Dipeptidyl Peptidase-4 Inhibitors in Chronic Kidney Disease: A Systematic Review of Randomized Clinical Trials

BACKGROUND

Chronic kidney disease (CKD) is common in patients with type 2 diabetes mellitus (T2DM) and limits therapeutic options. Dipeptidyl peptidase-4 (DPP-4) inhibitors represent a novel class of oral glucose-lowering agents and are known to be safe and effective in the general population.

METHODS

We searched Cochrane, EMBASE, and PubMed from the time of their inception until March 2015. We included randomized controlled trials analyzing the efficacy (change in hemoglobin A1C [HbA1C]) and safety of DPP-4 agents in individuals with reduced kidney function (estimated glomerular filtration rate <60 mL/min/1.73 m2). We extracted study characteristics, participants' baseline characteristics, and safety outcomes from eligible studies. We performed a random effects meta-analysis to summarize the change in HbA1C and the relative risk of cardiovascular events in patients with T2DM and CKD. We also collected data on hypoglycemia, other serious adverse events, and mortality.

RESULTS

We reviewed 12 studies with 4,403 patients with CKD and 239 on dialysis, finding a mean weighted decline in HbA1C of -0.48 (95% CI -0.61 to -0.35) with DPP-4 inhibitor therapy compared to placebo. DPP-4 inhibitors did not result in any additional adverse events, hypoglycemic episodes, or increased mortality. Restricting to studies with low risk of bias did not alter these findings.

CONCLUSIONS

DPP-4 inhibitors can lower HbA1C without increasing the risk of cardiovascular or other major adverse events in patients with CKD. Few studies reported critical adverse events such as heart failure and hypersensitivity. If compared with other oral antiglycemic drugs, the effect of DPP-4 inhibitors is limited; however, their low risk of hypoglycemia may favor their use in patients with CKD.

SUMMARY

This systematic review of DPP-4 inhibitors in CKD suggests that they reduce HbA1C by about 0.5%. Furthermore, there was not any increase in the risk for significant adverse events. More research is needed to determine the safety and efficacy of DPP-4 inhibitors in CKD.

An International Appraisal of the Minimum Duration of Chronic Animal Toxicity Studies

1 There are international differences in regulatory guidelines for the appropriate duration of chronic, two species repeat-dose animal tests for new medicines intended for long-term use in man, ranging from 6 months in Europe to 12 months in Japan and the USA.1

2 An adequate data base is necessary to support any challenge to the scientific rationale behind regulatory guidelines with regard to the design, duration and relevance of toxicity tests of new medicines.

3 The Centre for Medicines Research has established an international toxicology data base which has been expanded to enable a comparison of data obtained within 6 months, with information from longer periods, for 154 studies.

4 Although new findings were revealed after 6 months for 9/75 cases for which pathology data are available at 6 and 12 months or longer, and 21/80 with data at 1 or 3 (but not 6 months) and 12 months or longer, in no instance did these influence the decision to drop or further develop the compounds in question.

5 These data suggest that a 6-month period of dosing is all that is routinely required for evaluating the chronic toxic (excluding carcinogenic) potential of a new chemical entity intended for therapeutic use.

Frailty and physical function in chronic kidney disease: the CanFIT study

Background

Frailty, a manifestation of unsuccessful aging, is highly prevalent in people with chronic kidney disease (CKD) and is associated with comorbid conditions in cross-sectional studies. Longitudinal studies investigating the progression of frailty in those with advanced non-dialysis CKD are lacking.

Objectives

Canadian Frailty Observation and Interventions Trial (CanFIT). To determine the natural history, prevalence of perceived and measured frailty and its association with dialysis treatment choices and adverse outcomes in patients with advanced CKD.

Design

Longitudinal observational study, designed to collect data from 600 participants over 2 years.

Setting

Interprofessional non-dialysis CKD clinics at four tertiary health care centres in central Canada.

Patients

People with CKD stage 4 and 5 (eGFR <30 ml/min/1.73 m²) who are not on dialysis at enrollment.

Measurements

Multiple Frailty Definitions: Short Physical Performance Battery (SPPB), Fried Frailty Criteria, Frailty Index. Dialysis start: In-Centre Hemodialysis, Home Hemodialysis or Peritoneal Dialysis Outcomes: Death, Opt-out or Lost to follow up.

Methods

We will perform physical and cognitive assessments annually. We plan to analyze the relationships between frailty, treatment choices and patient centered outcomes.

Results

We have recruited 217 participants in 2 centres; of these, 56 % had reduced physical function at baseline, as defined by the SPPB. Risk of reduced physical function was 8 fold higher in those with diabetes after adjusting for age, gender, eGFR and comorbidities.

Limitations

Referred population, use of SPPB as a measure of frailty, inter-operator variability in measurement of hand grip and gait speed, cross-sectional analysis of baseline data in the subset recruited to date.

Conclusions

People with advanced CKD have a high burden of reduced physical function, especially those with diabetes. We will continue enrollment into the CanFIT study to further understand the clinical history of CKD and frailty in this population.

An Economic Assessment Model of Rural and Remote Satellite Hemodialysis Units

BACKGROUND

Kidney Failure is epidemic in many remote communities in Canada. In-centre hemodialysis is provided within these settings in satellite hemodialysis units. The key cost drivers of this program have not been fully described. Such information is important in informing the design of programs aimed at optimizing efficiency in providing dialysis and preventative chronic kidney disease care in remote communities.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

We constructed a cost model based on data derived from 16 of Manitoba, Canada's remote satellite units. We included all costs for operation of the unit, transportation, treatment, and capital costs. All costs were presented in 2013 Canadian dollars.

RESULTS

The annual per-patient cost of providing hemodialysis in the satellite units ranged from $80,372 to $215,918 per patient, per year. The median per patient, per year cost was $99,888 (IQR $89,057-$122,640). Primary cost drivers were capital costs related to construction, human resource expenses, and expenses for return to tertiary care centres for health care. Costs related to transport considerably increased estimates in units that required plane or helicopter transfers.

CONCLUSIONS

Satellite hemodialysis units in remote areas are more expensive on a per-patient basis than hospital hemodialysis and satellite hemodialysis available in urban areas. In some rural, remote locations, better value for money may reside in local surveillance and prevention programs in addition support for home dialysis therapies over construction of new satellite hemodialysis units.

Chronic kidney disease, frailty, and unsuccessful aging: a review

The global prevalence of chronic kidney disease (CKD) is rising, particularly among the elderly population. Defining aging as successful or unsuccessful has become clinically relevant in the last 15 years, with an increased recognition of the frail phenotype. Frailty has been shown to be associated with CKD and poorer outcomes, such as death or dialysis. It is likely that the mechanisms of disease in CKD such as altered protein metabolism, inflammation, oxidative stress, and anemia accelerate normal aging and lead to worsening frailty in elderly patients with CKD.

Association of frailty and physical function in patients with non-dialysis CKD: a systematic review

Background

Frailty is a condition characterized by a decline in physical function and functional capacity. Common symptoms of frailty, such as weakness and exhaustion, are prevalent in patients with chronic kidney disease (CKD). The increased vulnerability of frail patients with coexisting CKD may place them at a heightened risk of encountering additional health complications. The purpose of this systematic review was to explore the link between frailty, CKD and clinical outcomes.

