UK Nurses Delivering Physical Activity Advice: What Are the Challenges and Possible Solutions? A Qualitative Study

There are a multitude of health benefits gained from regular physical activity (PA). Currently, PA advice implementation from NHS nurses is inadequate despite their ever-increasing role in lifestyle and preventive medicine. By assessing their knowledge of current PA guidance, this study proposed to investigate the issues with regular PA advice being given and expand upon nurses' proposed barriers and solutions. A qualitative approach using semi structured interviews was undertaken between March and August 2023 involving 13 NHS nurses. Thematic analysis was undertaken using Braun and Clarke's six step approach. Four themes and fifteen subthemes emerged as barriers and solutions in delivering PA advice. Intrinsic barriers included a lack of nurse knowledge on the topic and PA being seen as an afterthought. Extrinsic barriers included time pressures and a lack of staff engagement. Solutions involved increasing staff awareness of guidelines through teaching, policy, encouraging staff to be active and optimising PA advice delivery through a piecemeal approach and utilising online and visual resources. This study displayed an insight into nurses' thoughts on their consultations with patients regarding PA, and proposed several barriers and solutions. Further work is needed to improve nurses' PA knowledge and to assess the proposed strategies to improve its delivery.

Outcomes following 'mini' percutaneous nephrolithotomy for renal calculi in children. A single-centre study

INTRODUCTION

This retrospective review was undertaken to identify the postoperative outcomes of children undergoing 'mini' percutaneous nephrolithotomy (MPCNL) at a single institution.

OBJECTIVE

Outcomes measured included: percentage of stone clearance, postoperative analgesia requirements, the need for intraoperative or postoperative blood transfusion, length of stay and morbidity.

STUDY DESIGN

A total of 46 patients were reviewed over a two-and-a-half-year period; the mean age was 7.3 years (range: 1-16 years). The MPCNL was performed with a radiological-guided peripheral puncture, followed by dilatation of the nephrostomy tract to a maximum Amplatz sheath size of 16-French; an 11-French nephroscope was used. Stone disintegration was achieved either with pneumatic or laser lithotripsy.

RESULTS

Complete stone clearance was achieved in 35/46 children (76%). The remaining 11 children had a stone clearance rate of over 80%. No patients required intraoperative/postoperative blood transfusion. A total of 39% of patients were managed on simple/non-opiate based analgesia, with 54% requiring opioid analgesia postoperatively for less than 24 h. There were no procedure-related complications and no mortalities. The mean length of stay was 2.24 days.

DISCUSSION

The management of urolithiasis can be challenging in children. The use of percutaneous nephrolithotomy, is becoming increasingly popular in the treatment of paediatric urolithiasis. The stone clearance rate in children undergoing standard PCNL, has been reported to be 50-98% in the literature [1,2,3,4]. Samad et al. [2] in 2006, reported their experience in 188 consecutive PCNLs, using a 17Fr or 26Fr nephroscope. Their largest sub group included children aged >5-16 yrs. Within this group, 57% were treated with a 17Fr nephroscope and 43% with the 26Fr nephroscope, achieving stone clearance of only 47% with PCNL monotherapy. In this group the transfusion rate was 3% [2]. Badawy et al., reported their experience of 60 children in 1999, using a 26 or 28Fr Amplatz sheath. They reported an 83.3% stone clearance with single session PCNL, with only one procedure being abandoned due to intraoperative bleeding requiring blood transfusion [3]. In 2007, Bilen et al. reported their experience and compared the use of 26Fr, 20Fr and 14Fr (mini) PCNL. Stone size, previous surgery and the mean haemoglobin drop postoperatively did not change between the groups, however the blood transfusion rate was higher in the 26Fr and 20Fr Amplatz sheath groups. The stone clearance was highest in the 'mini PCNL' group at 90%, compared to 69.5% in the 26Fr and 80% in the 20Fr group [4]. MPCNL has become increasingly popular over recent years, with stone clearance reported as 80-85% [5-7] following a single session of MPCNL as monotherapy. In 2012, Yan et al. reported 85.2% stone clearance with mini PCNL monotherapy (tract size 14-16Fr), with no children requiring blood transfusion [6]. Zeng et al. reported their experience of 331 renal units in children, with stone clearance rates reaching 80.4% and a blood transfusion rate of 3.1% [8]. In our centre, we do not perform postoperative haemoglobin levels as a matter of routine and any investigations are performed on an intention to treat principle. Bilen et al. reported no blood transfusions being required in their cohort of patients undergoing MPCNL [4] and this is supported by Yan et al. [6].

