Laser-Induced Axotomy of Human iPSC-Derived and Murine Primary Neurons Decreases Somatic Tau and AT8 Tau Phosphorylation: A Single-Cell Approach to Study Effects of Acute Axonal Damage.

The microtubule-associated protein Tau is highly enriched in axons of brain neurons where it regulates axonal outgrowth, plasticity, and transport. Efficient axonal Tau sorting is critical since somatodendritic Tau missorting is a major hallmark of Alzheimer's disease and other tauopathies. However, the molecular mechanisms of axonal Tau sorting are still not fully understood. In this study, we aimed to unravel to which extent anterograde protein transport contributes to axonal Tau sorting. We developed a laser-based axotomy approach with single-cell resolution and combined it with spinning disk confocal microscopy enabling multi live-cell monitoring. We cultivated human iPSC-derived cortical neurons and mouse primary forebrain neurons in specialized chambers allowing reliable post-fixation identification and Tau analysis. Using this approach, we achieved high post-axotomy survival rates and observed axonal regrowth in a subset of neurons. When we assessed somatic missorting and phosphorylation levels of endogenous human or murine Tau at different time points after axotomy, we surprisingly did not observe somatic Tau accumulation or hyperphosphorylation, regardless of their regrowing activity, consistent for both models. These results indicate that impairment of anterograde transit of Tau protein and acute axonal damage may not play a role for the development of somatic Tau pathology. In sum, we developed a laser-based axotomy model suitable for studying the impact of different Tau sorting mechanisms in a highly controllable and reproducible setting, and we provide evidence that acute axon loss does not induce somatic Tau accumulation and AT8 Tau phosphorylation. UV laser-induced axotomy of human iPSC-derived and mouse primary neurons results in decreased somatic levels of endogenous Tau and AT8 Tau phosphorylation.

[Diagnostics and clinical management of premalignant diseases of the pancreas]. / Diagnostik und klinisches Management prämaligner Erkrankungen des Pankreas.

Pancreatic cancer is one of the most aggressive solid tumors and still has a poor prognosis. A delayed diagnosis at advanced stages and a poor response to systemic treatment frequently make a curative treatment impossible. Therefore, the identification of high-risk patients and screening them regularly is the most promising approach to improve the prognosis. Chronic pancreatitis as well as neoplastic pancreatic cysts can greatly increase the risk of developing pancreatic cancer. Furthermore, familial syndromes and germline mutations also confer an increased risk for development of pancreatic cancer. This article provides an overview of the various premalignant diseases of the pancreas. The value of the various imaging modalities, such as magnetic resonance imaging and endosonography are particularly discussed as well as the screening interval and the indications for surgical treatment are explained.

Study protocol P-MAPS: microbiome as predictor of severity in acute pancreatitis-a prospective multicentre translational study.

BACKGROUND: Acute pancreatitis (AP) is an inflammatory disorder that causes a considerable economic health burden. While the overall mortality is low, around 20% of patients have a complicated course of disease resulting in increased morbidity and mortality. There is an emerging body of evidence that the microbiome exerts a crucial impact on the pathophysiology and course of AP. For several decades multiple clinical and laboratory parameters have been evaluated, and complex scoring systems were developed to predict the clinical course of AP upon admission. However, the majority of scoring systems are determined after several days and achieve a sensitivity around 70% for early prediction of severe AP. Thus, continued efforts are required to investigate reliable biomarkers for the early prediction of severity in order to guide early clinical management of AP patients. METHODS: We designed a multi-center, prospective clinical-translational study to test whether the orointestinal microbiome may serve as novel early predictor of the course, severity and outcome of patients with AP. We will recruit 400 AP patients and obtain buccal and rectal swabs within 72 h of admission to the hospital. Following DNA extraction, microbiome analysis will be performed using 3rd generation sequencing Oxford Nanopore Technologies (ONT) for 16S rRNA and metagenomic sequencing. Alpha- and beta-diversity will be determined and correlated to the revised Atlanta classification and additional clinical outcome parameters such as the length of hospital stay, number and type of complications, number of interventions and 30-day mortality. DISCUSSION: If AP patients show a distinct orointestinal microbiome dependent on the severity and course of the disease, microbiome sequencing could rapidly be implemented in the early clinical management of AP patients in the future. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04777812.

