Intrinsic Resistance of Chronic Lymphocytic Leukemia Cells to NK Cell-Mediated Lysis Can Be Overcome In Vitro by Pharmacological Inhibition of Cdc42-Induced Actin Cytoskeleton Remodeling

Natural killer (NK) cells are innate effector lymphocytes with strong antitumor effects against hematologic malignancies such as chronic lymphocytic leukemia (CLL). However, NK cells fail to control CLL progression on the long term. For effective lysis of their targets, NK cells use a specific cell-cell interface, known as the immunological synapse (IS), whose assembly and effector function critically rely on dynamic cytoskeletal changes in NK cells. Here we explored the role of CLL cell actin cytoskeleton during NK cell attack. We found that CLL cells can undergo fast actin cytoskeleton remodeling which is characterized by a NK cell contact-induced accumulation of actin filaments at the IS. Such polarization of the actin cytoskeleton was strongly associated with resistance against NK cell-mediated cytotoxicity and reduced amounts of the cell-death inducing molecule granzyme B in target CLL cells. Selective pharmacological targeting of the key actin regulator Cdc42 abrogated the capacity of CLL cells to reorganize their actin cytoskeleton during NK cell attack, increased levels of transferred granzyme B and restored CLL cell susceptibility to NK cell cytotoxicity. This resistance mechanism was confirmed in primary CLL cells from patients. In addition, pharmacological inhibition of actin dynamics in combination with blocking antibodies increased conjugation frequency and improved CLL cell elimination by NK cells. Together our results highlight the critical role of CLL cell actin cytoskeleton in driving resistance against NK cell cytotoxicity and provide new potential therapeutic point of intervention to target CLL immune escape.

Higher Incidence of B Cell Malignancies in Primary Immunodeficiencies: A Combination of Intrinsic Genomic Instability and Exocytosis Defects at the Immunological Synapse

Congenital defects of the immune system called primary immunodeficiency disorders (PID) describe a group of diseases characterized by a decrease, an absence, or a malfunction of at least one part of the immune system. As a result, PID patients are more prone to develop life-threatening complications, including cancer. PID currently include over 400 different disorders, however, the variety of PID-related cancers is narrow. We discuss here reasons for this clinical phenotype. Namely, PID can lead to cell intrinsic failure to control cell transformation, failure to activate tumor surveillance by cytotoxic cells or both. As the most frequent tumors seen among PID patients stem from faulty lymphocyte development leading to leukemia and lymphoma, we focus on the extensive genomic alterations needed to create the vast diversity of B and T lymphocytes with potential to recognize any pathogen and why defects in these processes lead to malignancies in the immunodeficient environment of PID patients. In the second part of the review, we discuss PID affecting tumor surveillance and especially membrane trafficking defects caused by altered exocytosis and regulation of the actin cytoskeleton. As an impairment of these membrane trafficking pathways often results in dysfunctional effector immune cells, tumor cell immune evasion is elevated in PID. By considering new anti-cancer treatment concepts, such as transfer of genetically engineered immune cells, restoration of anti-tumor immunity in PID patients could be an approach to complement standard therapies.

Escape of tumor cells from the NK cell cytotoxic activity

In recent years, NK cells, initially identified as potent cytotoxic effector cells, have revealed an unexpected complexity, both at phenotypic and functional levels. The discovery of different NK cell subsets, characterized by distinct gene expression and phenotypes, was combined with the characterization of the diverse functions NK cells can exert, not only as circulating cells, but also as cells localized or recruited in lymphoid organs and in multiple tissues. Besides the elimination of tumor and virus-infected cells, these functions include the production of cytokines and chemokines, the regulation of innate and adaptive immune cells, the influence on tissue homeostasis. In addition, NK cells display a remarkable functional plasticity, being able to adapt to the environment and to develop a kind of memory. Nevertheless, the powerful cytotoxic activity of NK cells remains one of their most relevant properties, particularly in the antitumor response. In this review, the process of tumor cell recognition and killing mediated by NK cells, starting from the generation of cytolytic granules and recognition of target cell, to the establishment of the NK cell immunological synapse, the release of cytotoxic molecules, and consequent tumor cell death is described. Next, the review focuses on the heterogeneous mechanisms, either intrinsic to tumors or induced by the tumor microenvironment, by which cancer cells can escape the NK cell-mediated attack.