CONCLUSION

Mini PCNL is an effective and safe procedure for the treatment of paediatric renal stones. In the present series, all children achieved greater than 80% stone clearance, none received a blood transfusion (intra/postoperatively) and there were no mortalities. Postoperative pain was managed with simple analgesia in 39%; however, the majority required opiate analgesia for less than 24 hours.

Paediatric post-septal and pre-septal cellulitis: 10 years' experience at a tertiary-level children's hospital

OBJECTIVE

To assess the incidence and complications of pre-septal (pre-SC) and post-septal (post-SC) cellulitis over 10 years. Pre-SC and post-SC are also known as periorbital and orbital cellulitis, respectively.

METHODS

Retrospective analysis of CT scans. Data included the presence of pre-SC and post-SC, paranasal sinus disease (PNS) and complications.

RESULTS

Among 125 patients scanned for these suspected diagnoses, 67 had both pre-SC and post-SC, 37 had pre-SC and 4 had post-SC; there were 17 normal scans. 110 patients had PNS. 68/71 (96%) patients with post-SC had PNS. Post-SC complications included orbital and/or subperiosteal abscess (50/71: 30 medial orbital, 10 superomedial, 3 lateral, 2 anteromedial, 2 inferomedial, 1 superior, 1 anterosuperior and 1 not specified), cavernous sinus thrombosis (CST) (1), superior ophthalmic vein (SOV) thrombosis (4) and subdural frontal empyema (2); 1 patient had SOV and CST and subdural empyema.

CONCLUSION

71/125 (57%) patients had post-SC. 50/125 (40%) patients imaged for pre-SC/post-SC had orbital abscess; 44/50 (88%) of these involved the medial orbit. Patients can develop solely superior or inferior abscesses that are difficult to identify by axial imaging alone, hence coronal reformatted imaging is essential. 5/125 (4%) patients developed major complications (SOV/CST/empyema), hence imaging review of the head and cavernous sinus region is essential. A diagnosis of post-SC on CT should alert the radiologist because this diagnosis can be associated with an increased incidence (5/71, 7%) of complications.

ADVANCES IN KNOWLEDGE

We recommend that all patients with a suspected diagnosis of post-SC should undergo CT scan (post-contrast orbits and post-contrast head, with multiplanar reformats and a careful review of the SOV and the cavernous sinus). Particular attention should be paid to exclude intracranial complications including subdural empyema and cerebral abscess. As soon as a diagnosis of post-SC is made, in addition to informing the referring clinical team, urgent opinion should be sought from ear, nose and throat (ENT), neurology and ophthalmology with a view to urgently drain of the paranasal sinuses`.

CT of the neonatal head

Computed tomography (CT) is used less often than other techniques on neonatal units. However, in the acute setting, CT can be invaluable in diagnosing or excluding potentially life-threatening conditions and guiding initial management in neonates. Common indications for scanning include trauma, suspected non-accidental injury, infection, or an acute hypoxic or metabolic event. The aim of this review is to provide an overview of the normal neonatal head at CT and compare this to the common pathological abnormalities. Several key features of each condition will be highlighted. It is important to note that some pathological conditions can have overlapping features at CT and, therefore, the clinical history and additional investigations are also of key importance in determining the diagnosis.

Management of isolated syringomyelia in the paediatric population--a review of imaging and follow-up in a single centre

OBJECTIVE

To assess the natural history of isolated syringomyelia in children.

METHODS

MRI reports from February 2007 to August 2011 mentioning syrinx were identified on Sheffield Children's PACS database. Scans with syringes having an AP diameter of > 1 mm and extending over at least two vertebral bodies were reviewed. Patients with an identifiable cause such as a Chiari malformation were then excluded.