Understanding the relationship between patient language and outcomes in internet-enabled cognitive behavioural therapy: A deep learning approach to automatic coding of session transcripts.

Objective: Understanding patient responses to psychotherapy is important in developing effective interventions. However, coding patient language is a resource-intensive exercise and difficult to perform at scale. Our aim was to develop a deep learning model to automatically identify patient utterances during text-based internet-enabled Cognitive Behavioural Therapy and to determine the association between utterances and clinical outcomes. Method: Using 340 manually annotated transcripts we trained a deep learning model to categorize patient utterances into one or more of five categories. The model was used to automatically code patient utterances from our entire data set of transcripts (∼34,000 patients), and logistic regression analyses used to determine the association between both reliable improvement and engagement, and patient responses. Results: Our model reached human-level agreement on three of the five patient categories. Regression analyses revealed that increased counter change-talk (movement away from change) was associated with lower odds of both reliable improvement and engagement, while increased change-talk (movement towards change or self-exploration) was associated with increased odds of improvement and engagement. Conclusions: Deep learning provides an effective means of automatically coding patient utterances at scale. This approach enables the development of a data-driven understanding of the relationship between therapist and patient during therapy.

Ventricular assist device therapy and heart transplantation: Benefits, drawbacks, and outlook.

End-stage heart failure is associated with significant morbidity and mortality. Heart transplantation has the potential to offer a return to daily activities for critically ill patients and is the gold standard therapy. However, heart transplantations are decreasing yearly with a historic low in Germany in 2017. By striking contrast, both waiting list numbers and waiting time have increased owing to a lack of acceptable donor organs. Ventricular assist devices (VAD) represent a reasonable therapeutic alternative for patients on heart transplantation waiting lists. Patients ineligible for transplantation may undergo VAD implantation as a destination therapy. However, the necessity for life-long anticoagulation must be weighed against bleeding complications in potential VAD candidates. VAD-dependent patients also face risks of driveline infections, in addition to restricted activities of daily living owing to limited battery capacities. Given Germany's low transplantation rate, VAD implantation may serve as a middle ground. With the recent events in transplantation medicine, trust among the German population has declined. Transplant centers must ensure graft quality and ongoing care, define minimum caseload for accreditation, and implement specialty care units in heart failure. Furthermore, the legislation shift from extended consent to dissent solution has the potential to end donor organ shortage.

Effects of morcellation on long-term outcomes in patients with uterine leiomyosarcoma.

OBJECTIVES: Clinical long-term outcomes of women with uterine leiomyosarcoma (ULMS) with different types of hysterectomy (open abdominal, vaginal, laparoscopic and switch from laparoscopic to open abdominal) were compared according to morcellation and other factors. MATERIALS: The clinical cancer registry Regensburg (Germany) registered 64 patients between 2004 and 2013 with ULMS. A retrospective cohort analysis was performed using the Kaplan-Meier method to estimate 5-year overall survival (OAS), recurrence-free survival (RFS) and recurrence rates. To compare surgery with or without morcellation log rank test was used. To adjust for age, FIGO stage, grading and other factors multivariable Cox regression models were applied to estimate hazard ratios (HR). RESULTS: In the cohort of 64 patients 15 underwent morcellation, preferably during laparoscopic surgery. Although numbers were small we performed analysis for OAS and RFS. Median OAS for morcellation was 10.6 vs. 6.4 years for non morcellation. 5y-OAS was 76.0 % for morcellation compared to 54.8 % in patients without morcellation (p = 0.115). Cox regression models rendered an unadjusted (univariable) HR 0.428 for morcellation vs. non-morcellation (p = 0.125) and an adjusted (multivariable) HR 0.644 (p = 0.406). 5y-RFR was 64.0 % compared to 42.8 % in patients without morcellation (p = 0.104; unadjusted HR 0.484, p = 0.111; adjusted HR 0.607, p = 0.306). CONCLUSION: In general, the prognosis of patients with ULMS is poor. In our cohort, women who underwent hysterectomy with morcellation had a better cumulative OAS and RFS than women without morcellation. Although we adjusted for differences between women with and without morcellation regarding age, grading and stage, there were no statistically significant differences between the groups.

