Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Serum amylase and C-reactive protein in risk stratification of pancreas-specific complications after pancreaticoduodenectomy

Background

Pancreas-specific complications (PSCs), comprising postoperative pancreatic fistula, haemorrhage and intra-abdominal collections, are drivers of morbidity and mortality after pancreaticoduodenectomy (PD). A serum amylase concentration of 130 units/l or more on postoperative day (POD) 0 has been shown to be an objective surrogate of pancreatic texture, a determinant of PSCs. This study evaluated serial measurements of C-reactive protein (CRP) to refine PSC risk stratification.

Methods

Consecutive patients undergoing PD between 2008 and 2014, with vascular resection if required and without preoperative chemoradiotherapy, had serum investigations from the day before operation until discharge. Receiver operating characteristic (ROC) curve analysis was used to identify a threshold value of serum CRP with clinically relevant PSCs for up to 30 days after discharge as outcome measure.

Results

Of 230 patients, 95 (41·3 per cent) experienced a clinically relevant PSC. A serum CRP level of 180 mg/l or higher on POD 2 was associated with PSCs, prolonged critical care stay and relaparotomy (all P < 0·050). Patients with a serum amylase concentration of 130 units/l or more on POD 0 who developed a serum CRP level of at least 180 mg/l on POD 2 had a higher incidence of morbidity. Patients were stratified into high-, intermediate- and low-risk groups using these markers. The low-risk category was associated with a negative predictive value of 86·5 per cent for development of clinically relevant PSCs. There were no deaths among 52 patients in the low-risk group, but seven deaths among 79 (9 per cent) in the high-risk group.

Conclusion

A serum amylase level below 130 units/l on POD 0 combined with a serum CRP level under 180 mg/l on POD 2 constitutes a low-risk profile following PD, and may help identify patients suitable for early discharge.

Rome IV. Gallbladder and Sphincter of Oddi Disorders

The concept that motor disorders of the gallbladder, cystic duct and sphincter of Oddi can cause painful syndromes is attractive and popular, at least in the USA. However, the results of commonly performed ablative treatments (cholecystectomy and sphincterotomy) are not uniformly good. The predictive value of tests that are often used to diagnose dysfunction (dynamic gallbladder scintigraphy and sphincter manometry) is controversial. Evaluation and management of these patients is made difficult by the fluctuating symptoms and the placebo effect of invasive interventions. A recent stringent study has shown that sphincterotomy is no better than sham treatment in patients with post-cholecystectomy pain and little or no objective abnormalities on investigation, so that the old concept of sphincter of Oddi dysfunction (SOD) type III is discarded. ERCP approaches are no longer appropriate in that context. There is a pressing need for similar prospective studies to provide better guidance for clinicians dealing with these patients. We need to clarify the indications for cholecystectomy in patients with Functional Gallbladder Disorder (FGBD) and the relevance of sphincter dysfunction in patients with some evidence for biliary obstruction (previously SOD type II, now called "Functional Biliary Sphincter Disorder - FBSD") and with idiopathic acute recurrent pancreatitis.

Staged multidisciplinary step-up management for necrotizing pancreatitis

Background

Some 15 per cent of all patients with acute pancreatitis develop necrotizing pancreatitis, with potentially significant consequences for both patients and healthcare services.

Methods

This review summarizes the latest insights into the surgical and medical management of necrotizing pancreatitis. General management strategies for the treatment of complications are discussed in relation to the stage of the disease.

Results

Frequent clinical evaluation of the patient's condition remains paramount in the first 24–72 h of the disease. Liberal goal-directed fluid resuscitation and early enteral nutrition should be provided. Urgent endoscopic retrograde cholangiopancreatography is indicated when cholangitis is suspected, but it is unclear whether this is appropriate in patients with predicted severe biliary pancreatitis without cholangitis. Antibiotic prophylaxis does not prevent infection of necrosis and antibiotics are not indicated as part of initial management. Bacteriologically confirmed infections should receive targeted antibiotics. With the more conservative approach to necrotizing pancreatitis currently advocated, fine-needle aspiration culture of pancreatic or extrapancreatic necrosis will less often lead to a change in management and is therefore indicated less frequently. Optimal treatment of infected necrotizing pancreatitis consists of a staged multidisciplinary ‘step-up’ approach. The initial step is drainage, either percutaneous or transluminal, followed by surgical or endoscopic transluminal debridement only if needed. Debridement is delayed until the acute necrotic collection has become ‘walled-off’.

