Quality improvements in radiation oncology clinical trials

Clinical trials have become the primary mechanism to validate process improvements in oncology clinical practice. Over the past two decades there have been considerable process improvements in the practice of radiation oncology within the structure of a modern department using advanced technology for patient care. Treatment planning is accomplished with volume definition including fusion of multiple series of diagnostic images into volumetric planning studies to optimize the definition of tumor and define the relationship of tumor to normal tissue. Daily treatment is validated by multiple tools of image guidance. Computer planning has been optimized and supported by the increasing use of artificial intelligence in treatment planning. Informatics technology has improved, and departments have become geographically transparent integrated through informatics bridges creating an economy of scale for the planning and execution of advanced technology radiation therapy. This serves to provide consistency in department habits and improve quality of patient care. Improvements in normal tissue sparing have further improved tolerance of treatment and allowed radiation oncologists to increase both daily and total dose to target. Radiation oncologists need to define a priori dose volume constraints to normal tissue as well as define how image guidance will be applied to each radiation treatment. These process improvements have enhanced the utility of radiation therapy in patient care and have made radiation therapy an attractive option for care in multiple primary disease settings. In this chapter we review how these changes have been applied to clinical practice and incorporated into clinical trials. We will discuss how the changes in clinical practice have improved the quality of clinical trials in radiation therapy. We will also identify what gaps remain and need to be addressed to offer further improvements in radiation oncology clinical trials and patient care.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Selection bias for treatments with positive Phase 2 results

In drug development, treatments are most often selected at Phase 2 for further development when an initial trial of a new treatment produces a result that is considered positive. This selection due to a positive result means, however, that an estimator of the treatment effect, which does not take account of the selection is likely to over-estimate the true treatment effect (ie, will be biased). This bias can be large and researchers may face a disappointingly lower estimated treatment effect in further trials. In this paper, we review a number of methods that have been proposed to correct for this bias and introduce three new methods. We present results from applying the various methods to two examples and consider extensions of the examples. We assess the methods with respect to bias of estimation of the treatment effect and compare the probabilities that a bias-corrected treatment effect estimate will exceed a decision threshold. Following previous work, we also compare average power for the situation where a Phase 3 trial is launched given that the bias-corrected observed Phase 2 treatment effect exceeds a launch threshold. Finally, we discuss our findings and potential application of the bias correction methods.

Video-assisted thoracoscopic surgery for ectopic mediastinal parathyroid adenoma

Background

Primary hyperparathyroidism (PHPT), caused by an ectopic mediastinal parathyroid adenoma, is uncommon. In the past, when the adenoma was not accessible from the neck, median sternotomy was advocated for safe and successful parathyroidectomy. Video‐assisted thoracoscopic surgical (VATS) parathyroidectomy represents a modern alternative approach to this problem.

Methods

Information on patients undergoing VATS was obtained from a specific database, including clinical presentation, biochemistry, preoperative imaging, surgical approach and patient outcomes. A comprehensive literature review was undertaken to draw comparisons with other publications.

Results

Over a 2‐year period, nine patients underwent VATS parathyroidectomy for sporadic PHPT. Five patients had persistent PHPT following previous unsuccessful parathyroidectomy via cervicotomy, and four had had no previous parathyroid surgery. The median duration of surgery was 90 (range 60–160) min. Eight patients were cured biochemically, with no major complications. One patient required conversion to a median sternotomy for removal of a thymoma that had resulted in false‐positive preoperative imaging.

Conclusion

With appropriate preoperative imaging, multidisciplinary input and expertise, VATS parathyroidectomy is an effective, safe and well tolerated approach to ectopic mediastinal parathyroid adenoma.