Actin Cytoskeleton Straddling the Immunological Synapse between Cytotoxic Lymphocytes and Cancer Cells

The immune system is a fundamental part of the tumor microenvironment. In particular, cytotoxic lymphocytes, such as cytolytic T cells and natural killer cells, control tumor growth and disease progression by interacting and eliminating tumor cells. The actin cytoskeleton of cytotoxic lymphocytes engaged in an immunological synapse has received considerable research attention. It has been recognized as a central mediator of the formation and maturation of the immunological synapse, and its signaling and cytolytic activities. In comparison, fewer studies have explored the organization and function of actin filaments on the target cancer cell side of the immunological synapse. However, there is growing evidence that the actin cytoskeleton of cancer cells also undergoes extensive remodeling upon cytotoxic lymphocyte attack, and that such remodeling can alter physical and functional interactions at the immunological synapse. In this article, we review the current knowledge of actin organization and functions at both sides of the immunological synapse between cytotoxic lymphocytes and cancer cells, with particular focus on synapse formation, signaling and cytolytic activity, and immune evasion.

Constitutive activation of WASp in X-linked neutropenia renders neutrophils hyperactive

Congenital neutropenia is characterized by low absolute neutrophil numbers in blood, leading to recurrent bacterial infections, and patients often require life-long granulocyte CSF (G-CSF) support. X-linked neutropenia (XLN) is caused by gain-of-function mutations in the actin regulator Wiskott-Aldrich syndrome protein (WASp). To understand the pathophysiology in XLN and the role of WASp in neutrophils, we here examined XLN patients and 2 XLN mouse models. XLN patients had reduced myelopoiesis and extremely low blood neutrophil number. However, their neutrophils had a hyperactive phenotype and were present in normal numbers in XLN patient saliva. Murine XLN neutrophils were hyperactivated, with increased actin dynamics and migration into tissues. We provide molecular evidence that the hyperactivity of XLN neutrophils is caused by WASp in a constitutively open conformation due to contingent phosphorylation of the critical tyrosine-293 and plasma membrane localization. This renders WASp activity less dependent on regulation by PI3K. Our data show that the amplitude of WASp activity inside a cell could be enhanced by cell-surface receptor signaling even in the context in which WASp is already in an active conformation. Moreover, these data categorize XLN as an atypical congenital neutropenia in which constitutive activation of WASp in tissue neutrophils compensates for reduced myelopoiesis.

Actin Cytoskeleton Remodeling Drives Breast Cancer Cell Escape from Natural Killer-Mediated Cytotoxicity

Elucidation of the underlying molecular mechanisms of immune evasion in cancer is critical for the development of immunotherapies aimed to restore and stimulate effective antitumor immunity. Here, we evaluate the role of the actin cytoskeleton in breast cancer cell resistance to cytotoxic natural killer (NK) cells. A significant fraction of breast cancer cells responded to NK-cell attack via a surprisingly rapid and massive accumulation of F-actin near the immunologic synapse, a process we termed "actin response." Live-cell imaging provided direct evidence that the actin response is associated with tumor cell resistance to NK-cell-mediated cell death. High-throughput imaging flow cytometry analyses showed that breast cancer cell lines highly resistant to NK cells were significantly enriched in actin response-competent cells as compared with susceptible cell lines. The actin response was not associated with a defect in NK-cell activation but correlated with reduced intracellular levels of the cytotoxic protease granzyme B and a lower rate of apoptosis in target cells. Inhibition of the actin response by knocking down CDC42 or N-WASP led to a significant increase in granzyme B levels in target cells and was sufficient to convert resistant breast cancer cell lines into a highly susceptible phenotype. The actin response and its protective effects were fully recapitulated using donor-derived primary NK cells as effector cells. Together, these findings establish the pivotal role of actin remodeling in breast cancer cell resistance to NK-cell-mediated killing.Significance: These findings establish the pivotal role of the actin cytoskeleton in driving breast cancer cell resistance to natural killer cells, a subset of cytotoxic lymphocytes with important roles in innate antitumor immunity. Cancer Res; 78(19); 5631-43. ©2018 AACR.

Wiskott-Aldrich syndrome gene mutations modulate cancer susceptibility in the p53± murine model

The Wiskott-Aldrich syndrome protein (WASp) is a key regulator of the actin cytoskeleton in hematopoietic cells and mutated in two severe immunodeficiency diseases with high incidence of cancer. Wiskott-Aldrich syndrome (WAS) is caused by loss-of-function mutations in WASp and most frequently associated with lymphoreticular tumors of poor prognosis. X-linked neuropenia (XLN) is caused by gain-of-function mutations in WASp and associated with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). To understand the role of WASp in tumorigenesis, we bred WASp⁺, WASp⁻, and WASp-XLN mice onto tumor susceptible p53^+/- background and sub-lethally irradiated them to enhance tumor development. We followed the cohorts for 24 weeks and tumors were characterized by histology and flow cytometry to define the tumor incidence, onset, and cell origin. We found that p53^+/-WASp⁺ mice developed malignancies, including solid tumors and T cell lymphomas with 71.4% of survival 24 weeks after irradiation. p53^+/-WASp⁻ mice showed lower survival rate and developed various early onset malignancies. Surprisingly, the p53^+/-WASp-XLN mice developed malignancy mostly with late onset, which caused delayed mortality in this colony. This study provides evidence for that loss-of-function and gain-of-function mutations in WASp influence tumor incidence and onset.

