Mass producible, robust SERS substrates based on metal film on nanosphere (MFON) on an adhesive substrate for detection of surface-adsorbed molecules and their evaluation by helium ion microscopy.

We have developed a SERS stamp that can be pressed directly onto a solid surface for characterization of surface-adsorbed target molecules. The stamp was fabricated by transfer of a dense monolayer of SiO2 nanospheres from a glass surface onto a piece of adhesive tape and subsequent evaporation of silver. The performance of the resulting SERS stamps was evaluated by their exposure to methyl mercaptan vapor, and immersion in rhodamine 6G and ferbam solutions. It was found that beside the nanosphere diameter and metal deposition thickness, the extent of burial of the nanospheres into the adhesive tape, dictated by the pressure during the nanosphere transfer process, had a significant effect. We carried out FDTD calculations of the near field. Models are based on morphological information obtained from helium ion microscopy, which can provide high-resolution images of poor electrical conductors such as our SERS stamp. While one of our main eventual goals is detection of pesticides on agricultural produce, we have begun to take a careful step by testing our SERS stamp on better characterized surfaces such as a porous gel surface, having been immersed in fungicides such as ferbam. We also present our preliminary results with ferbam on oranges. It is expected that our well-characterized SERS stamp will play a role in shedding light on the poorly studied transfer process of target molecules onto a SERS surface as well as serving as a new SERS platform.

Impact of dexamethasone in patients with aneurysmal subarachnoid haemorrhage.

BACKGROUND AND PURPOSE: The role of corticosteroids in the treatment of patients with aneurysmal subarachnoid haemorrhage (SAH) has remained controversial for decades. Recent studies have suggested that the administration of corticosteroids in SAH patients is associated with favourable outcomes. Given their significant adverse effects, it is essential to identify those patients who will benefit from treatment with corticosteroids. METHODS: A retrospective analysis of a prospectively collected cohort (n = 306) with SAH who were treated by microsurgical clipping or endovascular intervention was performed. The role of dexamethasone administration was analysed with regard to clinical conditions and SAH-related complications. Outcome was assessed at discharge and during follow-up using the Glasgow Outcome Scale (GOS). RESULTS: Patients treated with dexamethasone presented with more episodes of hyperglycaemia (P < 0.001), more overall infections (P < 0.001) and more ventriculostomy-related infections (P = 0.004). Multivariate analysis demonstrated that treatment with dexamethasone was associated with an unfavourable outcome at discharge (GOS 1-3) [odds ratio (OR) 2.814, 95% confidence interval (CI) 1.440-5.497, P = 0.002]. In the subgroup of microsurgically treated patients, dexamethasone administration was associated with a favourable outcome at follow-up (OR 0.193, 95% CI 0.06-0.621, P = 0.006). A higher risk for unfavourable outcome (OR 3.382, 95% CI 1.67-6.849, P = 0.001) at discharge was observed in endovascularly treated patients who received dexamethasone but this had no impact on the outcome at follow-up. CONCLUSIONS: Treatment with dexamethasone seems to be associated with a risk reduction for an unfavourable outcome in those patients who underwent microsurgical clipping. Despite an increased frequency of adverse effects, glucocorticoids may have a potential benefit in this specific surgical subgroup compared to endovascularly treated SAH patients.

Surgical management of pituitary metastases.