Conclusion

Outcome following necrotizing pancreatitis has improved substantially in recent years as a result of a shift from early surgical debridement to a staged, minimally invasive, multidisciplinary, step-up approach.

Exploiting inflammation for therapeutic gain in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy associated with <5% 5-year survival, in which standard chemotherapeutics have limited benefit. The disease is associated with significant intra- and peritumoral inflammation and failure of protective immunosurveillance. Indeed, inflammatory signals are implicated in both tumour initiation and tumour progression. The major pathways regulating PDAC-associated inflammation are now being explored. Activation of leukocytes, and upregulation of cytokine and chemokine signalling pathways, both have been shown to modulate PDAC progression. Therefore, targeting inflammatory pathways may be of benefit as part of a multi-target approach to PDAC therapy. This review explores the pathways known to modulate inflammation at different stages of tumour development, drawing conclusions on their potential as therapeutic targets in PDAC.

Investigation of immuno-regulatory mechanisms relating to poor surgical wound healing and breast cancer recurrence

Abstract #5045

Background: The factors leading to breast cancer recurrence are incompletely understood. We carried out a retrospective study of outcome for 1065 breast cancer patients for which we examined factors correlating with cancer recurrence. We found that infection of wounds after surgery for primary disease positively correlated with cancer recurrence (Murthy et al, BJC 2007). Patients with wound complications were 3 fold more likely to have systemic recurrences than those without (p&lt;0.0001). The aim of our study is to determine mechanisms responsible for this correlation. Our approach is based on two possible theories. First, patients may have an underlying immune dysfunction that predisposes them to developing both wound complications and also recurrence. Secondly, factors released at sites of wound complications may have direct influences on the remaining occult tumour cells, thereby increasing the likelihood of metastases.&#x2028; Methods: Patients with primary operable breast cancer were recruited prospectively. Blood was collected from patients pre-operatively, 4 and 16h post-operatively and again at 2 weeks, 3 and 6 months post-operatively. A variety of investigations were carried out on each sample to establish the immune status of the patient at that time point, and to identify potential mediators of cross talk between the immune system, the wound and any occult tumour cells. These investigations include: a) Full blood count; b) Immune cell phenotyping (absolute numbers/frequency of B, T lymphocytes and Natural Killer (NK) cell sub-types using multi-colour flow-cytometry); c) Cytokine profiling (using fluid phase cytometric multiplex immunoassays for 27 critical cytokines). Patients were followed up post-operatively for wound complications.&#x2028; Results:&#x2028; In our cohort of 57 patients, those who underwent a mastectomy were four times more likely to develop a post-operative wound infection than those who had breast conserving surgery (p=0.022). There was no significant difference in pre-operative absolute numbers of B and T lymphocytes or NK cells between the two groups. The percentage drop in absolute numbers of NK cells at 4 hours post-operatively was greater in the mastectomy group than in patients having breast conserving surgery (p=0.008). Mastectomy patients also dropped their CD45 counts by a significantly greater percentage (p=0.024). No significant difference was noted in the CD3, CD4, CD8 and CD19 counts between the two groups. Patients who developed wound infections showed peaks in levels of either Interleukin 5 or Interleukin 6.&#x2028; Conclusion&#x2028; Disruption of immune mechanisms as a result of increased surgical stresses in mastectomy patients contributes to a higher rate of wound complications. This may also provide a window of opportunity for the dissemination of tumour cells with their latent potential for reactivation and the development of metastases.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5045.

A randomized study of early nasogastric versus nasojejunal feeding in severe acute pancreatitis

BACKGROUND

After 50 yr in which nasoenteric feeding was considered contraindicated in acute pancreatitis (AP), several clinical studies have shown that early nasojejunal (NJ) feeding can be achieved in most patients. A pilot study of early nasogastric (NG) feeding in patients with objectively graded severe AP proved that this approach was also feasible. A randomized study comparing NG versus NJ feeding has been performed.

METHODS

A total of 50 consecutive patients with objectively graded severe AP were randomized to receive either NG or NJ feeding via a fine bore feeding tube. The end points were markers of the acute phase response APACHE II scores and C-reactive protein (CRP) measurements, and pain patterns by visual analogue score (VAS) and analgesic requirements. Complications were monitored and comparisons made of both total hospital and intensive-care stays.