Methods

We searched for cross sectional and prospective studies in the general population and in the CKD population indexed in EMBASE, Pubmed, Web of Science, CINAHL, Cochrane and Ageline examining the association between frailty and CKD and those relating frailty in patients with CKD to clinical outcomes.

Results

We screened 5,066 abstracts and retrieved 108 studies for full text review. We identified 7 studies associating frailty or physical function to CKD. From the 7 studies, we identified only two studies that related frailty in patients with CKD to a clinical outcome. CKD was consistently associated with increasing frailty or reduced physical function [odds ratios (OR) 1.30 to 3.12]. In patients with CKD, frailty was associated with a greater than two-fold higher risk of dialysis and/or death [OR from 2.0 to 5.88].

Conclusions

CKD is associated with a higher risk of frailty or diminished physical function. Furthermore, the presence of frailty in patients with CKD may lead to a higher risk of mortality. Further research must be conducted to understand the mechanisms of frailty in CKD and to confirm its association with clinical outcomes.

Application of synchrotron microprobe methods to solid-phase speciation of metals and metalloids in house dust

Determination of the source and form of metals in house dust is important to those working to understand human and particularly childhood exposure to metals in residential environments. We report the development of a synchrotron microprobe technique for characterization of multiple metal hosts in house dust. We have applied X-ray fluorescence for chemical characterization and X-ray diffraction for crystal structure identification using microfocused synchrotron X-rays at a less than 10 μm spot size. The technique has been evaluated by application to archived house dust samples containing elevated concentrations of Pb, Zn, and Ba in bedroom dust, and Pb and As in living room dust. The technique was also applied to a sample of soil from the corresponding garden to identify linkages between indoor and outdoor sources of metals. Paint pigments including white lead (hydrocerussite) and lithopone (wurtzite and barite) are the primary source of Pb, Zn, and Ba in bedroom dust, probably related to renovation activity in the home at the time of sampling. The much lower Pb content in the living room dust shows a relationship to the exterior soil and no specific evidence of Pb and Zn from the bedroom paint pigments. The technique was also successful at confirming the presence of chromated copper arsenate treated wood as a source of As in the living room dust. The results of the study have confirmed the utility of this approach in identifying specific metal forms within the dust.

Abstract P6-15-12: Preclinical Evaluation of a STAT3 Inhibitor in Breast Cancer

Breast cancer often arises from inappropriate activation of transcription factors involved in normal mammary development, such as the signal transducers and activators of transcription (STAT) family of transcription factors. STAT3, which plays an important role in mammary remodeling, is activated (as assessed by tyrosine phosphorylation) in approximately 70% of primary breast cancers, with many of these tumors being highgrade. Furthermore, inhibition of STAT3 leads to a loss of tumorigenicity of breast cancer cells. Therefore, targeting STAT3 in breast cancer would be a potentially beneficial form of therapy.

To identify small molecule STAT3 inhibitors, we developed a high throughput cell-based assay to identify compounds that inhibit STAT3- dependent transcriptional activity. We screened approximately 200,000 compounds, and specificity for STAT3 was ensured by eliminating molecules that inhibited either STAT1- or NF-kappaB-dependent transcriptional activity. From this screen, we identified 4-[4-(phenylmethyl) piperidin-1-yl] thieno[2,3-d]pyrimidine (PMPTP) (Probe ID ML116) as a potent inhibitor of STAT3 transcriptional activity, which has no effect on STAT1 or NF-kappaB-dependent transcriptional activity. Treatment with PMPTP of MDA-MB-468 breast cancer cells, which contain constitutively activated STAT3, leads to inhibition of expression of STAT3 target genes including bcl-x and mcl1. Furthermore, PMPTP is a potent inhibitor of viability of MDA-MB-468 breast cancer cells. By contrast, SK-BR-3 cells, which do not contain constitutively active STAT3, were only minimally affected. This suggests that PMPTP reduces the viability of cells that depend on constitutively active STAT3. PMPTP has no effect on STAT3 tyrosine or serine phosphorylation or STAT3 nuclear translocation, suggesting that PMPTP may be inhibiting STAT3 at the level of DNA binding or co-factor recruitment.

Importantly, PMPTP lowers the apoptotic potential of breast cancer cells thereby making them more susceptible to other forms of therapy. Building on this observation, we identified a number of beneficial combinations of PMPTP with cytotoxic drugs currently used in breast cancer therapy as well as novel anti-cancer agents. Additionally, we analyzed a number of structural analogues of PMPTP, and we identified two compounds that had approximately 4-fold increased potency in inhibiting the viability of breast cancer cells containing STAT3 activation.

Taken together, these findings identify PMPTP as a potential new form of therapy for breast cancers containing activated STAT3, which can be enhanced using conventional and non-conventional chemotherapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-15-12.

STAT5 represses BCL6 expression by binding to a regulatory region frequently mutated in lymphomas

Deregulated expression of BCL6 is a pathogenic event in many lymphomas. BCL6 blocks cellular differentiation by repressing transcription of its target genes, and this may promote tumorigenesis. Conversely, the transcription factor signal transducers and activators of transcription (STAT)5 promotes differentiation in many systems. STAT5 upregulates a number of genes repressed by BCL6, raising the possibility that STAT5 and BCL6 have opposing roles in transcriptional regulation. Therefore, we sought to determine the effects of STAT5 activation on BCL6 expression and function. We found that activation of STAT5 downregulates BCL6 expression in B-lymphoma cells and other hematopoietic cell lines. We identified two potential STAT-binding regions in the first exon and first intron of BCL6 that fell within regions of high inter-species homology, suggesting conservation of regulatory function. STAT5 can bind inducibly and regulate transcription at one of these regions, identifying BCL6 as a STAT5 target gene. Additionally, STAT5-mediated downregulation of BCL6 results in loss of BCL6 repression of its target genes, confirming that STAT5 is a negative regulator of BCL6 function. The STAT5 responsive region of the BCL6 gene is mutated frequently in B-cell lymphomas, suggesting that loss of the repressive effects of STAT5 on BCL6 might contribute to the pathogenesis of these cancers.

Vasectomy management in Morecambe Bay NHS Trust

INTRODUCTION

Vasectomy is a common method of contraception in the UK. However, there is a wide variation in management protocols. The aim of the present study was to identify differences within the hospitals of Morecambe Bay NHS Trust and to recommend a uniform practice.

PATIENTS AND METHODS

Retrospective case notes review of 395 vasectomy procedures performed within the Morecambe Bay NHS Trust in a 1-year period.

RESULTS

Inconsistency was found with regards to the anaesthetic technique, the vas histology request and the timing of the semen analysis. The non-compliance rate for postvasectomy semen analysis was 33.4%. The complication and failure rates were 4.04% and 0.51%, respectively. Motile sperm (n = 4) was submitted at an average time of 8 weeks' postvasectomy. In half of those cases, vasectomy proved unsuccessful. Immotile sperm (n = 41) was submitted at an average time of 9.5 weeks and, in 80% of those men, semen cleared at an average time of 15.5 weeks' postvasectomy. An azoospermic (n = 285) sample was submitted at an average time of 10.5 weeks. Eleven of those men submitted a second sample with immotile sperm at an average time of 12 weeks' postvasectomy and that was eventually clear at 18 weeks in the majority of cases.

