MyD88 and not TRIF knockout is sufficient to abolish LPS-induced inflammatory responses in bone-derived macrophages

Macrophages play an important role in the response to infection and/or repair of injury in tissues. To examine the NF-κB pathway in response to an inflammatory stimulus, we used wild-type bone-marrow-derived macrophages (BMDMs) or BMDMs with knockout (KO) of myeloid differentiation primary response 88 (MyD88) and/or Toll/interleukin-1 receptor domain-containing adapter-inducing interferon-β (TRIF) via CRISPR/Cas9. Following treatment of BMDMs with lipopolysaccharide (LPS) to induce an inflammatory response, translational signalling of NF-κB was quantified via immunoblot and cytokines were measured. Our findings reveal that MyD88 KO, but not TRIF KO, decreased LPS-induced NF-κB signalling, and 10% expression of basal MyD88 expression was sufficient to partially rescue the abolished inflammatory cytokine secretion observed upon MyD88 KO.

Clinical and translational science award T32/TL1 training programs: program goals and mentorship practices

INTRODUCTION

A national survey characterized training and career development for translational researchers through Clinical and Translational Science Award (CTSA) T32/TL1 programs. This report summarizes program goals, trainee characteristics, and mentorship practices.

METHODS

A web link to a voluntary survey was emailed to 51 active TL1 program directors and administrators. Descriptive analyses were performed on aggregate data. Qualitative data analysis used open coding of text followed by an axial coding strategy based on the grounded theory approach.

RESULTS

Fifty out of 51 (98%) invited CTSA hubs responded. Training program goals were aligned with the CTSA mission. The trainee population consisted of predoctoral students (50%), postdoctoral fellows (30%), and health professional students in short-term (11%) or year-out (9%) research training. Forty percent of TL1 programs support both predoctoral and postdoctoral trainees. Trainees are diverse by academic affiliation, mostly from medicine, engineering, public health, non-health sciences, pharmacy, and nursing. Mentor training is offered by most programs, but mandatory at less than one-third of them. Most mentoring teams consist of two or more mentors.

CONCLUSIONS

CTSA TL1 programs are distinct from other NIH-funded training programs in their focus on clinical and translational research, cross-disciplinary approaches, emphasis on team science, and integration of multiple trainee types. Trainees in nearly all TL1 programs were engaged in all phases of translational research (preclinical, clinical, implementation, public health), suggesting that the CTSA TL1 program is meeting the mandate of NCATS to provide training to develop the clinical and translational research workforce.

Pilot study on the use of infrared thermal imaging to predict infrainguinal bypass outcome in the immediate post-operative period

Objectives

Early bedside post-operative monitoring of infrainguinal bypass surgery is currently based on subjective clinical findings and handheld Doppler signals. Infrared thermal imaging is an objective and reproducible technique that has been proven to be a reliable and accurate method to measure skin temperature. The aim of this prospective study was to assess infrared thermal imaging as a predicting tool of bypass graft outcome in the immediate post-operative period and assess the angiosome concept.

Methods

This was a prospective cohort study of 25 patients undergoing infrainguinal bypass. Demographic and clinical data were prospectively collected and included gender, age, co-morbidities, pre- and post-operative ankle brachial pressure indices, surgery undertaken and patency of run-off vessels. Infrared thermal imaging was undertaken pre- and post-operatively to assess thermal changes to the feet following revascularisation.

Results

We found that an increase in temperature from pre- to post-operative was significantly associated with bypass patency. An increase in temperature was found to have a positive predictive value of 75%, a negative predictive value of 100%, a sensitivity of 100% and specificity of 89% for predicting graft patency.

Conclusions

Infrared thermal imaging can be used to measure temperature related changes of the microcirculation post-operatively and predict bypass outcomes in the immediate post-operative period.

LPS-stimulated NF-κB p65 dynamic response marks the initiation of TNF expression and transition to IL-10 expression in RAW 264.7 macrophages

During injury and infection, inflammation is a response by macrophages to effect healing and repair. The kinetics of the responses of proinflammatory TNFα, anti-inflammatory IL-10, and inflammatory master regulator NF-κB elicited by lipopolysaccharide (LPS) may be critical determinants of the inflammatory response by macrophages; however, there is a lack of homogeneous kinetic data in this pathway. To address this gap, we used the RAW 264.7 macrophage cell line to define intracellular signaling kinetics and cytokine expression in cells treated with LPS for 15 min to 72 h. The abundance of IκBα was maximally reduced 45-min following LPS treatment, but expression increased at 10-h, reaching a maximum at 16 h. NF-κB phosphorylation was significantly increased 45-min following LPS treatment, maximal at 2-h, and decreased to basal levels by 6-h. Nuclear NF-κB expression was elevated 30-min following LPS treatment, maximal by 45-min, and returned to basal levels by 24-h. Binding of nuclear NF-κB to consensus oligonucleotide sequences followed a similar pattern to that observed for p-NF-κB, but lasted slightly longer. Following LPS treatment, TNFα mRNA expression began at 1-h, was maximal at 6-h, and decreased starting at 10-h. TNFα protein secretion in conditioned growth medium began at 4-h and was maximal by 16-h. IL-10 mRNA expression was induced by LPS at 10-h, and was maximal at 16-h. IL-10 protein secretion was induced at 16-h and was maximal at 24-h. Our data reveal the temporal kinetics of pro- and anti-inflammatory signaling events that may be important therapeutic targets for inflammatory diseases.

