Rapid point-of-care detection of SARS-CoV-2 infection in exhaled breath using ion mobility spectrometry: a pilot study

BACKGROUND

An effective testing strategy is essential for pandemic control of the novel Coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Breath gas analysis can expand the available toolbox for diagnostic tests by using a rapid, cost-beneficial, high-throughput point-of-care test. We conducted a bi-center clinical pilot study in Germany to evaluate breath gas analysis using multi-capillary column ion mobility spectrometry (MCC-IMS) to detect SARS-CoV-2 infection.

METHODS

Between September 23, 2020, and June 11, 2021, breath gas measurements were performed on 380 patients (SARS-CoV-2 real-time polymerase chain reaction (PCR) positive: 186; PCR negative: 194) presenting to the emergency department (ED) with respiratory symptoms.

RESULTS

Breath gas analysis using MCC-IMS identified 110 peaks; 54 showed statistically significant differences in peak intensity between the SARS-CoV-2 PCR-negative and PCR-positive groups. A decision tree analysis classification resulted in a sensitivity of 83% and specificity of 86%, but limited robustness to dataset changes. Modest values for the sensitivity (74%) and specificity (52%) were obtained using linear discriminant analysis. A systematic search for peaks led to a sensitivity of 77% and specificity of 67%; however, validation by transferability to other data is questionable.

CONCLUSIONS

Despite identifying several peaks by MCC-IMS with significant differences in peak intensity between PCR-negative and PCR-positive samples, finding a classification system that allows reliable differentiation between the two groups proved to be difficult. However, with some modifications to the setup, breath gas analysis using MCC-IMS may be a useful diagnostic toolbox for SARS-CoV-2 infection.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov on September 21, 2020 (NCT04556318; Study-ID: HC-N-H-2004).

A slow-cycling subpopulation of melanoma cells with highly invasive properties

Melanoma is a heterogeneous tumor with different subpopulations showing different proliferation rates. Slow-cycling cells were previously identified in melanoma, but not fully biologically characterized. Using the label-retention method, we identified a subpopulation of slow-cycling cells, defined as label-retaining cells (LRC), with strong invasive properties. We demonstrate through live imaging that LRC are leaving the primary tumor mass at a very early stage and disseminate to peripheral organs. Through global proteome analyses, we identified the secreted protein SerpinE2/protease nexin-1 as causative for the highly invasive potential of LRC in melanomas.

[Reasons for Emergency Department Visits: Results of a Patient Survey]

OBJECTIVES

The number of patients visiting emergency departments (ED) is steadily increasing. The cause for this rise in Germany is unclear and less examined. This study aimed to assess the reasons of walk-in patients to visit EDs by using a direct survey.

METHODS

During a period of 4 weeks, 2 010 walk-in patients were anonymously surveyed in 2 major Berlin hospitals using a standardized questionnaire. Descriptive statistics were used for data analysis.

RESULTS

More than 90% of patients assessed themselves as an emergency and three-quarters of patients reported pain. The majority of patients (57%) tried to contact statutory health insurance (SHI) office-based physicians in advance and 59% of patients said they would make use of ambulatory emergency facilities if they were available and well established. However, 55% of patients were unaware of the emergency service of the association of SHI physicians.

CONCLUSION

The results indicate that centralized ambulatory emergency facilities should be available 24/7 at hospitals with EDs. Therefore, future planning of emergency services should integrate providers of ambulatory and inpatient sector. International experience suggests that different instruments aiming at better coordination of care, such as integrated call centers, extended ambulatory services and facilities for less urgent cases located in or nearby hospitals with EDs should also be implemented in Germany.

[Patients with Acute, Non-Traumatic Abdominal Pain in German Emergency Departments: A Prospective Monocentric Observation Study]

Background: Up to 11 % of patients in an Emergency Department (ED) present with non-traumatic acute abdominal pain. Based on this presenting symptom, this study aimed to analyse how residents (surgery, internal medicine, anaesthesiology and other fields) working in an ED during their second and third year of education treat these patients. Material and Methods: We performed a prospective, monocentric observation study in an ED in accordance with the STROBE recommendations, following the recommendations from the Ethics Committee of the University of Ulm (application no. 335/12) and the Declaration of Helsinki. The hospital's data protection officer approved the study. During a 12-month period (Dec. 2012 to Dec. 2013), a random sample of patients with non-traumatic abdominal pain was obtained in the ED of a major German acute care hospital by an independent observer, who was not part of the ED team. In addition to demographic data, the study focused on analysing processes and patient care (including medical history taking and physical examinations). In addition, subgroups were defined (clinical background of the treating physician, severity pursuant to the Manchester Triage Score [MTS]). Results: 143 patients met the inclusion criteria. The clinical background of the physician had no influence on the reviewed processes such as medical history taking, initial examinations, the request of consultative examinations or diagnostic procedures. Patients triaged as "urgent" were treated significantly earlier than patients triaged as "non-urgent" (time to first physician contact 26 ± 24 vs. 46 ± 34 min, p < 0.001). However, the overall time spent in the ED was equal (210 ± 79 vs. 220 ± 114 min, p = 0.555). Yet the initially estimated urgency was correlated with the need for hospitalisation (share: 57 %). Conclusion: The overall compliance with standards of care was high. The clinical background (surgery, internal medicine, anaesthesiology, other fields) of the physician in charge of initial treatment had no influence on the reviewed processes.