CONCLUSIONS

A uniform vasectomy practice should include vasectomy under local anaesthesia if possible, no vas histology and a request for a single sample at 12 weeks. If this is clear, vasectomy should be considered successful. If any sperm are present, then a further sample should be requested at 16 weeks' postvasectomy. Immotile sperm at that time should not justify any further samples and a 'special clearance' should be issued to those men.

Techniques for the endovascular management of complications following lower limb percutaneous transluminal angioplasty

OBJECTIVES

to determine the incidence of early complications following percutaneous transluminal angioplasty and to describe their management and outcome.

MATERIALS

five hundred and fifty consecutive patients undergoing angioplasty of 648 limbs, containing 1053 anatomical segments during a two year period were reviewed retrospectively.

RESULTS

early complications affected 109 segments (10%) in 92 limbs (14%) of 84 patients (15%). Of the 109 segments affected by early complications, 106 (97%) were managed by endovascular techniques with surgery being required on only three (3%) occasions. There were no deaths attributable to angioplasty.

CONCLUSIONS

although early complications occur in 14% of limbs undergoing percutaneous transfemoral angioplasty, the majority (97%) can be managed by endovascular techniques.

Subintimal angioplasty of native vessels in the management of occluded vascular grafts

OBJECTIVES

to assess the results of subintimal angioplasty of native vessels in the presence of an occluded vascular bypass graft.

DESIGN

retrospective case note review.

MATERIALS

twelve patients presenting with symptoms of lower limb ischaemia who had previously undergone infra-inguinal bypass surgery and in whom the bypass graft had occluded. These patients were treated by attempting subintimal angioplasty of the occluded native vessels.

RESULTS

there were seven technically successful procedures but after a median follow up of four weeks, only one case had persistent patency of the previously occluded segment.

CONCLUSIONS

although subintimal angioplasty of occluded native vessels in the presence of an occluded bypass graft appears attractive, the results are disappointing.

Sigmoid ischemia and the inflammatory response following endovascular abdominal aortic aneurysm repair

PURPOSE

To assess the relationship between sigmoid colonic perfusion, endotoxemia, and cytokine generation in patients undergoing elective open repair (OR) or endovascular repair (EVR) of infrarenal abdominal aortic aneurysms (AAA).

METHODS

Ten patients (9 males; average age 67.6 +/- 2.5 years, mean aneurysm diameter 6.9 +/- 0.6 cm) undergoing OR were compared to 10 patients (all males; average age 70.3 +/- 2.6 years, mean aneurysm diameter 6.5 +/- 0.5 cm) whose repair was performed using the EVR technique. The partial pressure of the carbon dioxide gap (PCO2gap = tissue PCO2 - arterial PCO2) of the sigmoid colonic mucosa was measured using a silicone tonometer to evaluate bowel perfusion. Blood samples were collected into pyrogen-free heparinized tubes for quantification of plasma concentrations of endotoxin, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) before, during, and after aortic repair.

RESULTS

Patients in the OR group had a significantly greater increase in PCO2gap, suggesting a greater degree of bowel ischemia compared to the EVR group. This was associated with significantly greater postoperative concentrations of endotoxin, TNF-alpha, and IL-6 in the OR group. A significant correlation was found between PCO2gap, IL-6, and postoperative core temperature.

CONCLUSIONS

The results suggest that the degree of bowel ischemia, endotoxemia, and cytokine generation following elective infrarenal AAA reconstruction may be reduced if the endovascular technique is used instead of conventional surgery.

Endovascular AAA repair: prevention of side branch endoleaks with thrombogenic sponge

PURPOSE

To report a technique that might decrease the incidence of lumbar artery endoleaks following endovascular repair (EVR) of abdominal aortic aneurysms (AAAs).

METHODS

Ninety-three patients (86 males, median age 72 years, range 56 to 88) undergoing EVR with the aortomonoiliac technique were entered into a study to detect and then occlude patent side branches before completion of the endografting procedure. Prior to deploying the iliac occluder, an aneurysmogram was performed to detect patent aortic side branches. If these side branches were found, an absorbable gelatin sponge was inserted into the aneurysm sac via the occluder introducer sheath. The patients were followed with contrast-enhanced spiral computed tomography (CT) at 1 week and 3, 6, and 12 months to detect the presence of endoleaks.

RESULTS

Forty-eight (52%) patients demonstrated patent side branches that were occluded by the insertion of gelatin sponges into the aneurysm sac. The remaining 45 patients without evidence of side branch flow were untreated. Ten (10.7%) patients died in the perioperative period, and 15 (16.1%) primary endoleaks (13 proximal, 2 distal) were detected. This left 68 (73.1%) patients for follow-up, 33 (48.5%) of whom had patent branch vessels treated with the thrombogenic sponge. The median follow-up was 4 months (range 1 to 17), during which time no side branch endoleak was detected on surveillance CT scans in any of the 68 patients, which included all patients treated with the thrombogenic sponge technique and those in whom no patent side branches had been identified.

CONCLUSIONS

We have demonstrated a safe and reliable method of preventing lumbar artery endoleaks following endovascular AAA repair.

Mortality rates following endovascular repair of abdominal aortic aneurysms

PURPOSE

To present the perioperative and late mortality following endovascular repair (EVR) of abdominal aortic aneurysms (AAAs).

METHODS

Data were collected prospectively on 221 patients undergoing AAA EVR over a 4-year period (median 5-month follow-up). Patients were classified preoperatively as high risk with at least 1 of these features: serum creatinine > 150 micromol/L, ischemic heart disease or poor left ventricular function, respiratory function < 50% of predicted normal, ruptured or symptomatic AAA, contraindication to or failed open repair, and age > 80 years.

RESULTS

One hundred forty (63.3%) patients were classified as high risk, the most common criterion being cardiac disease (n = 96, 68.6%). There were 25 (11.3%) deaths in the 30-day perioperative period, 22 (15.7%) in the high-risk group compared to 3 (3.7%) in the acceptable-risk group (p = 0.02). The most common causes of perioperative death were multisystem organ failure and myocardial infarction. A further 21 (9.5%) late deaths occurred, 16 (11.4%) in the high-risk group and 5 (6.2%) in the acceptable-risk group (p > 0.1).

CONCLUSIONS

The mortality of patients at acceptable risk undergoing EVR compares with the best published series for conventional open AAA repair. The perioperative and late mortality in the high-risk patients are substantially higher.

Peripheral thrombolysis for acute-onset claudication. Thrombolysis Study Group

BACKGROUND

The aim of this study was to determine the outcome of patients who presented with sudden onset of incapacitating claudication of less than 2 weeks' duration and who were treated with peripheral arterial thrombolysis.

METHODS

The database of the Thrombolysis Study Group was searched retrospectively for patients who received thrombolysis for acute-onset claudication. Some 108 patients (65 men, median age 69 (range 29-94) years) were treated with intra-arterial tissue plasminogen activator at 14 hospitals. The median duration of symptoms was 72 h (range from 2 h to 2 weeks). There were 52 graft and 56 native vessel arterial occlusions.