Induction of COX-2 expression by Helicobacter pylori is mediated by activation of epidermal growth factor receptor in gastric epithelial cells

Chronic infection of the gastric mucosa by Helicobacter pylori is associated with an increased risk of developing gastric cancer; however, the vast majority of infected individuals never develop this disease. One H. pylori virulence factor that increases gastric cancer risk is the cag pathogenicity island, which encodes a bacterial type IV secretion system. Cyclooxygenase-2 (COX-2) expression is induced by proinflammatory stimuli, leading to increased prostaglandin E₂ (PGE₂) secretion by gastric epithelial cells. COX-2 expression is increased in gastric tissue from H. pylori-infected persons. H. pylori also activates the epidermal growth factor receptor (EGFR) in gastric epithelial cells. We now demonstrate that H. pylori-induced activation of COX-2 in gastric cells is dependent upon EGFR activation, and that a functional cag type IV secretion system and direct bacterial contact are necessary for full induction of COX-2 by gastric epithelial cells. PGE₂ secretion is increased in cells infected with H. pylori, and this induction is dependent on a functional EGFR. Increased apoptosis in response to H. pylori occurs in cells treated with a COX-2 inhibitor, as well as COX-2-/- cells, indicating that COX-2 expression promotes cell survival. In vivo, COX-2 induction by H. pylori is significantly reduced in mice deficient for EGFR activation compared with wild-type mice with a fully functional receptor. Collectively, these findings indicate that aberrant activation of the EGFR-COX-2 axis may lower the threshold for carcinogenesis associated with chronic H. pylori infection.

Transactivation of EGFR by LPS induces COX-2 expression in enterocytes

Necrotizing enterocolitis (NEC) is the leading cause of gastrointestinal morbidity and mortality in preterm infants. NEC is characterized by an exaggerated inflammatory response to bacterial flora leading to bowel necrosis. Bacterial lipopolysaccharide (LPS) mediates inflammation through TLR4 activation and is a key molecule in the pathogenesis of NEC. However, LPS also induces cyclooxygenase-2 (COX-2), which promotes intestinal barrier restitution through stimulation of intestinal cell survival, proliferation, and migration. Epidermal growth factor receptor (EGFR) activation prevents experimental NEC and may play a critical role in LPS-stimulated COX-2 production. We hypothesized that EGFR is required for LPS induction of COX-2 expression. Our data show that inhibiting EGFR kinase activity blocks LPS-induced COX-2 expression in small intestinal epithelial cells. LPS induction of COX-2 requires Src-family kinase signaling while LPS transactivation of EGFR requires matrix metalloprotease (MMP) activity. EGFR tyrosine kinase inhibitors block LPS stimulation of mitogen-activated protein kinase ERK, suggesting an important role of the MAPK/ERK pathway in EGFR-mediated COX-2 expression. LPS stimulates proliferation of IEC-6 cells, but this stimulation is inhibited with either the EGFR kinase inhibitor AG1478, or the selective COX-2 inhibitor Celecoxib. Taken together, these data show that EGFR plays an important role in LPS-induction of COX-2 expression in enterocytes, which may be one mechanism for EGF in inhibition of NEC.

Learning from product labels and label changes: how to build pharmacogenomics into drug-development programs

The 2010 US FDA–Drug Industry Association (DIA) Pharmacogenomics (PGx) Workshop follows a series that began in 2002 bringing together multidisciplinary experts spanning regulatory authorities, medical research, healthcare and industry. This report summarizes the ‘Building PGx into Labels’ sessions from the workshop, which discussed the critical elements in developing PGx outcomes leading to product labels that inform efficacy and/or safety. Examples were drawn from US prescribing information, which integrated PGx knowledge into medical decisions (e.g., panitumumab, warfarin and clopidogrel). Attendees indicated the need for broader dialog and for guidelines on evidentiary considerations for PGx to be included into product labels. Also discussed was the understanding of appropriate PGx placement on labels; how to encourage adoption by medical communities of label recommendations on PGx tests; and, given the global nature of drug development, worldwide considerations including European Summary of Product Characteristics.