Comparison of the source of introduction to cariogenic food substance and caries prevalence in children

INTRODUCTION

Dental caries being a multi-factorial disease depends on lot of factors. Since awareness and exposure seems to have increased, in the present scenario it is difficult to assume that one particular source would increase the occurrence of dental caries. Children are exposed to different media sources and spend most of their free time watching them. They are attracted by messages of advertisers' and susceptible to stylish advertisements of foods often harmful to oral and general health.

AIM

To compare the effects of three different sources of introduction to cariogenic food substance among school children and their role in caries prevalence.

MATERIALS AND METHODS

A total of 300 school children were selected for the study and a questionnaire was prepared keeping in mind the various sources introducing cariogenic foods to children namely television advertisement, magazines/news paper, posters/banners. Following which oral examination will be done to determine the number of carious lesions in the subjects. The data will be acquired, computed and statistically analysed to compare the correlation between these sources and caries prevalence.

RESULTS

Children who watched television advertisements and asked for food items and soft drinks were found to have more caries and DMFT/dmft index.

CONCLUSION

A total ban on advertisements would not be practically possible. A more realistic approach would be to limit the number of advertisements that feature potentially cariogenic and unhealthy food products, and also ensure that they ideally carry statutory warnings.

A stress-induced early innate response causes multidrug tolerance in melanoma

Acquired drug resistance constitutes a major challenge for effective cancer therapies with melanoma being no exception. The dynamics leading to permanent resistance are poorly understood but are important to design better treatments. Here we show that drug exposure, hypoxia or nutrient starvation leads to an early innate cell response in melanoma cells resulting in multidrug resistance, termed induced drug-tolerant cells (IDTCs). Transition into the IDTC state seems to be an inherent stress reaction for survival toward unfavorable environmental conditions or drug exposure. The response comprises chromatin remodeling, activation of signaling cascades and markers implicated in cancer stemness with higher angiogenic potential and tumorigenicity. These changes are characterized by a common increase in CD271 expression concomitantly with loss of differentiation markers such as melan-A and tyrosinase, enhanced aldehyde dehydrogenase (ALDH) activity and upregulation of histone demethylases. Accordingly, IDTCs show a loss of H3K4me3, H3K27me3 and gain of H3K9me3 suggesting activation and repression of differential genes. Drug holidays at the IDTC state allow for reversion into parental cells re-sensitizing them to the drug they were primarily exposed to. However, upon continuous drug exposure IDTCs eventually transform into permanent and irreversible drug-resistant cells. Knockdown of CD271 or KDM5B decreases transition into the IDTC state substantially but does not prevent it. Targeting IDTCs would be crucial for sustainable disease management and prevention of acquired drug resistance.

Hepatitis C virus infection and kidney transplantation in 2014: what's new?

Chronic hepatitis C virus (HCV) infection remains an important health problem, which is associated with deleterious consequences in kidney transplant recipients. Besides hepatic complications, several extrahepatic complications contribute to reduced patient and allograft survival in HCV-infected kidney recipients. However, HCV infection should not be considered as a contraindication for kidney transplantation because patient survival is better with transplantation than on dialysis. Treatment of HCV infection is currently interferon-alpha (IFN-α) based, which has been associated with higher renal allograft rejection rates. Therefore, antiviral treatment before transplantation is preferable. As in the nontransplant setting, IFN-free treatment regimens, because of their greater efficacy and reduced toxicity, currently represent promising and attractive therapeutic options after kidney transplantation as well. However, clinical trials will be required to closely evaluate these regimens in kidney recipients. There is also a need for prospective controlled studies to determine the optimal immunosuppressive regimens after transplantation in HCV-infected recipients. Combined kidney and liver transplantation is required in patients with advanced liver cirrhosis. However, in patients with cleared HCV infection and early cirrhosis without portal hypertension, kidney transplantation alone may be considered. There is some agreement about the use of HCV-positive donors in HCV-infected recipients, although data regarding posttransplant survival rates are controversial.

The synthetic hydroxyproline-containing collagen analogue (Gly-Pro-Hyp)10 ameliorates acute DSS colitis

In experimental models of and humans with intestinal inflammation, increased levels of the matrix-degrading gelatinases MMP-2 and -9 in inflamed tissues can be detected. The synthetic collagen analogue (Gly-Pro-Hyp)10, (GPO)10, has been identified as a relevant binding structure for proMMP-2/-9 and promotes enzymatic activity of proMMP-2. Since targeted MMP strategies might offer promising anti-inflammatory treatment options, we for the first time studied in vivo actions exerted by (GPO)10 applying an acute dextrane sulfate sodium (DSS) induced colitis model. Seven-day intraperitoneal (GPO)10 treatment ameliorated clinical symptoms and histopathological colonic changes as compared to placebo controls with severe colitis. (GPO)10-treated mice displayed a diminished influx of neutrophils, and T- and B-lymphocytes into their colonic mucosa whereas numbers of regulatory T-cells and regenerative cells were higher as compared to placebo controls. Furthermore, IL-6 secretion was down-regulated in ex vivo colonic biopsies derived from (GPO)10-treated mice whereas higher concentrations of the anti-inflammatory cytokine IL-10 in extra-intestinal compartments such as MLN and spleen could be detected. Strikingly, influx of inflammatory cells into lungs was abolished following (GPO)10 application. We therefore propose (GPO)10 as a promising effective and safe treatment option of intestinal and extra-intestinal inflammatory conditions in humans.