Effect of ultra-low-dose estriol and lactobacilli vaginal tablets (Gynoflor®) on inflammatory and infectious markers of the vaginal ecosystem in postmenopausal women with breast cancer on aromatase inhibitors.

This study was a detailed microscopic analysis of the changes of vaginal microflora characteristics after application of 0.03 mg estriol-lactobacilli combination on the vaginal ecosystem in postmenopausal breast cancer (BC) survivors on aromatase inhibitors (AI) with severe atrophic vaginitis. A total of 16 BC women on AI applied daily one vaginal tablet of Gynoflor® for 28 days followed by a maintenance therapy of three tablets weekly for 8 weeks. During four follow up visits a smear from the upper lateral vaginal wall was analysed by phase contrast microscopy at 400 times magnification in order to classify the lactobacillary grades(LBG), bacterial vaginosis (BV), aerobic vaginitis (AV), vulvovaginal candidosis (VVC), proportional number of leukocytes and evidence of parabasal cells and epitheliolysis. LBG improved from 81% LBG-III at entry to 88% LBG-I&IIa after 2 weeks of initial therapy, which further improved upon follow up (p < 0.001). Whereas BV was a rare event, AV was frequent and substantially improved during treatment (p < 0.01). While at entry most patients had moderate or severe AV, after maintenance therapy no patient except one had AV. The number of leukocytes dropped dramatically from a score of 1.78 ± 0.70 to 1.06 ± 0.25 which was consistent till the end of the study (p < 0.01). Parabasal cells dropped from a score of 3.4 ± 0.64 at entry to 1.3 ± 0.60 at the final visit (p trend < 0.01). Starting from a low rate of Candida colonisation of 2/14 (14%), a sudden rise to 7/16 (44%) occurred after 2 weeks, to return back to base levels at subsequent visits. The vaginal use of ultra-low dose estriol and lactobacilli results in rapid and enduring improvement of all markers of the vaginal microflora and epithelial vaginal cell quality in women with breast cancer on AI with dyspareunia. Candida may develop soon after its use, but rapidly disappears again upon their prolonged use. Due to its excellent safety profiles and clinical efficacy we recommend this product as first choice in women on AI with severe dyspareunia.

Vaginal estriol-lactobacilli combination and quality of life in endocrine-treated breast cancer.

OBJECTIVE: We investigated the effect of a combination of vaginal ultra-low-dose estriol with lactobacilli on the sexual functioning domain of quality of life during the treatment of breast cancer survivors on an aromatase inhibitor with vaginal atrophy. SUBJECTS AND METHODS: This was an open-label, bicentric, exploratory, clinical study in 16 postmenopausal breast cancer survivors on aromatase inhibitors suffering from vaginal atrophy-induced sexual disorders. Atrophy symptoms were assessed by scoring with an 11-point estimation scale (0 = not at all, 10 = worst imaginable feeling). Sexuality parameters of quality of life and medication adherence were recorded in a patient's diary and in the Female Somatic Sexual Experience Instrument (FSSEI) questionnaire. Patients underwent an initial treatment for 4 weeks (one vaginal tablet of Gynoflor(®) containing 0.03 mg estriol daily), followed by maintenance therapy (three vaginal Gynoflor(®) tablets weekly) for 8 weeks. RESULTS: Vaginal dryness continuously improved from a median score of 8 at entry to a score of 4 at the end of initial therapy, and a median score of 2 at the end of maintenance therapy. Normal sexual activity before breast cancer diagnosis was reported by 14 women (88%). At study entry, only three women (19%) were sexually active. At the end of the Gynoflor(®) regimen, ten women (63%) reported sexual activity, of which seven (44%) reported sexual intercourse. The FSSEI demonstrated a non-significant trend of improvement of parameters related to sexuality. CONCLUSIONS: Local vaginal therapy with Gynoflor(®) in breast cancer survivors on aromatase inhibitors reporting atrophic vaginitis could be considered as a useful treatment for the quality of sexual life.

