Topological Stone-Wales Defects Enhance Bonding and Electronic Coupling at the Graphene/Metal Interface

Defects play a critical role for the functionality and performance of materials, but the understanding of the related effects is often lacking, because the typically low concentrations of defects make them difficult to study. A prominent case is the topological defects in two-dimensional materials such as graphene. The performance of graphene-based (opto-)electronic devices depends critically on the properties of the graphene/metal interfaces at the contacting electrodes. The question of how these interface properties depend on the ubiquitous topological defects in graphene is of high practical relevance, but could not be answered so far. Here, we focus on the prototypical Stone-Wales (S-W) topological defect and combine theoretical analysis with experimental investigations of molecular model systems. We show that the embedded defects undergo enhanced bonding and electron transfer with a copper surface, compared to regular graphene. These findings are experimentally corroborated using molecular models, where azupyrene mimics the S-W defect, while its isomer pyrene represents the ideal graphene structure. Experimental interaction energies, electronic-structure analysis, and adsorption distance differences confirm the defect-controlled bonding quantitatively. Our study reveals the important role of defects for the electronic coupling at graphene/metal interfaces and suggests that topological defect engineering can be used for performance control.

Topology Effects in Molecular Organic Electronic Materials: Pyrene and Azupyrene*

Pyrene derivatives play a prominent role in organic electronic devices, including field effect transistors, light emitting diodes, and solar cells. The flexibility in the desired properties has previously been achieved by variation of substituents at the periphery of the pyrene backbone. In contrast, the influence of the topology of the central π‐electron system on the relevant properties such as the band gap or the fluorescence behavior has not yet been addressed. In this work, pyrene is compared with its structural isomer azupyrene, which has a π‐electron system with non‐alternant topology. Using photoelectron spectroscopy, near edge X‐ray absorption fine structure spectroscopy, and other methods, it is shown that the electronic band gap of azupyrene is by 0.72 eV smaller than that of pyrene. The difference of the optical band gaps is even larger with 1.09 eV, as determined by ultraviolet–visible absorption spectroscopy. The non‐alternant nature of azupyrene is also associated with a more localized charge distribution. Further insight is provided by density functional theory (DFT) calculations of the molecular properties and ab initio coupled cluster calculations of the optical transitions. The concept of aromaticity is used to interpret the major topology‐related differences.

The nuts and bolts of core-hole constrainedab initiosimulation forK-shell x-ray photoemission and absorption spectra

X-ray photoemission (XPS) and near edge x-ray absorption fine structure (NEXAFS) spectroscopy play an important role in investigating the structure and electronic structure of materials and surfaces.Ab initiosimulations provide crucial support for the interpretation of complex spectra containing overlapping signatures. Approximate core-hole simulation methods based on density functional theory (DFT) such as the delta-self-consistent-field (ΔSCF) method or the transition potential (TP) method are widely used to predictK-shell XPS and NEXAFS signatures of organic molecules, inorganic materials and metal-organic interfaces at reliable accuracy and affordable computational cost. We present the numerical and technical details of our variants of the ΔSCF and TP method (coined ΔIP-TP) to simulate XPS and NEXAFS transitions. Using exemplary molecules in gas-phase, in bulk crystals, and at metal-organic interfaces, we systematically assess how practical simulation choices affect the stability and accuracy of simulations. These include the choice of exchange-correlation functional, basis set, the method of core-hole localization, and the use of periodic boundary conditions (PBC). We particularly focus on the choice of aperiodic or periodic description of systems and how spurious charge effects in periodic calculations affect the simulation outcomes. For the benefit of practitioners in the field, we discuss sensible default choices, limitations of the methods, and future prospects.

High-quality human and rat spermatozoal RNA isolation for functional genomic studies

Sperm RNA is a sensitive monitoring endpoint for male reproductive toxicants, and a potential biomarker to assess male infertility and sperm quality. However, isolation of sperm RNA is a challenging procedure due to the heterogeneous population of cells present in the ejaculate, the low yield of RNA per spermatozoon, and the absence of 18S and 28S ribosomal RNA subunits. The unique biology of spermatozoa has created some uncertainty in the field about RNA isolation methods, indicating the need for rigorous quality control checks to ensure reproducibility of data generated from sperm RNA. Therefore, we developed a reliable and effective protocol for RNA isolation from rat and human spermatozoa that delivers highly purified and intact RNA, verified using RNA-specific electrophoretic chips and molecular biology approaches such as RT-PCR and Western blot analysis. The sperm RNA isolation technique was optimized using rat spermatozoa and then adapted to human spermatozoa. Three steps in the sperm isolation procedure, epididymal fluid collection, sperm purification, and spermatozoon RNA extraction, were evaluated and assessed. The sperm RNA extraction methodology consists of collection of rat epididymal fluid with repeated needle punctures of the epididymis, somatic cell elimination using detergent-based somatic cell lysis buffer (SCLB) and the use of RNA isolation Kit. Rat sperm heads are more resistant to disruption than human spermatozoa, necessitating the addition of mechanical lysis with microbeads and heat in the rat protocol, whereas the human sperm protocol only required lysis buffer. In conclusion, this methodology results in reliable and consistent isolation of high-quality sperm RNA. Using this technique will aid in translation of data collected from animal models, and reproducibility of clinical assessment of male factor fertility using RNA molecular biomarkers.

Long term effects of gestational hypertension and pre-eclampsia on kidney function: Record linkage study

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We examine risk of chronic kidney disease (CKD) after pregnancy hypertension.

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We found increased risk of chronic kidney disease after gestational hypertension.

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Risk of chronic kidney disease was further increased after preeclampsia.

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Women with pregnancy hypertension develop CKD earlier than normotensive women.

Objective

To assess the long term effects of hypertensive disorders of pregnancy on renal function.

Design

Cohort study where exposure was gestational hypertension or preeclampsia in the first pregnancy. Normotensive women formed the comparison group.

Setting

Aberdeen, Scotland.

Participants

All women with date of birth on or before 30th June 1969 and at least their first singleton delivery recorded in the Aberdeen Maternity and Neonatal Databank.