The synthetic hydroxyproline-containing collagen analogue (Gly-Pro-Hyp)10 promotes enzymatic activity of matrixmetalloproteinase-2 in vitro

Diseases such as liver fibrosis and intestinal inflammation are characterized by accumulated components of the extracellular matrix (ECM). Given that fibrillar collagen structures were shown to serve as storage site for inactive proforms of matrixmetalloproteinases (MMPs), modulating this MMP-collagen interaction might offer a rational interventional (therapeutic) approach to enhance degradation of accumulated ECM. The synthetic triple helical collagen analogue (Gly-Pro-Hyp)10 - (GPO)10 - was shown to trigger release and enzymatic activation of collagen sequestered proMMP-2. In the presented study, we, for the first time, investigated how MMP-(GPO)10 interaction impacts cellular responses in vitro. We found that recombinant proMMP-2 induced proliferation of hepatic stellate cells (HSC), which was enhanced after addition of (GPO)10 reaching comparable levels following incubation with fully activated MMP-2. In addition, (GPO)10 induced HSC migration similar to the platelet-derived growth factor subunit-B. Further, the MMP-2-dependent invasion of HT1080 fibrosarcoma cells through an ECM membrane was enhanced after addition of (GPO)10. Since cellular proliferation and migration concomitant with matrix degradation is stimulated, we conclude that the MMP-(GPO)10 interaction also functions in a physiological environment. Thus, a potential therapeutic effect of (GPO)10 should be further tested in animal models for MMP-associated diseases such as colitis or fibrosis.

Role of mannose-binding lectin-2 polymorphism in the development of acute cellular rejection after transplantation for hepatitis C virus-induced liver disease

The development of liver and graft disease is suspected to be affected by genetic diversity. Mannose-binding lectin-2 (MBL-2) is an important immunomodulatory factor that is involved in complement activation. The aim of our study was to elucidate the role of MBL-2 genotypes after liver transplantation (LT) for hepatitis C virus (HCV)-induced liver disease regarding the incidence of acute cellular rejection (ACR), graft inflammation, fibrosis development, and antiviral treatment response.

METHODS

A group of 149 patients who underwent LT for HCV-induced liver disease were genotyped for MBL-2 (rs7096206; G/C) by TaqMan genotyping assay. We evaluated 518 post-LT protocol biopsies and at least 98 urgent liver biopsies regarding graft fibrosis stages, inflammation grades, and evidence for rejection within MBL-2 genotype groups.

RESULT

No association of MBL-2 polymorphisms was observed regarding inflammation, fibrosis, and antiviral treatment outcome. However, the C allele of the MBL-2 gene (P = 0.001) and gender compatibility (P = 0.012) were factors significantly associated with the incidence of ACR.

CONCLUSION

MBL-2 polymorphisms and gender are involved in the development of ACR after LT. CC genotype and gender match may be regarded as risk factors for ACR in HCV-positive graft recipients. Further studies are needed to confirm and verify this observation in non-HCV groups as well.

[Nodular regenerative hyperplasia as a side effect of azathioprine in a patient with Crohn's disease]

HISTORY

A 48-year-old patient with Crohn's disease was admitted to our hospital with fatigue, icterus, hepatosplenomegaly and ascites. INVESTIGARTIOS: The whole blood count revealed a pancytopenia, hyperbilirubinemia and slightly elevated transaminases. Examination of the liver histology showed areas of enlarged hyperplastic hepatocytes adjacent to areas of atrophic hepatocytes and dilated sinusoids.

DIAGNOSIS, TREATMENT AND COURSE

Pancytopenia was most likely azathioprine-related. Analysis of the liver histology was highly suggestive of an azathioprine-related, nodular regenerative hyperplasia (NRH). After discontinuation of azathioprine the patient's condition improved substantially.

CONCLUSIONS

NRH is a rare but potentially serious complication of azathioprine therapy. Other causes include various rheumatological, vascular and myeloproliferative diseases. When azathioprine is prescribed it must be borne in mind that it can cause NRH as a potential adverse effect, and liver enzymes should be measured at regular follow-up examinations.

Effect of paclobutrazol on water stress amelioration through antioxidants and free radical scavenging enzymes in Arachis hypogaea L

An investigation was carried out to find out the extent of changes occurred in groundnut (Arachis hypogaea L.) cultivars in response to paclobutrazol (PBZ) treatment under water deficit stress. Two groundnut cultivars namely ICG 221 and ICG 476 were used for the study. Individual treatment with PBZ and drought stress showed an increase in ascorbic acid, alpha-tocopherol and reduced glutathione, superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) activities. PBZ with drought stressed plants maintained higher levels of antioxidant and scavenging enzymes. Significant differences were observed between cultivars and treatments. These results suggests that the adverse effects of water stress can be minimized by the application of PBZ by increasing the antioxidant levels and activities of scavenging enzymes such as SOD, APX and CAT. The Cv. ICG 221 appears to be more tolerant to water stress than the ICG 476.

Induction of drought stress tolerance by ketoconazole in Catharanthus roseus is mediated by enhanced antioxidant potentials and secondary metabolite accumulation

A pot culture experiment was conducted to estimate the drought stress mitigating effect of ketoconazole (KCZ), a fungicide cum plant growth regulator, in Catharanthus roseus plants. The plants under pot culture were subjected to drought stress and drought stress with KCZ from 30 days after sowing (DAS) and regular irrigation was kept as control. Antioxidant contents and activities of antioxidant enzymes were estimated from root, stem and leaf of both control and treated plants. The alkaloid ajmalicine was extracted and estimated from the roots of control, drought stressed and KCZ treated plants. Individual and combined drought stress and KCZ treatments increased ascorbic acid, alpha-tocopherol contents, superoxide dismutase, ascorbate peroxidase, catalase and polyphenol oxidase activities when compared to control. There was a significant enhancement in ajmalicine production under KCZ treated plants under drought stress when compared to well watered control as well as drought stressed plants. The KCZ treatment resulted in partial mitigation of drought stress by increasing the antioxidant potentials in C. roseus plants.