RESULTS

A total of 27 patients were randomized to NG feeding and 23 to NJ. One of those in the NJ group had a false diagnosis, thereby reducing the number to 22. Demographics were similar between the groups and no significant differences were found between the groups in APACHE II score, CRP measurement, VAS, or analgesic requirement. Clinical differences between the two groups were not significant. Overall mortality was 24.5% with five deaths in the NG group and seven in the NJ group.

CONCLUSIONS

The simpler, cheaper, and more easily used NG feeding is as good as NJ feeding in patients with objectively graded severe AP. This appears to be a useful and practical therapeutic approach to enteral feeding in the early management of patients with severe AP.

Measurement of Vitamin D metabolites: an international perspective on methodology and clinical interpretation

The International Quality Assessment Scheme for Vitamin D metabolites (DEQAS) was introduced in 1989. Initially, the aim was to improve the reliability of 25-hydroxyvitamin D (25-OHD) assays but the scheme was extended in 1997 to include 1,25-dihydroxyvitamin D (1,25(OH)(2)D). DEQAS has 95 members in 18 countries (January 2003). Five serum samples are distributed quarterly and participants are given up to 6 weeks to return their results for statistical analysis. The majority of participants use commercial kits for both analytes. A performance target was set by an advisory panel in 1997 and, at present, requires participants to get 80% or more of their results within +/-30% of the All-Laboratory Trimmed Mean (ALTM). The performance targets are under continual review. In 2003, 59% of participants met the target (cf. 52% in 2000). A questionnaire, distributed in January 2003, requested information on methods and the interpretation of results. Reference ranges varied but there was reasonable agreement on the 25-OHD concentrations below which Vitamin D supplementation was advised. A minority (22%) of respondents was unsure whether Vitamin D(3) or Vitamin D(2) was used to treat patients in their locality. The majority (52%) of assays for 1,25(OH)(2)D were done 'on demand' and others for apparently spurious reasons. Most respondents thought participation in DEQAS extremely important and the planned introduction of on-line reporting should enhance its value.

Dynamic nature of early organ dysfunction determines outcome in acute pancreatitis

BACKGROUND

All patients with organ dysfunction are currently classified as having severe acute pancreatitis. The aim of this study was to characterize the systemic inflammatory response syndrome (SIRS) and early organ dysfunction in patients with acute pancreatitis and the relationship with overall mortality.

METHODS

Patients with predicted severe acute pancreatitis of less than 48 h duration had daily organ dysfunction scores and SIRS criteria calculated. These features were then correlated with outcome.

RESULTS

Of 121 patients, 68 (56 per cent) did not develop organ dysfunction; only two of these patients died (mortality rate 3 per cent). Fifty-three (44 per cent) had early organ dysfunction, of whom 11 died (21 per cent). Organ dysfunction and persistent SIRS were both associated with an increased mortality rate, but on multivariate analysis only deteriorating organ dysfunction was an independent determinant of survival.

CONCLUSION

Early organ dysfunction in acute pancreatitis usually resolves and in itself has no significant influence on mortality. In contrast, worsening organ dysfunction was associated with death in more than half of the patients (11 of 20); it is this group of patients who should be classified as having severe acute pancreatitis.

Mutational analysis and clinical correlation in Leber congenital amaurosis

Leber congenital amaurosis (LCA, MIM 204001) is a clinically and genetically heterogeneous retinal disorder characterized by severe visual loss from birth, nystagmus, poor pupillary reflexes, retinal pigmentary or atrophic changes, and a markedly diminished electroretinogram (ERG).

PURPOSE

To examine 100 consecutive patients with LCA in order to assess the relative burden of the three known genes involved in LCA, namely retinal guanylyl cyclase (GUCY2D), retinal pigment epithelium protein ( RPE65), and the cone-rod homeobox (CRX), and to define their clinical correlates.

METHODS

Mutational analysis and detailed clinical examinations were performed in patients diagnosed with LCA at the Johns Hopkins Center for Hereditary Eye Diseases and the Montreal Children's Hospital.

RESULTS

Mutations were identified in 11% of our patients: GUCY2D mutations accounted for 6%, while RPE65 and CRX gene mutations accounted for 3% and 2%, respectively. The clinical presentation was variable; however, the visual evolution in patients with mutations in GUCY2D and CRX remained stable, while individuals with mutations in the RPE65 gene showed progressive visual loss.

CONCLUSIONS

This study suggests that molecular diagnosis of Leber congenital amaurosis could provide important information concerning prognosis and course of treatment.