Methods

Participants were linked to the Renal Biochemistry Register, Scottish Morbidity Records, Scottish Renal Registry and National Register for deaths.

Main outcome measures

Occurrence of chronic kidney disease (CKD) as identified from renal function tests in later life, hospital admissions or death from kidney disease or recorded as receiving renal replacement therapy.

Results

CKD was diagnosed in 7.5% and 5.2% of women who previously had GH and PE respectively compared to 3.9% in normotensive women. The unadjusted odds ratio (95% confidence interval) of having CKD in PE was 2.04 (1.53, 2.71) and that for GH was 1.37 (1.15, 1.65), while the adjusted odds ratio (95% confidence interval) of CKD was 1.93 (1.44, 2.57) and 1.36 (1.13, 1.63) in women with PE and GH respectively. Kaplan–Meier curves of survival time to development of chronic kidney disease revealed that women with preeclampsia were susceptible to kidney function impairment earliest, followed by those with gestational hypertension.

Conclusions

There was an increased subsequent risk of CKD associated with hypertensive disorders of pregnancy. Women with GH and PE were also found to have CKD earlier than normotensive women.

The bowel cancer awareness campaign 'Be Clear on Cancer': sustained increased pressure on resources and over-accessed by higher social grades with no increase in cancer detected

AIM

To evaluate the impact of the national 'Be Clear on Cancer' bowel cancer reminder campaign on service and diagnosis at a single UK institution. Secondly, to evaluate the socio-economic background of patients referred before and after the reminder campaign compared with the regional demographic.

METHOD

Suspected cancer 2-week wait patients in the 3 months precampaign, postcampaign and after the reminder campaign were included. Demographics, investigations and diagnosis were recorded. The postcode was used to allocate a National Readership Survey social grade.

RESULTS

Three hundred and eighty-three referrals were received in the 3 months precampaign, 550 postcampaign and 470 postreminder campaign. There were significant increases in the monthly referral rates following the campaign (P < 0.001 in both the post- and postreminder periods). Significantly more patients from social grades AB and C1C2 than expected from regional demographics were referred precampaign and after the reminder campaign (P < 0.001 in each case). There were no significant differences between the proportions of patients diagnosed with colorectal cancer in the three study periods (P = 0.710).

CONCLUSION

The 'Be Clear on Cancer' bowel cancer campaign has had a significant sustained impact on resources. It has failed to increase referrals among lower socio-economic grades, leading to an increase in 'worried well' referrals and no change in numbers, or the stage, of colorectal cancers diagnosed.

Meeting the food and nutrition needs of the poor: the role of fish and the opportunities and challenges emerging from the rise of aquaculture

People who are food and nutrition insecure largely reside in Asia and Sub-Saharan Africa and for many, fish represents a rich source of protein, micronutrients and essential fatty acids. The contribution of fish to household food and nutrition security depends upon availability, access and cultural and personal preferences. Access is largely determined by location, seasonality and price but at the individual level it also depends upon a person's physiological and health status and how fish is prepared, cooked and shared among household members. The sustained and rapid expansion of aquaculture over the past 30 years has resulted in >40% of all fish now consumed being derived from farming. While aquaculture produce increasingly features in the diets of many Asians, it is much less apparent among those living in Sub-Saharan Africa. Here, per capita fish consumption has grown little and despite the apparently strong markets and adequate biophysical conditions, aquaculture has yet to develop. The contribution of aquaculture to food and nutrition security is not only just an issue of where aquaculture occurs but also of what is being produced and how and whether the produce is as accessible as that from capture fisheries. The range of fish species produced by an increasingly globalized aquaculture industry differs from that derived from capture fisheries. Farmed fishes are also different in terms of their nutrient content, a result of the species being grown and of rearing methods. Farmed fish price affects access by poor consumers while the size at which fish is harvested influences both access and use. This paper explores these issues with particular reference to Asia and Africa and the technical and policy innovations needed to ensure that fish farming is able to fulfil its potential to meet the global population's food and nutrition needs.

Modifiable and fixed factors predicting quality of life in people with colorectal cancer

Background:

People with colorectal cancer have impaired quality of life (QoL). We investigated what factors were most highly associated with it.

Methods:

Four hundred and ninety-six people with colorectal cancer completed questionnaires about QoL, functioning, symptoms, co-morbidity, cognitions and personal and social factors. Disease, treatment and co-morbidity data were abstracted from case notes. Multiple linear regression identified modifiable and unmodifiable factors independently predictive of global quality of life (EORTC-QLQ-C30).

Results:

Of unmodifiable factors, female sex (P<0.001), more self-reported co-morbidities (P=0.006) and metastases at diagnosis (P=0.036) significantly predicted poorer QoL, but explained little of the variability in the model (R²=0.064). Adding modifiable factors, poorer role (P<0.001) and social functioning (P=0.003), fatigue (P=0.001), dyspnoea (P=0.001), anorexia (P<0.001), depression (P<0.001) and worse perceived consequences (P=0.013) improved the model fit considerably (R²=0.574). Omitting functioning subscales resulted in recent diagnosis (P=0.002), lower perceived personal control (P=0.020) and travel difficulties (P<0.001) becoming significant predictors.

Conclusion:

Most factors affecting QoL are modifiable, especially symptoms (fatigue, anorexia, dyspnoea) and depression. Beliefs about illness are also important. Unmodifiable factors, including metastatic (or unstaged) disease at diagnosis, have less impact. There appears to be potential for interventions to improve QoL in patients with colorectal cancer.

A sweat test centered protocol for the disclosure and diagnosis of cystic fibrosis in a newborn screening program

We describe the development of a sweat test centered protocol for disclosure and diagnosis of Cystic Fibrosis. Our protocol aims to identify infants early, minimizes the time of uncertainty for the parents, and yet gives them time to begin to come to terms with the possibility of diagnosis. Over a 9-year period 295,247 newborn infants were screened for CF in Wales, of whom 121 infants were diagnosed as having CF. During this period there were four false negatives (3.3%). Parental satisfaction with the process appears very high 6 months after disclosure.