BACKGROUND: Pituitary metastases are rare and commonly described in case reports or small case series. Due to its rarity this entity is not subject to standardized treatment guidelines, there is debate about typical initial symptoms that may lead to finding the correct diagnosis and information about the clinical course is also sparse. METHODS: We have conducted a retrospective analysis of patients with pituitary metastases who were surgically treated via a transsphenoidal procedure at our institution between 2006 and 2014. Underlying primary disease, clinical and surgical course as well as adjuvant radiotherapy and follow-up data are presented. RESULTS: 14 patients met the inclusion criteria (8 female, 6 male). Mean age was 61.5 years. Most patients became symptomatic with visual symptoms--both visual deterioration and/or diplopia (n = 13)--and anterior lobe insufficiency (n = 8). Surprisingly diabetes insipidus was only seen in three patients. All patients underwent transsphenoidal surgery initially, four patients had to undergo surgery for residual tumor or recurrence, two of them via a transcranial route. Breast cancer was the most common entity (n = 6), followed by prostate cancer (n = 3), nsclc (n = 2) and melanoma, thyroid cancer and renal cancer in one case each. Postoperative MRI showed gross total resection in four cases and residual disease in eight cases (subtotal resection, partial resection and biopsy), two patients files were incomplete regarding MRI-results. All patients underwent adjuvant radiotherapy. Survival after the initial diagnosis of cancer was 36 and 16 months after diagnosis of pituitary metastases. CONCLUSION: Our results indicate that transsphenoidal surgery is a safe method to resect pituitary metastases and that the extend of resection does not have an influence on survival time. Our results also indicate that diabetes insipidus may not be the most common initial symptom of pituitary metastases and lack thereof should not lead to making a wrong diagnosis and delaying appropriate therapy.

NDRG1 prognosticates the natural course of disease in WHO grade II glioma.

There is a lack of relevant prognostic and predictive factors in neurooncology besides mutation of isocitrate dehydrogenase 1, codeletion of 1p/19q and promoter hypermethylation of O (6) -methylguanine-DNA-methyltransferase. More importantly, there is limited translation of these factors into clinical practice. The cancer genome atlas data and also clinical correlative analyses suggest a pivotal role for the epidermal growth factor receptor /protein kinase B/mammalian target of rapamycin (mTOR) pathway in both biology and the clinical course of gliomas. However, attempts to stratify gliomas by activating alterations in this pathway have failed thus far. The tumors of 40 patients with WHO grade II gliomas without immediate postoperative genotoxic treatment and known progression and survival status at a median follow-up of 12.2 years were analyzed for expression of the mTOR complex 2 downstream target N-myc downstream regulated gene (NDRG)1 using immunohistochemistry. Baseline characteristics for NDRG1 absent/low versus moderate/high patients were similar. Time to reintervention was significantly longer in the NDRG1 group (P = 0.026). NDRG1 may become a novel biomarker to guide the decision which WHO°II glioma patients may be followed without postsurgical intervention and which patients should receive genotoxic treatment early on. Validation of this hypothesis will be possible with the observational arm of the RTOG 9802 and the pretreatment step of the EORTC 22033/26032 trials.

Long-term follow-up and quality of life in patients with intracranial germinoma.

Intracranial germinomas are fairly rare tumors occurring mostly in children or young adults with a comparatively good prognosis. Radiation is the preferred treatment of choice for this diagnosis. It has been thoroughly studied to what extent radiation doses and fields can be limited in order to avoid side effects in these young patients. The role of chemotherapy remains unclear, whereas surgery is limited to biopsy for proof of histology. Regarding the good overall survival rate, quality of life is a significant aspect to consider in these patients. We present a single institution analysis of patients with intracranial germinoma and analyze the long-term outcome with special regard to quality of life. Thirty-three patients with intracranial germinomas were analyzed by chart review, telephone interview, and neurological assessment. Additionally, a survey on quality of life was performed. The 10-year overall survival rate was 82.1 % at a mean follow-up of 141 (22-306) months. Three quarters (76 %) of the patients reached a favorable neurological outcome on the Modified Rankin Scale (mRS 0-2). However, the self-reported quality of life was significantly worse in germinoma patients compared with a healthy control group (p < 0.001). Surgical resection of the tumor led to no improvement regarding overall survival, neurological outcome, and quality of life. In terms of cognitive functioning, patients with tumor resection were significantly more impaired than biopsied patients (p = 0.04). Although germinomas are efficiently treatable tumors, the restrictions in quality of life in these often young patients are considerable, including financial difficulties. There seems no justification for tumor resection in newly diagnosed cases suspicious for germinoma as the cognitive outcome is worse than in biopsied patients, and there is no effect on overall survival.