Effect of High-Dose Intravenous Eletriptan on Coronary Artery Diameter

The goal of this study was to evaluate the coronary vasoconstrictive effects of high doses of eletriptan compared with a standard dose of sumatriptan. Patients with no clinically significant coronary artery disease were randomized to receive high-dose intravenous eletriptan ( n = 24) vs a standard dose of sumatriptan ( n = 18; 6 mg subcutaneously) vs placebo ( n = 18). Serial angiograms were obtained. The primary non-inferiority analysis found equivalence between the mean maximum change in left anterior descending coronary artery diameter for eletriptan, -22% [95% confidence interval (CI) -26, -19], and sumatriptan, -19% (95% CI -22, -16). The change due to placebo was -16% (95% CI -20, -12). No individual cases of clinically significant vasoconstriction were observed. The results confirm that eletriptan has a broad cardiovascular safety margin, with plasma concentrations comparable to three to five times the Cmax of an oral 80-mg dose associated with modest vasoconstriction equivalent to standard therapeutic doses of sumatriptan.

How effective are disease-modifying drugs in delaying progression in relapsing-onset MS?

OBJECTIVE

Our objective was to estimate the effectiveness of disease-modifying drugs (DMDs) in delaying multiple sclerosis (MS) disability progression in relapsing-onset (R-onset) definite MS patients under "real-world" conditions.

METHODS

Treatment effect size, for DMDs as a class, was estimated in absolute terms and relative to MS natural history. A basic model estimated annual Expanded Disability Status Scale (EDSS) change before and after treatment. An expanded model estimated annual EDSS change in pretreatment years, treatment years on first drug, treatment years after drugs were switched, and in years after treatment stopped. Models were populated with 1980 through 2004 clinical data, including 1988 through 2004 data for all Nova Scotians treated with DMDs. Estimates were made for relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and R-onset groups.

RESULTS

Estimated pretreatment annual EDSS increases were approximately 0.10 of one EDSS point for the RRMS group, 0.31 for the SPMS group, and 0.16 for the R-onset group. Estimates of EDSS increase avoided per treatment year on the first drug were significant for the RRMS group (-0.103, 0.000), the SPMS group (-0.065, 0.011), and the R-onset group (-0.162, 0.000); relative effect size estimates were 112%, 21%, and 105%. Estimated EDSS progression was faster in years after drug switches and treatment stops.

CONCLUSIONS

Our estimates of disease-modifying drug (DMD) relative treatment effect size, in the context of "real-world" clinical practice, are similar to DMD treatment efficacy estimates in pivotal trials, though our findings attained statistical significance. DMDs, as a class, are effective in delaying Expanded Disability Status Scale progression in patients with relapsing-onset definite multiple sclerosis (MS) (90%), although effectiveness is much better for relapsing-remitting MS than for secondary progressive MS groups.

Bloodless hepatectomy technique

BACKGROUND

Surgical resection remains the gold standard in dealing with liver tumours. Blood loss, biliary leak and postoperative liver function are still the main concerns of surgeons operating on the liver, even though different techniques have been developed to allow safer liver resection. A novel concept for liver resection is described using a radiofrequency energy (RF) assisted technique.

METHOD

A patient with a large colorectal liver metastasis located in segments VI, VII, VIII underwent a right hepatectomy using this technique. At laparotomy the tumour was staged with intraoperative ultrasonography, and a 'cooled tipped' radiofrequency probe was used to achieve a 'zone of desiccation' in the liver parenchyma 2 cm away from the edge of the tumour. Liver parenchyma was subsequently divided with a surgical scalpel.

RESULTS

The resection time was 80 min with a blood loss of 30 ml. The patient was discharged on the ninth postoperative day without complications.

DISCUSSION

Liver resection assisted by RF energy is feasible and safe. This technique could offer a new method for 'transfusion-free' resection without the need for sutures, ties, staples, tissue glue or admission to the intensive care unit.

Epidural haematoma after dural puncture in a parturient with neurofibromatosis

A case of epidural analgesia in a parturient with neurofibromatosis (von Recklinghausen's disease) complicated by dural puncture and epidural haematoma is described and the management of the case is discussed. The case emphasizes the need for antenatal assessment of parturients with neurofibromatosis in order that the necessary investigations can be arranged and informed consent for analgesia and anaesthesia can be obtained.