Prospective multicentre clinical study on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori

OBJECTIVES

We report on a large prospective, multicentre clinical investigation on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori.

METHODS

Therapy-naive patients (n = 2004) who had undergone routine diagnostic gastroscopy were prospectively included from all geographic regions of Austria. Gastric biopsy samples were collected separately from antrum and corpus. Samples were analysed by histopathology and real-time PCR for genotypic resistance to clarithromycin and quinolones. Clinical and demographic information was analysed in relation to resistance patterns.

RESULTS

H. pylori infection was detected in 514 (26%) of 2004 patients by histopathology and confirmed in 465 (90%) of 514 patients by real-time PCR. PCR results were discordant for antrum and corpus in 27 (5%) of 514 patients, indicating inhomogeneous infections. Clarithromycin resistance rates were 17% (77/448) and 19% (84/455), and quinolone resistance rates were 12% (37/310) and 10% (32/334) in antrum and corpus samples, respectively. Combination of test results per patient yielded resistance rates of 21% (98/465) and 13% (50/383) for clarithromycin and quinolones, respectively. Overall, infection with both sensitive and resistant H. pylori was detected in 65 (14%) of 465 patients.

CONCLUSIONS

Anatomically inhomogeneous infection with different, multiple H. pylori strains is common. Prospective clinical study design, collection of samples from multiple sites and microbiologic methods that allow the detection of coinfections are mandatory for collection of reliable data on antimicrobial resistance patterns in representative patient populations. (ClinicalTrials.gov identifier: NCT02925091).

Intraductal papillary-mucinous tumors of the pancreas: presentation of eight cases

BACKGROUND AND STUDY AIMS

The mucinsecreting intraductal papillary-mucinous tumors of the pancreas are a rare entity with characteristic duodenoscopic and radiological features. These tumors have a broad spectrum of presentation. The diagnosis requires highly experienced and attentive endoscopists. Once diagnosed, resection of the tumor is recommended to prevent progression to malignancy. This surgical procedure has a low acceptance, mainly in the elderly patients. Therefore, a "wait and see" strategy may be necessary in those patients refusing operation.

PATIENTS AND METHODS

Between 1996 and 2000, intraductal papillary-mucinous tumors of the pancreas were diagnosed in eight patients (5 females, 3 males) using endoscopic retrograde cholangiopancreatography, and confirmed by brush cytology and/or histology and analyzed retrospectively.

RESULTS

The patients showed typical endoscopic and radiological findings: dilatation and mucin extrusion of the papillary orifice, easy passage of instruments into the dilated main pancreatic duct, which showed patchy filling defects after application of contrast medium. Patients were informed about the diagnosis in detail. Two patients were inoperable. Surgery was recommended to the other six patients. Two of the six patients agreed to surgical treatment. The remaining four patients were included in a follow-up protocol. These patients were observed for up to 5 years. Only one patient showed minor progression of ERCP-findings.

CONCLUSION

Intraductal papillary-mucinous tumors of the pancreas can be well characterized by means of endoscopy and radiology. Poor compliance to surgical treatment makes individual multidisciplinary management and follow-up necessary.

Duodenal ulcer healing rates in a one-year follow-up study with ranitidine bismuth citrate and antibiotics

BACKGROUND/AIMS

The aim of this study was to determine the one-year outcome of an eradication therapy with ranitidine bismuth citrate and antibiotics in Helicobacter pylori-positive duodenal ulcer patients in respect to ulcer and Helicobacter pylori relapse rates.

METHODOLOGY

This multicenter, randomized, double-blind study involved 648 duodenal ulcer patients and had been carried out to compare the following regimens: ranitidine bismuth citrate b.i.d. co-prescribed with either clarithromycin 250 mg q.i.d. or clarithromycin 500 mg b.i.d. or clarithromycin 500 mg b.i.d. plus metronidazole 400 mg b.i.d. for 2 weeks, followed by a further 14 days of treatment with ranitidine bismuth citrate 400 mg b.i.d. to facilitate ulcer healing. H. pylori eradication was assessed by 13C-urea breath test and histology at least 4 weeks, 26 weeks and 52 weeks after the end of treatment. Ulcer relapse and H. pylori status were assessed 4 weeks, 26 weeks and 52 weeks post-treatment or if ulcer symptoms recurred. For the remainder of the follow-up period only serious adverse events were collected.

RESULTS

At 12 months data of 438 (69%) patients were evaluable. The observed H. pylori eradication rates were 88-91%. H. pylori relapse rates were 2.1% after 26 weeks and 3.9% after 52 weeks. At the week 26 visit 26 patients (5.6%) and at the week 52 visit 25 patients (5.7%) had documented gastroesophageal reflux disease.