Chytrid infections exhibit historical spread and contemporary seasonality in a declining stream-breeding frog.

Species with extensive geographical ranges pose special challenges to assessing drivers of wildlife disease, necessitating collaborative and large-scale analyses. The imperilled foothill yellow-legged frog (Rana boylii) inhabits a wide geographical range and variable conditions in rivers of California and Oregon (USA), and is considered threatened by the pathogen Batrachochytrium dendrobatidis (Bd). To assess drivers of Bd infections over time and space, we compiled over 2000 datapoints from R. boylii museum specimens (collected 1897-2005) and field samples (2005-2021) spanning 9° of latitude. We observed a south-to-north spread of Bd detections beginning in the 1940s and increase in prevalence from the 1940s to 1970s, coinciding with extirpation from southern latitudes. We detected eight high-prevalence geographical clusters through time that span the species' geographical range. Field-sampled male R. boylii exhibited the highest prevalence, and juveniles sampled in autumn exhibited the highest loads. Bd infection risk was highest in lower elevation rain-dominated watersheds, and with cool temperatures and low stream-flow conditions at the end of the dry season. Through a holistic assessment of relationships between infection risk, geographical context and time, we identify the locations and time periods where Bd mitigation and monitoring will be critical for conservation of this imperilled species.

Insights from a Multicenter Study on Adult H3 K27M-Mutated Glioma: Surgical Resection's Limited Influence on Overall Survival, ATRX as Molecular Prognosticator.

BACKGROUND: H3 K27M-mutated gliomas were first described as a new grade 4 entity in the 2016 WHO classification. Current studies have focused on its typical appearance in children and young adults, increasing the need to better understand the prognostic factors and impact of surgery on adults. Here, we report a multicentric study of this entity in adults. METHODS: We included molecularly confirmed H3 K27M-mutated glioma cases in patients >18 years diagnosed between 2016 and 2022. Clinical, radiological, and surgical features were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors. RESULTS: Among 70 patients with a mean age of 36.1 years, the median overall survival (OS) was 13.6 + 14 months. Gross-total resection was achieved in 14.3% of patients, whereas 30% had a subtotal resection and 54.3% a biopsy.Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location in the mesencephalon/metencephalon showed a significantly longer OS (8.7 vs. 25.0 months, p=0.007). Preoperative Karnofsky Performance Score (KPS) < 80 showed a reduced OS (4.2 vs. 18 months, p=0.02). Furthermore, ATRX loss, found in 25.7%, was independently associated with an increased OS (31 vs. 8.3 months, p=0.0029). Notably, patients undergoing resection showed no survival benefit over biopsy (12 vs. 11 months, p=0.4006). CONCLUSION: The present study describes surgical features of H3 K27M-mutated glioma in adulthood in a large multicentric study. Our data reveal that ATRX status, location and KPS significantly impact OS in H3 K27M-mutated glioma. Importantly, our dataset indicates that resection does not offer a survival advantage over biopsy.

Gross total but not incomplete resection of glioblastoma prolongs survival in the era of radiochemotherapy.