Phenotyping established chronic lung allograft dysfunction predicts extracorporeal photopheresis response in lung transplant patients.

Chronic lung allograft dysfunction (CLAD) remains the leading cause of mortality in lung transplant recipients after the first year. Treatment remains limited and unpredictable. Existing data suggests extracorporeal photopheresis (ECP) may be beneficial. This study aimed to identify factors predicting treatment response and the prognostic implications. A single center retrospective analysis of all patients commencing ECP for CLAD between November 1, 2007 and September 1, 2011 was performed. In total 65 patients were included, 64 of whom had deteriorated under azithromycin. Median follow-up after commencing ECP was 503 days. Upon commencing ECP, all patients were classified using proposed criteria for emerging clinical phenotypes, including "restrictive allograft syndrome (RAS)", "neutrophilic CLAD (nCLAD)" and "rapid decliners". At follow-up, 8 patients demonstrated ≥10% improvement in FEV1 , 27 patients had stabilized and 30 patients exhibited ≥10% decline in FEV1 . Patients fulfilling criteria for "rapid decliners" (n=21, p=0.005), RAS (n=22, p=0.002) and those not exhibiting neutrophilia in bronchoalveolar lavage (n=44, p=0.01) exhibited poorer outcomes. ECP appears an effective second line treatment in CLAD patients progressing under azithromycin. ECP responders demonstrated improved progression-free survival (median 401 vs. 133 days). Proposed CLAD phenotypes require refinement, but appear to predict the likelihood of ECP response.

Effects of platelet concentrate storage time reduction in patients after blood stem cell transplantation.

OBJECTIVE: To evaluate the clinical effect of platelet concentrate (PC) transfusions after PC storage time reduction to 4 days. PATIENTS AND METHODS: This was a single-centre cohort study comparing two 3-month periods of time, before and after the reduction of PC storage time from 5 to 4 days. Seventy-seven consecutive patients with PC transfusions were enrolled after blood stem cell transplantation. Corrected platelet count increment (CCI) on the morning after transfusion, time to next platelet transfusion, need for red blood cell (RBC) transfusion and clinical bleeding symptoms were compared. RESULTS: Platelet concentrate storage time was reduced between period 1 (storage for up to 5 days, median storage time 78 h, range 11-136 h) and period 2 (storage for up to 4 days, median storage time 53 h, range 11-112 h). Patients were comparable for age, weight, body surface area, underlying disorder, type of transplantation and transfused platelet dose. The CCI increased from a median of 4 (range 0-20) to 8 (0-68) × 10(9) /l per 10(11) platelets/m(2) (P < 0·0001). Time to next PC transfusion increased from 1·1 to 2·0 days (P < 0·0001). Any bleeding symptom was noted in 20 of 36 patients (56%) vs. 9/41 patients (22%, P < 0·01). Nose bleeds, haematuria and bleeding at more than one site were significantly reduced. Frequency of RBC transfusion within 5 days after PC transfusion was reduced from 74 to 58% (P < 0·0001). CONCLUSION: Platelet concentrate storage time shortening was associated with highly significant CCI increase, reduced RC needs and lower patient numbers with bleeding events.

Chronic hepatitis E in hematopoietic stem cell transplant patients in a low-endemic country?