Reflections on the life of Monica Baly

Following the death last November of Monica Baly, we publish tributes from friends and colleagues in her memory. We begin with an obituary written by Laurence Dopson.

The London County Council Nursing Service 1929-48: the significance of the nursing leadership

'On the vesting day of the National Health Service, the LCC handed over to the NHS the largest and most comprehensive hospital system under a single authority that existed in the world' (1). The careers of the Matrons-in Chief, Dorothy Bannon and subsequently Rosalie Dreyer, demonstrate that the LCC had been able to attract nursing leaders from the voluntary hospitals. Both were able to use their new position within the LCC hierarchy to promote the interests of nursing. They took this opportunity to develop a nursing service which became a model to rival the hegemony of the voluntary hospitals.

A reassessment of the fat intake of children from meat and meat products and an estimate of haem iron intakes

BACKGROUND

It is possible that fat intake from red meat has declined as a consequence of changes in animal husbandry and butchery practices. In particular, a study of the intake of vegetarian and meat-eating children concluded that their fat intakes were similar, but the most recent information on the fat content of meat was not available. In addition, iron availability is probably as important as the total amount of iron consumed but estimates of haem iron intake are rarely made.

METHODS

The dietary intake of 50 omnivorous children was reanalysed to produce new estimates of fat and haem iron intakes. Fat intake from meat and meat products only was recalculated using supplements to the food tables not available to the initial survey. Haem iron intake was calculated by discriminating between the different types of meat consumed and estimates of the proportion of iron which is in the haem form.

RESULTS

The recalculated diets had significantly lower energy (8.03-7.50 MJ), fat (79-73 g) and carbohydrate (257-237 g) levels. The proportions of energy from fat (36%) and carbohydrate (51%) were unaffected. Meat supplied 3.2 mg (33%) of the iron intake (9.6 mg) of which 1.3-1.5 mg (13-16% of the total) was estimated to be in the haem form. Children may be relatively unaffected by the changes in the composition of meat as such, if they consume highly processed foods which include, for example, rusk, pastry, breadcrumbs and batter.

CONCLUSIONS

The original estimates of the intake of fat of these omnivorous children from meat and meat products do appear to have been overestimates, but only as the weight of fat consumed not as a percentage of energy. Haem iron was found to supply a substantial proportion of the iron intake of these children and may account for their higher haemoglobin values.

Salmeterol and fluticasone propionate given as a combination. Lack of systemic pharmacodynamic and pharmacokinetic interactions

OBJECTIVE

To investigate the potential for systemic pharmacodynamic and pharmacokinetic interactions between inhaled salmeterol and fluticasone propionate when repeat doses of the two drugs are given in combination to healthy subjects.

METHODS

Twenty-eight healthy subjects received salmeterol 100 microg, salmeterol 100 microg/fluticasone propionate 500 microg and fluticasone propionate 500 microg via a Diskus dry powder inhaler twice daily for 11 days according to a randomised, double-blind, placebo-controlled, crossover design. Subjects in the placebo group also received a single dose of salmeterol 100 microg on the morning of day 10. On day 10, the systemic effects of salmeterol [on pulse rate, blood pressure, corrected QT (QTc) interval and serum potassium and glucose levels] and fluticasone propionate (on 24-h urinary cortisol and morning plasma cortisol levels) were assessed. Maximal number and affinity of lymphocyte beta2-adrenoceptors and beta2-adrenoceptor polymorphism at loci 16 and 27 were also determined. Plasma pharmacokinetics of salmeterol and fluticasone propionate were determined after the morning dose on day 10. Dosing continued on the evening of day 10 and on day 11, and on day 12 the effect of repeat-dose treatment with salmeterol and salmeterol/fluticasone propionate on the systemic effects of cumulative doses of inhaled salbutamol (up to a total dosage of 3,200 microg) was evaluated.

