The stuck haemodialysis catheter-a case report of a rare but dreaded complication following kidney transplantation

BACKGROUND

Tunnelled cuffed haemodialysis catheters are at increased risk of incarceration or becoming 'stuck' via fibrotic adhesion to the central veins when left in situ for prolonged periods of time. Stuck catheters cannot be removed using standard techniques such as bedside dissection of the cuff. Whilst there are several strategies published for the removal of these incarcerated lines, there is no consensus on the best approach. Here we present a challenging case of a stuck haemodialysis catheter in the acute post transplantation period.

CASE PRESENTATION

A 66-year-old female on haemodialysis presented for kidney transplantation with a tunnelled-cuffed haemodialysis catheter in situ for five years. Following transplantation, removal of the line was unsuccessful despite dissection of the cuff, with traction causing a choking sensation with tracheal movement. Eventually, the line was removed without complications utilising sequential balloon dilatation by interventional radiology and the patient was discharged without complications.

CONCLUSIONS

This case serves as a timely reminder of the risks of long-term tunnelled haemodialysis catheters and as a caution towards proceeding with kidney transplantation in those with long-term haemodialysis catheters in situ. Greater nephrologist awareness of interventional radiology techniques for this challenging situation will help to avoid more invasive strategies. The risks of a stuck catheter should be included in the discussions about the optimal vascular access and transplantation suitability for a given patient.

Adapting the investigation of patients on urgent suspected cancer pathway with lower gastrointestinal symptoms across Wales during COVID-19

INTRODUCTION

The COVID-19 pandemic necessitated the introduction of revised diagnostic pathways for assessing urgent suspected cancer (USC) referrals. Combinations of faecal immunochemical testing (FIT) and minimal preparation computed tomography (CT) scans (MPCT) were used to manage referrals and prioritise access to clinical services or invasive tests. The effectiveness of these pathways across Wales is evaluated in this study.

METHODS

All consecutive patients referred from primary care on the USC pathway between 15 March and 15 June 2020 were included to reflect the effect of full lockdown measures. Data collected included demographics, presenting symptom(s), investigations and timelines and patient outcomes up to 90 days following initial referral.

RESULTS

A total of 1,050 patients across eight sites in Wales were included. Of these 1,050 patients, 52.6% were female with median age 68 (21-97) years; 50.5% had first-line clinical review, of which 61.1% were virtual consultations; 49.5% had primary investigations; 26.7% of patients had FIT and 13.1% had MPCT. COVID-response pathways achieved a 29.9% reduction in use of colonoscopy as first-line investigation and 79% of patients avoided face-to-face consultations altogether during this first wave of the pandemic. Overall, 6.8% of USC referrals were diagnosed with colorectal cancer (CRC). Median timescale from diagnosis to treatment for CRC was 65 (4-175) days. The negative predictive value (NPV) for FIT in this cohort was 99.6%. MPCT as the first modality had a NPV of 99.2%.

CONCLUSION

A modified investigation pathway helped maintain cancer diagnosis rates during the pandemic with improved resource utilisation to that used prepandemic.

TH3.8 Retrospective study on the use of colonic stents in malignancy; a bridge to surgery or the end of the line?

Aim

Colonic stenting is a management option for obstructed left sided colorectal malignancy in the emergency and elective setting. Stenting can provide a bridge to curative surgery or to adjuvant treatment. The aim of this study was to assess the role of colonic stenting in management of obstructed colorectal cancer.

Methods

This retrospective cohort study analyses prospectively collected data from two centres within one Health Board in Wales. Patients were recorded in a cancer database, who underwent colonic stenting for left sided colonic malignancy between January 2008 and December 2021. Patient demographics, treatment pathways, length of admission, stoma formation rates and morbidity were recorded.

Results

In total, 98 patients, with a mean age of 73.5 years (range 37–97) underwent a colonic stent. The majority were elective 55% (n=54). The sigmoid colon was the commonest site of tumour in 33 patients, with metastatic disease in 82% (n=80). The study found 86% (n=84) of patients were successfully stented. The mean length of admission was 13 days. The complication rate was 23% (n=23), most commonly stent obstruction (n=6). Stenting was a bridge to curative surgery for 3 patients, and 47% (n=46) received adjuvant treatment. Five-year survival was 19.3% (n=19). The overall stoma rate was 10.2% (10 patients).

Conclusion

This study shows colonic stenting is a viable alternative in surgical management for advanced obstructing colorectal malignancy but not as a bridge to surgery. The majority of this cohort returned home following stenting, had a low overall stoma rate and 19% survival at 5 years.

SP4.1.5The use of Faecal Immunochemical Testing (FIT) and Minimal Preparation Computed Tomography (MPCT) during COVID-19 for Urgent Suspected Cancer (USC) referrals in patients with lower gastro-intestinal symptoms

Aims

The COVID-19 pandemic necessitated introduction of revised diagnostic pathways for assessing Urgent Suspected Cancer (USC) referrals. Combinations of FIT and MPCT were used to manage referrals and prioritise access to clinical services or invasive tests. The effectiveness of these pathways are evaluated in this study.

Methods

All consecutive patients referred from primary care on the USC pathway between 15^th March – 15^th June 2020 were included to reflect the effect of full lockdown measures. Data collected included demographics, presenting symptom(s), investigations and timelines and patient outcomes up to 90 days following initial referral.