Percutaneous necrosectomy and sinus tract endoscopy in the management of infected pancreatic necrosis: an initial experience

OBJECTIVE

To describe the development of a minimally invasive technique aimed at surgical debridement in addition to simple drainage of the abscess cavity.

SUMMARY BACKGROUND DATA

Surgical intervention for secondary infection of pancreatic necrosis is associated with a death rate of 25% to 40%. Although percutaneous approaches may drain the abscess, they have often failed in the long term as a result of inability to remove the necrotic material adequately.

METHODS

Fourteen consecutive patients with infected necrosis secondary to acute pancreatitis were studied. The initial four patients underwent sinus tract endoscopy along a drainage tract for secondary sepsis after prior open necrosectomy. This technique was then modified to allow primary debridement for proven sepsis to be carried out percutaneously in a further 10 patients. The techniques and initial results are described.

RESULTS

Additional surgery for sepsis was successfully avoided in the initial four patients managed by sinus tract endoscopy, and none died. Of the following 10 patients managed by percutaneous necrosectomy, 2 died. The median inpatient stay was 42 days. There was one conversion for intraoperative bleeding. Eight patients recovered and were discharged from the hospital after a median of three percutaneous explorations. Only 40% of patients required intensive care management after surgery.

CONCLUSIONS

These initial results in an unselected group of patients are encouraging and show that unlike with percutaneous or endoscopic techniques, both resolution of sepsis and adequate necrosectomy can be achieved. The authors' initial impression of a reduction in postoperative organ dysfunction is particularly interesting; however, the technique requires further evaluation in a larger prospective series.

Diagnosis of chronic pancreatitis and newer aspects of pain control

The diagnosis of chronic pancreatitis in the UK largely rests on the combination of the clinical presentation which usually features pain which is often provoked by food and/or alcohol. There is usually a 30 to 40-min delay between the stimulus and the pain and, after exclusion of other causes of pain, an ERCP is performed. A minority of patients will have pancreatic function tests carried out while increasingly the diagnosis is being made by MR scanning. The control of pain is often the most important aspect of management to the patient. In those with large ducts due to compression of focal areas of the duct system surgical by-pass therapy is indicated. There is a bigger problem in patients with small ducts and chronic pancreatitis in whom extensive resection may be inappropriate. Our experience with minimally invasive thoracoscopic splanchnicectomy has been encouraging over the last three years. Having previously tried both percutaneous coeliac ganglion block and surgical excision of this nerve tissue, it is a great deal easier to carry out this procedure which usually takes only 15-20 min per side. Patients are usually only admitted for 48 h and the immediate beneficial effect usually results in opiate analgesia being discontinued with considerable improvement in the quality of life. While there is a slight drop-off in benefit between 6 and 12 months post-operatively, the clinical effectiveness of this approach is to be commended and the author's experience will be presented to support this view.

Effectiveness of screening instruments in detecting substance use disorders among prisoners

This study examined the effectiveness of several screening instruments in detecting substance use disorders among prison inmates. A sample of 400 male inmates were administered eight different substance abuse screening instruments and the Structured Clinical Interview for DSM-IV (SCID-IV), Version 2.0, Substance Abuse Disorders module. The latter was used as a diagnostic criterion measure to determine the presence of substance use disorders. Based on positive predictive value, sensitivity, and overall accuracy, the Texas Christian University Drug Screen, the Simple Screening Instrument, and a combined instrument-Alcohol Dependence Scale/Addiction Severity Index-Drug Use section were found to be the most effective in identifying substance abuse and dependence disorders.

High early mortality rate from acute pancreatitis in Scotland, 1984-1995

BACKGROUND

Death from acute pancreatitis within the first week after admission is usually a consequence of multiple organ dysfunction. Reports from specialist centres suggest that, with improvements in resuscitation and supportive care, such deaths are becoming uncommon but it is unclear if this is reflected in a decrease in early mortality rate from acute pancreatitis in the general population.

METHODS

Data concerning patients discharged with a diagnosis of acute pancreatitis (International Classification of Disease-9 code 577.0) between 1984 and 1995 were obtained from the Information and Statistics Division, National Health Service in Scotland, and analysed on a computer database.

RESULTS

The incidence of acute pancreatitis in Scotland continues to increase in both sexes. The in-hospital mortality rate (death from all causes) was 7.5 per cent and showed a slight but significant downward trend over the period of study. Death within 7 days of hospital admission accounted for 53.7 per cent of all deaths and the proportion of early deaths did not decline over the study interval.