CONCLUSIONS

Our data confirm the reduction of duodenal ulcer relapses after the cure of Helicobacter pylori infection.

Pantoprazole 20 mg is an effective maintenance therapy for patients with gastro-oesophageal reflux disease

OBJECTIVES

To compare the efficacy of 20 mg with 40 mg pantoprazole in maintaining symptomatic and endoscopic remission in patients with gastro-oesophageal reflux disease (GORD).

STUDY DESIGN

Patients (18-84 years old; n = 433) with healed GORD II or III were included in this prospective multi-centre, randomized, parallel, double-blind study. Pantoprazole was administered once daily for up to 1 year as either a 20 mg or 40 mg enteric-coated tablet to 221 and 212 patients, respectively. Symptoms of GORD were assessed every 3 months. Endoscopy was performed at entry, after 6 and 12 months, or when symptoms of GORD were perceived on at least three consecutive days. The primary efficacy parameter was the time until endoscopically proven relapse of GORD occurred (stage I or greater); the secondary parameters included tolerability, safety, and time until symptomatic relapse occurred.

RESULTS

In the 20 mg treatment group, 87% and 75% of patients were in endoscopic remission after 6 and 12 months, respectively; the corresponding rates in the 40 mg treatment group were 91% and 78%. In both treatment groups, GORD stage I accounted for about 50% of endoscopic relapses. The symptomatic remission rates in the 20 mg group were estimated as 85% and 77% after 6 and 12 months, respectively; the corresponding values in the 40 mg group were 87% and 76%. No correlation was seen either between the endoscopically proven relapse and perception of symptoms, or between the severity of the pre-treatment stage of GORD and the maintenance dose of pantoprazole. Both doses were well tolerated.

CONCLUSIONS

Both the 20 mg and 40 mg doses of pantoprazole are safe and effective in maintaining patients with healed reflux oesophagitis in remission. Moreover, for the majority of patients, the 20 mg dose provides adequate long-term therapeutic efficacy at a minimal drug exposure and lower costs.

Famotidine versus omeprazole in combination with clarithromycin and metronidazole for eradication of Helicobacter pylori--a randomized, controlled trial

BACKGROUND

One-week low-dose triple therapy is currently considered the gold standard regimen for treatment of Helicobacter pylori infection. However, the mechanisms involved in the synergy between antibiotics and proton pump inhibitors are controversial.

AIMS

To test the hypothesis that acid suppression represents the crucial mechanism by which the antibacterial activity of antibiotics can be enhanced, and to assess the impact of primary resistance on treatment outcome.

METHODS

One hundred and twenty patients with H. pylori infection and duodenal ulcer, gastric ulcer or non-ulcer dyspepsia were randomly assigned to a 1 week course of either famotidine 80 mg b.d., clarithromycin 250 mg b.d. and metronidazole 500 mg b.d. (FCM group; n = 60) or omeprazole 20 mg o.d., clarithromycin 250 mg b.d. and metronidazole 500 mg b.d. (OCM group; n = 60). Gastroscopy was performed at baseline and 5 weeks after completion of treatment. H. pylori status was assessed by biopsy urease test, histology and culture.

RESULTS

In the intention-to-treat analysis, eradication of H. pylori was achieved in 47 of 60 patients (78%; 95% CI: 66-88%) in the FCM group, compared to 44 of 60 patients (73%; 95% CI: 60-84%) in the OCM group (N.S.). Using per protocol analysis, eradication therapy was successful in 47 of 52 patients (90%; 95% CI: 79-97%) treated with FCM and 44 of 57 patients (77%; 95% CI: 64-87%) treated with OCM (N.S.). Primary metronidazole resistance was present in 27% and primary clarithromycin resistance in 8% of strains. Overall per protocol eradication rates in strains susceptible to both antibiotics and strains with isolated metronidazole resistance were 93% and 84%, respectively. No patient with clarithromycin resistance responded to treatment.

CONCLUSIONS

High-dose famotidine and omeprazole, combined with clarithromycin and metronidazole, are equally effective for eradication of H. pylori. In 1-week low-dose triple therapy, metronidazole resistance has no major impact on eradication rates whereas clarithromycin resistance is associated with a poor treatment outcome.

Efficacy and safety of pantoprazole in patients with gastroesophageal reflux disease using an intravenous-oral regimen. Austrian Intravenous Pantoprazole Study Group

BACKGROUND/AIMS

To investigate the efficacy and safety of an intravenous-oral regimen using the gastric proton pump inhibitor pantoprazole.