Results

816 patients across 8 sites in Wales were included in this initial analysis. 52.7% of patients were female with median age 69 (21 – 97) years. Of the 50.7% who had first-line clinical review, 70.5% were virtual consultations. 49.3% had primary investigations, with FIT in 31% of patients and MPCT in 18.3%. This was compliant with locally agreed pathways for 77.3% of referrals. COVID-response pathways achieved a 28.5% reduction in use of colonoscopy as first-line investigation and 84.3% of patients avoided face-to-face consultations altogether during this first wave of the pandemic.

Overall, 5.6% of USC referrals were diagnosed with CRC. Median timescale from diagnosis to treatment for CRC was 82 (4 – 175) days. The NPV for FIT in this cohort was 99.5%. MPCT as the first modality had a NPV of 99%.

Conclusion

A modified investigation pathway maintained cancer diagnosis during the pandemic with improved resource utilisation to that used previously.

Where have all the appendicectomies gone?

INTRODUCTION

The COVID-19 pandemic stimulated a national lockdown in the UK. The public were advised to avoid unnecessary hospital attendances and health professionals were advised to avoid aerosol-generating procedures wherever possible. The authors hypothesised that these measures would result in a reduction in the number of patients presenting to hospital with acute appendicitis and alter treatment choices.

METHODS

A multicentred, prospective observational study was undertaken during April 2020 to identify adults treated for acute appendicitis. Searches of operative and radiological records were performed to identify patients treated during April 2018 and April 2019 for comparison.

RESULTS

A total of 190 patients were treated for acute appendicitis pre-lockdown compared with 64 patients treated during lockdown. Patients treated during the pandemic were more likely to have a higher American Society of Anesthesiology (ASA) score (p = 0.049) and to have delayed their presentation to hospital (2 versus 3 days, p = 0.03). During the lockdown, the use of computed tomography (CT) increased from 36.3% to 85.9% (p < 0.001), the use of an antibiotic-only approach increased from 6.2% to 40.6% (p < 0.001) and the rate of laparoscopic appendicectomy reduced from 85.3% to 17.2% (p < 0.001). The negative appendicectomy rate decreased from 21.7% to 7.1% during lockdown (p < 0.001).

CONCLUSIONS

The COVID-19 lockdown was associated with a decreased incidence of acute appendicitis and a significant shift in the management approach. The increased use of CT allows the identification of simple appendicitis for conservative treatment and decreases the negative appendicectomy rate.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Widespread detection of highly pathogenic H5 influenza viruses in wild birds from the Pacific Flyway of the United States

A novel highly pathogenic avian influenza virus belonging to the H5 clade 2.3.4.4 variant viruses was detected in North America in late 2014. Motivated by the identification of these viruses in domestic poultry in Canada, an intensive study was initiated to conduct highly pathogenic avian influenza surveillance in wild birds in the Pacific Flyway of the United States. A total of 4,729 hunter-harvested wild birds were sampled and highly pathogenic avian influenza virus was detected in 1.3% (n = 63). Three H5 clade 2.3.4.4 subtypes were isolated from wild birds, H5N2, H5N8, and H5N1, representing the wholly Eurasian lineage H5N8 and two novel reassortant viruses. Testing of 150 additional wild birds during avian morbidity and mortality investigations in Washington yielded 10 (6.7%) additional highly pathogenic avian influenza isolates (H5N8 = 3 and H5N2 = 7). The geographically widespread detection of these viruses in apparently healthy wild waterfowl suggest that the H5 clade 2.3.4.4 variant viruses may behave similarly in this taxonomic group whereby many waterfowl species are susceptible to infection but do not demonstrate obvious clinical disease. Despite these findings in wild waterfowl, mortality has been documented for some wild bird species and losses in US domestic poultry during the first half of 2015 were unprecedented.

Comparison of parental estimate of developmental age with measured IQ in children with neurodevelopmental disorders

BACKGROUND

Formal IQ tests are an important part of the diagnostic and needs-based assessment process for children with neurodevelopmental disorders. However, resources for such assessments are not always available. It has been suggested that parental estimates of their child's developmental age could serve as a proxy IQ when formal measures are unavailable.

METHOD

Parental estimates of their child's developmental age were converted to a developmental quotient (DQ) in 197 children with Autism Spectrum Disorder (ASD) aged 4-9 years, and 108 children with ADHD and intellectual disability (ADHD + ID) aged 7-15 years. Formal IQ assessments were then conducted. Parents completed the Social Communication Questionnaire ((SCQ), a measure of autism symptomatology) and a demographic questionnaire.

RESULTS

In the ASD sample, 58% of parent estimates were within 15 points (i.e. one standard deviation) of the child's measured IQ score. Lower measured IQ and lower SCQ total score predicted higher parental accuracy. In the ADHD + ID sample, 74% of parental estimates were within 15 points of measured IQ. In this group, higher child IQ predicted greater parental accuracy. Parents in the ADHD + ID group were more likely to overestimate children's ability level than parents in the ASD group.

CONCLUSIONS

In this study, the majority of parents of children with ADHD and ID were able to estimate their child's intellectual ability level with some accuracy. Parents of children with ASD were less accurate, but this may be because these parents were focussing more on children's level of adaptive functioning, which is known to be typically lower than cognitive ability in ASD.