Alterations in osmoregulation, antioxidant enzymes and indole alkaloid levels in Catharanthus roseus exposed to water deficit

Catharanthus roseus (L.) G. Don plants were grown in different water regimes in order to study the drought induced osmotic stress and proline (PRO) metabolism, antioxidative enzyme activities and indole alkaloid accumulation. The plants under pot culture were subjected to 10, 15 and 20 days interval drought (DID) stress from 30 days after sowing (DAS) and regular irrigation was kept as control. The plants were uprooted on 41DAS (10DID), 46DAS (15DID) and 51DAS (20DID). The drought stressed plants showed increased aminoacid (AA), glycine betaine (GB) and PRO contents and decreased proline oxidase (PROX) and increased gamma-glutamyl kinase (gamma-GK) activities when compared to control. The antioxidative enzymes like peroxidase (POX) and polyphenol oxidase (PPO) increased to a significant level in drought stressed plants when compared to control. The drought stressed C. roseus plants showed an increase in total indole alkaloid content in shoots and roots when compared to well-watered control plants. Our results suggest that the cultivation of medicinal plants like C. roseus in water deficit areas would increase its PRO metabolism, osmoregulation, defense system and the level of active principles.

Pseudomonas fluorescens enhances biomass yield and ajmalicine production in Catharanthus roseus under water deficit stress

The effect of plant growth promoting rhizobacteria (PGPR) like Pseudomonas fluorescens on growth parameters and the production of ajmalicine were investigated in Catharanthus roseus under drought stress. The plants under pot culture were subjected to 10, 15 and 20 days interval drought (DID) stress and drought stress with Pseudomonas fluorescens at 1mgl(-1) and 1mgl(-1)Pseudomonas fluorescens alone from 30 days after planting (DAP) and regular irrigation was kept as control. The plants were uprooted on 41 DAS (10 DID), 46 DAS (15 DID) and 51 DAS (20 DID). Drought stress decreased the growth parameters and increased the ajmalicine content. But the treatment with Pseudomonas fluorescens enhanced the growth parameters under drought stress and partially ameliorated the drought induced growth inhibition by increasing the fresh and dry weights significantly. The ajmalicine content was again increased due to Pseudomonas fluorescens treatment to the drought stressed plants. From the results of this investigation, it can be concluded that, the seedling treatments of native PGPRs can be used as a good tool in the enhancement of biomass yield and alkaloid contents in medicinal plants, as it provides an eco-friendly approach and can be used as an agent in water deficit stress amelioration.

Water deficit stress mitigation by calcium chloride in Catharanthus roseus: Effects on oxidative stress, proline metabolism and indole alkaloid accumulation

The present investigation was conducted to determine whether CaCl(2) increases Catharanthus roseus drought tolerance and if such tolerance is correlated with changes in oxidative stress, osmoregulation and indole alkaloid accumulation. C. roseus plants were grown under water deficit environments with or without CaCl(2). Drought induced oxidative stress was measured in terms of lipid peroxidation (LPO) and H(2)O(2) contents, osmolyte concentration, proline (PRO) metabolizing enzymes and indole alkaloid accumulation. The plants under pot culture were subjected to 10, 15 and 20 days interval drought (DID) stress and drought stress with 5mM CaCl(2) and 5mM CaCl(2) alone from 30 days after planting (DAP) and regular irrigation was kept as control. The plants were uprooted on 41 DAS (10 DID), 46 DAS (15 DID) and 51 DAS (20 DID). Drought stressed plants showed increased LPO, H(2)O(2), glycine betaine (GB) and PRO contents and decreased proline oxidase (PROX) activity and increased gamma-glutamyl kinase (gamma-GK) activity when compared to control. Addition of CaCl(2) to drought stressed plants lowered the PRO concentration by increasing the level of PROX and decreasing the gamma-GK activities. Calcium ions increased the GB contents. CaCl(2) appears to confer greater osmoprotection by the additive role with drought in GB accumulation. The drought with CaCl(2)-treated C. roseus plants showed an increase in total indole alkaloid content in shoots and roots when compared to drought stressed and well-watered plants.

Mineral uptake and biochemical changes in Helianthus annuus under treatment with different sodium salts

Experiments were conducted to study the effects of different sodium salts viz., sodium chloride (NaCl), sodium sulphate (Na(2)SO(4)) and sodium carbonate (Na(2)CO(3)) on growth, dry matter production, mineral contents, biochemical constituent and enzyme activities of sunflower (Helianthus annuus L.). The germinating sunflower seeds were treated with 10, 20 and 50mM NaCl and Na(2)SO(4) and 5, 10 and 15 mM Na(2)CO(3). The seedling growth, minerals, chlorophyll content and biochemicals like protein and free amino acid contents with enzyme activities like ATPase and protease were analysed on 8 DAS. The seedlings were separated into root, stem, leaf and cotyledon on 8 DAS. All the treatments decreased the germination percentage; shoot length, root length, leaf area and dry weight, chlorophyll and protein contents significantly. Potassium, sodium and free amino acid contents; activities of ATPase and protease were increased when compared to control. This effect was very high in the Na(2)CO(3) treated seedlings this was followed by Na(2)SO(4) and NaCl treated seedlings. From the results of this investigation, it is clear that, the sunflower seedlings were affected significantly in the Na(2)CO(3) treatments, and followed by Na(2)SO(4) and NaCl treatments.