RESULTS

Thirty-nine patients were included with a mean age at diagnosis of 10.6 years. The average syrinx AP diameter was 3.30 mm. The rostrocaudal length of the syringes varied between 2 and 19 vertebral bodies. Twenty-seven out of 39 syringes were thoracic in origin. There were 3 and 6 syringes involving the cervicothoracic and thoracolumbar regions, respectively, with 3 involving the cervical area only. Eleven out of 39 (Group I) patients were found "incidentally" during work-up for adolescent idiopathic scoliosis and these were considered as a separate group. These patients did not have any significant symptoms and were discharged following their scoliosis correction surgery. Syrinx was incidental in 14 further patients (Group II). Of the 14 patients, 11 remained asymptomatic with no change in syrinx morphology throughout follow up. Of the 14 patients, 3 were lost to follow-up. Of the 39 patients, 14 (Group III) presented with progressive back pain without any obvious clinical cause. Of the 14, 10 either improved or remained the same. Of the 14 patients, 3 underwent lumbar puncture, 1/14 having myelography. All 4/14 patients reported significant pain reduction on follow up following intervention.

CONCLUSION

Idiopathic syrinx is a benign pathology, which can be managed expectantly. Most cases remain stable or improve over time. In a small minority who have progressive back pain, we have found that lumbar puncture may be helpful in reducing symptoms.

The encephalopathic child

Encephalopathy is a common paediatric emergency associated with a high risk of morbidity, mortality and long term neurodevelopmental delay in survivors. Prompt diagnosis of the cause of encephalopathy enables the paediatrician to deliver specific medical or surgical treatment that will facilitate a better short and long term outcome. Diagnostic imaging plays a pivotal role in diagnosis. Encephalopathy has many causes. The differential diagnosis includes non accidental injury, trauma, metabolic syndromes, meningo-encephalitis, toxins, hypoxia, demyelination, stroke, haemorrhage and tumours. We describe an approach that helps us formulate an imaging strategy using US, CT and MRI that facilitates patient care.

Role of imaging in the diagnosis of acute bacterial meningitis and its complications

Acute bacterial meningitis is a common neurological emergency and a leading cause of death and neurological disability worldwide. Diagnosis is based on clinical and microbiological findings with neuroimaging in the form of CT reserved for those with specific adverse clinical features or when an underlying cause such as mastoiditis is suspected. MRI is extremely useful for detecting and monitoring the complications of meningitis. These can be remembered by the mnemonic HACTIVE (hydrocephalus, abscess, cerebritis/cranial nerve lesion, thrombosis, infarct, ventriculitis/vasculopathy and extra-axial collection). Diffusion weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) are useful to distinguish abscess from other ring enhancing lesions.

Novel Michael addition products of bis(amino acidato)metal(II) complexes: synthesis, characterization, dye degradation, and oxidation properties

Michael addition reactions of bis(amino acidato)metal(II) complexes (metal = copper, nickel, zinc; amino acid = glycine, dl-alanine, l-alanine) with acrylonitrile have been carried out under various experimental conditions in the absence of a base, resulting in mono- and disubstituted products in high yield, including partially hydrolyzed products. A reaction mechanism for the Michael addition on the nitrogen atom of the coordinated amino acid moiety, replacing the amino hydrogen atom(s), is proposed. All of the products have been characterized by Fourier transform infrared spectroscopy, electron paramagnetic resonance spectra, and elemental and electrochemical analyses. The single-crystal structures of bis( N-cyanoethylglycinato)copper(II) monohydrate ( 1a), diaquabis( N-cyanoethylglycinato)nickel(II), aquabis( N, N-dicyanoethylglycinato)copper(II) ( 2a), and bis[( N-propionamido- N-cyanoethyl)glycinato]copper(II) dihydrate ( 4a) have been confirmed by X-ray diffraction techniques. The products 1a, 2a, 4a, and bis( N-propionamidoglycinato)copper(II) monohydrate ( 3a) have been used as catalysts for the degradation of a phenol red dye and mild oxidation of various organic substrates in the presence of hydrogen peroxide. The monosubstituted complexes have been found to catalyze the reactions to a greater extent than the disubstituted complexes.