Failure to learn from feedback underlies word learning difficulties in toddlers at risk for autism

Children's assignment of novel words to nameless objects, over objects whose names they know (mutual exclusivity; ME) has been described as a driving force for vocabulary acquisition. Despite their ability to use ME to fast-map words (Preissler & Carey, 2005), children with autism show impaired language acquisition. We aimed to address this puzzle by building on studies showing that correct referent selection using ME does not lead to word learning unless ostensive feedback is provided on the child's object choice (Horst & Samuelson, 2008). We found that although toddlers aged 2;0 at risk for autism can use ME to choose the correct referent of a word, they do not benefit from feedback for long-term retention of the word-object mapping. Further, their difficulty using feedback is associated with their smaller receptive vocabularies. We propose that difficulties learning from social feedback, not lexical principles, limits vocabulary building during development in children at risk for autism.

Reweaving the social fabric: antecedents of social support facilitation

Contemporary society leaves many individuals without a continuing support group. Continued integration into a network of supportive social relationships is demonstrably related to the prevention of breakdown in health in the widest variety of mental and physical forms. Yet the task of assuring continuity of supportive relationships has not been central to any professional discipline. The facilitation of social support is likely to become more central to community health education.To address this issue we examine seven different forms of intervention which address the problem of augmenting supportive relationships. The goal is to extract the essence of the professional role in the provision of social support and to suggest its relevance to community health education.

IQ in children with autism spectrum disorders: data from the Special Needs and Autism Project (SNAP)

BACKGROUND

Autism spectrum disorder (ASD) was once considered to be highly associated with intellectual disability and to show a characteristic IQ profile, with strengths in performance over verbal abilities and a distinctive pattern of 'peaks' and 'troughs' at the subtest level. However, there are few data from epidemiological studies.

METHOD

Comprehensive clinical assessments were conducted with 156 children aged 10-14 years [mean (s.d.)=11.7 (0.9)], seen as part of an epidemiological study (81 childhood autism, 75 other ASD). A sample weighting procedure enabled us to estimate characteristics of the total ASD population.

RESULTS

Of the 75 children with ASD, 55% had an intellectual disability (IQ<70) but only 16% had moderate to severe intellectual disability (IQ<50); 28% had average intelligence (115>IQ>85) but only 3% were of above average intelligence (IQ>115). There was some evidence for a clinically significant Performance/Verbal IQ (PIQ/VIQ) discrepancy but discrepant verbal versus performance skills were not associated with a particular pattern of symptoms, as has been reported previously. There was mixed evidence of a characteristic subtest profile: whereas some previously reported patterns were supported (e.g. poor Comprehension), others were not (e.g. no 'peak' in Block Design). Adaptive skills were significantly lower than IQ and were associated with severity of early social impairment and also IQ.

CONCLUSIONS

In this epidemiological sample, ASD was less strongly associated with intellectual disability than traditionally held and there was only limited evidence of a distinctive IQ profile. Adaptive outcome was significantly impaired even for those children of average intelligence.

Leukocyte reactivity as an objective means of quantifying mental loading during ergonomic evaluation

Psychological stress evokes rapid changes to the cardiovascular and neuroendocrine systems, responses that can become habituated following repeated exposure. This study, comprising of two phases, suggests that the immune system follows a similar trend. Phase 1: 15 healthy subjects (aged between 26 and 56years) provided capillary blood samples before and after completing three basic tasks using, in turn, two automotive touch screen interfaces (Interface 1-antecedent version, Interface 2-improved version). Using a chemiluminescent technique termed leukocyte coping capacity (LCC), the ability of leukocytes to produce reactive oxygen species in vitro was assessed. Significant differences in leukocyte activity were shown between treatment groups, where the greatest post-test decrease occurred after using Interface 1. Phase 2: a randomly selected sub-group (n=4) underwent weekly repeat testing using both interfaces. Significant differences in post-test leukocyte reactivity were exhibited between test weeks for each interface-the magnitude of response decreasing with successive exposure.

Measles vaccination and antibody response in autism spectrum disorders

OBJECTIVE

To test the hypothesis that measles vaccination was involved in the pathogenesis of autism spectrum disorders (ASD) as evidenced by signs of a persistent measles infection or abnormally persistent immune response shown by circulating measles virus or raised antibody titres in children with ASD who had been vaccinated against measles, mumps and rubella (MMR) compared with controls.

DESIGN

Case-control study, community based.

METHODS

A community sample of vaccinated children aged 10-12 years in the UK with ASD (n = 98) and two control groups of similar age, one with special educational needs but no ASD (n = 52) and one typically developing group (n = 90), were tested for measles virus and antibody response to measles in the serum.

RESULTS

No difference was found between cases and controls for measles antibody response. There was no dose-response relationship between autism symptoms and antibody concentrations. Measles virus nucleic acid was amplified by reverse transcriptase-PCR in peripheral blood mononuclear cells from one patient with autism and two typically developing children. There was no evidence of a differential response to measles virus or the measles component of the MMR in children with ASD, with or without regression, and controls who had either one or two doses of MMR. Only one child from the control group had clinical symptoms of possible enterocolitis.

CONCLUSION

No association between measles vaccination and ASD was shown.