Fit-for-purpose pharmacogenomic biomarkers in drug development: a project team case study with ‘what-ifs’

Over the past four years, the annual US FDA–DIA pharmacogenomic workshops have brought together attendees with wide-ranging expertise spanning industry, regulatory authorities and academia. This special report summarizes a breakout session using a novel, interactive case format as a way to engage participants, raise awareness and share diverse learnings via ‘real life’ decisions that project teams might face in developing a new medicine. This case was situated just prior to approval by a Regulatory Authority as a project team is finalizing a new medicine label. To effectively integrate new biomarkers such as pharmacogenomics into developing new medicines, this session highlighted the importance in considering medical practice implications as relevant (or not) to information or actions by a prescriber; progressing validation beyond assay to clinical; and fitting pharmacogenomics into context with other evidence often built over decades during a drug’s development. All converge onto a label that must communicate evidence–based use of a new medicine that is effective and safe.

The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride

BACKGROUND

Male pattern hair loss (MPHL) is a potentially reversible condition in which dihydrotestosterone is an important etiologic factor.

OBJECTIVE

Our aim was to evaluate the efficacy of the type 1 and 2 5alpha-reductase inhibitor dutasteride in men with MPHL.

METHODS

Four hundred sixteen men, 21 to 45 years old, were randomized to receive dutasteride 0.05, 0.1, 0.5 or 2.5 mg, finasteride 5 mg, or placebo daily for 24 weeks.

RESULTS

Dutasteride increased target area hair count versus placebo in a dose-dependent fashion and dutasteride 2.5 mg was superior to finasteride at 12 and 24 weeks. Expert panel photographic review and investigator assessment of hair growth confirmed these results. Scalp and serum dihydrotestosterone levels decreased, and testosterone levels increased, in a dose-dependent fashion with dutasteride.

LIMITATIONS

The study was limited to 24 weeks.

CONCLUSION

Dutasteride increases scalp hair growth in men with MPHL. Type 1 and type 2 5alpha-reductase may be important in the pathogenesis and treatment of MPHL.

Strategies to improve the effectiveness of abdominal aortic aneurysm screening programmes

OBJECTIVE

Ruptured abdominal aortic aneurysms (rAAAs) occurring in patients with screen-detected aneurysms could be regarded as a failure of screening and reduce effectiveness of screening. To understand this issue, we studied the reasons why rAAAs occur in screened patients and estimated the cost-benefit ratio if these ruptures could be prevented.

METHODS

All rAAAs occurring in the Huntingdon district in the UK during the study period (1991-2000) were traced via a combination of hospital admission, accident and emergency attendance, and intensive therapy unit admission records, operating theatre registers and post-mortem reports. Cross-referencing with the aneurysm-screening database identified those patients who had attended screening. Previously used cost-effectiveness models were used to estimate the cost benefits to screening.

RESULTS

Ninety-three rAAAs occurred in men over the study period, of whom 23 (25%) had been invited for screening and 13 (14%) had accepted the invitation. All who had been screened (mean age 75 [65-82]) had abnormal aortic diameters (>30 mm) on their first scan. Of those invited, 10/23 (43%) did not attend their screening appointment, 4/23 (17%) were deemed not fit for open surgery, 4/23 (17%) ruptured whilst being assessed for aneurysm repair, 2/23 (9%) ruptured whilst under six-monthly surveillance, and 3/23 (13%) failed to attend scheduled six-monthly surveillance appointments. Reducing screened ruptures by one half could increase the cost-effectiveness of screening by 27%.

CONCLUSION

There were no failures of the screening test. The benefits of aneurysm screening can be improved by increasing the uptake of screening, the compliance with surveillance, and by streamlining the work-up process before surgery.

Marked suppression of dihydrotestosterone in men with benign prostatic hyperplasia by dutasteride, a dual 5alpha-reductase inhibitor

Dihydrotestosterone (DHT) is the primary metabolite of testosterone in the prostate and skin. Testosterone is converted to DHT by 5alpha-reductase, which exists in two isoenzyme forms (types 1 and 2). DHT is associated with development of benign prostatic hyperplasia (BPH), and reduction in its level with 5alpha-reductase inhibitors improves the symptoms associated with BPH and reduces the risk of acute urinary retention and prostate surgery. A selective inhibitor of the type 2 isoenzyme (finasteride) has been shown to decrease serum DHT by about 70%. We hypothesized that inhibition of both isoenzymes with the dual inhibitor dutasteride would more effectively suppress serum DHT levels than selective inhibition of only the type 2 isoenzyme. A total of 399 patients with BPH were randomized to receive once-daily dosing for 24 wk of dutasteride (0.01, 0.05, 0.5, 2.5, or 5.0 mg), 5 mg finasteride, or placebo. The mean percent decrease in DHT was 98.4 +/- 1.2% with 5.0 mg dutasteride and 94.7 +/- 3.3% with 0.5 mg dutasteride, significantly lower (P < 0.001) and with less variability than the 70.8 +/- 18.3% suppression observed with 5 mg finasteride. Mean testosterone levels increased but remained in the normal range for all treatment groups. Dutasteride appeared to be well tolerated with an adverse event profile similar to placebo.

