Interobserver variability in the interpretation of renal digital subtraction angiography

OBJECTIVE

Our purpose was to analyze interobserver variability in the interpretation of renal digital subtraction angiography and to describe the main factors associated with observer discrepancies.

MATERIALS AND METHODS

Forty-nine cases of unilateral atheromatous renal artery stenosis of more than 60% were quantified first by local investigators in a multicenter study and then by five other radiologists. Differences between radiologists for the minimum diameter (Dmin), the reference diameter (Dref), and the percentage of stenosis of the renal arteries were analyzed. Interpretations by the local investigators were then compared with the gold standard, defined as the mean for the five radiologists.

RESULTS

The average SD for estimation of all renal artery stenoses by all radiologists was 7% for stenosis percentage, 0.5 mm for Dmin, and 0.7 mm for Dref. Main discrepancies occurred more frequently in cases of weakly opacified renal artery stenosis and poststenotic dilatation. The observations of local investigators disagreed by more than two SDs (14%) with the gold standard for 11 of 49 cases (22%).

CONCLUSION

The accuracy of digital subtraction angiography in renal artery interpretations is poor because of variations in evaluating both Dmin and Dref. Precise and reproducible methods for quantification of renal artery stenosis are required.

Inhibition of pentagastrin-induced gastric acid secretion by intravenous pantoprazole: a dose-response study

OBJECTIVE

The purpose of this study was to compare the gastric acid inhibitory ability of increasing doses of intravenous (i.i.) pantoprazole with that of i.v. famotidine and placebo. Pentagastrin was infused continuously in healthy subjects as a model for patients with Zollinger-Ellison syndrome.

METHODS

Pentagastrin (1 microg/kg/h) was infused to stimulate maximum acid output in 39 subjects over a 25-h period. After 60 min of pentagastrin infusion, subjects received a single dose of i.v. pantoprazole (20, 40, 80, or 120 mg), i.v. famotidine (20 mg), or saline placebo. The variables measured were onset of response (time until acid output fell to < 10 mEq/h), duration of response (time acid output remained < 10 mEq/h), and cumulative acid output over 24 h.

RESULTS

All doses of i.v. pantoprazole produced a dose-dependent suppression of acid output to < 10 mEq/h. Single i.v. doses of pantoprazole, 80 and 120 mg, suppressed acid output by > 90% in all subjects for < or = 21 h and had an onset of action of < 1 h.

CONCLUSIONS

Intravenous pantoprazole has a rapid onset and a clear dose-related effect, with a significantly longer duration of action than that of i.v. famotidine.

Docetaxel and cisplatin in combination as first-line chemotherapy for advanced epithelial ovarian cancer. Scottish Gynaecological Cancer Trials Group

PURPOSE

A prospective, nonrandomized, multicenter, open feasibility study of cisplatin and docetaxel as first-line chemotherapy in International Federation of Gynecology and Obstetrics (FIGO) stage IC-IV epithelial ovarian cancer was conducted. The primary end point was the incidence of severe fluid retention that necessitated treatment withdrawal.

PATIENTS AND METHODS

Cisplatin and docetaxel were administered every 3 weeks for six planned cycles, with a 5-day prophylactic dexamethasone regimen (8 mg two times per day). One hundred patients (median age, 53 years; range, 24 to 71 years) received a total of 512 cycles of chemotherapy in two cohorts: cohort 1, 49 patients, 258 cycles (cisplatin 75 mg/m(2) and docetaxel 75 mg/m(2)); cohort 2, 51 patients, 254 cycles (cisplatin 75 mg/m(2) and docetaxel 85 mg/m(2)).

RESULTS

No patients were taken off study because of fluid retention. Sixty-six patients completed six cycles of protocol therapy; 16 stopped early because of toxicity (neurotoxicity in six patients, nephrotoxicity in three, neutropenia in two, and hypersensitivity, diarrhea and vomiting, skin rash, clinical deterioration, and patient's wishes in one patient each). Grade 3/4 neutropenia was observed in more than 75% of patients and seemed to be cumulative. Patients in cohort 2 had significantly more severe neutropenia and lethargy than those in cohort 1. In addition, there were five treatment-related deaths in cohort 2 (three neutropenia and two upper gastrointestinal hemorrhage). Neurotoxicity (mainly sensory, > grade 1) was observed in 23 patients. The overall clinical response rate was 69% (complete response, 38%; partial response, 31%); CA-125 response rate was 73%. Median progression-free survival for the group was 12 months.