Corticosteroids and peritonsillar abscess formation in infectious mononucleosis

Peritonsillar abscess formation is an uncommon complication of infectious mononucleosis (IM). Early case reports implicated corticosteroids in the development of such abscesses, however, subsequent studies suggested that these drugs do not promote the formation of abscesses at several sites outside the central nervous system. It has recently been demonstrated that zwitterionic polysaccharides, in bacterial capsules, form complexes with CD4+ T lymphocytes leading to abscess formation. A patient is presented who developed peritonsillar abscess a few days after initiation of corticosteroid therapy for IM; the medical literature was reviewed in respect of this subject. It appears that the occurrence of these abscesses in IM is not strongly linked to corticosteroid treatment. The authors, therefore, recommend that steroids should not be withheld from patients with severe IM on the basis that they may precipitate the development of peritonsillar abscess.

Tea tree oil: in vitro efficacy in otitis externa

Objective: The purpose of this study was to determine the susceptibility of organisms causing otitis externa (OE) to the essential oil of Melaleuca alternifolia, or tea tree oil (TTO).

Methods: Fifty-seven swabs were taken from the ears of 52 patients with OE for culture and sensitivity. A broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of TTO for each organism.

Results: In 51 per cent of the swabs taken, pathogenic organisms were cultured. Of these cultures 71 per cent, both bacteria and yeast, were susceptible to TTO 2 per cent or less. The only organism showing resistance to TTO was Pseudomonas aeruginosa; however 25 per cent of these bacteria were sensitive.

Conclusion: Tea tree oil may have a role to play in the treatment of OE. However, more work needs to be done to enhance the anti-pseudomonal effect and to assess ototoxicity.

Welfare aspects of the transport by road of sheep and pigs

That transport can be stressful to pigs and sheep has been inferred from behavioral and physiological measurements. Duration of journey is more likely to cause stress in pigs than in sheep, but loading and the start of travel are stressful to both. Vibration, related to vehicle design, and the jolting, shocks, and sudden impacts caused by road conditions and manner of driving, are probably of more importance than noise. Ventilation and stocking density can modulate the effects of ambient temperature, which may influence meat quality in pigs. Deprivation of food and water does not appear to stress sheep unduly, but this can become a serious welfare concern in the case of pigs. However, most journeys undertaken by pigs in the European Union are relatively short. In sheep, transport may follow soon after other stressful experiences such as weaning, shearing, handling, or marketing; the interaction of these factors in causing cumulative stress has not been studied. In pigs, fighting after the mixing of previously unacquainted animals is well known to be a welfare issue that can compromise meat quality. Considering the public interest in livestock transport and the large amounts of money involved, surprisingly little research has been done in the area, and more is urgently needed for legislation and welfare codes to be soundly based on scientific knowledge.

Cervical osteophyte causing perforation of the nasopharynx

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The effect of a quaternary ammonium biocide on the performance and characteristics of laboratory-scale rotating biological contactors

AIMS

To study the effect of a quaternary ammonium biocide, didecyldimethylammonium chloride (DDAC), on the treatment efficiency of laboratory-scale rotating biological contactors (RBCs) as well as their component biofilms.

METHODS AND RESULTS

Biofilms were established on the RBCs and then exposed to 0-160 mg l(-)1 (p.p.m.) DDAC at a flow rate of 2.5 l h(-1). The treatment efficiency of the RBC and the microbial activity of the biofilms were markedly decreased when 40 mg l(-1) DDAC or greater were applied to the units. However, DDAC had no effect on the number of viable bacteria in the biofilms when DDAC concentrations up to 80 mg l(-1) were applied to the RBCs. No viable bacteria could be detected in the biofilm when DDAC was applied at 160 mg l(-1). Extended observation over a further 40 d with 20 and 80 mg l(-1) DDAC showed similar results in terms of chemical oxygen demand removal, ATP content and viability of biofilms compared with those values over the first 12 d of exposure.

CONCLUSIONS

There was at least a fourfold difference in the susceptibility of planktonic and sessile bacteria to DDAC. Cells acclimatized to DDAC did not increase their capability to degrade normal carbon sources or DDAC under the conditions used in this study.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results show that RBCs can be used to treat effluents containing DDAC at concentrations up to 20 mg l(-1) and that 160 mg l(-1) of DDAC was required to eliminate cells in established biofilms.

The effect of an aldehyde biocide on the performance and characteristics of laboratory-scale rotating biological contactors

The effect of an aldehyde biocide, glutaraldehyde, on the treatment efficiency of laboratory-scale rotating biological contactors (RBCs) as well as their component biofilms was studied. Biofilms were established on the RBCs and then exposed to 0-120 ppm glutaraldehyde at a flow rate of 2.5 l x h(-1). The results showed that glutaraldehyde up to 80 ppm did not cause any adverse effect on chemical oxygen demand (COD) removal of the RBC units, microbial activity (ATP content) of biofilms on the RBC disc and viability of the biofilms. Glutaraldehyde at 80 ppm could be almost totally removed by the units regardless of the presence of simple carbon sources. There was at least a fourfold difference in susceptibility of planktonic and sessile bacteria to glutaraldehyde. Cells acclimatized to glutaraldehyde did not increase their capability to degrade normal carbon sources or glutaraldehyde under the conditions used in this study.

Microbial quantification in activated sludge: the hits and misses

Since the implementation of the activated sludge process for treating wastewater, there has been a reliance on chemical and physical parameters to monitor the system. However, in biological nutrient removal (BNR) processes, the microorganisms responsible for some of the transformations should be used to monitor the processes with the overall goal to achieve better treatment performance. The development of in situ identification and rapid quantification techniques for key microorganisms involved in BNR are required to achieve this goal. This study explored the quantification of Nitrospira, a key organism in the oxidation of nitrite to nitrate in BNR. Two molecular genetic microbial quantification techniques were evaluated: real-time polymerase chain reaction (PCR) and fluorescence in situ hybridisation (FISH) followed by digital image analysis. A correlation between the Nitrospira quantitative data and the nitrate production rate, determined in batch tests, was attempted. The disadvantages and advantages of both methods will be discussed.