RESULTS

All treatments were safe and well tolerated. With the exception of a higher pulse rate after repeat administration of salmeterol [66.2 beats per minute (bpm) versus 63.6 bpm], there were no significant differences between the single-dose and repeat-dose salmeterol groups. The systemic pharmacodynamic effects of inhaled salmeterol were not affected by the co-administration of fluticasone propionate. Eleven days of treatment with salmeterol induced tachyphylaxis to the systemic effects of cumulative doses of salbutamol; however, co-administration of fluticasone propionate did not affect the response to salbutamol. Fluticasone propionate reduced 24-h urinary cortisol excretion (22.4 microg compared with 48.6 microg with placebo), but this was unaffected by the co-administration of salmeterol. Morning plasma cortisol levels were not reduced compared with placebo. There was no significant treatment effect on lymphocyte beta2-adrenoceptors and no correlation of beta2-adrenoceptor polymorphism at loci 16 and 27 with the development of tachyphylaxis. Salmeterol plasma concentrations were measurable only during the first half-hour after dosing. Co-administration of fluticasone propionate did not affect the peak plasma concentration (Cmax) of salmeterol. For fluticasone propionate, there were no statistically significant differences between salmeterol/fluticasone propionate and fluticasone propionate with respect to Cmax, plasma concentration at the end of the dosing interval (Ct), terminal elimination half-life (t1/2) or time to Cmax (tmax). The area under the concentration-time curve within a dosing interval (AUCt) for fluticasone propionate after inhalation of salmeterol/fluticasone propionate was statistically significantly higher (about 8%) than after inhalation of fluticasone propionate alone (P=0.0135). However, the 90% confidence intervals (CIs) for the AUCt and Cmax ratios for the two treatments were within the accepted limits for bioequivalence (1.03, 1.13 and 0.97, 1.12, respectively).

CONCLUSION

These results in healthy subjects indicate that there is no systemic pharmacodynamic or pharmacokinetic interaction between inhaled salmeterol and fluticasone propionate when given in combination.

Gene correction in hematopoietic progenitor cells by homologous recombination

Homologous recombination (gene targeting) has many desirable features for gene therapy, because it can precisely correct mutant genes and restore their normal expression, and random nonhomologous integration of DNA is infrequent in cells in which homologous recombination has occurred. There are, however, no reports of attempts to use homologous recombination to correct mutant genes in normal hematopoietic stem cells (HSCs), which are prime cells for therapy of a variety of hematological and other conditions, presumably because of their low abundance and uncertainty that homologous recombination can occur at a usable frequency in these cells. The experiments reported here encourage optimism in this respect by demonstrating targeted correction of a defective hypoxanthine phosphoribosyltransferase gene in hematopoietic progenitor cells that can form colonies in methylcellulose culture. These clonogenic cells are in the same lineage as HSCs but are more abundant and more mature and so less pluripotent. Corrected colonies were identified by their survival in selective medium after electroporation of correcting DNA into unfractionated mouse bone marrow cells and were confirmed by reverse transcription-PCR and sequencing. The observed frequency (4.4 +/- 3.3 x 10(-5) per treated clonogenic cell) is the same as in embryonic stem cells (2.3 +/- 0.4 x 10(-5)) with the same DNA and mutation. These data suggest that gene targeting to correct mutant genes eventually will prove feasible in HSCs capable of long-term bone marrow reconstitution.

Hematopoietic stem cells with controllable tEpoR transgenes have a competitive advantage in bone marrow transplantation