RESULTS

The immediate outcome of thrombolysis for native vessel arterial occlusion was thrombus clearance in 50 patients (89 per cent) and failed lysis in six (11 per cent). Thirty-six patients (64 per cent) had a secondary radiological or surgical procedure carried out after lysis. After 30 days four patients (7 per cent) had a major amputation, eight (14 per cent) had died, 38 (68 per cent) were symptom free and seven (12 per cent) continued to have claudication. Three patients (5 per cent) suffered a major haemorrhage. The immediate outcome of thrombolysis for graft occlusion was thrombus clearance in 48 patients (92 per cent) and failed lysis in four (8 per cent); 27 patients (52 per cent) had a secondary procedure. After 30 days four patients (8 per cent) had a major amputation, seven (13 per cent) had died, 32 (62 per cent) were symptom free and nine (17 per cent) had persistent claudication. Three patients (6 per cent) suffered a major haemorrhage.

CONCLUSION

Patients who presented with acute onset of incapacitating claudication had an outcome similar to that after thrombolysis for critical ischaemia. It is recommended that patients who present in this way should be observed and treated with thrombolysis only if they progress to critical ischaemia. Presented to the Association of Surgeons of Great Britain and Ireland, Edinburgh, UK, May 1998, and published in abstract form as Br J Surg 1998; 85(Suppl 1): 24

Vascular surgical society of great britain and ireland: prospective randomized double-blind placebo-controlled crossover study to assess the effect of sublingual glyceryl trinitrate in patients with intermittent claudication

BACKGROUND: The effect of sublingual glyceryl trinitrate (GTN) on the claudication distance (CD) and maximum walking distance (MWD) of patients with intermittent claudication was assessed. METHODS: Inclusion criteria were: history of intermittent claudication; resting ankle : brachial pressure index (ABPI) of 1.00 or less; fall in ABPI of more than 0.1 following exercise; and patient not taking nitrates. In the first study 22 patients (median age 69 (range 60-73) years, 16 men, five diabetic, median resting ABPI 0.57 (range 0.1-0.64)) had their CD and MWD measured on a treadmill set at 3.2 km h-1 and 10 per cent gradient. They were then randomized to either GTN or placebo spray, and the distances were remeasured. The crossover portion of the study was then completed. In the second study 28 patients (median age 68 (range 45-84) years, 20 men, six diabetic, median resting ABPI 0.57 (range 0.13-0.98)) were randomized to either GTN or placebo and walked at their own pace along a flat corridor for 15 min. Following a rest of 15 min, the crossover portion of the study was completed. Statistical analysis was by the Wilcoxon matched pairs signed rank test. RESULTS: CONCLUSION: GTN can increase the MWD by 19 per cent when patients with intermittent claudication are walked on a treadmill and by 9 per cent when walking at their own pace on a flat gradient.

Vascular surgical society of great britain and ireland: prevention of lumbar artery endoleaks following endovascular abdominal aortic aneurysm repair with the selective use of absorbable gelatin sponge

BACKGROUND: The aim of endovascular repair of an abdominal aortic aneurysm is to exclude the aneurysm from the systemic circulation in order to prevent aneurysm expansion and rupture. Lumbar artery (LA) endoleaks have been associated with continued expansion of the aneurysm sac and occur with a reported incidence of approximately 10 per cent. The aim of this study was to reduce the incidence of LA or inferior mesenteric artery (IMA) endoleaks. METHODS: Following deployment of an aortic uni-iliac graft an aneurysmograph was performed by injecting contrast into the aneurysm sac to look for patent aortic side branches. Patients with no visible side branches had an occluder deployed in the contralateral iliac artery. Patients with patent side branches had an absorbable gelatin sponge inserted into the aneurysm sac before occluder deployment. Patients had contrast-enhanced spiral computed tomography (CT) during follow-up at 1 week, and 3, 6 and 12 months. RESULTS: Fifty-four patients were studied. Eleven were excluded (two perioperative deaths, seven top endoleaks and two occluder endoleaks). Median follow-up was 2 (range 11-7) months. Of the 17 patients in whom patent vessels were demonstrated on an aneurysmograph, one had a patent IMA only, three had a patent LA and IMA, and the remainder had a patent LA. No patient within the study has had a LA or IMA endoleak identified at follow-up CT. CONCLUSION: An intraoperative aneurysmograph can help select patients for aneurysm sac packing with gelatin sponge and has been successful in the short term in preventing LA and IMA endoleaks.

Vascular surgical society of great britain and ireland: perioperative renal function following endovascular repair of abdominal aortic aneurysm with suprarenal and infrarenal stents

BACKGROUND: Endovascular repair (EVR) of abdominal aortic aneurysm (AAA) is feasible for selected patients. Placing an uncovered stent across the origins of the renal arteries may improve fixation and seal of the proximal end of the stent-graft. However, this has potential for problems (e.g. renal artery stenosis or microembolization). This study aimed to evaluate the short-term effect of a suprarenal stent on the function of the individual kidney. METHODS: In 30 patients undergoing EVR for AAA, renal function was assessed before and after operation by 99mTc-radiolabelled diethylenetriamine penta-acetate radionuclide renography and daily measurement of serum creatinine levels. Eleven patients had infrarenal stent-grafts using an aorta uni-iliac system (group 1); 19 patients had the device with an uncovered suprarenal stent (modified Gianturco Z stent), ten of which were aorta uni-iliac and nine bifurcated systems (group 2). Individual kidney function was expressed as the whole kidney transit time (WKTT). In addition, glomerular filtration rate (GFR) was measured from serial blood samples following renography. RESULTS: [Table: see text] CONCLUSION: No result reached statistical significance. Placing an uncovered stent over the origins of the renal arteries does not appear to impair kidney function in the short term.

Vascular surgical society of great britain and ireland: changes in proximal aortic neck dimensions following endovascular repair of abdominal aortic aneurysm

BACKGROUND: Dilatation of the proximal neck following conventional open repair of abdominal aortic aneurysm (AAA) has been reported. Such continued dilatation following endovascular repair (EVR) could potentially be a disaster resulting in graft slippage, endoleak and aneurysm rupture. The aim of this study was to detect any change in proximal neck diameter following EVR of AAAs. METHODS: One hundred patients had undergone EVR of an AAA over a 4-year period in whom contrast-enhanced spiral computed tomography was performed both before and after EVR (1 week, 3, 6 and 12 months and annually thereafter). Change in aortic proximal neck diameter, change in maximum aortic diameter, presence of endoleaks, and change in length from the lowest renal artery to the aortic bifurcation was sought. RESULTS: The median anteroposterior and transverse diameter decreased from 64 mm before operation to 56 and 54 mm respectively after operation. This trend in reduction in maximum diameter was not seen in patients with endoleaks. There was no significant change in proximal neck diameter when measured at 5-mm intervals following EVR. There was also no significant change in the aortic length following EVR. CONCLUSION: There was no evidence of proximal neck dilatation or aneurysm length reduction following EVR of AAAs.

A prospective study to assess changes in proximal aortic neck dimensions after endovascular repair of abdominal aortic aneurysms

OBJECTIVE

The purpose of this study was to detect any change in the proximal neck diameter after endovascular repair of abdominal aortic aneurysm.