Bone marrow hypervascularity in patients with myelofibrosis identified by infra-red thermography

Infra-red thermography was used to assess bone marrow vascularity in six patients with myelofibrosis secondary to myeloproliferative disorders (four primary myelofibrosis and two primary proliferative polycythaemia). The technique was evaluated with conventional static and dynamic radio-isotopic imaging and with immunohistochemical staining of bone marrow biopsies. Infra-red thermography identified increased bone marrow blood flow in patients with established myelofibrosis and correlated with dynamic radio-isotopic studies of blood flow and hypervascularity identified by immunohistochemistry. Increased bone marrow blood flow and vascular proliferation was not confined to the central bone marrow but also extended into the peripheral marrow of the long bones. Endothelial cell proliferation may be an initiating event in the pathogenesis of myelofibrosis but evaluation of bone marrow vascularity and blood flow has hitherto relied on invasive and complicated techniques. This study has identified bone marrow hypervascularity in patients with myelofibrosis and shown infra-red thermography to be a simple non-invasive method of assessing vascularity. This non-invasive technique may be used to study disease progression and response to therapeutic regimens in patients with myelofibrosis and to study bone marrow blood flow in other bone marrow disorders.

Effectiveness of intrathecal ziconotide in malignant pain: A combined analysis of two controlled trials

8552

Background: Ziconotide is a nonopioid, N-type calcium channel blocker that inhibits neuronal calcium influx, thereby reducing neurotransmitter release at primary pain afferents. Clinical trials have shown ziconotide is useful in managing severe chronic pain, including nociceptive and neuropathic pain of malignant etiology. We reviewed the effectiveness of ziconotide using the Visual Analog Scale of Pain Intensity (VASPI: 100 mm=worst possible pain, 0 mm=no pain). Methods: Cancer patients from two double-blind, placebo-controlled trials (Studies 95–001 and 301) were analyzed. Study 95–001 used a fast titration scheme over 5 to 6 days, enrolling only patients with malignant pain due to cancer or AIDS. In Study 95–001, the initial dosing regimen was based on a pilot trial and was later modified due to the frequency of adverse events (AEs). The final slower titration, lower dosing regimen resulted in a reduced AE rate. Only patients from the final dosing regimen of Study 95–001 were included in this analysis. Study 301 used a slower titration scheme over 21 days, enrolling patients with malignant or nonmalignant pain. A two-sided, two-sample t-test was used to evaluate the null hypothesis that the mean percent change in VASPI score from baseline to end of titration for the ziconotide group was not significantly different from that of the placebo group (intent-to-treat population). Results: A total of 67 patients with malignant pain were treated in the trials; 51 (35 ziconotide, 16 placebo) had both baseline and end of titration VASPI scores. The ziconotide and placebo groups had similar mean baseline VASPI scores (75.5 and 75.8 mm, respectively). The mean percent improvement in VASPI score was 36.5% in the ziconotide group and 8.6% in the placebo group (p=0.0230). Conclusions: These results indicated that ziconotide was effective in relieving malignant pain.

[Table: see text]

Silver absorption and antibacterial efficacy of silver dressings

OBJECTIVE

To evaluate the patterns of silver release from selected sustained silver-release dressings and the protective role of proteins in wound exudate and wound scale. The bactericidal action of silver in chronic wound therapy is also examined.

METHOD

Sequential microbiological examination of wound swabs from seven patients with chronic wounds and sampling of wound exudate and wound scale. Silver content was measured using atomic absorption spectrometry. The ability of Contreet Foam to absorb exudate and release silver was studied in punch biopsy wounds in a rodent model.

RESULTS

Silver accumulation in wound exudate correlated well with its viscosity and protein content. Silver bound to wound scale and debris was approximately proportional to the silver ion release from dressings. Bacterial burden was controlled, but not eliminated, following chronic silver therapy.

CONCLUSION

Silver dressings (Acticoat-7, Actisorb Silver, Contreet Foam, Aquacel Ag and Flamazine) were found to be safe for use in chronic wound therapy. Excess silver ion is bound by wound exudate and wound scale as a protective mechanism. Silver-release dressings are not likely to result in germ-free wounds. Further studies are needed to examine potential silver resistance.

Back injuries in young fast bowlers--a radiological investigation of the healing of spondylolysis and pedicle sclerosis

OBJECTIVE

To demonstrate the efficacy of various radiological diagnostic modalities in assessing lower back pain in young fast bowlers.

METHODS

Ten cricketers who presented to either a physiotherapist or a doctor with suspected spondylolysis underwent an X-ray, a single photon emission computed tomography (SPECT) bone scan and a computed tomography (CT) scan to assess the severity of the injury. Three and 12 months after the initial CT scan, second and third CT scans were performed in order to assess whether healing had taken place. After the initial radiological investigation the subjects diagnosed with spondylolysis or pedicle sclerosis underwent prescribed intervention and rehabilitation which included physiotherapy modalities, postural correction, and specific individually graded flexibility, stabilisation, strengthening and cardiovascular programmes.

RESULTS

Radiographs were normal in 8 subjects, while 2 had evidence of sclerosis. The isotope scan showed increased uptake in all of the subjects. The CT scans showed no fracture (N = 3), partial fractures (N = 3), complete fractures (N = 2) and old fractures bilaterally (N = 2). When the follow-up CT scan was carried out at 3 months, 1 of the subjects had developed a partial fracture of the left pars interarticularis on the inferior border, which showed complete union when CT scanned at 12 months. At 3 months the partial and complete fractures showed progressive healing in 2 subjects, with complete healing in all the other cases. Complete healing was achieved in all subjects at 12 months, with the exception of 1 subject who showed near-complete union, with a small area of fibrous union on the inferior border and 2 old bilateral fractures that remained un-united.