In a previous study, it was found that a truncated erythropoietin receptor transgene (tEpoR tg) enables multilineage hematopoietic progenitor amplification after treatment with erythropoietin (epo) in vitro and in vivo. This study used competitive bone marrow (BM) repopulation to show that tEpoR tg facilitates transplantation by hematopoietic stem cells (HSC). Individual multilineage colonies, committed myeloid progenitor colonies, and lymphoid colonies (pre-B colony-forming units) were grown from the marrow of animals 6 months after they received a 50/50 mixture of transgene and wild-type BM cells. In epo-treated recipients, the transgene-bearing cells significantly outcompeted the wild-type cells (84%-100% versus 16%-0%, respectively). In recipients treated with phosphate-buffered saline, the repopulation was minimally different from the donor mixture (49%-64% transgene versus 51%-36% wild-type). The epo-induced repopulation advantage is maintained in secondary transplants. In addition, neither accelerated HSC depletion nor uncontrollable proliferation occurred during epo-stimulated serial transplants of transgene-containing BM. Thus, the tEpoR tg functions in a benign fashion in HSC and allows for a significant and controllable repopulation advantage in vivo without excessive HSC depletion relative to wild-type BM. (Blood. 2000;95:3710-3715)

Teaching nursing history: the Redwood experience

This paper traces the development of nursing history from the great names approach of the early 20th century to the new analytical directions represented by the work of Davies and Maggs. It discusses the relevance of the study of nursing history in the present climate. The author shares the experiences of incorporating nursing history into a pre-registration diploma programme and suggests ways of evaluating this course of study.

Marketing the municipal model: the London County Council Nursing Service recruitment strategies 1930-45

Municipally administered, with its origins in the Poor Laws, the LCC Nursing Service could be said to have been a Cinderella Service in comparison with the prestigious London voluntary hospitals. This paper analyses the recruitment strategies of the London County Council Nursing Service within the context of the overall national situation during the 1930s and the Second World War. These can be categorised as cosmetic, reactive, innovative and pragmatic. An astute nursing leadership could use the resources of a large municipal authority to challenge the voluntary hospitals in the nursing labour market in the area of acute hospital care. The image of the acute hospitals could be favourably projected; however, local as well as national difficulty persisted in the recruitment of candidates to Cinderella services such as tuberculosis sanatoria.

A case of Isaacs' syndrome with associated central nervous system findings

We report a 44-year-old female with Isaacs' syndrome, peripheral motor neuropathy, and features of central pontine myelinolysis (CPM). The patient presented with stiffness and muscle spasms accompanied by profound sweating. She also had bilateral Babinski signs. Electrodiagnostic abnormalities were characteristic of Isaacs' syndrome. Magnetic resonance imaging demonstrated features of CPM. She gained modest relief from baclofen, valproate, and diazepam. She improved dramatically following plasmapheresis and continued to recover on prednisone. She was weaned from steroids without relapse.

A longitudinal study of the growth of matched pairs of vegetarian and omnivorous children, aged 7-11 years, in the north-west of England

OBJECTIVE

To assess the ability of a meat free diet to support normal growth of children.

DESIGN

A one year longitudinal observational case--comparison study of growth.

SETTING

Children were recruited mainly through schools from Merseyside and all measurements were taken in their homes.

SUBJECTS

Fifty 'free-living' children following meat free diets, aged 7-11 y (expected to be pre-pubertal), were compared with a control group of 50 omnivores matched for age, sex and ethnic group.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Height, weight, upper arm skinfold thicknesses and mid-upper arm circumference measurements were taken at baseline and one year later. The increments over one year were each analysed using a multiple stepwise regression model which derived predicted increments controlled for a variety of factors other than the diet factor.

RESULTS

Of all the anthropometric measurements examined only the predicted height increment of the vegetarians was slightly greater than that of the omnivores (difference in predicted height increment = 0.47 cm, P = 0.05). This difference was only apparent after allowing for father's height, maternal smoking habit and number of siblings. A tendency for the vegetarians to be leaner than the omnivores was not significant at the 5% level and both the vegetarian and omnivorous groups lay close to the 50th percentiles for both height and weight (Child Growth Foundation, 1994).

CONCLUSIONS

The results suggest that these children who followed a meat free diet and conventional lifestyles grew at least as well as children who ate meat.

Pre-radiation chemotherapy for malignant glioma in adults

PURPOSE

To review our experience with pre-radiation chemotherapy for malignant glioma.