BACKGROUND: This prospective multicenter study assessed the prognostic influence of the extent of resection when compared with biopsy only in a contemporary patient population with newly diagnosed glioblastoma. PATIENTS AND METHODS: Histology, O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, and clinical data were centrally analyzed. Survival analyses were carried out with the Kaplan-Meier method. Prognostic factors were assessed with proportional hazard models. RESULTS: Of 345 patients, 273 underwent open tumor resection and 72 biopsies; 125 patients had gross total resections (GTRs) and 148, incomplete resections. Surgery-related morbidity was lower after biopsy (1.4% versus 12.1%, P = 0.007). 64.3% of patients received radiotherapy and chemotherapy (RT plus CT), 20.0% RT alone, 4.3% CT alone, and 11.3% best supportive care as an initial treatment. Patients ≤60 years with a Karnofsky performance score (KPS) of ≥90 were more likely to receive RT plus CT (P < 0.01). Median overall survival (OS) (progression free survival; PFS) ranged from 33.2 months (15 months) for patients with MGMT-methylated tumors after GTR and RT plus CT to 3.0 months (2.4 months) for biopsied patients receiving supportive care only. Favorable prognostic factors in multivariate analyses for OS were age ≤60 years [hazard ratio (HR) = 0.52; P < 0.001], preoperative KPS of ≥80 (HR = 0.55; P < 0.001), GTR (HR = 0.60; P = 0.003), MGMT promoter methylation (HR = 0.44; P < 0.001), and RT plus CT (HR = 0.18, P < 0.001); patients undergoing incomplete resection did not better than those receiving biopsy only (HR = 0.85; P = 0.31). CONCLUSIONS: The value of incomplete resection remains questionable. If GTR cannot be safely achieved, biopsy only might be used as an alternative surgical strategy.

The combination of carmustine wafers and temozolomide for the treatment of malignant gliomas. A comprehensive review of the rationale and clinical experience.

Current treatment strategies in patients with newly-diagnosed glioblastoma include surgical resection with post-operative radiotherapy and concomitant/adjuvant temozolomide (the "Stupp protocol") or resection with implantation of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) wafers in the surgical cavity followed by radiotherapy. In clinical practice, patients with malignant glioma treated with BCNU wafer often also receive adjuvant temozolomide. However, current treatment guidelines are unclear on whether and how these treatment practices can be combined, and no prospective phase 3 study has assessed the safety and efficacy of combining BCNU wafers with temozolomide and radiation in high-grade malignant glioma. The rationale for multimodal therapy comprising surgical resection with adjunct local BCNU wafers followed by radiotherapy and temozolomide is based on complementary and synergistic mechanisms of action between BCNU and temozolomide in preclinical studies; a shared primary resistance pathway, methylguanine-DNA methyltransferase (MGMT); and the opportunity to overcome resistance through MGMT depletion to boost cytotoxic activity. A comprehensive review of the literature identified 19 retrospective and prospective studies investigating the use of this multimodal strategy. Median overall survival in 14 studies of newly-diagnosed patients suggested a modest improvement versus resection followed by Stupp protocol or resection with BCNU wafers, with an acceptable and manageable safety profile.

MGMT promoter methylation status and prognosis of patients with primary or recurrent glioblastoma treated with carmustine wafers.

The prognostic role of O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastoma patients treated with carmustine (BCNU) wafer implantation is unclear. Here, we report on a retrospective study of 47 patients with either newly diagnosed (30 patients) or recurrent (17 patients) glioblastoma (WHO grade IV) treated with BCNU (bis-chloroethylnitrosourea) wafers. Thirteen of the newly diagnosed patients received local BCNU and irradiation only (first-line BCNU), while 17 patients additionally received concomitant and adjuvant temozolomide (TMZ) radiochemotherapy (first-line BCNU + TMZ). Of the 17 patients treated for recurrent glioblastoma (second-line BCNU), 16 had received radiotherapy with concomitant and adjuvant TMZ as an initial treatment. Median overall survival (OS) did not significantly differ between 19 patients with MGMT promoter methylated tumors when compared to 28 patients with unmethylated tumors (18.9 vs 15.0 months; p = 0.1054). In the first-line BCNU + TMZ group, MGMT promoter methylation was associated with longer OS (21.0 vs 11.1 months, p = 0.0127), while no significant survival differences were detected in the other two subgroups. Progression-free survival did not significantly differ between patients with and without MGMT promoter methylated tumors in the entire patient cohort or any of the three subgroups. The first-line BCNU + TMZ group showed no significant difference in OS when compared to the first-line BCNU group (18.9 vs 14.7 months), but tended to have more therapy-related adverse effects (53% vs 24%, p = 0.105). In summary, MGMT promoter methylation showed a non-significant trend toward longer survival in our patient cohort. The combination of TMZ radiochemotherapy with local delivery of BCNU did not provide a significant survival benefit compared to local BCNU alone, but was associated with a higher rate of adverse effects. Owing to the small number of patients investigated, however, these findings would need to be corroborated in larger patient cohorts.