CONCLUSION

These results suggest that scope remains for considerable improvement in the early management of acute pancreatitis. There is an urgent need to improve the early recognition of severe pancreatitis coupled to a willingness on behalf of clinicians to transfer these patients at an early stage to a centre with high-dependency and intensive care facilities supervised by a multidisciplinary team with expertise in the endoscopic, radiological and surgical management of these patients.

Prevalence of DSM-IV substance abuse and dependence disorders among prison inmates

The study examined the 30-day and lifetime prevalence of DSM-IV alcohol and drug disorders among state prison inmates. A sample of 400 inmates consecutively admitted to a state prison reception center were assessed for alcohol and drug disorders using the Structured Clinical Interview for DSM-IV (SCID-IV). Test-retest reliabilities were calculated for the SCID-IV. Lifetime substance abuse or dependence disorders were detected among 74% of inmates, including over half who were dependent on alcohol or drugs. For the 30 days prior to incarceration, over half of the sample were diagnosed as having substance abuse or dependence disorders, including 46% who were dependent on alcohol or drugs. Black inmates were significantly less likely to be diagnosed as alcohol dependent than whites or Hispanics. The high rates of substance use disorders are consistent with previous findings from other studies conducted in correctional settings and reflect the need to expand treatment capacity in prisons.

The combination of laser recanalization and endoluminal intubation in the palliation of malignant dysphagia

Laser recanalization and endoluminal intubation have been combined to optimize the palliation of malignant dysphagia in 37 patients. Nine patients with an endoluminal tube in situ presented with secondary dysphagia due to tumour overgrowth. Patency of the prosthesis was restored in all patients by laser recanalization with no complications. Twenty-eight patients treated initially by laser recanalization required subsequent intubation. The indications were dysphagia secondary to external compression (n = 3), significant angulation (n = 9), tracheo-oesophageal fistula (n = 3), failure of laser recanalization (n = 8), poor palliation (n = 3) or a combination of these (n = 2). There were no complications associated with the insertion of the tube and all patients subsequently reported improved swallowing. Laser recanalization or endoluminal intubation in isolation provide adequate palliation in the majority of patients with malignant dysphagia. We have shown that the appropriate timed combination of these two modalities may optimize the palliation of dysphagia in patients in whom the primary treatment modality fails.

Prospective comparison of laparoscopy, ultrasonography and computed tomography in the staging of gastric cancer

A total of 103 consecutive patients with gastric adenocarcinoma was assessed for intra-abdominal spread of malignancy using ultrasonography, computed tomography (CT) and laparoscopy under general anaesthesia. Histologically proven metastases were to the liver in 27 patients, lymph nodes in 49 and directly to peritoneum in 13. All modalities showed a high specificity (92-100 per cent) for each type of metastasis. Laparoscopy was more sensitive in detecting hepatic, nodal and peritoneal metastases; the relative performance of laparoscopy was best with regard to hepatic metastases. Ultrasonography and CT were particularly poor at detecting nodal and peritoneal metastases. There was no significant morbidity and no mortality associated with laparoscopy, which was more accurate in preoperative staging of gastric cancer than ultrasonography or CT.

Generation of antigenic peptides by lymphocyte granule serine proteases (granzymes)

We have examined the ability of several serine proteases (granzymes) isolated from the granules of the rat natural killer cell line, RNK, to generate antigenic peptides of ovalbumin (Ova) that are capable of being recognized by Ova-specific CD8+ T cells. The mouse MHC class I-restricted cytotoxic T-cell clone, GX-1, which recognizes a trypsinized fragment of Ova in the context of H-2b, was able to lyse EL4 (H-2b) target cells in the presence of Ova and the granzymes but not in the presence of Ova or granzymes alone. Similar results were obtained using the murine Ova-specific CD8+ T cell hybridomas, RF33.70 and CD8OVA. In all cases, the T cells' responses were MHC class I-restricted as Ova:granzyme mixtures failed to mediate the lysis of the MHC-disparate target cell, P815 (H-2d). The purified rat granzyme preparations contained three distinct enzymatic specificities: asp-ase met-ase, and tryptase. Aprotinin, a protease inhibitor that only inhibits tryptase activity in vitro, completely abolished the CD8+ T-cell responses to Ova. These results, along with peptide loading studies using the RMA-S cell line, suggest that the granzyme treatment of Ova can generate the proper antigenic fragments which facilitate class I-restricted CTL responses both in vivo and in vitro. We believe that enzymes produced and released by NK or cytotoxic T cells within a tissue microenvironment may enhance the cleavage of target cell antigens as well as soluble antigens resulting in the improved uptake and processing of soluble antigens.