Two different pathways for D-xylose metabolism and the effect of xylose concentration on the yield coefficient of L-lactate in mixed-acid fermentation by the lactic acid bacterium Lactococcus lactis IO-1

In lactic acid bacteria, pentoses are metabolized via the phosphoketolase pathway, which catalyzes the cleavage of D-xylulose-5-phosphate to equimolar amounts of glyceraldehyde 3-phosphate and acetylphosphate. Hence the yield coefficient of lactate from pentose does not exceed 1.0 mol/mol, while that of Lactococcus lactis IO-1(JCM7638) at high D-xylose concentrations often exceeds the theoretical value. This suggests that, in addition to the phosphoketolase pathway, L. lactisIO-1 may possess another metabolic pathway that produces only lactic acid from xylose. In the present study, the metabolism of xylose in L. lactisIO-1 was deduced from the product formation and enzyme activities of L. lactisIO-1 in batch culture and continuous culture. During cultivation with xylose concentrations above ca. 50 g/l, the yield coefficient of L-lactate exceeded 1.0 mol/mol while those of acetate, formate and ethanol were very low. At xylose concentrations less than 5 g/l, acetate, formate and ethanol were produced with yield coefficients of about 1.0 mol/mol, while L-lactate was scarcely produced. In cells grown at high xylose concentrations, a marked decrease in the specific activities of phosphoketolase and pyruvate formate lyase (PFL), and an increase in those of transketolase and transaldolase were observed. These results indicate that in L. lactisIO-1 xylose may be catabolized by two different pathways, the phosphoketolase pathway yielding acetate, formate and ethanol, and the pentose phosphate (PP)/glycolytic pathway which converts xylose to L-lactate only. Furthermore, it was deduced that the change in the xylose concentration in the culture medium shifts xylulose 5-phosphate metabolism between the phosphoketolase pathway and the PP/glycolytic pathway in L. lactisIO-1, and pyruvate metabolism between cleavage to acetyl-CoA and formic acid by PFL and the reduction to L-lactate by lactate dehydrogenase.

Dexamethasone reduces pain after tonsillectomy in adults

The aim of this study was to assess the effect of a course of dexamethasone on postoperative pain and morbidity after adult tonsillectomy. We report the results of a double-blind, randomized, placebo-controlled trial of 200 adult patients undergoing elective tonsillectomy. Patients were randomized to three groups: one group received the non-steroidal anti-inflammatory drug piroxicam for 8 days postoperatively, one group received dexamethasone for the same period and the third group received both drugs. Patients recorded their pain scores and analgesic requirements daily for 10 days. Patients treated with a combination of piroxicam and dexamethasone recorded consistently lower pain scores than those treated with either drug alone. This difference was statistically significant (P < 0.05) on all days except the day of surgery and the second postoperative day. Patients treated with piroxicam alone had significantly higher analgesic requirements than in either of the other groups. Dexamethasone given in this regime reduces postoperative pain and analgesic requirements after adult tonsillectomy.

A novel bystander effect involving tumor cell-derived Fas and FasL interactions following Ad.HSV-tk and Ad.mIL-12 gene therapies in experimental prostate cancer

To enhance the NK population induced by Herpes Simplex virus thymidine kinase (HSV-tk) gene transduction and ganciclovir (GCV) treatment, adenovirus-mediated (Ad) expression of IL-12 was added to Ad.HSV-tk + GCV as combination gene therapy. This approach resulted in improved local and systemic growth suppression in a metastatic model of mouse prostate cancer (RM-1). In vitro assay of tumor infiltrating lymphocytes noted superior lysis of both RM-1 and Yac-1 targets with combination therapy, but in vivo depletion of NK cells only negatively impacted on systemic growth inhibition. TUNEL assay of primary tumors noted induction of apoptosis between two and four times higher than controls lasting for 6-8 days post-vector injection. After demonstrating that Ad.HSV-tk/GCV and Ad.mIL-12-induced IFN-gamma independently up-regulated expression of FasL and Fas, respectively, studies examined tumor cell-mediated death through Fas/FasL-induced apoptosis as a mechanism of primary tumor growth suppression. In vitro, combination therapy at low vector doses resulted in synergistic growth suppression, which could be negated by the addition of anti-FasL antibody. In vivo co-inoculation of an adenovirus expressing soluble Fas resulted in combination therapy-treated tumors, which were three times larger than expected, and a reduction in apoptosis to baseline levels. In FasL knockout mice, combination therapy maintained the superior results experienced in wild-type mice, indicating that tumor cell, not host cell FasL, was responsible for Fas transactivation. Therefore, the combination of Ad.HSV-tk/GCV + Ad.mIL-12 results in enhanced local growth control via apoptosis due to tumor cell expression of Fas and FasL and improved anti-metastatic activity secondary to a strong NK response.

Synovial sarcoma in the retropharyngeal space

Synovial sarcoma is an aggressive mesenchymal tumour, rarely occurring in the head and neck. Management guidelines are by extrapolation of management of sarcomas in the extremities. We present a case involving the retropharyngeal space in a 20-year-old male. Analysis of more data on head and neck synovial sarcoma is necessary to make meaningful management recommendations.

The development and use of real-time PCR for the quantification of nitrifiers in activated sludge

Chemical analytical data has long been used to monitor the performance of activated sludge plants even though the process relies on the performance of microorganisms. It is now evident that a rapid and reliable quantitative method is required, to be able to monitor the organisms responsible for nutrient transformation and their activities, allowing avenues for more efficient nutrient removal. The development of real-time or quantitative polymerase chain reaction (PCR) also known as TaqMan or 5'-nuclease assay has allowed the rapid, quantitative analysis of DNA templates, eliminating some of the variability traditionally associated with other quantitative techniques. In this study analysis of Nitrospira spp., one of the key organisms in nitrite oxidation in wastewater treatment, was used to validate real-time PCR for the their quantification in activated sludge. A probe and primer set, targeting the 16S rRNA gene of Nitrospira spp. was designed according to the constraints of the TaqMan specifications. Samples used to evaluate the method included DNA from the sludge from full-scale wastewater treatment plants and laboratory scale systems. The reproducibility, quantitative efficiency and specificity were assessed in the evaluation. It was concluded that the method is sensitive and reproducible but has some constraints on the quantitative efficiency. A survey of full-scale systems for Nitrospira spp. was carried out and the results are presented here.