METHODS

The study was performed in a teaching hospital with an endovascular program on 112 patients who had undergone endovascular repair of abdominal aortic aneurysm. The interventions were pre-endovascular and postendovascular repair of abdominal aortic aneurysms with contrast-enhanced, spiral computerized tomography, and the main outcome measures were change in aortic proximal neck diameter, change in maximum aortic diameter, presence of endoleaks, and change in length from lowest renal artery to aortic bifurcation.

RESULTS

The median anterior-posterior and transverse diameter decreased from 63.5 mm before surgery to 50.4 and 54.5 mm, respectively, after surgery in a period of 4 years. This trend in reduction in maximum diameter was not seen in the patients with endoleaks. There was no significant change in the proximal neck diameters when measured at 5-mm intervals after endovascular repair. There was also no significant change in the aortic length after endovascular repair.

CONCLUSION

We have not demonstrated any evidence for proximal neck dilatation after endovascular repair of abdominal aortic aneurysm.

Renal complications following endovascular repair of abdominal aortic aneurysms

PURPOSE

To investigate the renal complications associated with endovascular repair of abdominal aortic aneurysms (AAAs).

METHODS

Data were prospectively collected on 164 AAA patients (154 males; median age 72 years; interquartile range 51 to 88) undergoing endovascular grafting. Any history of renal failure and diabetes mellitus was recorded. Serum urea and creatinine levels were measured preoperatively and at regular intervals postoperatively. Renal impairment was defined as serum creatinine > 130 micromol/L.

RESULTS

There were no significant differences in pre- and 1-day postoperative serum urea and creatinine levels. Among 15 (9.1%) patients with preoperative renal failure, 7 (47%) died, 4 (27%) in the perioperative period. Of the 149 patients with normal renal function preoperatively, 4 (2.7%) developed renal failure as part of multisystem organ failure. Another 9 (6.2%) developed significant postoperative elevations (> 20%) in their creatinine levels compared to baseline; 4 of these patients died, 2 in the perioperative period. There was no significant difference in the median dose of intravascular contrast used for those patients that did and did not have a deterioration in their renal function (250 mL versus 300 mL).

CONCLUSIONS

In this study, approximately 6% of patients with normal preoperative renal function who undergo endovascular AAA repair develop renal dysfunction. For patients with preoperative renal impairment, the perioperative mortality rate is high, 27%, following endovascular aortic aneurysm repair.

A randomized, double-blind, placebo-controlled, crossover study to assess the immediate effect of sublingual glyceryl trinitrate on the ankle brachial pressure index, claudication, and maximum walking distance of patients with intermittent claudication

PURPOSE

The goal of the present study was to assess the immediate effect of sublingual glyceryl trinitrate (GTN) in patients with intermittent claudication.

METHODS

We conducted a randomized, double-blind, placebo-controlled crossover study. Inclusion criteria consisted of history of intermittent claudication, resting ankle brachial pressure index (ABPI) of 1.00 or less, a 20% or greater fall in ABPI after exercise, and maximum walking distance (MWD) of less than 250 m. Patients already receiving nitrates were excluded. In study 1, patients (n = 25) underwent a standard exercise test after randomization to receive either 800 microg of sublingual GTN or placebo. The postexercise ABPI was recorded. Then, the crossover portion of the study was performed. In study 2, patients (n = 22) had their claudication distance and MWD measured. They then were randomized to receive either GTN or placebo spray, and the exercise test was repeated, with the claudication distance and MWD recorded, followed by the crossover portion of the study. Statistical analysis was performed with the Wilcoxon matched pairs signed ranks test and the Mann-Whitney U test.

RESULTS

In study 1, the median postexercise ABPIs for placebo and GTN were 0.29 and 0.36 (P =.0001). In study 2, the median claudication distance for both placebo and GTN groups was 70 m (P =.59). The median MWD for the placebo and GTN groups was 105 and 125 m (P =.0084)

CONCLUSION

GTN can decrease the fall in ABPI after exercise and increase the MWD.

Blood product requirements in patients undergoing elective endovascular abdominal aortic aneurysm repair

OBJECTIVE

Endovascular repair (EVR) of abdominal aortic aneurysm (AAA) has many potential advantages, one of which may be reduced blood product requirements. The aim of this study was to compare the current blood product usage in our unit for three types of elective operation: EVR of AAA, open AAA repair and femorofemoral crossover grafts.

DESIGN

Prospective data analysis with historical controls.

MATERIALS

One-hundred and thirty-two patients undergoing elective EVR of AAA, 35 patients undergoing elective open repair of AAA and 37 patients having femorofemoral crossover grafts.

METHODS

Data was collected on the blood product requirements of patients having EVR of AAA, with open AAA repair and femorofemoral crossover graft providing historical controls.

RESULTS

There was no difference in the haematological parameters preoperatively between the three groups but postoperatively patients having EVR had a slightly lower haemoglobin than the open group (10.6 g/dl vs. 10.85 g/dl, p = 0.015). The number of patients who received blood transfusion in the EVR group was 82/132 (62%) and the open group 27/35 (77%), p = 0.4.

CONCLUSION

Patients undergoing EVR of AAA require blood transfusion in the same numbers when compared to those undergoing open repair.

Early complications of femorofemoral crossover bypass grafts after aorta uni-iliac endovascular repair of abdominal aortic aneurysms

OBJECTIVE

The following procedures are the 3 main methods of endovascular repair (EVR) of abdominal aortic aneurysms (AAA): aorto-aortic bypass grafting, bifurcated bypass grafting, and aorta uni-iliac grafts. The latter method has the potential disadvantage of requiring an extra anatomic graft (ie, a femorofemoral crossover bypass graft) to maintain contralateral pelvic and limb perfusion. The aim of this study was to assess the complications associated with the femorofemoral crossover bypass graft after aorta uni-iliac EVR of AAA.

METHOD

A prospective review was conducted of the complications attributable to the femorofemoral crossover bypass graft in 136 patients who underwent EVR of AAA with an aorta uni-iliac device.

RESULTS

During a median follow-up of 7 months (range, 0 to 36 months), 4 patients had superficial wound infections that required antibiotic treatment and 2 patients had bypass graft infections. Nine hematomas developed: 7 (5%) groin hematomas (6 in patients with Dacron bypass grafts), 1 scrotal hematoma, and 1 perigraft hematoma. One bypass graft thrombus developed.

CONCLUSION

The femorofemoral crossover bypass graft is a safe and a durable component of EVR of AAA with an aorta uni-iliac device. The results are similar to those with bifurcated devices.

A randomized controlled trial comparing a 21 G needle with a 23 G needle for fine needle aspiration of breast lumps

A randomized study was performed on patients in whom the clinical decision had already been made to excise a breast lump. The objective was to assess the difference in diagnostic results of 21 and 23 G needles in the fine needle aspiration cytology (FNAC) of breast lumps. Following induction of anaesthetic, (local or general), FNAC was performed with either a 21 or 23 G needle. The breast lump was then excised and the histology and cytology results analysed routinely. One hundred and twenty-five excised breast lumps were included. Sixty-one had FNAC performed with a 21 G needle and 64 had FNAC performed with a 23 G needle. Of the 61 21 G FNAC, histology revealed 45 breast cancers. Of the 64 23 G FNAC, 50 patients had breast cancer. There was no statistical difference between these two results. There is no difference in the cytological yield when a 21 G needle is compared with that of a 23 G needle.