Expression of uracil DNA glycosylase (UDG) does not affect cellular sensitivity to thymidylate synthase (TS) inhibition

Uracil DNA glycosylase (UDG) is a base excision repair enzyme responsible for the removal of uracil present in DNA after cytosine deamination or misincorporation during replication. Inhibition of thymidylate synthase (TS), an important target for cancer chemotherapy, leads to deoxythymidine triphosphate (dTTP) pool depletion and elevation of deoxyuridine monophosphate (dUMP) pools which may also result in the accumulation of deoxyuridine triphosphate (dUTP). Large quantities of dUTP are believed to overwhelm the pyrophosphatase dUTPase, leading to misincorporation of uracil into DNA. Uracil is removed from DNA by uracil DNA glycosylase (UDG) resulting in an abasic site, but since the ratio dUTP:dTTP may remain high during continuing TS inhibition uracil can become re-incorporated into DNA causing a futile cycle eventually leading to DNA damage and cell death. This study has used isogenic cell lines differing in their expression of UDG to investigate the role of this enzyme in sensitivity to the specific TS inhibitors, ZD9331 and raltitrexed. The study showed that although increased expression and activity of UDG may lead to increased cell growth inhibition after TS inhibition over the first 24 h of treatment (measured using 3-(4,5-dimethyl (thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), probably due to increased damage to single-stranded DNA, the level of enzyme expression does not affect cell viability or cell death (measured using clonogenic assay, cell counting of attached/detached cells and cleavage of both poly ADP-ribose polymerase (PARP) and caspase 3). Increased expression and activity of UDG did not affect sensitivity to TS inhibition at later time points (up to 72 h treatment). Therefore UDG does not appear to play a major role in the response to TS inhibition, at least in the model used, and the results suggest that other determinants of response previously investigated, such as TS and dUTPase, may be more important for the response to TS inhibition.

Dominant negative knockout of p53 abolishes ErbB2-dependent apoptosis and permits growth acceleration in human breast cancer cells

We previously reported that the ErbB2 oncoprotein prolongs and amplifies growth factor signalling by impairing ligand-dependent downregulation of hetero-oligomerised epidermal growth factor receptors. Here we show that treatment of A431 cells with different epidermal growth factor receptor ligands can cause growth inhibition to an extent paralleling ErbB2 tyrosine phosphorylation. To determine whether such growth inhibition signifies an interaction between the cell cycle machinery and ErbB2-dependent alterations of cell signalling kinetics, we used MCF7 breast cancer cells (which express wild-type p53) to create transient and stable ErbB2 transfectants (MCF7-B2). Compared with parental cells, MCF7-B2 cells are characterised by upregulation of p53, p21(WAF) and Myc, downregulation of Bcl2, and apoptosis. In contrast, MCF7-B2 cells co-transfected with dominant negative p53 (MCF7-B2/Delta p53) exhibit reduced apoptosis and enhanced growth relative to both parental MCF7-B2 and control cells. These data imply that wild-type p53 limits survival of ErbB2-overexpressing breast cancer cells, and suggest that signals of varying length and/or intensity may evoke different cell outcomes depending upon the integrity of cell cycle control genes. We submit that acquisition of cell cycle control defects may play a permissive role in ErbB2 upregulation, and that the ErbB2 overexpression phenotype may in turn select for the survival of cells with p53 mutations or other tumour suppressor gene defects.

Establishment of an isogenic human colon tumor model for NQO1 gene expression: application to investigate the role of DT-diaphorase in bioreductive drug activation in vitro and in vivo

Many tumors overexpress the NQO1 gene, which encodes DT-diaphorase (NADPH:quinone oxidoreductase; EC 1.6.99.2). This obligate two-electron reductase deactivates toxins and activates bioreductive anticancer drugs. We describe the establishment of an isogenic human tumor cell model for DT-diaphorase expression. An expression vector was used in which the human elongation factor 1alpha promoter produces a bicistronic message containing the genes for human NQO1 and puromycin resistance. This was transfected into the human colon BE tumor line, which has a disabling point mutation in NQO1. Two clones, BE2 and BE5, were selected that were shown by immunoblotting and enzyme activity to stably express high levels of DT-diaphorase. Drug response was determined using 96-h exposures compared with the BE vector control. Functional validation of the isogenic model was provided by the much greater sensitivity of the NQO1-transfected cells to the known DT-diaphorase substrates and bioreductive agents streptonigrin (113- to 132-fold) and indoloquinone EO9 (17- to 25-fold) and the inhibition of this potentiation by the DT-diaphorase inhibitor dicoumarol. A lower degree of potentiation was seen with the clinically used agent mitomycin C (6- to 7-fold) and the EO9 analogs, EO7 and EO2, that are poorer substrates for DT-diaphorase (5- to 8-fold and 2- to 3-fold potentiation, respectively), and there was no potentiation or protection with menadione and tirapazamine. Exposure time-dependent potentiation was seen with the diaziquone analogs methyl-diaziquone and RH1 [2, 5-diaziridinyl-3-(hydroxymethyl)-6-methyl-1,4-benzoquinone], the latter being an agent in preclinical development. In contrast to the in vitro potentiation, there was no difference in the response to mitomycin C when BE2 and BE vector control were treated as tumor xenografts in vivo. This isogenic model should be valuable for mechanistic studies and bioreductive drug development.