Efficacy and safety of 10% HES 130/0.4 versus 10% HES 200/0.5 for plasma volume expansion in cardiac surgery patients.

AIM: Hydroxyethyl starch (HES) solutions are frequently used for perioperative volume replacement. Whereas older HES specimen tended to accumulate in the plasma and to cause negative effects on hemostasis, more recent products, e.g., HES 130/0.4, are characterised by improved pharmacological properties. The present study was designed to compare the efficacy and safety of 10% HES 130/0.4 and 10% HES 200/0.5. METHODS: In this post-hoc analysis of a prospective, randomised, double-blind, multi-center therapeutic equivalence trial, 76 patients undergoing elective on-pump cardiac surgery received perioperative volume replacement using either 10% HES 130/0.4 (N.=37) or 10% HES 200/0.5 (N.=39) up to a maximum dose of 20 mL kg-1. RESULTS: Equivalent volumes of investigational medication were infused until 24 hours after the first administration (1577 vs. 1540 mL; treatment difference 37 [-150; 223] mL; P<0.0001 for equivalence). Whereas standard laboratory tests of coagulation were comparable between groups, von Willebrand factor activity on the first postoperative morning tended to be higher following treatment with 10% HES 130/0.4 as compared to 10% HES 200/0.5 (P=0.025) with this difference being statistically significant only in the per-protocol analysis (P=0.02). Treatment groups were comparable concerning other safety parameters and the incidence of adverse drug reactions. In particular, renal function was well preserved in both groups. CONCLUSION: Ten percent HES 130/0.4 was equally effective and safe as compared to 10% HES 200/0.5 for volume therapy in patients undergoing cardiovascular surgery. Postoperative coagulation and renal function, as measured by standard laboratory tests, were similar among groups.

Experiences with a 3D4K Digital Exoscope System (ORBEYE) in a Wide Range of Neurosurgical Procedures.

BACKGROUND: Exoscopic 3D4K video systems (EX) have recently been introduced as an alternative to conventional operating microscopes (OM). However, experience in handling and setup remains scarce. This study evaluated the practicability of exoscopic surgery in a wide range of procedures. MATERIAL AND METHODS: All EX operations performed between August 2018 and May 2020 were evaluated and compared with procedures using OM. A standardized questionnaire was used to evaluate surgeons' comfort, image quality (including fluorescence modes), and handling. RESULTS: In all, 513 EX operations were performed during the investigated period. EX was generally rated as a valuable surgical tool. In particular, the digital 5-aminolevulinic acid (5-ALA) fluorescence and the comfort level of posture during surgery were stated to be superior to OM (100 and 83%, respectively). CONCLUSION: EX has been used for a significant number of neurosurgical procedures. While presuming that the technical methodology as such will not influence outcome of glioma surgery, proof of equipoise between different techniques expands the spectrum of surgical environments giving neurosurgeons a choice to work according to their preferred ergonomics.

A survey on clinical study participation and study infrastructure at non-university hospitals in Germany.