RESULTS

From the results it is evident that when a young fast bowler presents with backache after bowling, it would be appropriate to do an X-ray, a bone scan and a CT scan to make the diagnosis. Discontinuing the fast bowling and following an active rehabilitation programme should result in spontaneous resolution and healing of the fractures. If it is not detected early a fibrous or non-union fracture could result.

Outcome of cancer pain consultations

BACKGROUND

All major cancer centers in the United States are equipped with pain management consultation services. We report on the outcome of such consultations within 24 hours from the intervention.

METHODS

All consecutive patients referred to the pain management service of a tertiary care cancer center were assessed before and 14-24 hours after the intervention.

RESULTS

A total of 45 patients completed the study. The mean current pain intensity score was 5.2 on the Visual Analogue Scale before the consultation and 2.7 after the consultation (P < 0.05). The pain was described as excruciating on the Categorical Scale by three patients before the consultation and by no patients after the consultation.

CONCLUSIONS

In hospitalized cancer patients with difficult to control pain, cancer pain consultations result in a measurable effect within 24 hours of the pharmacologic intervention. To avoid unnecessary suffering, timeliness is of the utmost importance when requesting and delivering cancer pain consultations.

An alternative algorithm for dosing transdermal fentanyl for cancer-related pain

Many cancer patients are undermedicated and inappropriately managed for pain, leading to a diminished quality of life. Patients with moderate to severe pain often require opioid analgesics. Recently published guidelines emphasize individualization of opioid treatment to provide the drug and route of administration that meet the needs of the particular patient. Intolerable side effects, ineffective pain relief, or a change in the patient's clinical status can dictate the need for a new pain management regimen. Physicians must be able to readily quantify relative analgesic potency when converting from one opioid to another or from one route of administration to another. Transdermal fentanyl (Duragesic) is an opioid agonist that has been shown to be safe and effective for the treatment of cancer pain. However, clinicians should realize that the manufacturer's recommendations for equianalgesic dosing of transdermal fentanyl may result in initial doses that are too low in some patients, and in a titration period that is too long. Under these circumstances, the patient is likely to experience unrelieved pain. An alternative dosing algorithm that considers both a review of the literature and our combined clinical experience with transdermal fentanyl should help clinicians individualize the treatment of pain.

Estimation of laser system pointing performance by use of statistics of return photons

Strategic laser systems are subject to residual pointing errors arising from vibrations and atmospheric turbulence, estimates of which may allow improved system performance. Field data from the Air Force Research Laboratory Floodbeam Experiments suggested a linear relationship between the mean and standard deviation of the shot-by-shot signals and the jitter. An ideal analytic solution and Monte Carlo simulations confirmed this result for a relatively large number of returns. A refined approach using statistical chi(2) techniques, which simultaneously estimates jitter and boresight, was developed to address results from satellite passes with relatively few returns and provides excellent jitter and boresight predictions.

Nucleosome structure completely inhibits in vitro cleavage by the V(D)J recombinase

Lineage specificity and temporal ordering of immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangement are reflected in the accessibility of recombination signal sequences (RSSs) within chromatin to in vitro cleavage by the V(D)J recombinase. In this report, we investigated the basis of this regulation by testing the ability of purified RAG1 and RAG2 proteins to initiate cleavage on positioned nucleosomes containing RSS substrates. We found that nicking and double-strand DNA cleavage of RSSs positioned on the face of an unmodified nucleosome are entirely inhibited. This inhibition was independent of translational position or rotational phase and could not be overcome either by addition of the DNA-bending protein HMG-1 or by the use of hyperacetylated histones. We suggest that the nucleosome could act as the stable unit of chromatin which limits recombinase accessibility to potential RSS targets, and that actively rearranging gene segments might be packaged in a modified or disrupted nucleosome structure.

Nebulized opioids to treat dyspnea

Breathlessness secondary to cancer and nonmalignant disease is very distressing and exhausting to patients and families. Patient quality of life and functionality can be greatly improved with effective management. The pathophysiology and treatment of dyspnea are where the science of pain management was 20 years ago. While the optimal therapy for dyspnea would be to treat the underlying cause, this is frequently not possible. Research results evaluating dosages and effectiveness of nebulized morphine are conflicting. Some researchers have reported dramatic benefit to patients in relieving the symptoms of dyspnea, increasing exercise endurance, and improving function. Other studies have reported no significant differences between nebulized morphine and saline with or without oxygen. Studies that administer single predetermined doses that are not titrated to relief in patients that do not have end-stage lung or cardiac disease may report false-negative results. Other factors such as the placebo effect of saline and oxygen, if not controlled, may cause false-positive results. The dramatic positive benefits documented warrant further investigation on the appropriate patient selection criteria and therapeutic potential. Clearly, large scale randomized trials on opioid nebulized treatments for patients with severe dyspnea need to be published to reach a clear consensus outlining efficacy and administration parameters. Until that time, we must rely on anecdotal reports for treatment options. Such reports of the effectiveness of nebulized morphine as an alternative to hospital or hospice admission are encouraging for patients and family members managing severe dyspnea in the home.