METHODS

Consecutive adults with newly diagnosed glioblastoma, anaplastic astrocytoma, anaplastic oligodendroglioma and anaplastic mixed glioma with a Karnofsky Performance Score of 60 or greater were treated with one cycle of procarbazine, lomustine and vincristine or lomustine alone, prior to radiation. Computed tomographic scans were obtained soon after surgery, eight weeks later, after radiation, and at regular intervals thereafter. The effects of chemotherapy and subsequent radiation and durations of tumor control and survival were assessed in this single arm, single center, prospective trial.

RESULTS

Thirty-seven patients started chemotherapy, 36 were rescanned eight weeks after diagnosis. Five patients (16%) responded to the first cycle of chemotherapy, three had glioblastoma and two anaplastic oligodendroglioma. Seven (19%) progressed during the first cycle, 6 had glioblastoma; with the addition of radiation one progressive case responded, three stabilized, and three continued to progress. Median times to progression and median durations of survival were 26 weeks and 60 weeks for the entire group, 24 weeks and 44 weeks for glioblastoma, and greater than 104 weeks for anaplastic astrocytoma.

CONCLUSIONS

Most patients with glioblastoma do not respond to one cycle of nitrosourea-based chemotherapy given prior to radiation, but patients with anaplastic oligodendroglioma sometimes do. Patients with anaplastic astrocytoma may not respond to one cycle of chemotherapy, but often respond to subsequent radiation. Judging by survival results, radiation can be delayed eight weeks without appearing to compromise patient outcome.

IMPLICATIONS

Pre-radiation chemotherapy with newer agents can be evaluated more fully in the future knowing that brief delays in radiation are unlikely to yield substantially inferior results.

The dietary intake of a group of vegetarian children aged 7-11 years compared with matched omnivores

There is a lack of information concerning the diet of vegetarian children. The present study compared the dietary intake of fifty vegetarian children, aged 7-11 years, with fifty matched omnivores. Three 3 d food records were completed by each child at intervals of 6 months. The day after completing the record each child was interviewed to clarify food items and assess portion sizes. Food records were analysed using Microdiet (University of Salford). Finger-prick cholesterol and haemoglobin measurements were taken from a subsample of the group. Only one child's family was a member of the Vegetarian Society and almost one-third of vegetarian children had omnivorous parents (seventeen of fifty subjects). The energy intake (MJ) of the vegetarians was significantly lower than that of the omnivores, 7.6 (SD 1.05) and 8.0 (SD 1.36) respectively; there were no significant differences in Fe or fat intakes. For the vegetarians polyunsaturated:saturated fat ratio (P:S 0.7 (SD 0.04)) and NSP intake (13.8 (SD 0.7) g/d) were significantly higher than those of the omnivores (P:S 0.5 (SD 0.02), NSP 10.3 (SD 0.4) g/d). There was no significant difference in cholesterol measurements (mmol/l) between the two groups: vegetarian 3.5 (SD 0.12), omnivores 3.7 (SD 0.15). The haemoglobin level (g/l) of the vegetarians (11.8 (SD 0.2)) was significantly below that of the omnivores (12.4 (SD 0.2)); 47.5% of the vegetarian children fell below the third percentile of the Dallman reference curves (Dallman & Siimes, 1979). The intake of the vegetarians more closely resembled current recommendations (Department of Health, 1991), although they need to be as aware as omnivores of the need to reduce fat intake. The haemoglobin levels of vegetarian children suggest that they need dietary advice to ensure optimal absorption of Fe.

Evaluating glioma therapies: modeling treatments and predicting outcomes

BACKGROUND

Intra-arterial chemotherapy with carmustine (BCNU) and interstitial radiation therapy with the use of stereotactically placed 125I sources are aggressive local therapies for malignant glioma. These therapies emerged in the 1980s and both appeared promising in phase II studies but yielded disappointing results in subsequent randomized controlled trials by the Brain Tumor Cooperative Group (BTCG). Florell and colleagues had prepared us for the possibility that brachytherapy would have less impact on survival than anticipated from the phase II experience by demonstrating that patients who were judged eligible for interstitial radiation, but treated conventionally, lived significantly longer than those who were ineligible and had better than average outcomes.