Postradiation prostatic sarcoma: de novo carcinogenesis or dedifferentiation of prostatic adenocarcinoma?

Postradiation sarcoma (PRS) of the prostate is rare. We describe the second case associated with brachytherapy for adenocarcinoma and review the literature on prior cases of PRS as well as carcinosarcoma, a dedifferentiated form ofadenocarcinoma that may be confused with true prostate sarcoma. It is clear that radiation to the prostate confers a significantly increased risk for subsequent sarcoma, although not within the prostate. Because many of the reported cases of PRS were admixed with adenocarcinoma and had relatively short latency periods, we conclude that these cases of PRS ofthe prostate are, in fact, carcinosarcoma. Therefore, with only one case reported following therapeutic irradiation, PRS of the prostate is extremely rare.

Independent contributions of GR-1+ leukocytes and Fas/FasL interactions to induce apoptosis following interleukin-12 gene therapy in a metastatic model of prostate cancer

In a mouse model of prostate cancer, adenovirus-mediated interleukin-12 (Ad.mIL-12) gene therapy resulted in significant growth inhibition of both the injected primary tumor and synchronous metastases. Within 2 days of vector injection, two distinct patterns of apoptosis were detected within the primary tumor, the inhibition of which with a caspase inhibitor substantially negated growth suppression. The dominant pattern displayed localized sheets of apoptotic cells in close association with necrosis containing polymorphic neutrophils (PMNs). Depletion of PMNs resulted in the loss of this pattern of apoptosis and reduced growth suppression. A second major wave of growth suppression within the primary tumor was mediated by an immune response. Natural killer (NK) cell activity was detected within tumor-infiltrating lymphocytes (TIL) by the eighth day post-vector injection, the depletion of which resulted in a significant loss of survival enhancement. A more modest role for T cells was identified, which in the absence of documented cytotoxic T lymphocyte (CTL) activity may be related to a significant reduction in interferon-gamma (IFN-gamma) levels found in mice depleted of T cells, thereby reducing the secondary influences of IFN-gamma. However, depletion of NK cells or T cells had no discernible negative effect on IL-12-mediated anti-metastatic activity. Attention focused on the role of IFN-gamma, observed following Ad.mIL-12 therapy, to mediate the diffuse pattern of apoptosis seen in the primary and metastatic lesions. In vitro studies noted the ability of IFN-gamma to up-regulate tumor cell expression of Fas and FasL to mediate apoptosis, whereas in vivo blockage of Fas/FasL interactions with soluble Fas resulted in a modest reduction in primary tumor growth suppression but complete abrogation within metastatic lesions.

A study of the effect of isothiazolones on the performance and characteristics of a laboratory-scale rotating biological contactor

AIMS

To study the effect of the isothiazolone biocide (Kathon WT) on the performance of laboratory-scale rotating biological contactors (RBCs) and their component biofilms.

METHODS AND RESULTS

Biofilms were established on the RBCs and then exposed to 0.7-15 p.p.m. isothiazolones. Young, 1-week-old, biofilms were found to attain treatment efficiency equal to that of mature, 2-month-old, biofilms. Isothiazolone concentrations at 3 p.p.m. and above caused a progressive decline in treatment efficiency and 15 p.p.m. isothiazolones inhibited all microbial activity and resulted in the death of the biofilms. Bio-oxidation and the biodegradation of isothiazolones within the biofilms ontinued unhindered at concentrations which caused the total inhibition of planktonic bacteria.

CONCLUSION

There was at least a 10-fold difference in susceptibility of planktonic and biofilm bacteria to isothiazolones. The chemical oxygen demand (COD) test was shown to be a reliable tool for investigating the efficiency of wastewater treatment units when the influent contains isothiazolones, while the biochemical oxygen demand (BOD) was unreliable due to the inhibition of bio-oxidation by the biocide.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results show that RBCs can be used to treat effluents containing isothiazolones at concentrations up to 1.5 p.p.m.

Effect of superficial heat, deep heat, and active exercise warm-up on the extensibility of the plantar flexors

BACKGROUND AND PURPOSE

Warm-up prior to static stretching enhances muscle extensibility. The relative effectiveness of different modes of warm-up, however, is unknown. The purpose of this study was to evaluate the effectiveness of superficial heat, deep heat, and active exercise warm-up prior to stretching compared with stretching alone on the extensibility of the plantar-flexor muscles.

SUBJECTS

Ninety-seven subjects (59 women, 38 men) with limited dorsiflexion range of motion (ROM) were randomly assigned to 1 of 5 groups. Female subjects had a mean age of 27.6 years (SD=7.68, range=17-50), and male subjects had a mean age of 26.8 years (SD=6.87, range=18-48).

METHODS

The first group (group 1) was a control group and did not perform the stretching protocol. The 4 experimental groups (groups 2-5) performed a stretching protocol 3 days per week for 6 weeks. Group 2 performed the static stretching protocol only; group 3 performed active heel raises before stretching; group 4 received 15 minutes of superficial, moist heat to the plantar-flexor muscles before stretching; and group 5 received continuous ultrasound for 7 minutes before stretching. Dorsiflexion ROM measurements were taken initially and after 2, 4, and 6 weeks.

RESULTS

All experimental groups increased active and passive range of motion (AROM and PROM). The mean AROM/PROM differences at 6 weeks were 1.11/1.39 degrees for group 1, 4.10/6.11 degrees for group 2, 4.16/4.21 degrees for group 3, 4.38/4.90 degrees for group 4, and 6.20/7.35 degrees for group 5. The group receiving ultrasound before performing the stretching protocol (group 5) displayed the greatest increase in both AROM (6.20() and PROM (7.35().

DISCUSSION AND CONCLUSION

Among the modalities tested, the use of ultrasound for 7 minutes prior to stretching may be the most effective for increasing ankle dorsiflexion ROM.