OBJECTIVE: In order to participate in multicenter clinical trials a fair amount of infrastructure and human resources has to be provided by hospitals. Therefore clinical trials are carried out predominantly in university hospitals. Data concerning participation in clinical trials and the infrastructure of study centers in non-university hospitals in Germany do not exist. A survey was thus conducted to evaluate the current status of clinical study performance in non-university hospitals. MATERIALS AND METHODS: A questionnaire comprising 10 questions covering hospital infrastructure, local study history, and the individual interest in performing studies was sent to 790 non-university hospitals in Germany. RESULTS: 58.7% of questionnaires were returned for evaluation. 74.1% of nonuniversity hospitals participate in clinical studies. Hospital size is a significant predictor of study participation. 25.5% of hospitals have established a multidisciplinary study center. 86.2% have a certified study nurse and in 34.5% this nurse is the only person running the study center. Only 25.5% of hospitals were not interested in participating in clinical studies at all, even if an individual tailored concept were to be offered. CONCLUSIONS: The demand for more hospitals to participate in clinical trials is urgent since high quality studies are a fundamental part of clinical research. Even though 75% of non-university hospitals in Germany already participate in clinical trials, it may be possible to increase this number. In addition by establishing and developing study centers in hospitals the quality of studies will presumably rise, and due to the concentration of study resources, the number of clinical trials may increase.

How to deal with incompletely treated AVMs: experience of 67 cases and review of the literature.

INTRODUCTION: Despite the availability of multimodal treatment options, some arteriovenous malformations remain difficult to treat, either for intrinsic reasons at initial presentation or for reasons evolving during the course of treatment. Frequently, such cases can be easily resolved with further therapy, but some become a continuously growing treatment dilemma while exhausting dwindling therapeutic options. PATIENTS AND METHODS: A retrospective analysis was performed to identify patients with cerebral AVM who were treated unsuccessfully. Treatment was termed "not successful" if (1) postoperative angiography showed a residual AVM or missing flow reduction after palliative embolization, (2) therapy was associated with a substantial deterioration of existing neurological deficits or death, or (3) rebleeding from residual AVM occurred after therapy. Special interest was focused on the angiographic appearance of residual AVMs, their characteristic features, and their follow-up regarding second and third therapies. RESULTS: According to these criteria we identified 46 internal patients from our own series of 474 patients and 21 external patients who were referred from other institutions or sought a second opinion after incomplete treatment elsewhere. Out of those 67 cases, 50 patients (74.6%) were diagnosed with a residual AVM. Eleven patients (16.4%) experienced a deterioration of their clinical condition under therapy. Six patients did not show a flow reduction after palliative embolization. Twenty-five of the 67 patients were readmitted because of an ICH, either originating from an AVM residual or under palliative embolization. Thus, an increased risk of re-hemorrhage was found for palliative embolization (n = 16) in partially treated lesions (n = 10) and in patients with AVM grade IV and V located in eloquent regions (n = 22). In dealing with residual AVMs, microsurgical resection alone or in combination was found to be the most efficient therapeutic option, being successful in 58.9% of cases. CONCLUSION: An estimated 10% of AVM treatments may fail because of inadequate selection of either patients or management. Besides, for thorough decision-making, angiographic follow-up in all AVM patients is mandatory to allow an early identification of patients with an incompletely treated AVM requiring a second attempt. Major attention should be focused especially on high-risk subgroups with complex AVMs, partially treated AVMs, or those treated by only a palliative regimen.

Molecular phylogeny of the subfamily Amphistichinae (Teleostei: Embiotocidae) reveals parallel divergent evolution of red pigmentation in two rapidly evolving lineages of sand-dwelling surfperch.

Pigment evolution was reconstructed in the subfamily Amphistichinae, a six-species clade of the surfperches, family Embiotocidae. Assignment was confirmed for all species within the subfamily, but low levels of differentiation were found among species within the subfamily, suggesting a recent radiation. The new phylogeny differs from previous hypotheses by the placement of the spotfin surfperch Hyperprosopon anale at the base of the subfamily, while still preserving the calico surfperch Amphistichus koelzi and the redtailed surfperch Amphistichus rhodoterus as sister species. Phenotypically, A. rhodoterus, A. koelzi and the silver surfperch Hyperprosopon ellipticum express high levels of red pigmentation. The barred surfperch, Amphistichus argenteus and the walleye surfperch Hyperprosopon argenteum express little to no red pigment, while basal H. anale expresses an intermediate amount of red pigment. Red pigmentation is proposed to have experienced parallel divergent evolution in each genus within the subfamily.