A non-insulin secreting malignant insulinoma of the pancreas

We report a rare case of a non-insulin secreting malignant insulinoma of the pancreas and discuss its medical and surgical management. Surgical excision of malignant insulinoma produces good palliation and can increase survival.

Getting to grips with business plans, audit and applications

Practice profiles are reflective pieces written by nurses in practice and based on continuing professional development articles. This week Sheila Hobbs discusses article NS10. Brocklehurst N et al (1999) Getting into business: how nurses can make a difference.

Phthalimide analogs of CB 1954: synthesis and bioactivation

Four novel 4-substituted 5-nitrophthalimides (5-substituted-6-nitro-1,3-dihydro-isoindol-1,3-diones), 6, 7, 10 and 11, and the known 5 are prepared as analogs of the dinitrobenzamide prodrug CB 1954, 1, and considered as potential candidates for gene-directed enzyme prodrug therapy. All the phthalimides are poor substrates for Escherichia coli nitroreductase compared to CB 1954. However, 6, 7, 10 and 11 are reduced by both the human and rat forms of DT-diaphorase; 10 is a particularly good substrate but 7 decomposes in phosphate buffer. A cell-line panel consisting of V79 cells that have been engineered to express various levels of either the human or rat forms of DT-diaphorase in an identical cellular background was used to evaluate these compounds as prodrugs activated by this enzyme. The cytotoxic effect of CB 1954 is proportional to the activity of either the rat or human enzyme but cells expressing the rat enzyme were much more sensitive (10000-fold at higher levels of DT-diaphorase activity) than cells expressing comparable levels of the human enzyme. These results demonstrate that the resistance of human tumors to CB 1954 can be accounted for solely by the kinetic properties of the enzyme for this prodrug. The nitrophthalimide analogs overcome this kinetic failing of CB 1954. However, these compounds are not activated to produce cytotoxicity in these DT-diaphorase-expressing cell lines. It is postulated their reduction products fail to undergo an acylation reaction in a manner analogous to CB 1954. Thus, reduction by DT-diaphorase is not predictive of cytotoxicity in this class of prodrugs.

Duodenal diverticulum as a cause of massive gastrointestinal bleeding

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Burning the midnight oil

A requirement for all trained nurses is that they undertake to follow a structured programme of professional development. Unfortunately, the prospect of copious amounts of study is the stuff of which bad dreams are made and the thought of enrolling for any course, let alone one at degree level, remains a very real source of anxiety. Because of my interest in using massage therapy in the Trust where I then worked, I enrolled for a part-time course at the University of Exeter, a centre well known in nursing circles for its research into complementary medicine. The following account of my experience of combining study with a full-time job is intended to provide encouragement for anyone who may be currently in the process of considering a similar course of action.

Development of a bicistronic vector driven by the human polypeptide chain elongation factor 1alpha promoter for creation of stable mammalian cell lines that express very high levels of recombinant proteins

We have developed a new vector for the stable expression of recombinant protein in mammalian cells. In this vector, designated pEFIRES-P, both the recombinant cDNA and the puromycin resistant gene (pac) are transcribed as a single message driven by the strong human polypeptide chain elongation factor 1alpha promoter. The presence of an internal ribosome entry site ensures any clones that are resistant to puromycin also express high levels of recombinant protein encoded by cDNA cloned upstream from the pac gene. We report the use of this vector to generate stable cell lines expressing human pyruvate carboxylase and show that following transfection and clonal selection, all twenty colonies that conferred high dose resistance to puromycin also expressed very high levels of functional pyruvate carboxylase. Use of pEFIRES-P should permit the rapid and efficient generation of stable cell lines for the characterisation of recombinant proteins.