Protection of Vigna unguiculata (L.) Walp. plants from salt stress by paclobutrazol

A pot culture experiment was conducted to estimate the stress ameliorating ability of paclobutrazol, a triazole fungicide in Vigna unguiculata (L.) Walp. plants. Treatments were given as 80 mM NaCl, 80 mM NaCl+15 mg l(-1) paclobutrazol and 15 mg l(-1) paclobutrazol alone. The samples were collected on 60 and 80 days after sowing (DAS). NaCl stress inhibited the root and stem length, total leaf area, fresh weight (FW), dry weight (DW) and activities of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX). Plants treated with NaCl with paclobutrazol increased these parameters to a larger extent when compared to NaCl stressed plants. The results showed that the paclobutrazol significantly ameliorated the adverse effects of NaCl stress in V. unguiculata plants.

Carbohydrate metabolism in Dioscorea esculenta (Lour.) Burk. tubers and Curcuma longa L. rhizomes during two phases of dormancy

We have examined the changes in carbohydrate metabolism in food yam (Dioscorea esculenta (Lour.) Burk.) tubers and in an economically important spice cum medicinal plant turmeric (Curcuma longa L.) rhizomes under storage. Both specimens showed varied levels of dormancy and sprouting appeared at the end of dormant period. Harvested, fully matured tubers of yam and rhizomes of turmeric were stored in wooden boxes under the conditions of 28+/-2 degrees C temperature and 65-75% relative humidity (RH) in dark. The starch, sugars, enzymes of starch degradation, respiration, glycolysis, tricarboxylic acid (TCA) cycle and oxidative pentose phosphate pathway (PPP) were studied during 1-70 days after harvest (DAH). This investigation revealed that, the starch degradation and the enzymes involved, viz. alpha-amylases and starch phosphorylase showed a lower level of activity during early period of dormancy, while sugar content and enzymes of carbohydrate metabolism increased rapidly during sprouting. The isoenzymic profiles of alpha-amylases showed marked variations in these two phases. The key enzymes of glycolysis, TCA cycle and PPP, viz. aldolase, succinic dehydrogenase, malic dehydrogenase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were increased even before the visible appearance of sprouting and their activities were at their maximum during sprouting. Based of the observations the dormancy period may be distinctly divided into peak period of rest and presprouting period.

Changes in antioxidant metabolism of Vigna unguiculata (L.) Walp. by propiconazole under water deficit stress

In the present study, a pot culture experiment was conducted to estimate the ameliorating effect of propiconazole (PCZ) on drought stress in cowpea (Vigna unguiculata (L.) Walp.) plants. From 30 days after sowing (DAS), the plants were subjected to 3, 6 and 9 days interval drought (DID) stress and drought stress with PCZ at 15 and 15 mg l(-1) PCZ alone and 1 day interval irrigation was kept as control. The plant samples were collected on 34 DAS (3 DID), 37 DAS (6 DID) and 40 DAS (9 DID). The plants were separated into root, stem and leaf for estimating the antioxidant contents and activities of antioxidant enzymes. Individual and combined drought stress and PCZ treatments increased ascorbic acid (AA), alpha-tocopherol (alpha-toc) contents, superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and polyphenol oxidase (PPO) activities when compared to control. The PCZ treatment mitigated the adverse effects of drought stress by increasing the antioxidant potentials and thereby paved the way for overcoming drought stress in V. unguiculata plants.

Growth, biochemical modifications and proline metabolism in Helianthus annuus L. as induced by drought stress

In the present investigation, two watering treatments, viz., 100% and 60% field capacity (FC) were used to understand the effects of water deficit on early growth, biomass allocation, pigment and biochemical constituents and proline metabolism of five varieties of Sunflower (Helianthus annuus L.) plants. We found that there was a significant difference in early growth, dry matter accumulation, pigment, biochemical constituents and proline metabolism among the five varieties. The root length, shoot length, total leaf area, fresh and dry weight, chlorophyll a, b, total chlorophyll and carotenoid were significantly reduced under water stress treatments. Water stress increased the proline, free amino acid and glycinebetaine contents along with increased activity of gamma-glutamyl kinase but the activity of proline oxidase reduced as a consequence of water stress.

Detection of HLA class II-dependent T helper antigen using antigen phage display

Major histocompatibility complex (MHC) class II-dependent antigens not only activate CD4+ T helper (Th) cells, but also cytolytic T lymphocytes and effector cells of the innate immune system. These antigens therefore are candidate vaccines against cancer and infectious agents. We have developed a novel approach using a model antigen, tetanus toxoid (TT), which provides the basis for the establishment of a novel strategy of cloning Th antigens. In the TT model system, a cDNA library encoding part of the TT light chain which contained a TT-associated Th epitope recognized by TT-specific Th clones was displayed on a phage vector (TT-phage) and presented to TT-specific Th cells by autologous Epstein-Barr virus-transformed B cells (APC). These TT-phages were able to specifically activate two different TT-specific CD4+ Th cell lines as demonstrated both in [3H]thymidine incorporation and cytokine release assays. Th cell stimulation by TT-phages was significant at a ratio of one TT-phage in 50 irrelevant phages. The described approach provides the basis for the development of a novel strategy of cloning MHC class II-dependent Th antigens, using available Th cells. This strategy has several potential advantages over existing antigen cloning methods or biochemical peptide isolation.