A study on the patency of the inferior mesenteric and lumbar arteries in the incidence of endoleak following endovascular repair of infra-renal aortic aneurysms

OBJECTIVE

An endoleak is defined as the presence of contrast medium within the aneurysm sac on post-operative contrast-enhanced computed tomography scans (CT) in patients following endovascular repair (EVR) of abdominal aortic aneurysms (AAA). The aim of this study was to correlate the incidence of endoleaks with the presence of patent lumbar (LA) and inferior mesenteric arteries (IMA) as seen on pre-operative angiography.

DESIGN, MATERIALS AND METHODS

Forty-seven patients were assessed pre-operatively by both CT and angiography by a blinded radiologist prior to EVR of AAA. The number and size of patent vessels was recorded and correlated with the incidence of LA or IMA endoleaks on follow-up CT. Patent lumbar vessels were scored: 1 = small, 2 = medium, 3 = large.

RESULTS

Five patients were noted to have patent IMA on pre-operative angiography but none developed an endoleak. In this series, five patients had an endoleak due to a patent LA. The median score for patients with no endoleak was 1 (0-9) and for those with a lumbar endoleak 2 (0-5) (P = 0.26, Mann-Whitney U-test). The number of patent lumbar arteries was not predictive of a subsequent endoleak. Two out of nine (22 %) patients with large patent LA subsequently developed an endoleak. If a policy of pre-operative embolization on the basis of large patent LA had been adopted, seven patients would have had an unnecessary invasive procedure.

CONCLUSION

Pre-operative angiography to look for patent LA and IMAs is not required in patients undergoing EVR or AAA.

A 10-year follow-up of patients presenting with ischaemic rest pain of the lower limbs

OBJECTIVES

To determine the 10-year outcome of patients presenting with rest pain.

METHODS

One hundred and three consecutive patients presenting with ischaemic rest pain in 1987 were followed up after 10 years. Hospital notes, death certificates and telephone interviews with patients were used to determine outcome.

RESULTS

Follow-up data is available for 97 (94%) patients. Thirteen patients are alive (13.7%) after 10 years, 12 presented with rest pain alone and one had ulceration. Three of these had amputation. The commonest cause of death was myocardial infarction (n = 21, 25%). In those who had died, the median age of onset of symptoms was 72 years (49-93) for rest pain, 74 years (56-87) for ulceration and 71.5 years (45-85) for gangrene. Their survival after admission was a mean of 39 months with rest pain, 33 months with ulceration and 42 months with gangrene. The overall 5-year survival was 31% and the 10-year survival 13%.

CONCLUSION

Patients presenting with ischaemic rest pain have a poor prognosis. The presence or absence of ulceration or gangrene does not influence the outcome. Most patients die from smoking-related diseases.

Intercessory prayer in the treatment of alcohol abuse and dependence: a pilot investigation

OBJECTIVE

To conduct a pilot study of the effect of intercessory prayer on patients entering treatment for alcohol abuse or dependence.

DESIGN

In addition to standard treatment, 40 patients admitted to a public substance abuse treatment facility for treatment of alcohol problems who consented to participate were randomized to receive or not receive intercessory prayer (double-blind) by outside volunteers. Assessments were conducted at baseline, 3 months, and 6 months.

RESULTS

No differences were found between prayer intervention and nonintervention groups on alcohol consumption. Compared with a normative group of patients treated at the same facility participants in the prayer study experienced a delay in drinking reduction. Those who reported at baseline that a family member or friend was already praying for them were found to be drinking significantly more at 6 months than were those who reported being unaware of anyone praying for them. Greater frequency of prayer by the participants themselves was associated with less drinking, but only at months 2 and 3.

CONCLUSION

Intercessory prayer did not demonstrate clinical benefit in the treatment of alcohol abuse and dependence under these study conditions. Prayer may be a complex phenomenon with many interacting variables.

The Canadian Organ Replacement Register

The analyses presented in this chapter are a subset of the yearly audit of organ donation and transplantation in Canada published in the CORR Annual Report. They represent the collaborative efforts and the voluntary contributions of many of the transplant physicians, surgeons, nurses and coordinators in Canada. In Canada, organ donation has remained static at approximately 14 per million population. Despite many local and provincial as well as corporate initiatives, this rate is approximately half the current rate in many regions of the U.S.A. and Spain. The modest increases in transplant activity represent an increase in the use of living donors, reassessment of the traditional donor risk factors (including age) and expansion of the potential donors for each organ. Analysis of the renal transplant activity has determined that the likelihood of being transplanted during the first year on the list was less than 40%. A graft loss rate of 4% per year after the first year was observed for a cadaveric kidney, compared with graft loss rates of 3% and 2% per year for living-related and living-unrelated donor kidneys, respectively. Cox regressional analysis identified that the major determinants of patient survival were the transplant year, the region where the transplant was performed, the presence of diabetes, the recipient's age, and whether the kidney was from a living donor. Liver transplantation has increased each year at the transplant centers in Vancouver, Edmonton, London, Toronto, Montreal, and Halifax. Patient and graft survival rates have improved since 1985 and the most significant determinant of patient survival following transplantation was the patient's medical status at the time of transplantation. Living-related liver donor transplant programs have begun in London and Toronto. Pancreas transplantation remains limited across Canada, but with the development of new pancreas programs in Toronto and Halifax, an increase in the availability of this therapy for Type 1 diabetics is anticipated. Heart transplantation has recovered from a decline in 1991-1992 to approximately 6 hearts per million population. There has been a trend towards better one- and 3-year patient survival rates since 1985. With the development of a lung transplantation program in Winnipeg, lung transplantation has increased. This likely reflects increased utilization of the available donor lungs. A particular increase in double-lung transplants was noted.

Chlorsulfuron residues are not accumulating in soils of southern Queensland

Chlorsulfuron persistence was measured in soils (to a depth of 150 cm) at 4 sites in the winter cereal region of southern Queensland. The residual herbicide had been applied 6-14 times in the previous 7-14 years. Residues here measured using a bioassay based on suppression of root growth of maize (Zea mays cv. GH5010). Less than 3% of the total applied chlorsulfuron (96-210 g a.i./ha) was detected 6-12 months after the last application, and residues were <0.7 ng/g soil in the surface 30 cm, and <0.3 ng/g below 30 cm. The limited vertical movement of residues was associated with the herbicide being applied in early winter, several months before leaching rains. Changes in residue concentration with time were also measured at a site in central Queensland, and in a fallow management experiment in southern Queensland. Persistence was greater at the cooler, drier site in southern Queensland than in central Queensland; 4544% compared with 3 4 % of applied dose remained 3 months after application respectively. Stubble retention had no effect on persistence, but tillage during the summer fallow increased persistence slightly. There was no evidence of chlorsulfuron residues accumulating and only limited leaching in these alkaline agricultural soils of southern Queensland. Persistence within a season was influenced by soil and climatic factors.