Matrix metalloproteinase expression in an experimentally-induced DTH model of multiple sclerosis in the rat CNS

In an experimentally-induced DTH model of MS, we examined mRNA and protein expression of a range of MMPs and of TNFalpha to establish the contribution that individual MMPs might make to the pathogenesis. In control rat brain, mRNA for all of the MMPs examined was detectable. However, by immunohistochemistry, only MMP-2 could be detected. In the DTH lesions, significant increases in the level of mRNA expression were observed for MMP-7, MMP-8, MMP-12, and TNFalpha. Where expression of MMP mRNA was increased, there was a corresponding increase in protein expression detected by immunohistochemistry. To determine whether the upregulated MMPs could invoke destructive events in the CNS, highly purified activated MMP-7, MMP-8, and MMP-9 were stereotaxically injected into the brain parenchyma. All provoked recruitment of leukocytes and BBB breakdown. In addition, MMPs 7 and 9 induced loss of myelin staining. In conclusion, specific MMPs are upregulated in DTH lesions; for the most part, measurement of mRNA was a predictor of increased protein expression. From our injections of MMPs, it is clear that the upregulated MMPs in the DTH lesions could participate in the disruption of the BBB, leukocyte recruitment, and tissue damage.

Asymmetric linker histone association directs the asymmetric rearrangement of core histone interactions in a positioned nucleosome containing a thyroid hormone response element

We describe histone-DNA cross-linking in a positioned nucleosome containing a thyroid hormone response element (TRE) from the Xenopus laevis thyroid hormone receptor betaA gene (TRbetaA). Histones H3 and H4 are cross-linked to DNA in the nucleosome core within 30 base pairs to either side of the dyad axis. Histone H2A cross-links to DNA in the core at the dyad axis, and histones H2A and H2B have extensive interactions with DNA 40-80 bp away from the dyad axis. Linker histone H5 and the globular domain of Xenopus H1(0) associate asymmetrically with DNA at one edge of the TRbetaA nucleosome. Nevertheless, the asymmetric association of H5 leads to a significant rearrangement of core histone-DNA contacts at the dyad axis of the nucleosome. In the presence of linker histone, cross-linkings of H4 within 15 bp to one side of the dyad axis, of histone H2A at the dyad axis, and of H2A and H2B 40-80 bp to one side of the dyad axis are all reduced. This reduction in cross-linking occurs preferentially on the side of the nucleosome to which H5 is bound. Our results indicate that core histone contacts within mononucleosomes are conformationally dynamic and that linker histone incorporation at the edge of the nucleosome can influence core histone-DNA interactions in an asymmetric way including contacts at the dyad axis.

A continuous patient activity monitor: validation and relation to disability

The measurement of patient activity over prolonged periods has been attempted with accelerometer-based devices, but these summate total acceleration and deceleration over time periods, are difficult to relate to recognizable activities and are influenced by passive movement. We describe the development of a portable monitor of ambulation. This logs posture (sitting, standing and lying) and number and vigour of steps in real time over prolonged periods, usually 24 h. This is based on a system of position sensors and an accelerometer which is sampled when the subject is standing. Data are processed through an interface and stored on a Psion Series 3 'palm top' computer. The system has been validated against observation, and the relationship of activity to disability in rheumatoid arthritis explored.

Matrix metalloproteinases, tumor necrosis factor and multiple sclerosis: an overview

The matrix metalloproteinases (MMPs) are a family of at least 14 zinc-dependent enzymes which are known to degrade the protein components of extracellular matrix. In addition, MMPs and related enzymes can also process a number of cell surface cytokines, receptors, and other soluble proteins. In particular we have shown that the release of the pro-inflammatory cytokine, tumor necrosis factor-alpha, from its membrane-bound precursor is an MMP-dependent process. MMPs are expressed by the inflammatory cells which are associated with CNS lesions in animal models of multiple sclerosis (MS) and in tissue from patients with the disease. MMP expression will contribute to the tissue destruction and inflammation in MS. Drugs which inhibit MMP activity are effective in animal models of MS and may prove to be useful therapies in the clinic.

Becoming a father. First-time fathers' experience of labor and delivery

In this study, ethnographic interviews were used to identify first-time fathers' experiences of the birth of their first child. Fourteen fathers were interviewed, and prenatal expectations of the experience are compared with the fathers' perceptions after the birth. Although the fathers expected to be treated as part of a laboring couple, they found that they were relegated to a supporting role. Initially the fathers were confident of their ability to support their wives, but they found that labor was more work than they had anticipated. They became fearful of the outcome, but hid these fears from their partners. Later, they found that their focus moved from their wives to their babies at the time of birth. The men all completed the experience with an enhanced respect for their wives. Fathers should be included in labor management plans and need support for their role as coach, particularly when their wives experience pain. They also need to be encouraged to eat and take a break from their wives' labor when appropriate.

Patients' perceptions of outcomes of a Canadian hospitalization

Notes that with health care reform moving at tremendous speed throughout Canada, a great deal of interest in outcomes research has been generated. States that the research team consisted of 17 professional practice leaders from eight disciplines. Proposes, through the research, to identify from the perspective of former patients what results they hoped to achieve prior to discharge from hospital and what facilitated and hindered them in achieving these results. Reports that a representative sample was selected for the study. Forty-one former patients each participated in up to two focus groups, with a total of 16 focus groups conducted. Hierarchical analysis revealed themes that fell within the framework of structure, process and outcomes. The findings will assist in ensuring that more appropriate and effective care is offered to patients by a variety of disciplines.