Anti-idiotypic antibody (ab2) vaccines: coupling of Ab2 BR3E4 to KLH increases humoral and/or cellular immune responses in animals and colorectal cancer patients

The colorectal carcinoma (CRC)-associated CO17-1A/GA733 antigen (Ag) has been the target of a phase II/III randomized trial of passive immunotherapy with monoclonal antibody CO17-1A (Ab1), and phase I active immunotherapy trials with polyclonal anti-idiotypic antibodies (Ab2) mimicking the CO17-1A or GA733 epitope of the Ag. However, monoclonal rat Ab2 BR3E4 directed against Ab1 CO17-1A was superior to polyclonal Ab2 in inducing antigen-specific humoral and cellular immune responses in mice and rabbits. Various forms of Ab2 BR3E4, i.e., BR3E4-F(ab')2 precipitated with aluminum-hydroxide (alum), BR3E4-F(ab')2 coupled to KLH and precipitated or non-precipitated with alum, and BR3E4-IgG in alum or incomplete Freund's adjuvant were compared for their capacity to induce in rabbits anti-anti-idiotypic antibodies (Ab3) that specifically bind to the CO17-1A Ag. BR3E4-F(ab')2 coupled to KLH and precipitated with alum was shown to induce the highest Ab3 titers, followed by Ab2 BR3E4-IgG in alum. Therefore Ab2 BR3E4 as intact IgG (IgG group) or as F(ab')2 coupled to KLH (KLH group), was administered in a phase I trial to 45 patients with CRC, stage Dukes'D (UICC stage IV), with the goal to modulate patients' immune responses to their tumors. Fifteen of 23 patients in the IgG group developed Ab3 binding specifically to Ab2, and in four of these patients the Ab3 also specifically bound to Ag-positive CRC cells. Lymphoproliferative responses to Ab2 and/or GA733-2E Ag stimulation were observed in three of these patients. Eighteen of the 22 KLH group patients tested developed Ab3 and the Ab3 bound specifically to CRC cells in eight patients. Five of the 15 KLH group patients tested developed lymphoproliferative responses to Ab2 and/or GA733-2E Ag. Thus, there was a trend for the KLH group demonstrating higher immune response rates than the IgG group. Clinical responses were rare in these patients with liver metastases.

Matrix as a modulator of hepatic fibrogenesis

The extracellular matrix (ECM) provides cells with positional information and a mechanical scaffold for adhesion and migration. It consists of collagens, glycoproteins, proteoglycans, glycosaminoglycans and molecules that are bound specifically by the ECM, such as certain growth factors/cytokines, matrix metalloproteinases (MMPs) and processing enzymes such as tissue transglutaminase and procollagen propeptidases. This finely tuned ecosystem is dysbalanced in chronic fibrogenesis, which can be regarded as a continuous wound-healing process and which results in scar formation. Importantly, the ECM directs cellular differentiation, migration, proliferation, and fibrogenic activation or deactivation. Partially via defined oligopeptide sequences or structural domains, the ECM transfers specific signals to cells that act in concert with growth factors/cytokines. These signals either confer stress activation, with a resultant fibrogenic response, or stress relaxation, with a fibrolytic response. Alternatively, ECM-derived peptides can modulate angiogenesis, or growth factor and MMP availability and activity. Current ECM-related antifibrotic strategies are based on the identification and in vivo application of ECM-derived biomodulatory peptides, peptide sequences, or their nonpeptidic mimetics. The latter open the opportunity of oral application and an extended biological half-life. Examples are peptides derived from collagens VI (stress activation) and XIV (stress relaxation), or collagenous consensus peptides that remove ECM-bound MMPs and growth factors. Furthermore, certain peptides can be used as targeting structures to the fibrogenic lesion.

Anti-idiotypic antibody and recombinant antigen vaccines in colorectal cancer patients

The colorectal carcinoma (CRC)-associated GA733 antigen (also known as CO17-1A, KS1-4, KSA or EpCAM) has been the target of a phase II/III randomized trial of passive immunotherapy with monoclonal antibody CO17-1A and phase I active immunotherapy trials with polyclonal anti-idiotypic antibodies mimicking the CO17-1A or GA733 epitope on the antigen. The CO17-1A antigen was molecularly cloned and the extracellular domain expressed in baculovirus (BV) GA733-2E. Whereas, anti-idiotypic antibody mimics a single epitope on the antigen, BV GA733-2E expresses multiple potentially immunogenic epitopes. In animals, the immunogenicity of BV GA733-2E in aluminum hydroxide was superior to that of anti-idiotype in the same adjuvant. Here, we compared the immunogenicity of anti-idiotypic antibody and GA733-2E antigen in CRC patients. These studies indicate that the antigen is superior to the anti-idiotype antibody in inducing humoral and cellular immunity in CRC patients.