Cases of chronic hepatitis E have been described in patients after kidney and liver transplantation. In addition, hepatitis E virus (HEV) reactivation was reported after hematopoietic stem cell transplantation (HSCT). We here evaluated if HEV infection might explain elevated liver enzymes in a well selected cohort of allogeneic HSCT patients with biochemical evidence of hepatitis (n = 52). Of note, none of the subjects tested positive for HEV RNA, including 2 HSCT patients who had been infected with HEV already before transplantation. Thus, both chronic courses of HEV infections and HEV reactivations seem to be rather rare events in HSCT patients in a non-endemic country.

Vaginal estrogen therapy in postmenopausal breast cancer patients treated with aromatase inhibitors.

INTRODUCTION: Breast cancer is the most frequent cancer among women with about 1.38 million new cases worldwide every year. Most of these patients are postmenopausal and suffer from hormone receptor positive breast tumors. About 50% of postmenopausal women between 50 and 60 years and 72% of women over 70 years suffer from vulvovaginal athrophy (VVA). Adjuvant treatment with aromatase inhibitors (AIs) improves outcomes in postmenopausal women with hormone receptor positive early stage breast cancer compared with tamoxifen. A frequent side effect of AI use is VVA with symptoms like vaginal dryness, vaginitis, pruritus, dyspareunia and cystitis. MATERIALS AND METHODS: We searched major databases (i.e. pubmed) with the following selection criteria: breast cancer, hormone therapy, vaginal estrogen, aromatase inhibitor, vaginal atrophy, serum estrogen levels. CONCLUSIONS: Vaginal administration of estradiol is a well known and safe alternative to systemic estrogen therapy, but studies demonstrated significant increases in plasma concentrations of estradiol. Such observations have also been reported in postmenopausal breast cancer patients treated with AIs. Further studies are needed to explore risk of breast cancer recurrence after vaginal estrogen application for patients on adjuvant endocrine therapy with AIs.

Targeted chemotherapy of endometrial, ovarian and breast cancers with cytotoxic analogs of luteinizing hormone-releasing hormone (LHRH).

Receptors luteinizing hormone-releasing hormone (LHRH) are expressed in about 80 % of human endometrial and ovarian cancers and account for more than 50 % of breast cancers including triple negative breast cancers. Apart from the pituitary and reproductive organs, no other organs or hematopoietic stem cells express LHRH (GnRH) receptors. Thus, these receptors can be regarded as an ideal target for a personalized medicine approach in cancer therapy. AEZS-108 (formerly known as AN-152) in which doxorubin is linked to the LHRH agonist [D: -Lys(6)]LHRH, appears to be the most advanced compound in late stage clinical development. Results of phase I and phase II clinical trials in patients with gynecological cancers demonstrated anticancer activity without any cardiotoxicity even in highly pretreated patients. AEZS-108 is therefore being considered for phase II trials in triple negative breast cancers and phase III studies in advanced endometrial cancers positive for LHRH-receptor. EP-100 is a membrane-disrupting peptide targeted to LHRH receptors, which is undergoing early clinical studies in ovarian cancer patients.

German-Austrian-Swiss Consensus Conference on clinical practice in chronic graft-versus-host disease (GVHD): guidance for supportive therapy of chronic cutaneous and musculoskeletal GVHD.

Supportive therapy plays a central role in the management of cutaneous and musculoskeletal manifestations of chronic graft-versus-host disease (cGVHD), either alone or in combination with systemic approaches. We present results from the German-Austrian-Swiss Consensus Conference on clinical practice in cGVHD, held in Regensburg, Germany, in November 2009. The intention was to achieve a consensus on current evidence-based treatment options as well as to provide guidelines for daily clinical practice. Skin is the most common organ involved in cGVHD. Its clinical presentation varies considerably. Patients may have pruritus, rash, pain, dyspigmentation and fibrotic or sclerodermatous lesions, often leading to contractures. Treatment options for supportive therapy in cutaneous cGVHD include topical therapies such as topical steroids and topical calcineurin inhibitors, as well as phototherapy and physiotherapy. The most relevant manifestation in musculoskeletal cGVHD is fasciitis which must be distinguished from sclerodermatous skin cGVHD. Physiotherapy is the mainstay of supportive treatment in fasciitis in cGVHD. Successful therapy of cutaneous and musculoskeletal cGVHD depends on interdisciplinary management to improve patients' quality of life.