Continuously proliferative stem germ cells partially repopulate the aged, atrophic rat testis after gonadotropin-releasing hormone agonist therapy

Aging in the male human is accompanied by testicular atrophy, although relatively little is known about the mechanisms underlying germ cell loss. Testicular atrophy in the aged Brown Norway rat, an animal model for studies of aging in the human, has been attributed to a loss of spermatogonial stem cells. However, examination of testicular cross-sections from 27-mo-old Brown Norway rats indicated that approximately 14% of type A spermatogonia were stem cells. Furthermore, using bromodeoxyuridine labeling, we found that approximately 47% of these stem cells were actively dividing, with a cell cycle time of approximately 12.6 days. Both serum and testicular interstitial fluid testosterone levels were depressed in the aged rat. Therapy with the GnRH agonist, leuprolide, which has been empirically shown to reverse testicular atrophy in other models of germ cell loss, also partially restored spermatogenesis in the aged Brown Norway rat. The extent of testicular atrophy varied considerably, not only within the control and leuprolide-treatment groups but also between the left and right testes of the same animals. No significant difference was found between the mean percentage of populated tubules in 31-mo-old control animals (16.2 +/- 28%, mean +/- SD) and 31-mo-old leuprolide-treated animals (20.9 +/- 19.8%), but categorical comparisons showed that significantly fewer leuprolide-treated animals and testes contained < or = 1% populated tubules, indicating that GnRH agonist therapy stimulates differentiation of type A spermatogonia. An increase in the ratio of soluble to membrane stem cell factor mRNA levels was present in aged rats and partially reversed following leuprolide therapy.

Effects of vehicle movements during transport on the stress responses and meat quality of sheep

Two groups of 26 lambs were transported for 15 hours either on smooth highways or on rougher secondary roads. Nine of the animals in each group were monitored for heart rate and the plasma levels of cortisol, creatine kinase and lactate dehydrogenase, before the journey began, after four, eight and 12 hours and at slaughter. The pH of the meat was measured 45 minutes and 24 hours postmortem and its colour was assessed 24 hours postmortem. The lambs transported on smooth roads had a lower heart rate and lower plasma cortisol concentrations after eight and 12 hours than the lambs transported on rougher roads. Twenty-four hours after slaughter the pH of the meat of the lambs transported on smooth roads was lower than that of the lambs transported on rougher roads.

Adenovirus mediated cytosine deaminase gene transduction and 5-fluorocytosine therapy sensitizes mouse prostate cancer cells to irradiation

PURPOSE

We assess the ability of adenovirus mediated expression of the Escherichia coli cytosine deaminase gene in conjunction with the prodrug 5-fluorocytosine to result in radiation sensitization in the mouse prostate cancer cell line RM-1 in vitro.

MATERIALS AND METHODS

To document cytotoxicity of gene therapy, RM-1 cells were exposed to escalating doses of adenovirus mediated cytosine deaminase and a fixed dose of 5-fluorocytosine or phosphate buffered saline. Viable cells as determined by exclusion of trypan blue were counted the following day. Cytosine deaminase expressing RM-1 cells were then irradiated as single cell suspensions at various doses of radiation in a cesium source (4.4 Gy. per minute) and randomized to receive 5-fluorocytosine therapy at different times in relation to the external radiation therapy. End points were determined in a clonogenic assay by counting colonies with greater than 50 cells 7 days after replating.

RESULTS

Use of adenovirus mediated cytosine deaminase plus 5-fluorocytosine demonstrated viral dose dependent killing of RM-1 cells to a maximum of 85%, while either therapy alone was nontoxic. Neither adenovirus mediated cytosine deaminase infection nor 5-fluorocytosine alone influenced external radiation therapy killing. However, after controlling for death due to gene therapy alone, the combination of adenovirus mediated cytosine deaminase plus 5-fluorocytosine and external radiation therapy resulted in synergistic activity to approximately 2 logs of cell kill at low doses of radiation (p = 0.001). While altering the chronology of prodrug exposure in relation to external radiation therapy maintained synergy in all scenarios tested, starting 5-fluorocytosine 24 hours before external radiation therapy resulted in the most profound killing (p = 0.04), which indicates the importance of maintaining prodrug therapy during external radiation therapy.

CONCLUSIONS

The combination of adenovirus mediated cytosine deaminase plus 5-fluorocytosine and radiation therapy resulted in radiation sensitization with clinically relevant doses of radiation suggesting a potential usefulness of this treatment in patients with prostate cancer.

Direct exposure of mouse spermatogenic cells to high doses of adenovirus gene therapy vector does not result in germ cell transduction

The potential for adenovirus gene therapy vectors to gain access to male germ cells was rigorously tested in the mouse by injecting high titers of the vector directly into the testis and epididymis, or by exposing sperm to the vector immediately prior to or during in vitro fertilization. The adenovirus vector carried the bacterial lacZ gene (Adbeta-Gal) driven by the Rous sarcoma virus (RSV) promoter, and infection was assessed by testing for lacZ expression, either with antibodies to LacZ protein or by staining for LacZ enzymatic activity. A total of 109 plaque-forming units (PFU) was inserted into the testis or epididymis, and in vitro fertilization was performed after sperm were exposed either to 10 or 100 PFU per sperm cell. lacZ expression was examined within testes for several weeks after injection, and in preimplantation embryos produced by in vitro fertilization with sperm exposed to the gene therapy vector. Direct injection of Adbeta-Gal into either the testis or epididymis resulted in lacZ expression only within the interstitium of the testis and not within seminiferous tubules. Despite direct exposure of spermatogenic cells or mature sperm to high titers of virus, lacZ expression was likewise not detected in embryos. These findings are consistent with the conclusion that the risk is minimal for germ line integration of adenovirus vectors exposed to male reproductive cells.