Proton beam therapy for loco-regional control of a recurrent mixed malignant germ cell tumor of the skull in a 22-month-old girl.

BACKGROUND: Germ cell tumors (GCT) situated in the head and neck region are very rare and occur predominantely in newborns or young infants. Recurrent CTs are often resectable only by mutilating surgery and the need for alternative treatment strategies is obvious. In this situation radiation therapy is the most important treatment option for loco-regional tumor control, but bear in this area the risk of possible impairment of brain function and face deformation as long term effects. CASE REPORT: In a girl with a connatal expansive growing teratoma of the skull the tumor recurred in spite of repeated surgery as mixed malignant GCT at the age of 15 months. Tumor control could not be achieved with chemotherapy and additional surgery seemed not promising. Therefore high dose proton beam therapy (PT) (54 Gy) has been administered to the child at the age of 22 months and led to local tumor control with only mild side effects. CONCLUSION: PT treatment may be an option for specific clinical conditions in germ cell tumors where local tumor control cannot be achieved by chemotherapy and/or surgery and long lasting side effects of conventional radiotherapy due to tumor localization and age have to be considered. However, PT should be implemented in treatment protocols for specific situations to guarantee supervised application, central documentation and follow-up.

[Local therapy of primary brain tumors]. / Lokale Therapien bei hirneigenen Tumoren.

In recent years further forms of local treatment for primary brain tumors have been developed in addition to resection and radiation. There are basically three principles for local therapy, intralesional therapy for primary or recurrent non-resectable tumors as well as intracavitary and pericavitary therapy following microscopic surgical complete resection. Local therapy procedures are complex and suffer from special difficulties in the evaluation of their effectiveness by imaging techniques, because they are inevitably accompanied by alterations in the imaging, barrier disturbances and contrast medium uptake.

G protein beta subunit-null mutants are impaired in phagocytosis and chemotaxis due to inappropriate regulation of the actin cytoskeleton.

Chemotaxis and phagocytosis are basically similar in cells of the immune system and in Dictyostelium amebae. Deletion of the unique G protein beta subunit in D. discoideum impaired phagocytosis but had little effect on fluid-phase endocytosis, cytokinesis, or random motility. Constitutive expression of wild-type beta subunit restored phagocytosis and normal development. Chemoattractants released by cells or bacteria trigger typical transient actin polymerization responses in wild-type cells. In beta subunit-null cells, and in a series of beta subunit point mutants, these responses were impaired to a degree that correlated with the defect in phagocytosis. Image analysis of green fluorescent protein-actin transfected cells showed that beta subunit- null cells were defective in reshaping the actin network into a phagocytic cup, and eventually a phagosome, in response to particle attachment. Our results indicate that signaling through heterotrimeric G proteins is required for regulating the actin cytoskeleton during phagocytic uptake, as previously shown for chemotaxis. Inhibitors of phospholipase C and intracellular Ca2+ mobilization inhibited phagocytosis, suggesting the possible involvement of these effectors in the process.

[Sepsis-associated Guillain-Barré syndrome]. / Das Sepsis-assoziierte Guillain-Barré-Syndrom.

This article reports on the case of a multiple trauma patient, who was admitted to the intensive care unit with haemorrhagic shock and severe hypoxaemia. Following posttraumatic septic shock the patient developed quadriplegia 3 weeks after admittance. After having excluded any traumatic and cerebral origins, an analysis of the cerebrospinal fluid was performed and revealed a"dissociation albuminocytologique". This finding in association with limb quadriplegia led to the diagnosis of Guillain-Barré syndrome. Therapy with high-dose i.v. immunoglobulins led to a complete recovery.