Growth hormone-releasing hormone antagonists inhibit growth of human ovarian cancer.

Epithelial ovarian carcinoma is the leading cause of cancer-related deaths among women with gynecologic malignancies. Antagonists of the growth hormone-releasing hormone (GHRH) have been shown to inhibit growth of various cancers through endocrine, autocrine, and paracrine mechanisms. In this study, we have investigated the effects of GHRH antagonists (GHRHa) in ES-2 human clear cell ovarian cancer and in UCI-107 human serous ovarian cancer in vitro and in vivo. We evaluated the expression of mRNA for GHRH receptor, the binding to GHRH receptors, in specimens of ES-2 ovarian cancer. We evaluated also the in vitro effects of GHRHa on ES-2 cells and the in vivo effect of 2 different GHRHa on ES-2 and UCI-107 tumors. Nude mice bearing xenografts on ES-2 and UCI-107 ovarian cancer were treated with JMR-132 and MZ-J-7-118, respectively. Tumor growth was compared to control. ES-2 cells expressed mRNA for the functional splice variant SV1 of the GHRH receptor. JMR-132 inhibited cell proliferation in vitro by 42% and 18% at 10 and 1 µM concentration, respectively. Specific high affinity receptors for GHRH were detected in ES-2 cancer samples. In vivo daily subcutaneous injections of GHRHa significantly reduced tumor growth compared to a control group in both animal models. Our results indicate that GHRHa such as JMR-132 and MZ-J-7-118 can inhibit the growth of human ovarian cancer. The efficacy of GHRHa in ovarian cancer should be assessed in clinical trials.

Tetramer monitoring to assess risk factors for recurrent cytomegalovirus reactivation and reconstitution of antiviral immunity post allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Reactivation of cytomegalovirus (CMV) is a major cause of morbidity after allogeneic hematopoietic stem cell transplantation (HSCT). In healthy individuals, virus-specific T cells (CMV-CTL) control the reactivation of latent CMV. The monitoring of virus-epitope-binding CD8(+) T cells using major histocompatibility complex-I-peptide complexes (tetramers) has recently been established, allowing assessment of the reconstitution of CMV-CTL post HSCT. PATIENTS AND METHODS: In order to study immune reconstitution and reactivation control through CMV-CTL, we regularly monitored all patients undergoing allogeneic HSCT in our department for 2 years, who matched at least 1 of 6 commercially available tetramers for common human leukocyte antigen (HLA) types. To verify risk factors for CMV reactivations in our cohorts, clinical characteristics of all patients transplanted within the last 10 years were included in statistical analyses determining the relative risk for single and recurrent CMV reactivations. RESULTS: As expected, CMV serostatus, HLA match, and donor source significantly influenced the risk of recurrent CMV reactivation. Applying CMV-CTL tetramer monitoring for 2 years allowed the monitoring of 114 (85%) of 134 patients, by testing a set of tetramers representing 6 epitopes from 3 different CMV proteins. The presence of CMV-CTL before day + 50 and their expansion post reactivation seem to protect against recurrent CMV reactivations. The mean number of CMV-CTL by day +100 was >5-fold higher in the recipient CMV-positive/donor-positive (R +/D +) group (91/µL) compared with the R +/ D- (13/µL) and the R -/D +(2/µL) group. Seventy-nine percent of patients from the R +/D + setting recovered >10 CMV-CTL per µL by day + 100, while almost 50% of the other groups failed to mount a CMV-specific response by that time (R +/D -: 58%; R -/D +: 43%). CONCLUSION: Tetramer monitoring can help to predict (recurrent) CMV reactivation and is a useful approach to monitor individual patients with increased risk for recurrent reactivation post HSCT; thus, it could help to identify patients in need of adoptive transfer of CMV-CTL or to optimize the use of antiviral drugs.