Cloning and expression of a second human natural killer cell granule tryptase, HNK-Tryp-2/granzyme 3

Cytotoxic lymphocytes possess a number of serine proteases (granzymes) usually localized in cytoplasmic granules. To date, the DNA sequences of four human granzymes have been reported. A fifth human granzyme (granzyme 3) has been biochemically purified and its N-terminal amino acid sequence has been reported. This enzyme was described as possessing tryptase activity, cleaving synthetic substrates after arginine or lysine. We recently cloned a rat granzyme tryptase (RNK-Tryp-2), and used this cDNA to screen human cDNA libraries. Isolation of cDNA fragments of a human gene could be overlapped to provide a complete cDNA sequence, which we designated HNK-Tryp-2. The N-terminal amino acid sequence deduced from HNK-Tryp-2 was identical to that reported for granzyme 3. This gene appears to be a single copy gene that is expressed in isolated natural killer cells and T cells as well as in tissues containing these cells.

Indium-111 leucocyte scintigraphy and ultrasound scanning in the detection of intra-abdominal abscesses in patients without localizing signs

The clinical records of 45 patients with suspected intra-abdominal sepsis but without localizing abdominal signs were retrospectively reviewed. All had undergone both indium-111 leucocyte scintigraphy and real time ultrasound. Twenty-two of the 45 patients were subsequently shown to have intra-abdominal abscesses. Twenty-one patients were identified correctly by indium-111 scintigraphy (sensitivity 95%) and 10 by ultrasound (US: sensitivity 45%). There were two false positive scintiscans (specificity 91%) but no false positive US scans (specificity 100%). There was no correlation between the peripheral white cell count and the presence of absence of an abscess or the likelihood of obtaining a positive scintiscan result. Because of the excellent specificity ultrasound scanning should remain the initial investigations in this group of critically ill patients with indium-111 scintigraphy being used to clarify the US findings or in US negative patients.

Alpha and beta chemokines induce NK cell migration and enhance NK-mediated cytolysis

Chemokines have been shown to play an important role in both the adhesion and migration of numerous leukocytic cell types, including granulocytes, monocytes, mast cells, and T lymphocytes. However, the biologic effects of chemokines on NK cells remain to be defined. Chemotaxis studies using purified human NK cells and a panel of human recombinant chemokines revealed that macrophage inflammatory protein (MIP)-1 alpha and IFN-inducible protein-10 (IP-10) are potent NK cell chemoattractants in vitro. Modest but significant chemotactic (not chemokinetic) responses were also observed in response to RANTES, MCP-1, MCP-2, MCP-3, and MIP-1 beta. Chemokine receptor expression on human NK cells was determined through displacement and Scatchard analyses, using a panel of radiolabeled chemokines, and revealed the presence of both distinct and shared chemokine receptors with affinities similar to those previously described for other cell types. Functional studies have also revealed that the beta chemokines and IP-10 are capable of augmenting NK- but not LAK- or ADCC-specific cytolytic responses in both a dose- and donor-dependent fashion. Neutralization analysis using Abs specific for various adhesion molecules revealed that NK:tumor cell conjugate formation is required for chemokine-induced NK killing. In addition, NK cells incubated in the presence of beta chemokines and IP-10 for 4 h induced the release of granule-derived serine esterases, suggesting a possible mechanism for chemokine-mediated NK killing. These results suggest that chemokines not only play an important role in the recruitment of NK cells, but also may be important mediators of NK cell degranulation augmenting local tumor cell destruction.