Lack of a role for MRP1 in platinum drug resistance in human ovarian cancer cell lines

The level of expression of the multidrug resistance-associated protein (MRP1) in a panel of human ovarian carcinoma cell lines and their variants with acquired cisplatin resistance was determined using Western blotting. No overexpression of MRP1 was detected in any of the cell lines. In addition, we have transfected the MRP1 gene into an intrinsically cisplatin-resistant cell line SKOV3, previously shown to have elevated levels of glutathione (GSH). The MRP1-transfected line SKOV3-S2 was shown to be cross-resistant to doxorubicin, vincristine and etoposide but not to paclitaxel, vinblastine and platinum agents, such as cisplatin, JM216 [bis-acetato-ammine-dichloro-cyclohexylamine platinum (IV)] and AMD473 [cis-ammine dichloro (2-methyl-pyridine) platinum (II)]. No cross-resistance to any of the platinum agents was observed in a MRP1-overexpressing human lung cancer cell line with acquired doxorubicin resistance. Reduction of GSH levels (80-90%) by buthionine sulphoximine (BSO) produced significant potentiation in cisplatin sensitivity in the parental SKOV3, the vector-alone control SKOV3-puro and the MRP1-transfected line SKOV3-S2. The degree of sensitization was similar in all cell lines (1.6-fold). However, selective sensitization by BSO to vincristine was observed in the MRP1-transfected line (4.1-fold) but not in the vector control. No significant differences were observed in cisplatin accumulation in the SKOV3-puro and the SKOV3-S2 cells, although both these transfected lines accumulated significantly more than the parental line. Our results suggest that MRP1 does not play a significant role in platinum resistance in the human tumour cell lines investigated in this study.

Critical review of how nurses research massage therapy: are they using the best methods?

Complementary therapies comprise only a fraction of nursing care, yet it is interesting that their use is being considered by an ever-increasing number of nurses. Within the Rhondda NHS Trust, holistic massage therapy is offered to patients both in hospital and in the community, nurses and occupational therapists successfully combining their massage skills with everyday patient care. During the process of devising a research protocol for implementation within the Trust, certain questions began to emerge to which there were no answers. The attempt to answer them is the origin of this paper, which explores some commonly experienced difficulties with reference to the literature and puts forward merits of adapting current methodology to investigate the benefits of massage therapy.

Sumatriptan suppositories for the acute treatment of migraine. S2B351 Study Group

A randomised, double-blind, parallel-group, placebo-controlled trial was undertaken to assess the efficacy and tolerability of the sumatriptan suppository in 184 patients with acute migraine. Patients used a sumatriptan suppository (12.5 mg or 25 mg) or placebo at home for the treatment of a moderate or severe migraine attack and those who experienced headache recurrence within 24 hours of dosing had the option to repeat the dose. By 2 hours post-dose, 68% of patients in the sumatriptan 25 mg group and 47% of patients in the sumatriptan 12.5 mg group compared with 25% of placebo patients achieved headache relief. Relief rates 2 hours post-dose for nausea, vomiting, photophobia and phonophobia were similar to those reported 2 hours post-dose for headache. Post hoc review of the recurrence data showed that administration of a second suppository was effective in alleviating recurrent headache in over 80% of the sumatriptan-treated patients experiencing recurrence. No serious or unusual adverse events were reported, and the pattern and incidence of adverse events did not vary as a function of dose. These data demonstrate that the sumatriptan suppository is a well-tolerated, effective treatment for the acute treatment of migraine pain and its associated symptoms.

The effectiveness of psychiatric treatment for HIV-infected patients

The study sought to determine the effectiveness of a model program of psychiatric care for human immunodeficiency virus (HIV)-infected patients. This was a cohort study of 126 HIV-positive outpatients referred for psychiatric evaluation and treatment (average follow up of 14 months) in a HIV-dedicated primary-care outpatient clinic in the inner city. A global outcome measure (encompassing symptom relief, functioning, and HIV-risk behaviors), and a measure of abstinence from alcohol and illicit substances were used. Fifty percent of patients improved, with 19% "nearly well" at follow-up. Abstinence was achieved 48% of the time. Good compliance with treatment and the absence of injection drug use were the primary predictors of good outcomes. Of the compliant patients, 94% improved, with 45.7% being nearly well. Psychiatric treatment of HIV-infected patients is effective when located in the HIV primary-care setting and administered by a multidisciplinary team under the direction of a psychiatrist, using evidence-based interventions.

Selective cell ablation in transgenic mice expression E. coli nitroreductase

The gene encoding E. coli nitroreductase (NTR) was expressed in the luminal cells of the mammary gland of transgenic mice using the ovine beta-lactoglobulin promoter. Treatment of NTR expressing animals with the prodrug CB1954 (5-aziridin-1-yl-2-4-dinitrobenzamide) resulted in a rapid and selective killing of this population of cells whereas the closely associated myoepithelial cells were unaffected. NTR-mediated inducible cell ablation offers a number of advantages over the use of HSV1-tk for the selective killing of cells in vivo.

Adolescents' perceptions of the role of part-time work

In contrast to the U.S., research on child employment in Britain has been relatively rare. This paper reports the findings from a study in which 1,220 students, 12-16 years of age, in two comparable schools in England and Scotland completed questionnaires on their employment. While the nature and extent of employment were assessed by means of a questionnaire, a sub-sample of students (N = 56) participated in interviews to provide more detailed information on their experience of employment. Results indicate that Green (1990) may have been overly optimistic in arguing against the negative stereotype of the student worker, at least as far as the United Kingdom is concerned. Although students may be able to control whether they work, the interview data indicate that they have little control over their work environment and do not always view employment in a positive light.