METHODOLOGY

Outpatients, with endoscopically diagnosed moderate or severe gastro-esophageal reflux disease (GERD stage II and III, respectively, Savary-Miller classification), were recruited from ten hospitals or private practice centers and enrolled into an open-labeled study (intention-to-treat population n=110, age 20-88 years; per-protocol population n=98). Patients were treated once daily with 40 mg pantoprazole which was administered as an intravenous injection for the initial 5-7 consecutive days, then as a tablet, for up to 8 weeks. The efficacy parameters were complete healing of lesions evaluated endoscopically after week 4 and 8, and relief from symptoms assessed after week 2 and 4.

RESULTS

Complete healing was achieved in 85/98 (87%) and 93/98 (95%) per-protocol patients, after 4 and 8 weeks, respectively. The corresponding results for the intention-to-treat population were 85/110 (77%) and 93/110 (85%), respectively. After 2 weeks of treatment, heartburn, acid regurgitation, and pain on swallowing resolved in 97%, 98%, and 100% of the per-protocol patients, respectively. Faster healing was observed in non-smokers, those infected with Helicobacter pylori, and those with initial GERD stage II. The intravenous and oral administration phases were well tolerated.

CONCLUSIONS

Pantoprazole (40 mg), applied as an intravenous-oral regimen to patients with GERD led to fast resolution of symptoms and high healing rates. For patients, temporarily unable to take oral medications, this regimen offers safe and reliable gastric acid suppression and allows the possibility of changing between the oral and intravenous administration without the need for dose adjustment.

Hormonal therapy in chronic radiation colitis

Severe gastrointestinal bleeding is a rare complication of radiation therapy that requires frequent transfusions. This case report describes a patient with severe bleeding from radiation colitis after treatment of bladder cancer. During 5 months of therapy with multiple drugs, the patient needed 26 units of packed red cells. A subsequent hormone therapy consisting of an estrogen-progesterone combination significantly reduced the need for blood transfusions and hospitalization. We conclude that hormones might provide a promising new additional symptomatic therapy for bleeding radiogenic colitis.

Eradication of Helicobacter pylori by a 1-week course of famotidine, amoxicillin and clarithromycin

OBJECTIVES

The combination of a proton pump inhibitor (PPI) such as omeprazole with amoxicillin and clarithromycin constitutes one of the most effective treatments for the eradication of Helicobacter pylori. Nevertheless, the mechanisms of interaction between these drugs remain unclear. It has been shown that minimal inhibitory concentration values of both antibiotics are considerably lower at neutral pH levels than in an acid environment. Further, omeprazole possesses bacteriostatic activity. To evaluate the significance of these mechanisms we replaced omeprazole with famotidine, a drug which only suppresses acid production, but has no intrinsic antimicrobial activity.

METHODS

We evaluated the efficacy of a 1-week course of famotidine 80 mg b.i.d., amoxicillin 1000 mg b.i.d. and clarithromycin 500 mg b.i.d. in a pilot study (20 patients), and then confirmed our results in a larger replication study (87 patients). A total of 107 patients with H. pylori-associated duodenal ulcer (n = 54), gastric ulcer (n = 14) or non-ulcer dyspepsia (n = 39) were included. Endoscopy was performed at baseline and 4-6 weeks after discontinuation of treatment. H. pylori status was assessed by the urease test and histology.

RESULTS

H. pylori was successfully eradicated in 94 of 104 patients who completed the study (90.4%; CI 95%, 83.0-95.3%). By intention-to-treat analysis, the eradication rate was 87.9% (CI 95%, 80.1-93.4%). Ulcer healing was observed in 98.1% of duodenal ulcers and 92.9% of gastric ulcers (based on per-protocol analysis). Mild side effects that did not require termination of treatment were reported by seven patients (6.7%).

CONCLUSION

A 1-week course of famotidine, amoxicillin and clarithromycin is a highly effective, simple and safe eradication regimen. Our data indicate that acid suppression is the crucial mechanism by which the activity of amoxicillin and clarithromycin against H. pylori is enhanced, whereas additional antimicrobial activity or other specific effects of PPIs seem to be less important.

Ranitidine bismuth citrate with clarithromycin given twice daily effectively eradicates Helicobacter pylori and heals duodenal ulcers

OBJECTIVE

Ranitidine bismuth citrate (RBC) b.i.d. with clarithromycin q.i.d. eradicates Helicobacter pylori (H. pylori) in 82-94% of patients, and heals duodenal ulcers in 88-90% of patients. This double blind, placebo-controlled study examines the efficacy of a simpler b.i.d. treatment regimen, and examines the potential benefit of including a second antibiotic, metronidazole, to the b.i.d. treatment regimen.

METHODS

A total of 648 patients with active duodenal ulcer received RBC 400 mg b.i.d. for 4 wk, coprescribed with clarithromycin 250 mg q.i.d., clarithromycin 500 mg b.i.d., or clarithromycin 500 mg b.i.d. with metronidazole 400 mg b.i.d. for the first 2 wk of treatment. Endoscopies were performed prestudy, after 4 wk of treatment, and at least 4 wk posttreatment. H. pylori status was assessed by CLOtest, 13C-urea breath test (UBT), and histology prestudy, and by UBT and histology at least 4 wk posttreatment. Adverse events were recorded at each visit.