The value of information generated by long-term toxicity studies in the dog for the nonclinical safety assessment of pharmaceutical compounds

Data on 117 pharmaceutical compounds in the CMR toxicology database have been analyzed to determine what new toxicological information was provided by the dog in chronic (6 months or longer) toxicity testing. For more than half of the 117 compounds, all salient effects in the dog were seen for the first time within 3 months. For just under one-third of the compounds, any effects that occurred for the first time beyond 3 months in the dog were also seen in studies in the rat. Only 13 of the 117 compounds showed new and possibly important effects in the chronic study. No particular therapeutic class nor any other single circumstance was implicated in these 13 cases. Types of late-onset findings in the dog occurring with more than 1 compound included nonspecific effects or hypertrophic/hyperplastic changes. There may be several reasons, pragmatic as well as scientific, why it can sometimes be desirable to carry out chronic repeat-dose studies of 6 months or longer in the dog. However, the results of this retrospective evaluation have demonstrated that in the large majority of cases analyzed, long-term toxicity studies in the dog provide relatively little qualitatively new toxicological information not already gained from a short-term (3 month) study in the dog in conjunction with short- and long-term studies in the rat.

Psychiatric disorders of opioid addicts entering treatment: preliminary data

Psychiatric disorders have become an increasing concern in the treatment of substance abusers. The introduction of the Human Immunodeficiency Virus (HIV) into this population has further complicated treatment. This study examines the prevalence of psychiatric disorders in an opioid dependent population maintained on methadone. Results from this preliminary analysis show high rates of psychiatric disorders in this population. Additionally, needle sharing behavior appears to be increased in patients with a diagnosis of dysthymia. These findings have direct implications for aggressive screening and treatment of psychiatric disorders in methadone maintenance clinics.

New chemical entity output of the international pharmaceutical industry from 1970 to 1992

A database has been established that contains confidential information, together with publicly available data, on various aspects of the development of 1106 new chemical entities and biological compounds (including products of biotechnology) first marketed as medicines since 1970 on one or more of 20 major international markets. These data have been used to examine the performance of the European, U.S., and Japanese pharmaceutical industries by examining the numbers and types of new medicines reaching the marketplace from 1970 to 1992 and the companies responsible for introducing them. Although the European marketing companies dominate in total numbers first marketed over this period, there has been a significant decline in their annual output. In contrast, the Japanese companies have shown a significant increase in the number of new compounds marketed annually. However, European marketing companies remain the most successful in terms of sales because they are responsible for first marketing approximately 50% of the top 50 products by international sales in 1992. The main therapeutic areas of output by all three regions have remained relatively unchanged over the 23-year period: cardiovascular system (21%), nervous system (18%), and anti-infectives (16%). This article provides insight into the changing status of the international pharmaceutical industry over the last 23 years in terms of output from research and development.

Intracerebral propagation of interictal activity in partial epilepsy: implications for source localisation

The hypothesis that focal scalp EEG and MEG interictal epileptiform activity can be modelled by single dipoles or by a limited number of dipoles was examined. The time course and spatial distribution of interictal activity recorded simultaneously by surface electrodes and by electrodes next to mesial temporal structures in 12 patients being assessed for epilepsy surgery have been studied to estimate the degree of confinement of neural activity present during interictal paroxysms, and the degree to which volume conduction and neural propagation take part in the diffusion of interictal activity. Also, intrapatient topographical correlations of ictal onset zone and deep interictal activity have been studied. Correlations between the amplitudes of deep and surface recordings, together with previous reports on the amplitude of scalp signals produced by artificially implanted dipoles suggest that the ratio of deep to surface activity recorded during interictal epileptiform activity on the scalp is around 1:2000. This implies that most such activity recorded on the scalp does not arise from volume conduction from deep structures but is generated in the underlying neocortex. Also, time delays of up to 220 ms recorded between interictal paroxysms at different recording sites show that interictal epileptiform activity can propagate neuronally within several milliseconds to relatively remote cortex. Large areas of archicortex and neocortex can then be simultaneously or sequentially active via three possible mechanisms: (1) by fast association fibres directly, (2) by fast association fibres that trigger local phenomena which in turn give rise to sharp/slow waves or spikes, and (3) propagation along the neocortex. The low ratio of deep-to-surface signal on the scalp and the simultaneous activation of large neocortical areas can yield spurious equivalent dipoles localised in deeper structures. Frequent interictal spike activities can also take place independently in areas other than the ictal onset zone and their interictal propagation to the surface is independent of their capacity to trigger seizures. It is concluded that: (1) the deep-to-surface ratios of electromagnetic fields from deep sources are extremely low on the scalp; (2) single dipoles or a limited number of dipoles are not adequate for surgical assessment; (3) the correct localisation of the onset of interictal activity does not necessarily imply the onset of seizures in the region or in the same hemisphere. It is suggested that, until volume conduction and neurophysiological propagation can be distinguished, semiempirical correlations between symptomatology, surgical outcome, and detailed presurgical modeling of the neocortical projection patterns by combined MEG, EEG, and MRI could be more fruitful than source localization with unrealistic source models.

Initial activity of atrazine and chlorsulfuron residues is greater in the grey clays than in the black earths of southern Queensland

Commercial experience is that soil type appears to be a major factor influencing initial weed control from soil applications of atrazine and chlorsulfuron. We tested this by collecting 26 soils from the major cropping areas in southern Queensland. Initial activity was determined by measuring the dose required for 50% inhibition (ID50) of seedling growth in Wimmera ryegrass in controlled environment cabinets. The mean ID50 for atrazine and chlorsulfuron in black earths was 3 and 4 times greater, respectively, than in grey clays. Lower activity in the black earths was probably due to higher clay and cation contents and, consequently, greater adsorption of the herbicides. These results suggest that application rates of atrazine and chlorsulfuron can be adjusted for differences in initial activity between soil types.

The responses of sorghum and sunflowers to 2,4-D and dicamba residues in clay soils in central Queensland

The residual phytotoxicity of 2,4-D mine and dicamba to sorghum (Sorghum bicolor L.) and sunflowers (Helianthus annuus L.) was investigated under central Queensland conditions of variable rainfall and high temperatures. Effects of soil water content, sowing depth, and leaching in clay soils were determined. Phytotoxicity, as measured by decreases in shoot dry matter in pots, increased with herbicide rate and decreased rapidly in moist soil (34% w/w) but was maintained for at least 14 days in dry soil (114% w/w). 2,4-D and dicamba were phytotoxic when leached into the soil but not when they remained on the soil surface. Seedling growth and yield were not affected by 2 kg 2,4-Dha applied at 7 or more days pre-sowing, or by 0.5 kg 2,4-D/ha and 0.14 kg dicamba/ha applied at 1 day pre-sowing, in 5 field environments. When either herbicide was applied at higher rates 1 day pre-sowing, seedling growth was reduced if 25 mm of irrigation was received within 4 days of sowing, and yields were reduced in the field environment that received 144 mm of rainfall within 14 days of sowing.

An ASSEMBLER routine for on-line graphic display and averaging of data acquired on a personal microcomputer

An ASSEMBLER routine is described for data acquisition and "on-line" averaging, artefact rejection and graphic display of data on a personal microcomputer (IBM compatible). The user determines the number of input channels, sampling frequency, number of samples, input range, stimulation frequency (epoch frequency) and the number of epochs to be acquired and averaged. Data from each epoch are scanned in search of saturating artefacts and will be added to previous epochs if none is found. Data are then graphically displayed as voltage versus time before acquiring next epoch. Display options can be defined by the user at run time by means of the keyboard and include: display of last epoch, display of the average, storage screen and refreshing screen after every epoch. High data transfer rates and program speed allows for high stimulation rates in the presence of on line graphic display. The computer then behaves as a multichannel digital oscilloscope with access to large memory buffers, disk storage, high averaging capabilities, artefact rejection and wide potential for data analysis. Its applications to the recording of magnetic and electric evoked responses are illustrated. The program is available from the authors.