Immunogenicity of recombinant GA733-2E antigen (CO17-1A, EGP, KS1-4, KSA, Ep-CAM) in gastro-intestinal carcinoma patients

Targeting the GA733 antigen (also known as CO17-1A, EGP, KS1-4, KSA, Ep-CAM) by monoclonal antibody CO17-1A or anti-idiotypic antibodies mimicking the CO17-1A or GA733 epitope has induced prolonged survival and specific immune responses to the antigen, respectively, in colorectal cancer (CRC) patients. In pre-clinical studies in mice and rabbits, recombinant baculovirus-derived GA733-2E antigen was superior to anti-idiotypic antibodies at modulating specific immune responses. Our aim was to evaluate the immunogenicity and potential toxicity of alum-precipitated GA733-2E in a phase I trial in patients with resected CRC or pancreatic cancer. Six patients with advanced pancreatic carcinoma and 6 with CRC Dukes' stage A, B or C received between 4 and 7 doses of alum-precipitated GA733-2E at 50, 200 or 800 microg/dose at monthly intervals. Antibody binding to GA733-2E or antigen-positive CRC cells was determined, as were antigen-specific proliferative, cytolytic T-lymphocyte and delayed-type hypersensitivity responses. Six of the 12 patients developed antigen-specific humoral immune responses after immunotherapy, and 8 developed cellular immune responses. The overall immune response rate, including patients with humoral and/or cellular immune responses, was 83%. Median overall survival of the CRC and pancreatic cancer patients was 39.8 and 11.2 months, respectively. Following 18 years of single-epitope targeting of the GA733 antigen, immunization of patients against multiple epitopes of the antigen frequently induces an immune response in the absence of significant toxicity, despite relatively widespread expression of this antigen on normal epithelial cells.

Isolation of the melanoma-associated antigen p23 using antibody phage display

The general responsiveness of human melanoma to immunotherapy has been well established, but active immunotherapy of melanoma has been hampered by insufficient information on the immunogenicity of melanoma-associated Ags in patients. In this study, we isolated a recombinant phage-Fab clone (A10-5) from a phage-Fab library derived from the B cells of a melanoma patient in remission after immunotherapy. Purified A10-5 Fab bound at high levels to cultured melanoma cell lines and to tissue sections of metastatic and vertical growth phase primary melanoma, but not to radial growth phase primary melanoma, nevi, or normal skin. A10-5 Fab bound to both the surface and the cytoplasm of cultured melanoma cells, but only to the cytoplasm of cultured fibroblasts. Western blot analysis revealed A10-5 Fab reactivity with a 33- and a 23-kDa glycoprotein under nonreducing conditions, and with a 23-kDa protein only under reducing conditions. A cDNA with an open reading frame predicted to encode a 23-kDa protein was cloned by screening a melanoma cell cDNA library with A10-5 Fab. This protein (p23) is the human homologue of the murine tumor transplantation Ag P198 that interacts with the cytoplasmic domain of ErbB-3 expressed by melanoma cells. Thus, the Ab phage display method has identified a novel, stage-specific melanoma-associated Ag that may have therapeutic and diagnostic value.

Collagens serve as an extracellular store of bioactive interleukin 2

The binding of certain growth factors and cytokines to components of the extracellular matrix can regulate their local availability and modulate their biological activities. We show that interleukin 2 (IL-2), an important stimulator of T cell growth, preferentially binds to collagen types I, III, and VI and to a lesser degree to collagen types II, IV, and V, immobilized on polystyrene or nitrocellulose. These interactions are inhibited by denatured, single collagen chains or a subset of their cyanogen bromide peptides in a dose-dependent manner. Cross-inhibition experiments and ligand blotting of collagen-derived peptides point to a limited set of collagenous consensus sequences mediating the binding of IL-2. This interaction is saturable, with dissociation constants of approximately 10(-)(8) m, and estimated molar ratios of 4-6 molecules of IL-2 bound to one molecule of triple helical collagen. Furthermore, collagen-bound IL-2 stimulates proliferation of mouse lymphocytes. We conclude that its specific binding to the abundant interstitial collagens leads to a spatial pattern of bioavailable IL-2 which is dictated by the local organization of the collagenous extracellular matrix. This interaction may contribute to the particular phenotype of stromal lymphocytes and could be exploited for devising collagenous peptide analogues that modulate IL-2 bioactivity.

Promotion of smoking cessation by New Zealand general practitioners: a description of current practice

AIMS

To describe the advice and support New Zealand general practitioners (GPs) reported providing to patients about smoking cessation, to explore barriers encountered in providing this advice, and to compare reported practice with recommended best practice.

METHODS

450 GPs were surveyed from four different localities using a structured postal questionnaire.

RESULTS

Questionnaires were returned by 283 GPs, giving a response rate of 63%. Approximately one-third of GPs asked every adult patient about their smoking status. Fewer recorded this information in the patient's notes. GPs, based on their own experience, considered nicotine replacement therapy (NRT) and their own advice to quit to be the two most useful smoking cessation strategies. They perceived patient resistance and time pressures as the main barriers limiting their ability to give advice to patients about smoking cessation.

CONCLUSIONS

GPs provide smoking cessation advice to many patients, but this needs to be viewed in the context of the New Zealand fee-for-service primary care system and competing demands placed on the limited time available within a consultation. There is potential to increase the practice nurse's involvement in providing smoking cessation advice.