Prospects for herpes-simplex-virus thymidine-kinase and cytokine gene transduction as immunomodulatory gene therapy for prostate cancer

In completed and ongoing clinical trials, adenovirus-mediated (Ad.) expression of herpes-simplex-virus thymidine-kinase (HSV-tk) gene transduction followed by ganciclovir (GCV) therapy has produced limited toxicity and evidence of antitumor activity following injection of the prostate. Furthermore, this system has been shown to direct systemic antitumor activity in several experimental cancer models, including that of prostate cancer, which may serve as the basis for in-situ immunomodulatory gene therapy. In a mouse model of prostate cancer, natural killer (NK) cells have been identified as the mediator of antimetastatic activity following Ad.HSV-tk + GCV, resulting in the combination of Ad.HSV-tk and adenovirus-mediated expression of interleukin 12 (Ad.IL-12) to exploit this cytokine's ability to enhance NK proliferation and cytotoxicity. Combination therapy demonstrated superior local and systemic growth suppression over that obtained with either therapy alone. Importantly, when the metastatic tumor burden was increased to an extent that negated the growth-suppressive activity directed by Ad.HSV-tk + GCV or Ad.IL-12 alone, combination therapy continued to demonstrate significant growth suppression. Examination of tumor-infiltrating lymphocytes documented enhanced NK lytic activity following combination therapy. Therefore, it appears that the combination of Ad.HSV-tk and Ad.IL-12 should be validated in a clinical trial for the treatment of prostate cancer.

Prodrug activation gene therapy and external beam irradiation in the treatment of prostate cancer

OBJECTIVES

Gene therapy may represent a new avenue for the development of multimodal treatment for men with locally advanced prostate cancer. This study explores the potential benefits of combining adenovirus-mediated (ADV) herpes simplex virus thymidine kinase gene (HSV-tk) transduction and ganciclovir (GCV) therapy with external beam radiation therapy (XRT) to enhance the therapeutic efficacy of each treatment alone.

METHODS

ADV/HSV-tk-transduced mouse prostate cancer cells, RM-1, were irradiated as single-cell suspensions at escalating doses in a cesium source (4.4 Gy/min). HSV-tk-expressing cells were randomized to receive varying doses and varying chronologies of GCV therapy in relation to XRT to fully evaluate potential cooperative activities. End points were determined in a clonogenic assay by counting colonies with greater than 50 cells 7 days after replating. The potential role of apoptosis as a mediator of enhanced cell killing was addressed by a TUNEL assay 12 and 24 hours after therapy.

RESULTS

Neither ADV infection nor GCV alone affected XRT killing. However, the combination of ADV/HSV-tk+GCV plus XRT maintained the 1 log of cell kill from gene therapy alone through escalating doses of radiation. Radiation sensitization was noted at higher doses of radiation (8.8 Gy or more). Although decreasing the GCV dose had a profound negative influence on HSV-tk+GCV-mediated killing, combination therapy continued to maintain the degree of HSV-tk+GCV killing through escalating doses of XRT in an additive fashion but did not result in radiosensitization. Changing the chronology of GCV exposure in relation to XRT did not significantly alter the additive activities of combination therapy. Studies of apoptosis noted a doubling of apoptotic activity with HSV-tk+GCV compared with HSV-tk+PBS with or without XRT. However, there was no significant change in apoptotic activity in combination therapy over HSV-tk+GCV alone within the 24-hour period after GCV exposure.

CONCLUSIONS

The combination of ADV/HSV-tk+GCV and XRT appears to result in at least additive, and with higher doses of radiation, synergistic killing activities, indicating a potential usefulness of this treatment strategy for patients with prostate cancer.

Cooperative therapeutic effects of androgen ablation and adenovirus-mediated herpes simplex virus thymidine kinase gene and ganciclovir therapy in experimental prostate cancer

Adenovirus-mediated transduction of the herpes simplex thymidine kinase gene (HSV-tk) in conjunction with ganciclovir (GCV) has been shown to result in significant growth suppression and to enhance survival in a model of mouse prostate cancer. However, this therapeutic activity is not sustained, because in most cases tumors eventually regrow and ultimately cause the death of the host. Androgen ablation, an inducer of apoptosis in prostate cells which is used widely as palliative therapy in patients with prostate cancer, was combined with HSV-tk plus GCV using an androgen-sensitive mouse prostate cancer cell line. The combination of castration and HSV-tk plus GCV led to markedly enhanced tumor growth suppression in both subcutaneous and orthotopic models compared with either treatment alone and resulted in an enhanced survival in which combination-treated animals lived twice as long as controls in the subcutaneous model and over 50% longer than controls in the orthotopic model. Further analysis of apoptotic activity demonstrated high levels of apoptosis only in combined androgen ablation and HSV-tk plus GCV-treated tumors after 14 days of growth in an androgen-depleted environment and 8 days after HSV-tk plus GCV therapy. At this time, the apoptotic index, but not the percent of necrotic tissue, was significantly higher for combination therapy-treated tumors relative to control-treated tumors or either treatment alone. These data indicate that the therapeutic effects of androgen ablation and HSV-tk plus GCV are cooperative and that increased apoptosis may, in part, underlie these activities.

Traditional livestock in semi-arid north eastern Zimbabwe: Mashona cattle

Productivity data were gathered from Mashona cows (n = 187) in 28 traditionally managed herds in two areas, separated by a corridor 20-30 km wide of almost uninhabited bush in NE Zimbabwe. Cattle are kept primarily to provide oxen for work. Cows in the southern area, which had been more affected by drought in 1991-92, were younger (7.2 vs. 9.1 years) and had a longer median calving interval (548 vs. 406 days). Metrical data (n = 105 cows) showed these cattle to be larger-bodied than those in the northern area (heart girth 146 vs. 144 cm). Market prices, estimated by respondents, were higher for oxen and herds were smaller in the south, and calf survival was believed by owners to be more influenced by season of birth in this area. Data were obtained on 531 calves. Before the age of 12 months 6.2% died, a low proportion compared with other studies. Most were retained in herds but 11.5% were slaughtered, sold or given away. All owners practised castration, selecting fast growing, strong bull calves for breeding.