Macrophage metalloelastase degrades matrix and myelin proteins and processes a tumour necrosis factor-alpha fusion protein

The matrix metalloproteinases (MMPs) are a group of enzymes which have the ability to degrade extracellular matrix. They also cleave non-matrix proteins such as myelin basic protein and alpha 1-antitrypsin and they are able to process tumour necrosis factor-alpha (TNF) to its mature form. We have cloned, expressed and purified human macrophage metalloelastase (EC 3.4.24.65), an MMP recognised for its ability to degrade elastin, but whose substrate specificity has not yet been defined. With the exception of type I collagen this enzyme degraded all matrix proteins tested, namely: type IV collagen, type I gelatin, fibronectin, laminin, vitronectin and proteoglycan. It also degraded myelin basic protein, cleaved alpha 1-antitrypsin and released TNF from a pro-TNF fusion protein. Thus, in common with several other MMPs, macrophage metalloelastase has a broad substrate range which extends beyond that of elastin alone.

Matrix metalloproteinases degrade myelin basic protein

Matrix metalloproteinases (MMPs) are a group of enzymes responsible for the degradation of interstitial connective tissue and basement membrane. The coding sequences for five of the human MMPs, viz. interstitial collagenase, 72 kDa gelatinase, stromelysin-1, matrilysin and 92 kDa gelatinase, were cloned and expressed in Chinese hamster ovary cells, and the proteins purified. The enzymes were compared for their ability to digest myelin basic protein, the major extrinsic membrane protein of central nervous system myelin. The most active on this substrate was 72 kDa gelatinase, followed by stromelysin-1; interstitial collagenase, matrilysin and 92 kDa gelatinase were of comparable but lesser activity. Production of these enzymes by glia or infiltrating inflammatory cells could therefore contribute to demyelination in neuroinflammatory disease.

Guidelines for the clinical use of transdermal fentanyl

Transdermal (TTS) fentanyl therapy has emerged as an effective alternative to the use of oral opioids for the control of pain in certain cancer patients. These patients are those with moderate to severe chronic pain, with a stable baseline pain pattern. Patients receiving this treatment should first be titrated to stable pain relief with oral opioids and should have recourse during therapy to fast-acting, short-duration analgesics for the control of incident pain. TTS fentanyl dosing schedules should be based upon the patient's requirement for rescue dosing and duration of effective pain control. The average requirement to change fentanyl patches is every 72 h, although 48-h dosing is necessary in a few patients. This novel route of fentanyl administration allows convenient outpatient treatment, the possibility of a lower incidence of side effects, and may thus aid compliance.

Characterization of the effect of cholecystokinin (CCK) on neurons in the periaqueductal gray of the rat: immunocytochemical and in vivo and in vitro electrophysiological studies

The periaqueductal gray (PAG) is an important integration site for pain, autonomic functions, vocalization, fear and anxiety. Cholecystokinin (CCK) is a major neurotransmitter in the PAG and CCK receptors are heterogeneously distributed within the PAG. Since CCK antagonists are anxiolytic and potentiate morphine analgesia, it is possible that these effects of CCK are mediated through alteration of neuronal activities in the PAG. The goals of this study were to examine the anatomical and physiological properties of the PAG CCK containing systems. The distribution of CCK-containing axons and boutons in PAG was examined using immunohistochemical procedures. These studies show that CCK-like immunoreactive (CCK-LIR) fibers and terminals are present throughout PAG, but are particularly heavily concentrated in a focal column that runs longitudinally throughout the rostrocaudal axis of dorsolateral PAG and in nucleus cuneiformis which represents a caudolateral extension of PAG. The physiological effects of CCK on PAG neurons were examined in both in vivo and in vitro preparations. In the in vivo experiments multibarreled electrodes were used to record from PAG neurons and to apply CCK and the CCK antagonists, CR1409 and proglumide. Of 37 neurons recorded in vivo, CCK caused excitation in 25 cells, inhibited 7 cells and had no effect on 5 cells. The excitatory effect was blocked by CR1409 in 11/11 cells tested. Proglumide blocked the excitatory response of CCK in 12/14 cells. Proglumide blocked the inhibitory effect in 2 of 7 cells, but CR1409 had no effect on CCK-evoked inhibition in 7 cells tested. Extracellular, conventional intracellular and whole cell patch clamping procedures were used to study CCK actions in the in vitro slice preparation. In the extracellular recording experiments, responses of PAG cells to CCK were measured in slices that were maintained at 22 degrees C (room temperature) and at 32 degrees C. CCK excited 40/56, inhibited 7/56 and had no effect on 9/56 cells; excitatory responses were blocked by CR1409 in 32/36 cells and by proglumide in 25/27 cells tested. Inhibitory responses to CCK were unaffected by CR1409, but were blocked in 3/7 cells by proglumide. Conventional intracellular recordings were made from 13 cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Distribution of calcium binding protein mRNAs in rat cerebellar cortex

The distribution of three calcium binding protein mRNAs in the rat cerebellar cortex was investigated using alkaline phosphatase labelled specific antisense oligodeoxynucleotide probes. Calbindin D28k mRNA was detected in the Purkinje cells, parvalbumin mRNA was located in the Purkinje cells and also in basket/stellate cells of the molecular layer. Calretinin in contrast was found only in the granule cell layer. Use of multiple alkaline phosphatase (AP)-labelled oligodeoxynucleotides resulted in an increase in signal strength and reduced detection time with no increase in background staining indicating the utility of these enzyme labelled probes for non-isotopic in situ.