Colorectal cancer vaccines: antiidiotypic antibody, recombinant protein, and viral vector

The colorectal cancer antigen GA733 (also termed CO17-1A, KSI-4, Ep-CAM, KSA) has proved to be a useful target in passive immunotherapy with monoclonal antibody and in active immunotherapy with antiidiotypic antibodies in cancer patients. The GA733 antigen was molecularly cloned and expressed in baculovirus (BV), adenovirus (AV), and vaccinia virus (VV). Recombinant BV-, VV-, and AV-GA733 induced antigen-specific cytotoxic antibodies and proliferative and delayed-type hypersensitive lymphocytes. However, only the AV recombinant induced antigen-specific cytolytic T lymphocytes and regression of established tumors. Cured mice were protected against challenge with antigen-negative tumors, indicating antigen spreading of immune responses. In a model of active immunotherapy against the murine homologue of the human GA733 antigen, murine epithelial glycoprotein (mEGP), BV-derived mEGP protein in various adjuvants did not protect mice against a challenge with mEGP-positive tumors. AV mEGP, only when combined with interleukin-2, significantly inhibited growth of established mEGP-positive tumors. This is in contrast to the same vaccine expressing the human antigen that was effective without interleukin-2. AV GA733, in combination with interleukin-2, is a candidate vaccine for colorectal cancer patients.

CD4(+), HLA class I-restricted, cytolytic T-lymphocyte clone against primary malignant melanoma cells

The involvement of HLA-class I in target cell lysis by CD4(+) cytolytic T cells (CTL) has been a controversial issue. A CTL clone of CD4 phenotype was derived from the peripheral blood lymphocytes of a patient with primary melanoma. The CTL clone stably lysed the autologous primary melanoma cells for approximately 9 months in culture. Both the Valpha2/Vbeta8 T-cell receptor and CD4 were involved in CTL cytotoxicity. Of a large panel of allogeneic primary and metastatic melanoma or colorectal carcinoma cells, autologous and allogeneic Epstein-Barr virus-transformed B cells and autologous fibroblasts, only allogeneic metastatic melanoma cells matched with the autologous tumor cells for HLA-class I (B57[17]) were lysed and induced IFN-gamma secretion by the CTL clone. Lysis of the autologous tumor cells was significantly blocked by monoclonal antibody to HLA-B17. Importantly, allogeneic, HLA-class I- and class II-unmatched melanoma cells were lysed by the CTL only following transfection of the cells with B57[17] cDNA. Our results provide direct evidence for the involvement of both CD4 and HLA-class I in tumor cell lysis by CD4(+) CTL.

Soluble collagen VI drives serum-starved fibroblasts through S phase and prevents apoptosis via down-regulation of Bax

We previously showed that soluble, pepsin-solubilized collagen VI increases de novo DNA synthesis in serum-starved HT1080 and 3T3 fibroblasts up to 100-fold compared with soluble collagen I, reaching 80% of the stimulation caused by 10% fetal calf serum. Here we show that collagen VI also inhibits apoptotic cell death in serum-starved cells as evidenced by morphological criteria, DNA laddering, complementary apoptosis assays (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, enzyme-linked immunosorbent assay, and fluorescence-activated cell sorting), and quantification of apoptosis-regulating proteins. In the presence of starving medium alone or collagen I, the proapoptotic Bax was up-regulated 2-2.5-fold, compared with soluble collagen VI and fetal calf serum, whereas levels of the antiapoptotic Bcl-2 protein remained unaffected. In accordance with its potent stimulation of DNA synthesis, soluble collagen VI carries serum-starved HT1080 and Balb 3T3 fibroblasts through G(2) as shown by fluorescence-activated cell sorting analysis, whereas cells exposed to medium and collagen I where arrested at G(1)-S. This was accompanied by a 2-3-fold increase in cyclin A, B, and D1 protein expression. Collagen VI-induced inhibition of apoptotic cell death may be operative during embryogenesis, wound healing, and fibrosis when elevated tissue and blood levels of collagen VI are observed, thus initiating a feedback loop of mesenchymal cell activation and proliferation.

Soluble collagen VI induces tyrosine phosphorylation of paxillin and focal adhesion kinase and activates the MAP kinase erk2 in fibroblasts

Signals from the extracellular matrix can modulate cellular differentiation and gene expression. We have shown previously that in contrast to other extracellular matrix molecules pepsin-solubilized collagen VI (CVI) can stimulate DNA synthesis of various mesenchymal cell types, apparently independent of integrin-mediated signal transduction. In order to further elucidate collagen VI-induced signaling events, we exposed mouse 3T3 fibroblasts and human HT1080 fibrosarcoma cells to soluble CVI. CVI induced tyrosine phosphorylation of proteins that associate with focal adhesions, such as paxillin, focal adhesion kinase (FAK), and p130CAS. Furthermore, it activated the mitogen-activated protein kinase, erk2. Kinetic analysis showed that these phosphorylations were transient, reaching a maximum after 5 min for transformed HT1080 cells and 30 min for 3T3 fibroblasts. These effects were partly inhibited by a beta1-integrin function blocking antibody and by single chains of CVI. Our results indicate that soluble fragments of native collagen VI, a ubiquitous component of the interstitial extracellular matrix, can mediate stimulation of DNA synthesis via tyrosine phosphorylation of paxillin, FAK, p130CAS, and erk2 in the absence of classical growth factors. Thus, CVI may serve as a matrix-derived sensor that allows for rapid reconstitution of a tissue defect by activating nearby mesenchymal cells.

[1st successful immunization of pancreas and colorectal carcinoma patients with CO17-1A-vaccine]

The baculovirus-derived extracellular domain of the CO17-1A antigen induced cellular and/or humoral immune responses in curatively resected colorectal and pancreatic cancer patients after at least three applications of the vaccine. The vaccine application was safe and non-toxic. The clinical efficacy of the vaccine needs to be evaluated in larger, randomized clinical trials.