced complete removal of these ligands from the receptor. In vitro EBV infection of B lymphocytes, on the other hand, was abrogated by mAbs FE8 and OKB7 with similar dose-response characteristics. As FE8 was shown to recognize a discontinuous epitope, a series of overlapping peptides derived from SCR1 and -2 and immobilized on cellulose was screened with FE8. The results suggest that up to five discontinuous sequences contributed to the epitope. The sequence 63-EYFNKYS-69, located between the two SCR units, reacted most intensively. Two other sequences, 16-YYSTPI-21 and 105-NGNKSVWCQANN-116, are located between Cys1 and Cys2 of SCR1 and around Cys3 of SCR2, respectively. Based on the solution structure for two factor H SCRs, a three-dimensional model of SCR1 and -2 was generated. The FE8 binding peptide sequences were located in relative proximity to each other, bounding the recess formed between SCR1 and -2. This potential of mAb FE8 is currently unique and may be exploited for interfering with conditions of unwanted recognition of C3dg-coated structures by the immune system.

Expression in insect cells of the functional domain of CD21 (complement receptor type two) as a truncated soluble molecule using a baculovirus vector

We have made use of the plasmid vector pBSV-8His recently established for baculovirus-mediated expression of His-tagged proteins for the production of a truncated soluble complement regulator protein. The protein comprised the N-terminal part, i.e. short consensus repeats (SCRs) 1-4, of the B-cell membrane protein complement receptor type two (CR2; CD21) and contained the functional epitopes which mediate the binding of the complement component C3 fragments C3dg and iC3b. This recombinant protein, termed rsCR2.1-4, was furnished with a C-terminal histidine-tag for easy purification from insect cell supernatant. The yield of > 90% pure rsCR2.1-4 was 3 micrograms/ml supernatant at day eight p.i. RsCR2.1-4 was expressed as two proteins with a M(r) of 29 and 31 representing differentially glycosylated forms. Both reacted specifically with anti-CR2 mAb HB5 directed against SCRs 3-4, but not with anti-CR2 mAbs recognizing SCRs beyond SCR 4. RsCR2.1-4 was able to bind C3dg and to block binding of C3dg-coated beads to Raji cells. Used as antigen for immunization, it allowed the efficient and well-aimed generation of antisera which specifically blocked attachment of C3dg-coated beads to Raji B cells. Thus, insect cell derived rsCR2.1-4 has proved a valuable tool to study the functional domain of CR2 and its immunoregulatory capacity in B-lymphocytes.

A novel mechanism of alternative pathway complement activation accounts for the deposition of C3 fragments on CR2-expressing homologous cells

Complement receptor type 2 (CD21, CR2), the receptor for the C3 fragment C3dg, activates complement via the alternative pathway and also serves as a preferential acceptor site for C3 fragments. The molecular basis for this phenomenon, which has recently been demonstrated for B lymphocytes in vivo, is currently not understood. Here we present a model for this CR2-dependent complement activation. The inactive C3 (iC3), which forms spontaneously in serum in low amounts by reaction of native C3 with H2O, binds noncovalently to the N-terminal part of CR2. Subsequent association of properdin and factor B, and cleavage of factor B by factor D lead to formation of a C3 convertase associated with CR2, thus focussing covalent C3 deposition to CR2 itself. This model is supported by the following experimental findings. 1) By FACS analysis and radioreceptor assays we showed that iC3, properdin, and factor B bound to CR2 on Raji B cells, MT2 T cells, and peripheral blood B cells. 2) Both binding of these proteins and complement activation by CR2-expressing cells were reduced in parallel by Abs against CR2. 3) 125I-labeled C3b was covalently deposited on CR2, when hemolytically active 125I-labeled C3 was added to Raji cells preincubated with iC3, factor B, properdin, and factor D, thus proving functionality of CR2-bound C3 convertase. This model of C3 convertase activity formed on CR2 domains inaccessible for decay-accelerating factor offers an explanation for the deposition of C3 found on CR2-expressing cells.

A novel mechanism of alternative pathway complement activation accounts for the deposition of C3 fragments on CR2-expressing homologous cells

Complement receptor type 2 (CD21, CR2), the receptor for the C3 fragment C3dg, activates complement via the alternative pathway and also serves as a preferential acceptor site for C3 fragments. The molecular basis for this phenomenon, which has recently been demonstrated for B lymphocytes in vivo, is currently not understood. Here we present a model for this CR2-dependent complement activation. The inactive C3 (iC3), which forms spontaneously in serum in low amounts by reaction of native C3 with H2O, binds noncovalently to the N-terminal part of CR2. Subsequent association of properdin and factor B, and cleavage of factor B by factor D lead to formation of a C3 convertase associated with CR2, thus focussing covalent C3 deposition to CR2 itself. This model is supported by the following experimental findings. 1) By FACS analysis and radioreceptor assays we showed that iC3, properdin, and factor B bound to CR2 on Raji B cells, MT2 T cells, and peripheral blood B cells. 2) Both binding of these proteins and complement activation by CR2-expressing cells were reduced in parallel by Abs against CR2. 3) 125I-labeled C3b was covalently deposited on CR2, when hemolytically active 125I-labeled C3 was added to Raji cells preincubated with iC3, factor B, properdin, and factor D, thus proving functionality of CR2-bound C3 convertase. This model of C3 convertase activity formed on CR2 domains inaccessible for decay-accelerating factor offers an explanation for the deposition of C3 found on CR2-expressing cells.