PURPOSE

To further examine the impact of patient selection on outcome, we used the database of Florell et al. to assess the survival of patients with malignant glioma who were eligible or ineligible for chemotherapy by three intra-arterial methods, one of which was similar to that employed by the BTCG in its randomized, controlled trial evaluating intra-arterial BCNU.

METHODS

The medical records and computed tomography (CT) scans of 102 consecutive patients with malignant glioma receiving standard treatment (i.e., maximum feasible surgical resection, external-beam radiotherapy, and often adjuvant systemic chemotherapy) at a single cancer center in Canada during the calendar years 1988 and 1989 were used for this analysis. Based on CT imaging and blind to outcome, an interventional neuroradiologist decided which patients were eligible or ineligible for intra-arterial chemotherapy via injection of two major arteries, via injection of one major artery, or via selective middle-cerebral artery injection. A Karnofsky performance score of greater than or equal to 60 was required. The percent of eligible patients, the median survival time, and the distribution of prognostic factors were analyzed for each group of eligible and ineligible patients. Median survival times were compared with the use of the generalized Wilcoxon (Breslow) test. All P values were based on two-tailed tests.

RESULTS

For two-vessel treatment, 72.5% of the patients (74 of 102) were eligible; the eligible patients on average lived longer than the ineligible patients (14.8 versus 3.5 months; P < .00001). For one-vessel treatment, 48% of the patients (49 of 102) were eligible; again, the eligible patients lived longer than the ineligible patients (18.4 versus 5.1 months; P < .00001). For middle-cerebral artery treatment, 30% of the patients (31 of 102) were eligible, and these eligible patients did live somewhat longer than the ineligible patients, but this result did not reach statistical significance (13.6 versus 9.9 months; P = .1304). Trends were similar for patients with glioblastoma multiforme and anaplastic glioma. The median duration of survival was 11.4 months for all patients.

CONCLUSIONS

Patients who were eligible for intra-arterial chemotherapy lived significantly longer or somewhat longer (depending on the selection criteria used) than patients who were ineligible and had better than expected outcomes. Patients who were judged eligible for intra-arterial chemotherapy by the two-vessel method and the control group in the BTCG phase III trial of intra-arterial chemotherapy had similar median survival times (14.8 versus 14.0 months).

IMPLICATIONS

Modeling treatments with the use of a comprehensive clinical and imaging database of unselected, conventionally treated patients may help investigators decide if new therapies warrant definitive evaluation in randomized trials by measuring the degree to which patient selection may have enhanced phase II study outcomes.

A mouse model for beta 0-thalassemia

We have used a "plug and socket" targeting technique to generate a mouse model of beta 0-thalassemia in which both the b1 and b2 adult globin genes have been deleted. Mice homozygous for this deletion (Hbbth-3/Hbbth-3) die perinatally, similar to the most severe form of Cooley anemia in humans. Mice heterozygous for the deletion appear normal, but their hematologic indices show characteristics typical of severe thalassemia, including dramatically decreased hematocrit, hemoglobin, red blood cell counts, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration, as well as dramatically increased reticulocyte counts, serum bilirubin concentrations, and red cell distribution widths. Tissue and organ damage typical of beta-thalassemia, such as bone deformities and splenic enlargement due to increased hematopoiesis, are also seen in the heterozygous animals, as is spontaneous iron overload in the spleen, liver, and kidneys. The mice homozygous for the b1 and b2 deletions should be of great value in developing therapies for the treatment of thalassemias in utero. The heterozygous animals will be useful for studying the pathophysiology of thalassemias and have the potential of generating a model of sickle cell anemia when mated with appropriate transgenic animals.