Diagnostic difficulties in the management of H-type tracheoesophageal fistula

PURPOSE

To evaluate the diagnostic difficulties and pitfalls in establishing the diagnosis of congenital H-type tracheoesophageal fistula.

MATERIAL AND METHODS

A retrospective review of all cases of H-type tracheoesophageal fistula that were diagnosed in a single unit over a 6-year period. The variables assessed were age at presentation, presenting symptoms, time to diagnosis, investigations, and time to surgical repair of H-type fistula. The investigations leading to a definitive diagnosis are assessed and discussed.

RESULTS

Between 1998 and 2004, five cases of H-type tracheoesophageal fistula presented to our unit. All cases had an upper gastrointestinal contrast study/tube esophagogram. In addition, four cases had a chest radiograph, three cases had a bronchoscopy, and one case an esophagoscopy. The median delay from the time of first presentation to diagnosis of H-type tracheoesophageal fistula was 14 days (7-58 days). Median age at surgery was 15 days (8-60 days).

CONCLUSION

Although symptoms are usually present from birth, the diagnosis of H-type fistula is difficult and often delayed. The various diagnostic techniques are not entirely reliable and fistula identification can be elusive. The authors present recommendations for the diagnostic work-up, which may increase the diagnostic potential and avoid unnecessary delays in the diagnosis and management of H fistula.

Idiopathic maxillary antral mucocele in a child: a rare presentation

We report a case of a large maxillary sinus mucocele in a 14-year-old girl presenting with epiphora, proptosis and dental pain. This was marsupialized endoscopically, with complete resolution of symptoms over three months' follow up. The literature is reviewed.

Short-course chemotherapy for paediatric respiratory tuberculosis: 5-year report

This report presents the 5-year follow-up of 137 children with respiratory tuberculosis enrolled in a randomised clinical trial of two different anti-tuberculosis regimens 9HR and 2HRZ3/4RH2. Both regimens had similar cure rates, with low relapse rates and mortality. Of 134 children followed up to 5 years, 86% had normal radiographs, with more sequelae in the 9HR group (15% vs. 1.5%, P < 0.01). One patient relapsed and there was one accidental death. Short-course chemotherapy in children is safe, effective and well tolerated, and leads to excellent long-term results, with a small proportion of children left with radiological sequelae.

HuA and tristetraprolin are induced following T cell activation and display distinct but overlapping RNA binding specificities

AU-rich elements found in the 3'-untranslated regions of cytokine and proto-oncogene transcripts regulate mRNA degradation and function as binding sites for the mRNA-stabilizing protein HuA and the mRNA-destabilizing protein tristetraprolin. Experiments were performed to evaluate the expression of HuA and tristetraprolin in purified human T lymphocytes and to evaluate the ability of these proteins to recognize specific AU-rich sequences. HuA is a predominantly nuclear protein that can also be found in the cytoplasm of resting T lymphocytes. Within 1 h after stimulation of T lymphocytes with anti-T cell receptor antibodies or a combination of a phorbol myristate acetate and ionomycin, an increase in cytoplasmic HuA RNA-binding activity was observed. Although absent in resting cells, cytoplasmic tristetraprolin protein was detected 3-6 h following activation. HuA recognized specific AU-rich sequences found in c-jun or c-myc mRNA that were poorly recognized by tristetraprolin. In contrast, tristetraprolin recognized an AU-rich sequence in interleukin-2 mRNA that was poorly recognized by HuA. Both HuA and tristetraprolin, however, recognized AU-rich sequences from c-fos, interleukin-3, tumor necrosis factor-alpha, and granulocyte/macrophage colony-stimulating factor mRNA. HuA may transiently stabilize a subset of AU-rich element-containing transcripts following T lymphocyte activation, and tristetraprolin may subsequently mediate their degradation.