RESULTS

All three regimens were highly effective and well tolerated. H. pylori eradication rates were 84-94% and duodenal ulcer healing rates were 92-96% (observed data). Highest H. pylori eradication and ulcer healing rates were achieved with RBC 400 mg b.i.d. with clarithromycin 500 mg b.i.d.

CONCLUSION

Ranitidine bismuth citrate with clarithromycin 500 mg b.i.d. provides an effective, simple and well tolerated regimen for the eradication of H. pylori and healing of duodenal ulcers.

Short-course therapy with amoxycillin-clarithromycin triple therapy for 10 days (ACT-10) eradicates Helicobacter pylori and heals duodenal ulcer. ACT-10 Study Group

BACKGROUND

Whilst the role of Helicobacter pylori eradication in managing duodenal ulcers has been established, consensus regarding the ideal regimen has not been achieved.

METHODS

Patients with H. pylori-positive active duodenal ulcer were randomly assigned to receive triple therapy with amoxycillin 1000 mg b.d. + clarithromycin 500 mg b.d. + omeprazole 20 mg daily for 10 days (ACT-10) or dual therapy with clarithromycin 500 mg t.d.s. + omeprazole 40 mg daily for 14 days (Dual). No additional acid suppression was provided following eradication therapy. Endoscopy, with biopsy for culture and histology, as well as 13C-urea breath testing (13C-UBT) were performed pre-treatment to assess H. pylori infection. H. pylori eradication was established at 4-6 weeks follow-up with culture (2 antral, 1 corpus biopsies), histology (2 antral biopsies), and 13C-UBT. Ulcer healing by endoscopy and change in clinical symptoms were also assessed at 4-6 weeks.

RESULTS

Two hundred and sixty-seven (267) patients were randomized to ACT-10 (n = 137) or Dual therapy (n = 130). By per-protocol and intention-to-treat analyses, H. pylori eradication at 4-6 weeks follow-up was 91% (115/127) and 88% (120/136), respectively, for ACT-10 patients and 59% (68/115) and 55% (72/130), respectively, for Dual therapy patients (P < 0.001 for both analyses). Ulcer healing was high in both treatment groups: ACT-10, 93% (118/127) and 90% (122/136), respectively; and Dual therapy, 91% (104/114) and 85% (111/130), respectively. Pre-treatment resistance to clarithromycin was low (4%, 8/214) as compared to metronidazole resistance which was over 40%. Emergence of resistance to clarithromycin was observed in 2% of patients receiving ACT-10 and in 25% of those receiving Dual therapy. ACT-10 and Dual therapy patients experienced similar rates of drug-related adverse events (33% vs. 32%, respectively) and discontinuation from therapy due to an adverse event (1.5% vs. 5%, respectively). More than 90% of patients were compliant with each prescribed medication.

CONCLUSION

In patients with active duodenal ulcer, a 10-day course of amoxycillin-clarithromycin-based triple therapy without additional acid suppression is highly effective in eradicating H. pylori and healing duodenal ulcer.

A spark counter as a control unit of a radio frequency surgery device

A new approach in radio frequency (rf) electrosurgery, used for tissue treatment, is achieved by using a new process control method. An external control unit allows a commonly available rf-generator to automatically supply the appropriate power for differing tissue types, thus ensuring best cutting quality. The sparks, generated during the scalpel electrode interaction with the tissue, appear statistically distributed. The spark rate depends on various factors and is monotonic with the supplied electrical power. This allows it to be used as the controlled variable in the cutting process. The ac current passing through the tissue is evaluated by an external control unit using an analyzation algorithm to determine the number of sparks. The external unit is comprised of a system, which measures the spark rate, and a subsequent proportional integral (P.I.) controller. The functionality of the control method as well as the electrical circuitry is verified through cuts with different degrees of carbonization and cuts through tissue heterojunctions.

Development of an in vitro human nasal epithelial (HNE) cell model

The upper respiratory tract is mainly involved in reactions to airborne substances. So the primary culture of human nasal tissue may provide an application model for assessment of toxic or inflammatory processes caused by environmental pollutants. HNE cells were isolated from nasal tissue biopsies by protease digestion and cultured in serum-free hormone-supplemented medium. When grown on porous membranes at the air-liquid interface, a higher portion of ciliated cells developed within 2 weeks compared with cells maintained submerged. Submerged grown cultures on collagen gel matrix maintained a cuboidal epithelial-like morphology and stained positive for cytokeratin. The primary cultures of nasal cells exhibited a marked activity for acid phosphatase. Second passage HNE cells exhibited marked enzymatic reactivity upon treatment with particulate matter. Induction of the lysosomal marker enzyme acid phosphatase was stronger in cells treated with toluene-extracted diesel exhaust particles compared with cells treated with native diesel exhaust particles. Non-specific esterase activity was increased more than 7-fold by native diesel particles, whereas the induction of esterase activity by extracted particles was relatively low compared with the control group.