Alpha and beta chemokines induce NK cell migration and enhance NK-mediated cytolysis

Chemokines have been shown to play an important role in both the adhesion and migration of numerous leukocytic cell types, including granulocytes, monocytes, mast cells, and T lymphocytes. However, the biologic effects of chemokines on NK cells remain to be defined. Chemotaxis studies using purified human NK cells and a panel of human recombinant chemokines revealed that macrophage inflammatory protein (MIP)-1 alpha and IFN-inducible protein-10 (IP-10) are potent NK cell chemoattractants in vitro. Modest but significant chemotactic (not chemokinetic) responses were also observed in response to RANTES, MCP-1, MCP-2, MCP-3, and MIP-1 beta. Chemokine receptor expression on human NK cells was determined through displacement and Scatchard analyses, using a panel of radiolabeled chemokines, and revealed the presence of both distinct and shared chemokine receptors with affinities similar to those previously described for other cell types. Functional studies have also revealed that the beta chemokines and IP-10 are capable of augmenting NK- but not LAK- or ADCC-specific cytolytic responses in both a dose- and donor-dependent fashion. Neutralization analysis using Abs specific for various adhesion molecules revealed that NK:tumor cell conjugate formation is required for chemokine-induced NK killing. In addition, NK cells incubated in the presence of beta chemokines and IP-10 for 4 h induced the release of granule-derived serine esterases, suggesting a possible mechanism for chemokine-mediated NK killing. These results suggest that chemokines not only play an important role in the recruitment of NK cells, but also may be important mediators of NK cell degranulation augmenting local tumor cell destruction.

Partial degradation of T-cell signal transduction molecules by contaminating granulocytes during protein extraction of splenic T cells from tumor-bearing mice

Flavone-8-acetic acid plus recombinant human interleukin 2 is a successful antitumor therapy in mice bearing the Renca murine renal cell carcinoma. This report demonstrates that T cells, particularly CD8+ T cells, are critical for the generation of this response. Initial experiments examining T-cell signal transduction proteins demonstrated that T cells from Renca-bearing mice had undetectable levels of p56lck and zeta-chain of the T-cell receptor and that flavone-8-acetic acid and recombinant human interleukin 2 therapy could be used as a model for reversal of these alterations. However, further experimentation showed that the majority of the reduction in zeta-chain and part of the reduction in p56lck was due to degradation of these molecules during protein extraction caused by mature granulocytes contaminating the enriched T-cell population. This was not the case for nuclear c-Rel or NF kappa B p65, which remained at undetectable/reduced levels in the absence of granulocytes, confirming our previous data that transcription factor alterations exist in tumor-bearing mice. Thus, most of the reduction in zeta-chain in T cells from Renca-bearing mice is due to granulocyte contamination and emphasizes the need to use pure T-cell populations and/or sufficient amounts and types of protease inhibitors when quantitating proteins in T cells from tumor-bearing mice.

Cloning and characterization of a novel NK cell-specific serine protease gene and its functional 5'-flanking sequences

Rat natural killer cell Met-ase-1 (RNK-Met-1) is a 30,000 M(r) serine protease (granzyme) found in the cytolytic granules of CD3- large granular lymphocytes (LGL) with natural killer (NK) activity. To characterize the genomic sequences responsible for the CD3- LGL-restricted expression of this gene, we screened a rat genomic library with RNK-Met-1 cDNA, and obtained bacteriophage clones that contained the RNK-Met-1 gene. The RNK-Met-1 gene comprises 5 exons and spans approximately 5.2 kilobases (kb), exhibiting a similar structural organization to a class of CTL-serine proteases with protease catalytic residues encoded near the borders of exons 2, 3, and 5. The 5'-flanking region of the RNK-Met-1 gene contains a number of putative promoter and enhancer regulatory elements and shares several regions of homology with the 5'-flanking region of the mouse perforin gene. We have prepared nested deletions from approximately 3.3 kb of the 5'-flanking region of the RNK-Met-1 gene, and inserted these upstream of the chloramphenicol acetyltransferase (CAT) reporter gene. These 5'-flanking RNK-Met-1-CAT constructs were transiently transfected into rat LGL leukemia, T-lymphoma, and basophilic leukemia cell lines. The transcriptional activity of the RNK-Met-1 5'-flanking region was strong, restricted to the RNK-16 LGL leukemia and controlled by several positive cis-acting regions spread over at least 3.3 kb. The longest and most active 5'-flanking region (-3341 to -33) was also used to drive specific expression of beta-galactosidase in RNK-16. These data are consistent with the NK cell-specific expression of RNK-Met-1 and suggest the potential utility of this gene promoter in the development of transgene models of NK cell biology in vivo.