Induction of potent antitumor natural killer cell activity by herpes simplex virus-thymidine kinase and ganciclovir therapy in an orthotopic mouse model of prostate cancer

Adenovirus-mediated transduction of the herpes simplex virus-thymidine kinase (HSV-tk) gene followed by ganciclovir is suspected to induce immune-mediated, systemic antitumor activities in the RM-1 mouse prostate cancer model (S. J. Hall et al., Int. J. Cancer, 70: 183-187, 1997). Although numerous investigators have also implied a role for the immune system in both local and systemic effects resulting from HSV-tk treatment, the candidate effector cell(s) mediating these activities are unknown. Fresh lymphocytes harvested from treated tumors (tumor-infiltrating lymphocytes) generated significant in vitro lytic activity against the parental cell line, RM-1, and an unrelated prostate cancer cell line. In vitro antibody and complement depletion of CD3+ T cells and natural killer (NK) cells from tumor-infiltrating lymphocytes indicated that NK cells were the dominant mediator of the observed tumor cell lysis. Concurrently, no cytotoxic T-cell activity was ascertained within splenocytes of treated mice. In vivo depletion of NK cells resulted in a 20% reduction in growth suppression within the primary tumor and complete abrogation of the inhibition of preestablished lung metastases. Depletion of T cells had no effect on either response. Here, we identify the presence of NK cells within adenovirus/HSV-tk- and ganciclovir-treated tumors, which serve to mediate both local and systemic antitumor activities in this model, and lay the mechanistic groundwork for further improvements in this gene therapy strategy.

Local inflammatory response and vector spread after direct intraprostatic injection of a recombinant adenovirus containing the herpes simplex virus thymidine kinase gene and ganciclovir therapy in mice

We have evaluated the safety and potential toxicity of an adenoviral vector containing the herpes simplex virus thymidine kinase gene (adenovirus/Rous sarcoma virus thymidine kinase in a preclinical model for prostate cancer. Clinical grade vector prepared for human trials was injected directly into the dorsolateral prostate of C57Bl/6 mice in a volume of 5 microL at doses of 2.5 x 10(6), 2.5 x 10(7), or 2.5 x 10(8). The mice received intraperitoneal injections of either ganciclovir or saline twice daily for 6 days, beginning 12 hours after vector injection. Representative tissues and fluids were collected for evaluation the day after the final dose. Microscopic pathologic evaluation revealed inflammatory infiltration without necrosis within the dorsolateral and ventral prostate, but no necrosis or leukocyte infiltration was observed in sample tissues from lung, liver, large intestine, bladder, seminal vesicle, testis, or epididymis. DNA was extracted from the above tissues as well as pelvic lymph nodes, blood, seminal fluid, urine, and sperm and analyzed by polymerase chain reaction for the presence of vector sequences. The vector was readily detected in the dorsolateral prostate, the site of injection. The amount of vector detected was reduced in some samples from ganciclovir-treated animals. At the highest dose, vector spread was observed in the ventral prostate, seminal vesicle, testis, pelvic lymph nodes, gut, and liver. Spread to the testis was observed in only one animal. Vector DNA was not detected in urine, seminal fluid, or sperm but was detected in the blood of one animal. This adenoviral vector, therefore, appears to have minimal spread to sites distant from the site of injection and no detectable pathological sequelae within this dose range in this preclinical model for prostate cancer, which may be generalizable to other solid tumors.

Spontaneous but not experimental metastatic activities differentiate primary tumor-derived vs metastasis-derived mouse prostate cancer cell lines

We previously developed an in vivo mouse prostate reconstitution (MPR) model of metastatic prostate cancer using p53 'knockout' mouse urogenital sinus tissue for retroviral transduction of ras and myc oncogenes (Thompson et al., Oncogene, 10, 869, 1995). We further demonstrated contrasting responses to transforming growth factor beta-1 (TGF-beta1) in three matched pairs of early passage cell lines derived from primary prostate tumors and lung metastases generated by this model system (Sehgal et al., Cancer Res, 56, 3359, 1996). In this study we tested these cell lines for growth potential in subcutaneous and orthotopic (dorso-lateral prostate) locations and metastatic activities in both spontaneous and experimental assays. Subcutaneous and orthotopic tumors produced by cell lines derived from metastatic lesions tended to grow less rapidly but demonstrated greater spontaneous metastatic potential than the cell lines derived from primary tumors. In contrast all cell lines produced lung colonies in an experimental metastasis assay (tail vein inoculation) with the primary tumor-derived cell lines yielding higher activities in two of three matched pair analyses. The ability of all cell lines to produce lung metastases in the experimental assay, while only the metastasis-derived cell lines retain the ability to initiate and complete the entire metastatic pathway in the spontaneous assay, suggests that intravasation may be the rate-limiting step in metastasis in this model system.

Identification of a P-glycoprotein-deficient subpopulation in the CF-1 mouse strain using a restriction fragment length polymorphism

There is a subpopulation of the CF-1 mouse strain that is very sensitive to the neurotoxicity induced by the avermectins, a class of natural products widely used in veterinary and human medicine as anti-parasitic agents. This sensitivity results from a lack of P-glycoprotein in the intestine and brain of sensitive animals, allowing increased penetration of these compounds in the blood and brain, respectively. We describe a restriction fragment length polymorphism that is able to predict which animals will be deficient in this protein, confirming at the genetic level a heterogeneous population of this mouse strain. Breeding studies demonstrated that the inheritance of the markers follows a normal Mendelian autosomal pattern. Sensitive "-/-" animals are deficient in P-glycoprotein in those tissues known to express primarily mdr1a, but have normal P-glycoprotein levels in tissues known to express primarily mdr1b or mdr2, suggesting that the defect in the sensitive animals is limited to the mdr1a gene. The P-glycoprotein expression in the brain is dependent on the genotype, which also determines the susceptibility to the avermectin-induced neurotoxicity, with the "-/-" animals being most sensitive, and the "+/-" animals having less P-glycoprotein and therefore increased CNS sensitivity compared to the "+/+" animals. The ability to segregate this strain into -/- and +/+ animals may prove useful for examining the physiological role of P-glycoprotein in drug absorption and distribution and related toxicity. These data also provide a warning that experiments carried out with P-glycoprotein substrates in the heterogeneous population of the CF-1 mouse must be interpreted with caution.