Concerted dephosphorylation of the transcription factor NFAT1 induces a conformational switch that regulates transcriptional activity

NFAT transcription factors are highly phosphorylated proteins that are regulated by the calcium-dependent phosphatase calcineurin. We show by mass spectrometry that NFAT1 is phosphorylated on fourteen conserved phosphoserine residues in its regulatory domain, thirteen of which are dephosphorylated upon stimulation. Dephosphorylation of all thirteen residues is required to mask a nuclear export signal (NES), cause full exposure of a nuclear localization signal (NLS), and promote transcriptional activity. An inducible phosphorylation site in the transactivation domain contributes to transcriptional activity. Our data suggest that dephosphorylation promotes NFAT1 activation by increasing the probability of an active conformation, in a manner analogous to that by which depolarization increases the open probability of voltage-gated ion channels. This conformational switch paradigm may explain modification-induced functional changes in other heavily phosphorylated proteins.

Rational treatment of empyema in children

HYPOTHESIS

Efficacious and cost-effective treatment of pediatric empyema can be accomplished following a protocol based on its radiographic appearance. Therapeutic modalities include thoracostomy tube drainage (TTD) with or without fibrinolytic therapy (FT) and video-assisted thoracoscopic debridement (VATD).

DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

RESULTS

From 1995 through 1999, 31 children were treated ranging in age from 11 months to 18 years (mean age, 5.1 years). Twenty-seven (87.1%) underwent TTD; of these, 22 (81.5%) received FT with urokinase. The TTD failed in 4 children (14.8%) who required salvage VATD. Primary VATD was performed in another 4 children (12.9%). The mean length of stay was 14.6 days (TTD, 14.1 days; salvage VATD, 20. 0 days; primary VATD, 11.5 days), ranging from 8.0 to 30.0 days. Complications included readmission for fever (2 patients [6.5%]) and gastrointestinal bleeding (1 patient [3.2%]). There were no anaphylactic reactions or bleeding episodes due to urokinase. Two patients (7.4%) treated with TTD and FT developed an air leak that resolved spontaneously. The mean hospital charges were $78,832 (TTD with or without FT, $75,450; salvage VATD, $107,476; primary VATD, $69,634). The procedural charges were highest for salvage VATD.

CONCLUSIONS

Most cases of pediatric empyema can be treated by TTD with or without FT. This therapy is safe and effective for children with nascent disease. Primary VATD is preferred in children with advanced disease. Cost-effectiveness could be further improved through better prediction of those patients likely to fail TTD and require salvage VATD. An algorithmic approach based on findings from computed tomography or (better) ultrasonography of the chest may be the best way to make this distinction and rationalize care.

Use of arm veins for lower extremity arterial bypass--results, anatomical features and technical considerations

Forty lower limb bypasses using arm veins were performed on 37 patients. The indications for surgery were limb threat in 50% of cases, graft failure in 33%, aneurysms in 10% and claudication in 7%. Saphenous veins were absent because of prior use in 73% of cases, and because they were unsuitable in 27%. A single vein was used in 48%, 2 veins in 40% and 3 veins in 12% of cases. Seventy-four per cent of cases had a single-vessel run-off below the distal anastomosis. Eighty-two per cent of the distal anastomoses were to infrapopliteal arteries. The primary and secondary rates of these 40 bypasses at a mean follow-up of 14 months (range 1-40 months) were 74% and 90%, respectively. Limb salvage was 94%. Peri-operative morbidity and mortality were 23% and 3%, respectively. The anatomical and technical aspects of harvesting arm veins are critical to the success of this procedure and will be emphasised. We have found arm veins to be a durable source of accessible autogenous grafts for lower limb revascularisation in the absence of suitable saphenous veins.

Guanosine tetraphosphate-induced dissociation of open complexes at the Escherichia coli ribosomal protein promoters rplJ and rpsA P1: nanosecond depolarization spectroscopic studies

We have measured the fluorescence anisotropy decays of various transcription complexes formed between Escherichia coli RNA polymerase (RNAP) and the rplJ, rpsA P1 and lacUV5 promoters, where the sigma 70-subunit of RNAP is covalently labeled with the fluorescent probe 1,5-IAEDANS. The observed changes in the rotational correlation times (phi r) of the sigma 70-bound probe upon ppGpp or NTP addition to preformed open complexes, were used to directly infer the extent of association of the sigma-subunit with these transcription complexes. At the rplJ and rpsA P1 promoters, the addition of ppGpp (in the absence of heparin and nucleotides), results in the dissociation of RNAP from the binary complex. This is either accompanied by, or leads to the dissociation of a fraction of the holoenzyme-bound sigma 70. At the lacUV5 promoter, only a marginal dissociation of RNAP is observed. We propose a model where two types of ppGpp-bound RNAP interact with the ribosomal protein promoters. One is transcription-competent and releases sigma 70 upon elongation, while the other dissociates from the open complex. A fraction of the latter species releases the sigma 70 subunit and is unable to form a transcription-competent holoenzyme. Our data supports the mechanism of open complex-destabilization at stringent promoters by ppGpp.