Prior convictions of child molesters

Both the stereotypes held by investigating officers and the clinical literature assume that child molesters have distinct characteristics. these are generally expected to be reflected in a prior offence history of assaults on children and sexually deviant behaviour. A further assumption is that there is an escalation of offending, less serious crimes being precursors to more serious ones. To test these assumptions the criminal convictions, if any, prior to the offence were examined for all 416 detected offenders who had committed sexual offences upon children aged between 5 and 12 years, in the Lancashire Police area, during 1987, 1988 and 1989. Of the 183 (44%) of offenders who had previous convictions, 72 involved indecency, 17% of the total sample. Only 9 (2%) of offenders had an exclusive conviction history in respect of indecency. Previous convictions for theft, burglary and violence were all much more frequent. The results also do not generally support the hypothesis that serious offenders have progressed from less serious offences against children. A criminal opportunist model is proposed as of more value for guiding investigations than the existing stereotypes.

Injury and death as a result of seizures

The literature contains little information regarding the incidence of injury or death in the general population caused by seizures. We prospectively surveyed all patient visits to the four emergency departments serving adults in the Halifax-Dartmouth metropolitan area (adult population 260,935) from September 1, 1990 to August 31, 1991 to identify patients treated as a result of a seizure. The medical examiner's records were also surveyed for deaths related to seizures. We identified 560 patient visits precipitated by seizures of all types and etiologies except those secondary to acute trauma. Injuries or deaths occurred during 84 of 560 seizures (15%). Sixty-three patients incurred 89 injuries during 77 seizures (some patients had more than one injury, and some patients had injuries on more than one occasion). The incidence of seizures resulting in injury was 29.5 in 100,000 population. The most common injuries were head contusions and head lacerations. Most injuries were minor and required little or no treatment. Deaths occurred during seven seizures (1.2%). The incidence of death as a complication of seizures was 2.68 in 100,000 population. Deaths were not restricted to patients with epilepsy. We conclude that the incidence of seizures causing injury or death in the general population was 32.2 in 100,000 population and that 15% of seizures brought to medical attention resulted in injury or death. Most injuries were minor but seven patients died during seizures, indicating that seizures remain a life-threatening event.

Changes in prelicensure training rules leaving sour taste in medical students' mouths

Images

The ventilatory and acid-base physiology of the toad, Bufo marinus, during exposure to environmental hyperoxia

Bufo marinus which were exposed to a step increase of 330-350 torr O2 for a 20 h period ceased lung ventilations and buccal movements were markedly decreased. Toads which were sitting in water did not show elevations in PaCO2 or a depressed pHe but animals which were dehydrated for a 24 h period prior to high O2 exposure developed a mild acidosis, which, typical of most amphibian species, was uncompensated.

Immediate and long-term effects on visual acuity of surgically induced strabismus in kittens

In order to isolate some of the factors responsible for strabismic amblyopia as well as to ascertain the time course of its development, frequent measurements were made of the visual acuity of the two eyes of kittens following imposition of surgically induced strabismus. Following behavioural training on a jumping stand, strabismus was induced in all but one animal by simple section of either the lateral (esotropia) or medial (exotropia) rectus muscle of one eye. The one exception was a kitten on which esotropia was induced by another common but more radical surgical procedure that involved removal of the body of both the lateral rectus and superior oblique muscles of one eye. There was a surprising difference between the immediate consequences for vision of section of the lateral and medial rectus muscles that were reflected by equally large differences in the magnitude of the amblyopia that developed eventually in the two situations. Following section of the lateral rectus muscle, there was an immediate reduction in the visual acuity of the operated eye of as much as 2 octaves after which vision returned to normal levels over 4 to 8 days. The acuity of the two eyes remained comparable for a few days after which the vision of the operated eye began to decline once more, signalling the onset of amblyopia some 10 to 12 days following imposition of strabismus. In contrast to the severity of these effects, the effects observed following section of the medial rectus were both mild and transitory. Furthermore, whereas all kittens that were rendered esotropic early developed amblyopia, none of the kittens that were made exotropic at the same age did so. Together, these results suggest that factors associated with the immediate consequences of the surgical procedure employed to produce a misalignment of the visual axes may contribute to the severity of the effects of surgically induced strabismus.