Duration of effects of isradipine during twice daily therapy in angina pectoris

Isradipine, a 1,4 dihydropyridine calcium channel antagonist, is a potent coronary artery dilator that increases coronary blood flow with little effect on cardiac contractility. Isradipine is an approved antihypertensive agent, but its antianginal effects have not been well documented. In this placebo-controlled, double-blind, parallel-group design study we evaluated the duration of effects and safety of isradipine 10 mg bid in male patients with chronic stable angina pectoris. Seventy-two patients experiencing moderately severe angina between 3 and 7.5 minutes during a standard Bruce exercise test received placebo in a single-blind manner for 8-14 days. Sixty-one of these patients had reproducible treadmill exercise test results on three consecutive occasions and underwent further exercise tests at 3, 8, and 12 hours after a placebo period. Patients were then randomized (double blind) to either placebo or isradipine 10 mg bid for 2 weeks. Symptom-limited exercise tests were repeated predose and at 3, 8, and 12 hours after the 0800 hour dose dosing. Exercise duration increased significantly from baseline (last qualifying test during the single-blind placebo therapy, i.e., 0800 hours predose at visit 4) in the isradipine group compared to the placebo group prior to the administration of the 0800 hour dose (i.e., 12 hours after the 2000 hour dose) by 51 vs. 18 seconds, p = 0.04; and after the administration of the 0800 hour dose at 3 hours by 78 vs. 29 seconds, p = 0.005; and at 8 hours by 54 vs. 18 seconds, p = 0.04. Similarly, statistical significance was achieved when exercise data were analyzed using visit 4 (single-blind placebo therapy) corresponding time points as baseline. At 12 hours after the 0800 hour dose, exercise tolerance did not increase significantly after isradipine compared to placebo. Time to 1-mm ST-segment depression increased significantly after isradipine at 3 hours post 0800 hour dose compared to placebo (87 vs. 7 seconds, p < 0.01) but not at the 0, 8, or 12-hour postdose time points, regardless of which baseline was used. Isradipine therapy did not affect the rate-pressure double product. A significant correlation between the mean increase in total exercise time and mean plasma isradipine concentration was also present (p = 0.0295). During double-blind treatment, drug-related adverse events were experienced by four patients in the isradipine group and two patients in the placebo group. None of the patients experienced ischemic complications during the study.(ABSTRACT TRUNCATED AT 400 WORDS)

Roles of erythropoietin, insulin-like growth factor 1, and unidentified serum factors in promoting maturation of purified murine erythroid colony-forming units

We have used 75% to 90% pure murine erythroid colony-forming units (CFU-E) to delineate the processes and factors underlying their maturation. These CFU-E form 32 cell colonies and are drawn from what we term generation I of a six-generation long maturation sequence (Landschulz et al, Blood 79:2749, 1992). Applying assays of 59Fe-heme biosynthesis and colony numbers as measures of maturation and analyses of DNA degradation as an index of programmed cell death, we find that (1) erythropoietin (Epo) enhances maturation throughout most of its course; (2) Epo first seems able to forestall DNA degradation when CFU-E reach generation II; (3) the processes that Epo elicits thereafter start to persist when Epo is withdrawn; (4) insulin-like growth factor I (IGF-I) also forestalls DNA breakdown, but later loses effectiveness; (5) IGF-I adds little to maturation when Epo levels are high, but when Epo levels are low, enhances it substantially; and (6) for maturation to be entirely optimal, an unidentified serum factor(s) is probably required when Epo levels are high and is certainly needed when Epo levels are like those in normal animals. Quantitatively, about 40% of optimal in vitro erythropoiesis at normal Epo levels depends on Epo alone, another 30% or less on the addition of IGF-I, and the remaining 30% or more on the addition of unidentified serum factor(s). Applied together, these three or more factors lead to two-thirds of the maximum maturation realized with saturating Epo levels. Because we also find that heme accumulated in CFU-E culture can closely approach levels in red blood cells, we suppose that our conclusions apply as well to CFU-E maturation in vivo.