Endoscopic laser treatment of diffuse gastric antral vascular ectasia

Eight patients (six women and two men) were found to have iron deficiency anaemia due to diffuse gastric antral vascular ectasia. The mean age of the patients was 74.6 years (range 57-83). All required repeated blood transfusions (mean 18 units/year) before treatment. Five patients were classified as having the 'watermelon stomach' (group A) and three the 'honeycomb stomach' (group B), according to criteria described in previous reports. All were treated using neodymium:YAG laser photocoagulation. Significant endoscopic improvement and reduction in blood requirements were noticed in group A in which only one patient required a transfusion after treatment. Results in group B were disappointing. One patient was operated on and the other two still require blood transfusions. Laser treatment was safe in both groups and no major complications were encountered.

Classification of impulse radar waveforms using neural networks

In this paper, it is demonstrated that multilayer neural networks, trained with the backpropagation algorithm and radial basis functions, can classify impulse radar waveforms from three different asphalt-covered bridge decks, each with its own structure. It might be thought that the thickness of asphalt and the depth of concrete over the reinforcing bars would be nearly constant for any one bridge deck; however in practice this is not the case. There are often significant changes in the thickness of the asphalt and the cover over reinforcement. Furthermore, a certain amount of damage to the concrete caused by severe winter climate often produces a random variation in the reflected waveforms obtained from different locations. These factors lead to a significant number of combinations of waveforms that can be obtained from any given structural type of deck. The classification accuracies achieved ranged between 89.9% and 100%. The accuracies achieved after using principal components analysis to reduce the dimensionality of the input data ranged between 95.6% and 100%.

Goals and Strategies for Aboriginal Cattle Enterprises

In recent years Aboriginal people have regained ownership of large areas of rangeland, and in many cases are considering pastoral enterprises in their move towards self-sufficiency. New developments in research and extension must be made accessible to them. Rangeland researchers have recognised the need to focus much more on integrating scientific results with a better social understanding of managers' goals. Recent research indicates that goals and strategies in the commercial industry are often neither optimal nor singular. This applies particularly to Aboriginal communities; these have an even broader range of land use goals relating to traditional and non-traditional elements, the latter stemming partly from the introduced pastoral industry. Past assessments of Aboriginal pastoral projects have paid scant attention to identifying Aboriginal management goals and considering how they may interact with the project or conflict with each other. Attitudes to risk and production stability have rarely been determined, and consequently the impact of climatic variability has not been adequately considered. This has lead to the imposition of inappropriate management strategies and an over-optimistic view of potential returns. Based on goals that Aboriginal communities may have, this paper shows in principle how a pastoral enterprise study could take account of climatic variability in assessing stability and risk. One major set of alternative management strategies has been modelled with RANGEPACK Herd-Econ. This highlights certain features of low stocking approaches which may be lower in risk, more stable in turn-off, and more compatible with other Aboriginal community goals. Assessment of Aboriginal pastoral projects should place more emphasis on identifying what the goals of the communities and managers really are, how these goals interact, and consequently what form of enterprise is most appropriate. Some important points for the assessment of options are suggested. Some case studies need to be undertaken to document the interaction between community aspirations and a range of enterprise types, and hence to evaluate the potential effectiveness of these approaches to assessment.

The augmentation of lymphokine-activated killer activity following pulsing of human peripheral blood mononuclear cells with recombinant human interleukin-2

The short-term exposure of peripheral blood mononuclear cells (PBMC) to recombinant human interleukin-2 (rhIL-2) at 37 degrees C leads to the generation of lymphokine-activated killer (LAK) activity similar in magnitude to that obtained by the exposure of PBMC to rhIL-2 continuously for 3-5 days. In order to investigate whether the required signal for LAK induction occurred during the short exposure to rhIL-2 or at a later point in the induction phase, PBMC were exposed to rhIL-2 for 1 h at 4 degrees C and then exposed to a low-pH wash to remove bound IL-2 from its receptor. PBMC treated in such a way showed increased LAK activity and proliferation compared to cells exposed to rhIL-2 alone. Expression of the p55 (alpha) subunit of the IL-2 receptor was also increased. In order to cause the augmentation, a lowering of the pH below 4.0 was necessary, and exposure of PBMC to low pH alone (in the absence of rhIL-2) failed to cause activation. Another relevant feature was a transient increase in the expression of the p75 subunit of the IL-2 receptor (beta chain) immediately following the exposure to low pH and the release of interferon gamma, tumour necrosis factor alpha and IL-6; activation was blocked by the inclusion of neutralising antisera raised against rhIL-2 and interferon gamma, thus demonstrating that the endogenous release of these cytokines is important for activation.

A Pleuropneumonia-like Organism Associated with Infectious Atrophic Rhinitis of Swine

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