CONCLUSION

Cisplatin and docetaxel can be administered at doses of 75 mg/m(2) and 75 mg/m(2), respectively, every 3 weeks, and the utility of this regimen is not limited by fluid retention. However, 33 of 100 patients were unable to complete the planned six cycles, which may explain, in part, the poor overall progression-free survival. Increasing the docetaxel dose to 85 mg/m(2) adds unacceptable hematologic toxicity and potential risks to the patient.

Electron beam CT features of the pulmonary artery in Takayasu's arteritis

OBJECTIVE

Pulmonary artery involvement in Takayasu's arteritis is suggestive of the disease. Our aim was to use electron beam CT to study pulmonary artery changes in patients with Takayasu's arteritis.

CONCLUSION

Diffuse wall thickening and dilatation or stenosis were significantly more frequent on CT in patients with Takayasu's arteritis than in the control subjects. Knowledge of these findings may be of value when assessing pulmonary artery involvement and thus may be helpful for the diagnosis of Takayasu's arteritis.

The prevalence and associated variables of deep venous thrombosis in patients with advanced cancer

The prevalence of venous thromboembolism (VTE) in cancer patients has been estimated as up to 15% antemortem, and higher (over 50% in pancreatic tumours) postmortem owing to the asymptomatic nature of many episodes of VTE. We investigated the prevalence of deep venous thrombosis (DVT) in a population of 298 hospice inpatients with advanced cancer. They were screened for the presence of DVT using light reflection rheography; 258 (86.6%) patients were evaluable for DVT, which was found in 135 (52%; 95% confidence interval 46-58). Factors associated (multivariate analysis) with the presence of DVT were: poor mobility, reduced serum albumin level and higher serum urea. A DVT risk assessment index was calculated using these variables. The three highest categories all had significant rates of DVT and, although the lowest category had a low rate of DVT, it accounted for less than 10% of all patients tested. DVT is common in patients with advanced cancer. It was found to be significantly associated with the above variables, but a combined index was of limited clinical application. In view of the number of patients identified with DVT, repeated small pulmonary emboli may be responsible for more symptoms than previously recognized in cancer patients.

Modulation of drug resistance mediated by loss of mismatch repair by the DNA polymerase inhibitor aphidicolin

Loss of expression of mismatch repair (MMR) proteins leads to resistance of tumor cells to a variety of DNA-damaging agents, including bifunctional alkylating and monofunctional methylating agents such as cis-diaminedichloroplatinum II (CDDP) and N'-methyl-N-nitrosourea (MNU). It has been suggested that coupling to cell death does not occur in the absence of MMR, but instead, DNA lesions are bypassed during replication, giving a drug-tolerant phenotype. In the present study, we have used aphidicolin (Ap), an inhibitor of DNA polymerases, to study the role of replicative bypass in drug resistance mediated by loss of MMR. We have examined the survival of matched ovarian carcinoma cell lines with known MMR status after sequential treatment with CDDP or MNU and Ap. We show that Ap increases the sensitivity of MMR-deficient cell lines to CDDP and MNU to a greater extent than their MMR-proficient counterparts. Furthermore, loss of MMR correlates with loss of CDDP-induced G2 arrest, but this is partially restored after Ap treatment. These data support Ap sensitizing drug-resistant cancer cells that have lost MMR to CDDP and MNU and suggest that the potential use of Ap as a modulator of drug resistance should be targeted to MMR-defective tumors.

Oxidative stress induced in pathologies: the role of antioxidants

Exposure to oxidant molecules issued from the environment (pollution, radiation), nutrition, or pathologies can generate reactive oxygen species (ROS for example, H2O2, O2-, OH). These free radicals can alter DNA, proteins and/or membrane phospholipids. Depletion of intracellular antioxidants in acute oxidative stress or in various diseases increases intracellular ROS accumulation. This in turn is responsible for several chronic pathologies including cancer, neurodegenerative or cardiovascular pathologies. Thus, to prevent against cellular damages associated with oxidative stress it is important to balance the ratio of antioxidants to oxidants by supplementation or by cell induction of antioxidants.