Coupled down-regulation of the RB retinoblastoma and c-myc genes antecedes cell differentiation: possible role of RB as a "status quo" gene

The ability of the well known morphogen, retinoic acid (RA), as well as 1,25-dihydroxy-vitamin D3 (VD), whose receptor complex binds a DNA consensus sequence related to that of the retinoic acid receptor, to regulate expression of the retinoblastoma (RB) tumor suppressor gene in a context of induced cell differentiation was characterized. HL-60 human promyelocytic leukemia cells were induced to undergo myeloid or monocytic terminal cell differentiation by these agents. To investigate the potential coupling between down-regulation of RB and c-myc oncogene expression with cell differentiation, dose response relationships for the induced down-regulation of RB and c-myc expression were compared with each other and with induced cell differentiation. The total amount of RB protein per cell increased as cells advanced through the cell cycle, but the amount of RB protein relative to the total cell mass remained approximately constant. Treated with RA or VD, an early progressive decrease in cellular content of the RB protein occurred in all cell cycle phases well before any cell cycle modulation or phenotypic differentiation. For a differentiation-defective variant HL-60 cell line, failure to differentiate was preceded by a failure to down-regulate cellular levels of the RB protein. In dose response experiments, progressively increasing RA or VD concentrations caused progressively greater reductions in RB as well as c-myc expression with an increasing fraction of cells terminally differentiating. For both RA and VD, the dose response relationships for reductions in RB and c-myc expression were similar suggesting that their down-regulation may be coupled. These observations are consistent with a model whereby RB expression acts as a cellular brake to sustain a developmentally ordained state of differentiation (i.e., preserve the "status quo"); and the down-regulation of heterogeneously distributed RB protein per cell below a threshold is part of the metabolic cascade culminating in terminal cell differentiation. Thus, RB may have a role in this developmental context.

Inducers of leukemic cell differentiation cause down-regulation of RB gene expression

Expression of the retinoblastoma (RB) tumor suppressor gene during cell differentiation induced by dimethyl sulfoxide or sodium butyrate was studied in HL-60 human promyelocytic leukemia cells. As cells progressed through the cell cycle, the amount of RB protein per cell increased with homeostasis maintained, so that the amount of RB protein relative to the total cell mass remained almost constant. Dimethyl sulfoxide was used to induce these promyelocytic leukemia cells to undergo terminal differentiation into mature myeloid cells. There was an early reduction in the RB protein expressed per cell. The reduction in expression was similar for cells in all cell cycle phases. There was also progressively reduced expression at later times as cells terminally differentiated. This was compared to the case in which sodium butyrate was used to induce the differentiation of HL-60 cells into mature monocytic cells. An early reduction in RB protein expression per cell also occurred. It occurred for cells in all cell cycle phases as well. Thus, the induced differentiation of HL-60 cells along either the myeloid or the monocytic differentiation lineage involves an early reduction in RB expression, which is common to both pathways. The reduction anteceded proliferative arrest or differentiation. In both cases, the final, resulting G0-differentiated cells had less RB protein per cell than the proliferating, immature, leukemic precursor cells.

Regulated expression of the RB "tumor suppressor gene" in normal lymphocyte mitogenesis: elevated expression in transformed leukocytes and role as a "status quo" gene

Expression of the RB retinoblastoma tumor suppressor gene product is regulated early during the stimulation of normal human peripheral blood lymphocytes, suggesting a regulatory role for the amount of this protein in mitogenesis of normal cells. When normal human peripheral blood lymphocytes were mitogenically stimulated with pokeweed mitogen, bivariate flow cytometric measurements of cellular DNA and RB protein content showed an early decrease in the amount of RB protein per cell, anteceding onset of S phase. A subsequent increase in the amount of RB protein per cell occurred with cell proliferation. Thus the amount of RB protein relative to the total cell mass underwent a biphasic response with mitogenesis. The resulting proliferating cells had a slightly elevated level of RB protein per cell compared to the unstimulated cells. Comparison of other proliferating leukocytes to normal lymphocytes showed that both EBV virally transformed lymphocytes and human promyelocytic leukemia cells (HL-60) had elevated levels of RB protein per cell compared to normal peripheral blood lymphocytes. Mitogenic stimulation or transformation by other means thus is associated with regulation of the amount of RB protein per cell, suggesting a regulatory role for the RB protein in normal cell growth control.

Cytomegalovirus testing: antibody determinations and virus cultures with recommendations for use

Human cytomegalovirus is a ubiquitous virus with the property of becoming latent in the immunocompetent host. It can also cause devastating infections in the immunocompromised patient. Several different assays are available to detect either cytomegalovirus antibodies or cytomegalovirus itself, five of which are used at the University of Wisconsin Hospitals and Clinics and the Wisconsin State Laboratory of Hygiene. The latex agglutination (LA) test is used to detect antibody positivity in transplant donors, transplant recipients, and others. The complement fixation (CF) test is used to detect seroconversion or reactivation of infection in the CMV positive host. The immunofluorescent antibody-IgM (IFA-IgM) test is used to diagnose infection in congenitally or neonatally infected infants. The "routine" CMV culture is the "gold standard" for the detection of the cytomegalovirus in patient secretions. The shell vial assay, a rapid method of detecting virus, is most useful when contemplating therapy for active CMV infection. The advantages and limitations, as well as the timing and appropriateness of each test, are reviewed.