Influence of spasmolytic analgesics on motility of sphincter of Oddi

The effects on the sphincter of Oddi of intravenous administration of dipyrone, 2.5 g; tramadol, 50 mg; indomethacin, 75 mg; N-butylscopolamine, 20 mg; and nitroglycerin, 1 mg, in comparison to physiological saline were assessed in a single-blind study in 36 patients hospitalized with upper abdominal pain. Basal sphincter pressure and sphincter motility were measured for a 5-min period after treatment by endoscopic manometry. Nitroglycerin and dipyrone both caused a significant fall in basal sphincter pressure, while N-butylscopolamine and nitroglycerin produced a significant decrease in contraction frequency. Therefore, dipyrone, in contrast to tramadol and indomethacin, exhibits spasmolytic activity in addition to analgesia in biliary pain.

A multicenter, randomized, double-blind comparison of roxatidine with ranitidine in the treatment of patients with uncomplicated benign gastric ulcer disease. The Multicenter Roxatidine Cooperative Study Group

Roxatidine (150 mg, 312 patients) was compared with ranitidine (300 mg, 308 patients) in a randomized, double-blind, parallel-group, 6-week therapeutic study for the treatment of patients with uncomplicated, benign gastric ulcer disease. The study end points (verified by using endoscopy results) were fully healed ulcers at 4 or 6 weeks. The results of roxatidine therapy were comparable to those of ranitidine therapy: healing rates of 52% and 54% at week 4 and 77% and 76% at week 6 were recorded for roxatidine and ranitidine, respectively. The drugs produced comparable reductions in ulcer diameters and decreases in abdominal pain. Adverse events associated with both roxatidine (27%) and ranitidine (28%) were headache, diarrhea, and dizziness; rash was associated in 6 of 8 cases and in only 1 case with roxatidine. In this trial, roxatidine 150 mg once daily was as efficacious and safe as ranitidine 300 mg once daily for treatment of patients with uncomplicated, benign gastric ulcer disease.

[Rhinosinusitis in AIDS patients]

We examined microbic infections and topical immunity in 36 AIDS patients with rhinosinusitis (AIDS CDC stage IV b-d) who had an average serum CD4 count of 90/microliters. We also examined the presence of the HIV genome in nasal mucous. Microbiological examination revealed an increased number of fungal infections in addition to bacterial infections with multiresistant strains. There was no evidence of CD4-T cells or HIV reverse transcriptase. The size of study was too small to permit generalised conclusions about the infectious risk of nasal mucous.

Paraneoplastic polymyositis associated with a renal carcinoma

A 56-year-old patient was admitted to hospital because of difficulties in swallowing and in opening his mouth. The serological transaminases were increased. Over the next 6 weeks a bioptically proven polymyositis (more proximally located) caused a respiratory insufficiency which had to be treated by artificial respiration. A tetraplegia connected with a large increase of creatine-kinase was also seen. The general investigations were focused on malign processes with a particular search for bronchial carcinoma. At first a kidney cyst detected by ultrasound but was classified as harmless by several investigators. Finally, a computer tomogram of the abdomen demonstrated a cystic degenerated renal carcinoma, which had been cytologically tested also. The clinical course showed a typical aspect of a paraneoplastic syndrome: after extended nephrectomy a distinct regression of the musculary symptoms developed, but with the development of metastases the symptoms increased again. The interdependence of polymyositis and primary renal carcinoma would appear to be proven.

Effect of ranitidine and amoxicillin plus metronidazole on the eradication of Helicobacter pylori and the recurrence of duodenal ulcer

BACKGROUND

Persistent infection with Helicobacter pylori is associated with the recurrence of duodenal ulcer. Whether the efficacy of bismuth therapy in reducing the rate of recurrence of duodenal ulcer is due to its antimicrobial effects on H. pylori or to a direct protective action on the mucosa is still a matter of debate.

METHODS

To study the effect of the eradication of H. pylori on the recurrence of duodenal ulcer, we treated 104 patients with H. pylori infection and recurrent duodenal ulcer with either amoxicillin (750 mg three times daily) plus metronidazole (500 mg three times daily) or identical-appearing placebos, given orally for 12 days. All patients also received ranitidine (300 mg each night) for 6 or 10 weeks. Endoscopy was performed before treatment and periodically during follow-up for up to 12 months after healing.