Optimizing force and velocity: mandible muscle fibre attachments in ants

To be able to perform swift and powerful movements, ant mandible closer muscles are composed of two subpopulations of muscle fibres: fast fibres for rapid actions and slow fibres for forceful biting. All these fibres attach to a sturdy and complex apodeme which conveys force into the mandible base. Fast muscle fibres attach directly to the apodeme. Slow fibres may attach directly or insert at individual thin filament processes of the apodeme which vary in length. Comparisons of different ant species suggest two basic principles underlying the design of mandible muscles. (1) Ants specialized for fast mandible movements generally feature long heads which contain long fast muscle fibres that attach to the apodeme at small angles. Their muscles comprise only a few filament-attached fibres and they maximize speed of action at the expense of force output. (2) Ants performing particularly forceful mandible movements, such as seed cracking, rely on many short parallel muscle fibres contained within a broad head capsule. Their slower muscles incorporate a large proportion of filament-attached fibres. Two simple models explain how the attachment angles are optimized with respect to force and velocity output and how filament-attached fibres help to generate the largest power output from the available head capsule volume.

Primary bacterial colonization of implant surfaces

The purpose of this study was to assess the effects of modifying titanium surfaces, in terms of wettability, roughness, and mode of sterilization, on the ability of the oral bacterium Streptococcus sanguis to colonize. An in vitro model system was developed. All surfaces were colonized by the bacteria, but to significantly different levels. Titanium samples that exhibited rough or hydrophobic (low wettability) surfaces, along with all autoclaved surfaces, were preferentially colonized (P < .01). Titanium surfaces that had been repeatedly autoclaved were colonized with the levels of bacteria 3 to 4 orders of magnitude higher than other modes of sterilization. This may have implications relative to the commonly used method of autoclaving titanium implants, which may ultimately enhance bacterial biofilm formation on these surfaces.

The economic consequences of smoking in Ontario

Smoking causes health and social problems such as sickness, death, fire, injury, pain and suffering. This paper provides an estimate of the economic burden imposed by the adverse health and social consequences of smoking in Ontario in 1992. The cost-of-illness method, in particular, the human-capital approach is used to estimate the prevalence-based economic costs of smoking. The direct and indirect components of smoking-related costs are estimated and the total cost in Ontario is US$2.91 billion. Associated with these economic costs are health-related harms: 69,318 hospital separations; 1,007,647 days stay in hospitals; 11,648 deaths resulting in more than 171,443 person-years lost.

Fatal bleomycin pulmonary toxicity in the west of Scotland 1991-95: a review of patients with germ cell tumours

We conducted a retrospective review of fatal bleomycin pulmonary toxicity in patients treated for germ cell tumours during 1991-95 at the Beatson Oncology Centre, Glasgow. Case notes of patients treated with bleomycin were reviewed with respect to cumulative bleomycin dose, renal impairment, exposure to supplemental oxygen, thoracic radiotherapy and age. A total of 194 patients underwent chemotherapy, of whom 180 received bleomycin-containing regimens. Five fatal cases of pulmonary toxicity were identified, an incidence of 2.8%. These cases were older than the remaining patients (P < 0.001), with a median age at diagnosis of 55 vs 33 years. The incidence of fatal pulmonary toxicity increased with each decade of life above age 30. Renal function also differed between the two groups, with the worst glomerular filtration rate recorded at the time of bleomycin administration for each patient, lower in the fatal group, median 69 vs 107 ml min(-1) (P < 0.001). There was no difference with respect to cumulative bleomycin dose or exposure to supplemental oxygen. For patients aged over 40 years, especially those with renal function in the lower range of normal, the risk of developing fatal toxicity may exceed 10%. The benefits of bleomycin could be questioned for this age group.