[Histopathology of graft-versus-host disease]. / Histopathologie der Graft-versus-Host-Erkrankung.

Graft-versus-host disease (GvHD) occurs as a major complication in 35%-50% of all patients undergoing allogeneic stem cell transplantation. A distinction is made between acute and chronic GvHD depending on the time of onset, type of clinical symptoms and histology. Both forms preferably show manifestations in the skin, mucosal membranes, gastrointestinal tract, liver and (less often) lung. As the clinical presentation is rather unspecific, particularly for the diagnosis of acute GvHD, histology is important to exclude infectious diseases or drug reactions. This review covers the diagnostic morphological criteria and differential diagnoses of GvHD in the skin, gastrointestinal tract and the liver.

Phaeochromocytoma-associated critical peripheral ischaemia.

Limb Ischaemia is an exceptional complication of catecholamine toxicity caused by a phaeochromocytoma. We present a middle-aged female patient with severe subacute peripheral ishaemia, gangrene and eventual amputation of all four distal limbs due to a large non-metastatic left adrenal gland phaeochromocytoma and summarise the available literature concerning previously reported cases.

Susceptibility of Aethina tumida (Coleoptera: Nitidulidae) larvae and pupae to entomopathogenic nematodes.

In this study, we evaluated the potential use of entomopathogenic nematodes as a control for the beetle Aethina tumida Murray (Coleoptera: Nitidulidae). In particular, we conducted 1) four screening bioassays to determine nematode (seven species, 10 total strains tested) and application level effects on A. tumida larvae and pupae, 2) a generational persistence bioassay to determine whether single inoculations with nematodes would control multiple generations of A. tumida larvae in treated soil, and 3) a field bioassay to determine whether the nematodes would remain efficacious in the field. In the screening bioassays, nematode efficacy varied significantly by tested nematode and the infective juvenile (IJ) level at which they were applied. Although nematode virulence was moderate in screening bioassays 1-3 (0-68% A. tumida mortality), A. tumida mortality approached higher levels in screening bioassay 4 (nearly 100% after 39 d) that suggest suitable applicability of some of the test nematodes as field controls for A. tumida. In the generational persistence bioassay, Steinernema riobrave Cabanillas, Poinar & Raulston 7-12 strain and Heterorhabditis indica Poinar, Karunaka & David provided adequate A. tumida control for 19 wk after a single soil inoculation (76-94% mortality in A. tumida pupae). In the field bioassay, the same two nematode species also showed high virulence toward pupating A. tumida (88-100%) mortality. Our data suggest that nematode use may be an integral component of an integrated pest management scheme aimed at reducing A. tumida populations in bee colonies to tolerable levels.

Commensurability and mobility in two-dimensional molecular patterns on graphite.

Two-dimensional molecular patterns were obtained by the adsorption of long-chain alkanes, alcohols, fatty acids, and a dialkylbenzene from organic solutions onto the basal plane of graphite. In situ scanning tunneling microscopy (STM) studies revealed that these molecules organize in lamellae with the extended alkyl chains oriented parallel to a lattice axis within the basal plane of graphite. The planes of the carbon skeletons, however, can be oriented either predominantly perpendicular to or predominantly parallel with the substrate surface, causing the lamellar lattice to be either in or near registry with the substrate (alkanes and alcohols) or not in registry (fatty acids and dialkylbenzenes). In the case of the alcohols and the dialkylbenzene the molecular axes are tilted by +30 degrees or -30 degrees with respect to an axis normal to the lamella boundaries, giving rise to molecularly well-defined domain boundaries. Fast STM image recording allowed the spontaneous switch between the two tilt angles to be observed in the alcohol monolayers on a time scale of a few milliseconds.