RESULTS

Among the 52 patients given antibiotics, H. pylori was eradicated in 46, as compared with 1 of the 52 given placebo (89 percent vs. 2 percent, P < 0.001). After six weeks, the ulcers were healed in 48 patients given antibiotics and 39 given placebo (92 percent vs. 75 percent, P = 0.011). Side effects, mainly diarrhea, occurred in 15 percent of the patients given antibiotics. Among the patients followed up for 12 months, duodenal ulcers recurred in 4 of 50 patients given antibiotics and 42 of 49 given placebo (8 percent vs. 86 percent, P < 0.001). Ulcers recurred in 1 of 46 patients in whom H. pylori had been eradicated, as compared with 45 of 53 in whom H. pylori persisted (2 percent vs. 85 percent, P < 0.001).

CONCLUSIONS

In patients with recurrent duodenal ulcer, eradication of H. pylori by a regimen that does not have any direct action on the mucosa is followed by a marked reduction in the rate of recurrence, suggesting a causal role for H. pylori in recurrent duodenal ulcer.

[Effect of pirenzepine on motility of Oddi's sphincter]

Pirenzepine (Gastrozepin) has a proven positive effect in the treatment of peptic ulcers by blocking the so called muscarinic acetylcholine receptors of the gastric glands. Reports of positive results with pirenzepine in the treatment of acute pancreatitis led to new discussions about its biological effects. It is thought that there are three ways by which pirenzepine acts in the pancreas. It decreases enzymatic secretion and it increases the secretion of sodium bicarbonate and water. Furthermore, it is said to have a spasmolytic effect on the sphincter of Oddi. To prove this spasmolytic effect we performed endoscopic manometry at the sphincter of Oddi with intubation of the pancreatic duct in 12 healthy patients. After two minutes of manometric registration of the normal sphincter activity 6 patients received 10 mg pirenzepine i.v. while a control group of 6 patients received 2 ml of 0.9% NaCl i.v. During the next 5 minutes the basal pressure of the sphincter, the amplitude of concentrations, as well as their frequency and duration were monitored. There were no changes noticed in the placebo group. However, pirenzepine caused a considerable decrease of the 4 manometric parameters of the sphincter of Oddi in all patients. Within 5 minutes the basal tonus fell from 14.3 +/- 5.1 mm of mercury to 9.0 +/- 6.0 (p less than 0.01). The frequency of contractions dropped from 5.8 +/- 2.7 per minute to 2.0 +/- 2.1 (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Stapedius reflex. 1. Stapedius reflex threshold and recruitment]

The stapedius reflex threshold and pure tone threshold of 173 patients with normal hearing and cochlear disorders were examined (using Madsen ZO 73 equipment).

CONCLUSIONS

1. The aetiology of the cochlear hearing disorders does not influence the stapedial reflex threshold. 2. A linear regression between hearing loss and threshold difference was found in cochlear hearing disorders. 3. No correlation could be found between individual pure tone threshold and stapedial reflex threshold.

[Stapedius reflex. 2. Latency periods of the stapedial reflex]

The reflex thresholds and initial latency times of the stapedial reflex of 50 patients with normal hearing and cochlear hearing loss were examined using Madson ZO 73 equipment. The following results were obtained: 1. The initial latency times of the stapedius reflex diminish proportional to the supra-threshold loudness. 2. No significant difference of the latency times was found between 0.5, 1, 2 and 4 kHz. 3. The initial latency times of patients with positive recruitment (cochlear hearing loss) do not differ from those of patients with normal hearing.

[Functional results in unilateral auditory canal atresia]

42 patients with unilateral congenital atresia of the ear were examined postoperatively. The results were as follows: 1. Tympanoplasty type III, stapes elevation by autologous ossicula, gave the best results on the average. 2. The discrimination tests gave poorer results than had been expected from the pure-tone threshold audiograms. 3. As a result of the operation, only one-third of the patients obtained a sense of hearing which made them fit for social contacts; hence, the indication for surgery should be examined critically before any action is taken.

[Impedance measurements and otosclerosis (author's transl)]

Impedance measurements (model Madsen ZO 72) were performed on 158 patients with otosclerosis and compared with the operative findings. It was found that otosclerosis shows in 95% of the cases a symmetrical tympanogram, type A. Its amplitude does not differ from the standard values: that means that otosclerosis does not correlate with a flattened amplitude of the tympanogram. In addition there is no correlation between the intraoperative finding and the ampitude. The stapedius reflex could not be elicitated by acoustic stimuli.

[Determination of the impaired ear's frequency selectivity using psychoacoustical tuning curves (author's transl)]

An apparatus for clinical use is described by which simplified psychoacoustical tuning curves can be measured near 500 Hz and near 4 kHz. Data produced by four groups (normal hearing, conductive hearing loss, noise induced hearing loss and degenerative hearing loss) are separately averaged and compared. The first mentioned two groups as well as the third in the low frequency range show good frequency resolution, the others, however, show largely decreased frequency resolution.