Early closure of a randomized trial: surgery and postoperative radiotherapy versus radiotherapy in the management of intra-oral tumours

Tumours of the oral cavity/oropharynx occur relatively infrequently in the UK. The management of such lesions, especially the squamous cell carcinomas, is still a little controversial. Some centres advocate radiotherapy while others adopt surgery and radiotherapy. In an attempt to resolve the question of which approach gives the better results, a multicentre randomized trial was established to compare surgery plus postoperative radiotherapy with radical radiotherapy alone. It was anticipated that 350 patients would be required to give a statistically significant result, but, after 35 patients had been entered, the trial was closed prematurely with a marked difference in overall survival in favour of the combination arm (P = 0.0006). At this analysis, carried out 23 months after trial closure, the survival difference between the two arms remains statistically significant for all causes of mortality (P = 0.001; relative death rate = 0.24; 95% CI 0.10-0.59).

Chronic diarrhoea among HIV-infected adult patients in Nairobi, Kenya

OBJECTIVES

Chronic diarrhoea and wasting are well recognized features of AIDS in Africa. However, because of resource constraints few comprehensive aetiological studies have been conducted in sub-Saharan Africa which have included a broad range of microbiological investigations. We undertook a prospective cross-sectional study of adult patients admitted to a government hospital in Nairobi, Kenya, to determine possible bacterial, mycobacterial, parasitic and viral causes of diarrhoea; to consider which may be treatable; and to relate microbiological findings to clinical outcome.

METHODS

Stool specimens from 75 consecutive HIV-seropositive patients with chronic diarrhoea admitted to a Nairobi hospital were subjected to microbiological investigation and results were compared with clinical findings and outcome. Stool samples were cultured for bacteria and mycobacteria and underwent light and electron microscopy; lawns of Escherichia coli were probed for pathogenic types and aliquots were tested for the presence of Clostridium difficile cytotoxin. Blood cultures for mycobacteria and other bacterial pathogens were performed as clinically indicated.

RESULTS

Thirty-nine (52%) patients yielded putative pathogens, the most common being Cryptosporidium sp. (17%), Salmonella typhimurium (13%), and Mycobacterium tuberculosis (13%). Of 41 patients investigated for pathogenic Escherichia coli, enteroaggregative E. coli and diffusely adherent E. coli were each found in four patients. Thirty-one (41%) patients died. Detection of cryptosporidium cysts was the single most significant predictor of death (X2 = 5.2, P<0.05). Many patients did not improve (21; 28%) or self-discharged whilst still sick (5; 7%) but five (7%) were diagnosed ante mortem with tuberculosis and treated and a further 13 (17%) showed improvement by time of discharge.

CONCLUSIONS

HIV-infected patients with chronic diarrhoea in Nairobi have a poor outcome overall, and even with extensive investigation a putative pathogen was identified in only just over half the patients. The most important step is to exclude tuberculosis; and the most useful investigation appears to be Ziehl-Neelsen staining. Other potentially treatable gram-negative bacterial pathogens, S. typhimurium, Shigella sp. and adherent E. coli were, however, common but require culture facilities which are not widely accessible for definitive identification. Further studies focussing on simple ways to identify sub-groups of patients with treatable infections are warranted.

Randomized multicentre trial of filgrastim as an adjunct to combination chemotherapy for Hodgkin's disease. West of Scotland Lymphoma Group