The differential effects of guanosine tetraphosphate on open complex formation at the Escherichia coli ribosomal protein promoters rplJ and rpsA P1

The effects of guanosine tetraphosphate (ppGpp) on inhibition of single-round in vitro transcription and on the kinetics of open complex formation were investigated at the Escherichia coli ribosomal protein promoters rplJ and rpsA P1. The two promoters differ in their saturation characteristics and sensitivities to ppGpp. With a 10:1 molar ratio of RNA polymerase (RNAP) to DNA, saturation of transcription activity and weak inhibition (approximately 30%) are observed at rplJ, in contrast to the weak activity and strong inhibition (approximately 80%) at rpsA P1. In the absence of ppGpp, the two promoters show a threefold difference in the overall rate constants of association (ka) (6.5 x 10(7) M-1 s-1 at rplJ and 2.0 x 10(7) M-1 s-1 at rpsA P1), while the dissociation rate constants (kd) are similar (approximately 4.8 x 10(-5) s-1). The addition of ppGpp causes a twofold reduction in k2 (isomerisation constant) rplJ and a threefold decrease in KB (equilibrium constant of RNAP binding) at rpsA P1. There is a significant twofold increase in kd at rplJ, compared with smaller changes at rpsA P1 and at the non-stringent lacUV5 promoter. These results indicate that ppGpp affects the formation and stability of the open complex at the rplJ promoter, in contrast to the inhibition of RNAP binding to the rpsA P1 promoter.

Selective inhibition of NFAT activation by a peptide spanning the calcineurin targeting site of NFAT

NFAT transcription factors play a key role in the immune response. The activation of NFAT proteins is controlled by calcineurin, the calmodulin-dependent phosphatase that is inhibited by the immunosuppressive drugs cyclosporin A and FK506. Here we identify a short conserved sequence in NFAT proteins that targets calcineurin to NFAT. Mutation of a single residue in this sequence impairs the calcineurin-mediated dephosphorylation and nuclear translocation of NFAT1. Peptides spanning the region inhibit the ability of calcineurin to bind to and dephosphorylate NFAT proteins, without affecting the phosphatase activity of calcineurin against other substrates. When expressed intracellularly, a corresponding peptide inhibits NFAT dephosphorylation, nuclear translocation, and NFAT-mediated expression in response to stimulation. Thus, disruption of the enzyme-substrate docking interaction that directs calcineurin to NFAT can effectively block NFAT-dependent functions.

Interaction of calcineurin with a domain of the transcription factor NFAT1 that controls nuclear import

The nuclear import of the nuclear factor of activated T cells (NFAT)-family transcription factors is initiated by the protein phosphatase calcineurin. Here we identify a regulatory region of NFAT1, N terminal to the DNA-binding domain, that controls nuclear import of NFAT1. The regulatory region of NFAT1 binds directly to calcineurin, is a substrate for calcineurin in vitro, and shows regulated subcellular localization identical to that of full-length NFAT1. The corresponding region of NFATc likewise binds calcineurin, suggesting that the efficient activation of NFAT1 and NFATc by calcineurin reflects a specific targeting of the phosphatase to these proteins. The presence in other NFAT-family transcription factors of several sequence motifs from the regulatory region of NFAT1, including its probable nuclear localization sequence, indicates that a conserved protein domain may control nuclear import of all NFAT proteins.