Ca(2+)-dependent inactivation of P-type calcium channels in nerve terminals

Rapid Ca2+ signals evoked by K+ depolarization of rat cerebral cortical synaptosomes were measured by dual-channel Ca2+ spectrofluorometry coupled to a stopped-flow device. Kinetic analysis of the signal rise phase at various extracellular Ca2+ concentrations revealed that the responsible voltage-dependent Ca2+ channels, previously identified as P-type Ca2+ channels, inactivate owing to the rise in intracellular Ca2+ levels. At millimolar extracellular Ca2+ concentrations the channels were inactivated very rapidly and the rate was dependent on the high influx rate of Ca2+, thus limiting the Ca2+ signal amplitudes to 500-600 nM. A slower, probably voltage-dependent regulation appears to be effective at lower Ca2+ influx rates, leading to submaximal Ca2+ signal amplitudes. The functional feedback regulation of calcium channels via a sensor for intracellular Ca2+ levels appears to be responsible for the different inhibition characteristics of Cd2+ versus omega-agatoxin IVa.

GABAB-receptor-mediated inhibition of calcium signals in isolated nerve terminals

Time-resolved fluorometric monitoring of rapid changes in intracellular Ca(2+)-concentrations [Ca2+]i was employed to analyze the effect of gamma-aminobutyric acid (GABA) on evoked Ca(2+)-signals in rat hippocampal synaptosomes. The inhibitory action of GABA was mimicked by Baclofen, the selective agonist for GABAB-receptors, and also by the nonhydrolyzable GTP-derivative GTP-gamma-S. Preincubation of synaptosomes with GABA or baclofen for up to 250 ms before depolarization resulted in a maximal inhibition. The GABA-induced attenuation of the evoked rise in [Ca2+]i was maximal during the first milliseconds after depolarization. The inhibitory action of GABA apparently does not involve second messengers, such as cAMP or IP3/DAG; the GABA-induced inhibition of presynaptic voltage-dependent Ca(2+)-channels may be mediated directly by G-proteins.

Analysis of rapid calcium signals in synaptosomes

A combination of the stopped-flow technology with dual channel spectrofluorometry of Ca(2+)-indicators was utilized for the measurement of rapid Ca(2+)-signals in rat cerebral cortical synaptosomes evoked by K(+)-depolarization. There was no observable contribution of Ca(2+)-ions from intracellular stores to the rise in [Ca2+]i. The kinetics of the fast increase in intracellular Ca2+ concentration was analysed in relation to the depolarization strength. The maximal increase in [Ca2+]i and the time course of Ca(2+)-channel inactivation were determined for depolarizations obtained by different extracellular K(+)-concentrations ([K+]o). An apparent threshold was observed at about 18 mM [K+]o; a maximal Ca(2+)-signal amplitude was estimated at about 40 mM [K+]o. Pharmacological properties of the involved Ca(2+)-channels were determined using selective Ca(2+)-channel blockers (Dihydropyridines, omega-Conotoxin, omega-Agatoxins); the results suggest that a P-type voltage-dependent Ca(2+)-channel is the relevant channel type, generating the evoked Ca(2+)-signals in rat cerebral cortical synaptosomes.

[Comparative studies on the drug therapy of gonarthroses]

The clinical effectiveness of an anti-arthrotic drug was investigated in a comparative trial. 106 patients suffering from moderate arthrosis of the knee were placed into two groups in accordance with a random table and treated by intramuscular injection of Arteparon forte or an analogous control product. The criteria of assessment were pain on movement, pain at rest, limitation of active and of passive movement. The number of patients who at the end of treatment and at the time of follow up, three months later, had no or insignificant residual symptoms and signs, were greater in the Arteparon forte group than in the control group. This difference was statistically significant two months after the beginning of treatment for the criterion pain at rest, and five months after beginning of treatment for all criteria. A global assessment of the results was carried out according to the number of pronouncedly improved criteria in the individual patients. According to this assessment, the results of treatment at the termination of treatment amounted to 73.6% in the Arteparon forte group and 56.6% in the control group. At the time of follow up the corresponding value of the Arteparon forte group was 68.4%, thus significantly greater than that of the control group (29.4%).