This study was intended to ascertain whether the adjunctive administration of filgrastim (r metHuG-CSF, Amgen) would influence the dose intensity of chemotherapy or the morbidity of myelosuppression in patients receiving MOPP or MOPP/EVAP hybrid chemotherapy for Hodgkin's disease. In a prospective randomized trial, two regimens for the treatment of Hodgkin's disease were compared. The substudy described here randomized patients receiving either regimen to receive filgrastim on the days when chemotherapy was not administered. During chemotherapy, parameters of myelosuppression were documented, including dose delays, the severity and duration of neutrophil and platelet nadirs, infective episodes, and resulting hospital admissions. In the MOPP arm, 13/25 eligible patients, and, in the MOPP/EVAP arm, 12/22 eligible patients, received filgrastim. The use of filgrastim made no statistically significant difference to the administered dose intensity for either MOPP (P = 0.57, 95% confidence interval (CI) 15-point increase to 8-point reduction) or MOPP/EVAP (P = 0.53; 95% CI 7-point increase to 11-point reduction). In patients receiving MOPP, filgrastim reduced the median duration of leucopenia (P = 0.007) and the severity of the white blood cell nadir (P = 0.036); however, no statistically significant effect (at the 5% level) was seen in platelet or haemoglobin nadirs, the number of days of in-patient hospitalization, the number of admissions for infective complications, the incidence, grade or duration of infections, or the incidence of febrile neutropenia. In patients receiving MOPP/EVAP, filgrastim had no significant effect on the duration or depth of leucopenia but was associated with a reduction in the median haemoglobin (P = 0.002) and platelet nadirs (P = 0.015). No effect on the above listed sequelae of myelosuppression was influenced by the administration of filgrastim. This study, although small, suggests that the routine use of filgrastim, aimed at influencing the administered dose intensity of conventional dose chemotherapy in Hodgkin's disease, is not warranted.

Bolus/infusional 5-fluorouracil and folinic acid. A report on two prospective, consecutive phase II studies with 5-fluorouracil dose escalation

We have used a relatively new trial methodology, the group sequential design, to prospectively evaluate two dose levels of bolus/infusional 5-fluorouracil (5-FU) and folinic acid in 192 consecutive-patients with advanced colorectal carcinoma. On day 1, all patients received 200 mg m(-2) of folinic acid infusion over 2 h. Cohort A (n = 102 patients) received 500 mg m(-2) 5-FU by i.v. 15-min infusion followed by an infusion of 500 mg m(-2) 5-FU over 22 h. Treatment was repeated on day 2 and further cycles given 2-weekly. After sequential analysis excluded a response rate of over 40%, cohort B (n = 90 patients) received an increased dose of 600 mg m(-2) 5-FU bolus and infusion. Patients had received no prior 5-FU therapy and the two cohorts had similar demographic features. In 179 evaluable patients, the overall response rate was 18% (95% CI 12-24%) with CR of 6% and PR of 12%, with no difference between the two cohorts. Overall median survival was 34 weeks (95% CI 30-39) with no significant difference between cohorts (median survival 32 and 37 weeks in cohort A and B respectively; P = 0.27). On multivariate analysis, poor performance status, elevated initial WBC and alkaline phosphatase and low serum albumin were associated with reduced survival (P < 0.05), and initial raised WBC showed an association with reduced likelihood of response (P = 0.002). Overall toxicity was low with CTC grade 3 mucositis, diarrhoea, nausea or vomiting in < or = 6% of patients and no treatment-related deaths. Significant (grade 3 or above) leucopenia was more common in cohort B than in cohort A (9% and 1% respectively); there were more dose reductions, and the median administered dose intensity was lower in cohort B than in cohort A (89% and 97% respectively; P = 0.006). In this group of relatively unselected patients, we have confirmed a relatively low objective response rate and median survival of 7.8 months with this regimen. There was no significant difference in outcome between the two dose levels but the higher dose of 5-FU was associated with more dose reductions and greater toxicity.

[Diagnostic approach of pulmonary embolism by spiral angioscanner]

Spiral volumetric computerized tomography (CT) allows the exploration of the whole chest during a single contrast injection and breath-hold. For the diagnosis of central pulmonary embolisms, the sensibility is between 78 and 98% and the specificity between 86 and 94% depending on the direct visualization of the endoluminal defect. Detection of intercurrent parenchymal pathologies or of non-obstructive arterial thrombi explain some false positive or inconclusive results of the ventilation-perfusion scintigraphy. Sub-segmental thrombi are less easily detected and sensibility for both central and sub-segmental embolisms is only 63%, explaining some rare false negatives of the CT on isolated sub-segmental embolisms. Chronic thrombi are outlying and contiguous with the arterial wall. They are associated with arterial stenosis, cut-off and loops and an oligemic mosaic pattern of the parenchyma. CT allows pre-operative staging before surgical recanalization and the intra-venous injection does not interfere with the arterial pressure. CT is a non-invasive, reliable and easily available technique which clearly plays an important role in the diagnosis of pulmonary embolism.