Negative inotropic effect of intravenous nifedipine in coronary artery disease: relation to plasma levels

The relative extent of the vasodilator versus direct negative inotropic effects of nifedipine was studied in 15 male patients with documented coronary artery disease and normal left ventricular function. At the time of diagnostic cardiac catheterization, three groups of five patients received dose of 1, 2, and 3 mg intravenous nifedipine at a rate of 0.33 mg/min. Hemodynamic measurements and blood collections were made before, during, and every 5 minutes for 30 minutes after infusion of nifedipine. Heart rate increased and mean arterial pressure decreased significantly after the 2 and 3 mg doses of nifedipine. Systemic vascular resistance was significantly decreased and cardiac index increased after all doses of nifedipine. Maximal left ventricular dp/dt (dp/dtmax) was significantly decreased after the 3 mg infusion. The reduction in dp/dtmax was most consistent with a reduction in left ventricular contractility as opposed to changes in loading conditions. Plasma concentrations of nifedipine were significantly correlated with bidirectional changes in dp/dtmax (r = 0.86). Nifedipine concentrations below 28.2 ng/ml were associated with a rise in dp/dtmax, whereas concentrations above that level were associated with a reduction in dp/dtmax. These data indicate that intravenous nifedipine produces dose- and concentration-dependent depression of myocardial contractility in patients with coronary artery disease. Nifedipine concentrations associated with negative inotropic effects are readily achievable with common oral and sublingual doses.

Tumour necrosis factor in man: clinical and biological observations

Eighteen patients with advanced cancer have been treated intravenously with human recombinant tumour necrosis factor (rhTNF). The drug produced febrile reactions at all doses although these were preventable by steroids and indomethacin. Doses at or above 9 x 10(5) units (400 micrograms)m-2 were associated with hypotension, abnormal liver enzymes, leucopenia and mild renal impairment in a substantial proportion of patients. RhTNF was cleared from plasma with a half life of approximately 20 minutes but non-linear pharmacokinetics lymphoma, improvements in their tumours were recorded. RhTNF was noted to produce rapid increases in serum C-reactive protein concentrations. Endogenous TNF levels were not found to be elevated in 72 cancer patients. TNF deserves further therapeutic evaluation and these observations support its biological importance as an endogenous pyrogen, mediator of acute phase protein responses, and a mediator of endotoxic shock.

Exponential and diphasic ventilatory response to hypoxia in conscious lambs

This study was undertaken to test the hypothesis that in the neonate the hypoxic chemoreflex drive adapts to steady-state hypoxia but not to progressive hypoxia. First we have compared the ventilatory (VE) response of 2-day-old conscious lambs to steady-state hypoxia with their response to progressive hypoxia. Second, we have quantified the chemoreceptor excitatory function operating at the end of each period of hypoxia by studying the immediate VE response to the withdrawal of the hypoxic stimulus. Lambs responded to steady-state hypoxia [fractional concentration of inspired O2 (FIO2) = 0.08] by a diphasic VE response but responded to progressive hypoxia (FIO2 0.21-0.08) by an exponential VE increase. Hyperventilation in steady-state hypoxia was transient; VE increased immediately from 532 to a mean peak response of 712 ml X kg-1 X min-1 and decreased to 595 ml X kg-1. min-1 within 10 min. With progressive hypoxia, VE increased within 13 min from 514 to 705 ml X kg-1 X min-1. At the end of steady-state and progressive hypoxia the abrupt withdrawal of the hypoxic drive caused an instantaneous VE decrease to 390 and 399 ml X kg-1 X min-1, respectively; the VE decrease was respectively 306 and 205 ml X kg-1 X min-1 (P less than 0.05). This demonstrates that during steady-state hypoxia the lambs had suffered a loss of one third of the chemoreceptor excitatory function.(ABSTRACT TRUNCATED AT 250 WORDS)

Abolition of ventilatory response to caffeine in chemodenervated lambs

In this study we have evaluated the role of the peripheral chemoreceptors in the ventilatory response to caffeine at a dose currently used in human infants for treatment of central apneas (10 mg/kg). Twelve lambs were studied; six had carotid body denervation (CBD) and six had a sham denervation (intact). The denervation was done the 2nd wk of life, and the study of the response to caffeine infusion was carried out at a mean age of 82 days. The awake and nonsedated animals received 10 mg/kg of caffeine, and caffeine blood levels were, respectively, 8.8 and 9.0 mg/l in the intact and in the CBD lambs. The intact lambs responded to caffeine by a significant immediate increase in minute ventilation (VE) of 46% from 274 to 400 ml X min-1 X kg-1 (P less than 0.001), 1 min after caffeine infusion. This response rapidly faded, but VE was still increased at 2 h, 314 ml X min-1 X kg-1. The increase in ventilation was brought about by a change in mean inspiratory flow (VT/TI), which increased from 9.9 to 14.0 ml X s-1 X kg-1 within 1 min (P less than 0.01); VT/TI was still increased at 11.2 ml X s-1 X kg-1 2 h later. In contrast, for the CBD lambs there was no response to caffeine infusion as measured by VE or VT/TI. We conclude that bolus caffeine infusion produces a rapid response in VE followed by a fall in VE that remained above base line until at least 2 h postinfusion, and the intact chemoreceptor function appears as an essential mediator for these increases in ventilation, since the peripheral chemodenervation has completely abolished the VE response to this particular dose of caffeine.