Immunosuppressive drugs prevent a rapid dephosphorylation of transcription factor NFAT1 in stimulated immune cells

The immunosuppressive drugs cyclosporin A and FK506 interfere with the inducible transcription of cytokine genes in T cells and in other immune cells, in part by preventing the activation of NF-AT (nuclear factor of activated T cells). We show that transcription factor NFAT1 in T cells is rapidly dephosphorylated on stimulation, that dephosphorylation occurs before translocation of NFAT1 into the cell nucleus, and that dephosphorylation increases the affinity of NFAT1 for its specific sites in DNA. Cyclosporin A prevents the dephosphorylation and the nuclear translocation of NFAT1 in T cells, B cells, macrophages, and mast cells, delineating at least one mechanism that contributes to the profound immunosuppressive effects of this compound.

Evidence for a ppGpp-binding site on Escherichia coli RNA polymerase: proximity relationship with the rifampicin-binding domain

On amino acid starvation, Escherichia coli cells exhibit an adaptive facility termed the stringent response. This is characterized by the production of high levels of a regulatory nucleotide, ppGpp, and concomitant curtailment in rRNA synthesis. Various studies reported earlier indicated that RNA polymerase is the site of action of ppGpp although a direct demonstration of the interaction of ppGpp with E. coli RNA polymerase is still lacking. Here we report the labelling of ppGpp with a fluorescent probe, 1-aminonapthalene-5-sulphonate (AmNS), at the terminal phosphates. AmNS-ppGpp responded much like a ppGpp molecule in an in vitro total transcription assay at selective promoters. Fluorescence titration of the tryptophan emission of RNA polymerase by AmNS-ppGpp indicated a unique binding site in the absence of template DNA. Competition experiments showed that unlabelled ppGpp binds to the enzyme at the same site. Sigma factor seems to have no effect on this binding. The titration profile is also characterized by a single slope in the Scatchard analysis. The presence of GTP or GDP does not influence the binding of AmNS-ppGpp with RNA polymerase. Forster's distance measurement was carried out which placed AmNS-ppGpp 27 A away from the rifampicin-binding domain of RNA polymerase.

Release of oxygen radicals by articular chondrocytes: a study of luminol-dependent chemiluminescence and hydrogen peroxide secretion

We previously established that normal articular chondrocytes, like macrophages, express class II major histocompatibility antigens, present antigen, and induce mixed and autologous lymphocyte stimulation. In a recent study using the trapped indicator 2',7'-dichlorofluorescein diacetate, we were able to measure levels of intracellular hydrogen peroxide within normal articular chondrocytes (J Immunol 245:690-696, 1990). In the present study, we utilized the technique of chemiluminescence and the biochemical method of quantitating hydrogen peroxide release to measure the production of reactive oxygen intermediates by articular chondrocytes. Chondrocytes, in suspension or adherent to coverslips, showed luminol-dependent chemiluminescence that was dependent on the number and viability of cells. There was a dose-dependent increase in chemiluminescence in response to soluble stimuli, such as phorbol myristate acetate (PMA), concanavalin A (ConA), and f-Met-Leu-Phe (FMLP). Azide inhibited chemiluminescence, suggesting that the light emission in chondrocytes is myeloperoxidase dependent. The antioxidant, catalase, inhibited chemiluminescence but superoxide dismutase had no effect, suggesting that luminol-dependent chemiluminescence in chondrocytes mostly measured hydrogen peroxide. Chemiluminescence was also observed in fragments of live cartilage tissue, indicating that chondrocytes that are cartilage matrix bound can generate the respiratory burst response. Using the scopoletin oxidation assay, we confirmed the release of increasing amounts of hydrogen peroxide by chondrocytes exposed to interleukin-1, rabbit interferon, and tumor necrosis factor alpha. Tumor necrosis factor alpha had both priming and enhancing effects on reactive oxygen intermediate production by chondrocytes. Reactive oxygen intermediates have been shown to play a significant role in matrix degradation. We suggest that reactive oxygen intermediates produced by chondrocytes play an important role in the degradation of matrix in arthritis.

Completion thyroidectomy for thyroid carcinoma

We have reviewed the charts of 149 patients who underwent completion thyroidectomies for cancer of the thyroid. The purpose of the study was to evaluate extent of residual disease in the thyroid, and morbidity and mortality of the operation. Residual cancer was found in 58% of the cases, the morbidity was low, and there was no operative mortality.