The need for a control animal pathology database: an international survey

1. The sensitivity of long-term toxicity tests is impaired due to the 'background noise' of spontaneous lesions which are unrelated to treatment. 2. The need for a comprehensive source of computerized information concerning the occurrence and incidence of spontaneous lesions in control animals has been highlighted by initiatives in Europe and the USA. It is, however, essential to identify the potential users, and the type of information required for such a database to be of value. 3. This information has been acquired following an international survey of the pharmaceutical industry in Europe, Japan and the USA, including responses from 48 toxicologists and toxicopathologists representing 38 company groups. 4. Thirty-eight respondents indicated that they would use a historical control database that was regularly updated with the majority of respondents suggesting that they currently use external sources (Breeder's data, the literature, other companies) occasionally to acquire information on control animal pathology data. 5. The majority (94%) of the respondents indicated that a control animal database should contain information on both neoplastic and non-neoplastic lesions for use in evaluating long-term studies, in particular carcinogenicity studies. 6. The survey confirms the need for a historical control animal pathology database wider then those currently available.

Harmonization of guidelines for toxicity testing of pharmaceuticals by 1992

In the past there has been considerable disagreement between various regulatory authorities regarding the type and design of animal tests that should be required before a new medicine can be used ethically and safely in the clinic. However, regulatory variations have largely been removed within politically and geographically similar regions (e.g., the U.S.A., the European Community, the Nordic countries) and there now appears to be a consensus regarding the value of harmonizing international requirements. In order to assist the process of harmonization, a detailed table of preclinical toxicity requirements in the U.S.A., Canada, Japan, and the European Community for each test (acute, subacute, chronic, carcinogenicity, mutagenicity, reproduction) has been compiled. This has been circulated to the relevant regulatory authorities to ensure that it accurately reflects current requirements. The major differences between authorities were found to be the duration of chronic, repeated-dose tests and the design of reproduction studies. International pharmaceutical companies were asked to complete a questionnaire, indicating how they design their preclinical testing program to comply with varying regulatory requirements. Most of the respondent companies indicated that chronic tests of longer than 6 months were conducted solely to comply with some regulatory requirements. Many companies repeat reproduction studies in order to comply with Japanese requirements. This emphasizes the need to harmonize these guidelines and discussions are currently underway to attempt to develop protocols acceptable to the FDA, the EC, and the Japanese Ministry of Health and Welfare.

Novel medicines marketed in the UK (1960-87)

1. A total of six hundred and eighty three new chemical entities (NCEs), were marketed in the UK between 1960 and 1987. The number of NCEs introduced annually onto the UK market declined to an average of 20 per year in 1964 and subsequently to only 7 in 1985. 2. Average development times have increased fourfold since 1960 to a peak value of 13 years in 1984. The concomitant decline in effective patent life has resulted in a mean effective patent life of less than 10 years since the mid 1960s and no more than 6 years since the early 1980s, except for the cohort marketed in 1987. 3. The largest contribution to total development time was made by the clinical phase. For NCEs marketed in the mid 1960s it was 3.3 years increasing to a peak of almost 8 years in the early 1980s, and representing on average two-thirds of research and development time. 4. Between 1960 and the early 1970s total development time for central nervous system (CNS) agents, cardiovascular products and anti-infectives had doubled to 9, 8 and 7.3 years respectively. By the 1980s it was averaging 13 years for CNS agents and was 54% and 28% longer than for anti-infectives and cardiovascular compounds respectively.

Properties of isolated nonciliated bronchiolar cells from mouse lung

Nonciliated bronchiolar cells (Clara cells) are thought to provide important respiratory secretions in the small airways and to have other metabolic functions. In mice, nonciliated bronchiolar cells have been the subject of special investigation because tumors of these cells can be specifically induced by chemical carcinogens. A method for isolating nonciliated bronchiolar cells from mice has been reported. However, we have developed a method to isolate these cells from the lungs of BDF1 mice with approximately 80% purity. Cells were identified by electron microscopy, nitroblue tetrazolium dye reduction in the presence of NADPH, immunocytochemical staining of cytochrome P450 isozymes, and mitochondrial staining with rhodamine 123. The isolated cells were examined in culture for synthesis and secretion of proteins and phospholipids. Protein synthesis and secretion were examined in cells labeled with [34S]methionine for 16 h. Fresh medium was added to washed cells and the cells were incubated for an additional 3h. The secreted proteins were precipitated with 10% trichloroacetic acid. Molecular weights of the most prominent radiolabeled secreted proteins were 6, 36, 43, and 45 kDa. Phospholipid synthesis and secretion were examined in cells labeled with [14C]acetate and 32P. Less than 1% of the radioactive lipids was found in the medium, and secretion of lipid was not stimulated by terbutaline or tetradecanoylphorbol acetate compounds, which stimulate phospholipid secretion by type II cells. These data support the hypothesis that nonciliated bronchiolar cells synthesize and secrete proteins but do not secrete phospholipids in any appreciable amount.

Monoclonal antibodies specific for antigens expressed by rat type II alveolar epithelial and nonciliated bronchiolar cells

Markers specific for various lung cells are useful for studies of cellular differentiation and function. We have produced monoclonal antibodies that bind to isolated rat type II alveolar epithelial cells in an ELISA. Two such antibodies, 2C1 and 3F9, specifically labeled type II cells and nonciliated bronchiolar cells by indirect immunofluorescence of rat lung. A third antibody, 2A3, recognized isolated type II cells by ELISA and immunofluorescence, but did not bind to sections of whole lung. Further immunofluorescence studies on adult rat tissue showed that neither 2C1 nor 3F9 labeled other lung cells or cells in kidney, small intestine, brain, or trachea. The antigen or antigens recognized by 2C1 and 3F9 was not detectable at day 15 of fetal lung gestation but was detectable by day 21. Immunofluorescence studies carried out on 0.5-microns frozen sections of lung tissue demonstrated that both 2C1 and 3F9 bound to cell surface antigens, which are expressed in a highly polarized fashion on the luminal surface of the alveolus and bronchiole. The rat cell line, L2, which displays some similarities to type II cells, did not display positive immunofluorescence to 2A3, 2C1, or 3F9. The antibodies 2C1 and 3F9 are distinct from and apparently more specific than previously described monoclonal antibodies raised to rat type II cells. Alveolar type II and nonciliated bronchiolar cells share several common features. Both cell types contain the surfactant apoprotein SP-A, proliferate in response to lung injury, develop in the late stages of gestation, take up and catabolize platelet-activating factor, contain high levels of cytochrome P-450, and can be induced to form tumors in response to chemical carcinogens. The recognition of highly specific surface antigen(s) on both nonciliated bronchiolar cells and type II cells demonstrates yet another characteristic shared by the two cell types.