[Melatonin. Neurobiological background and neuropsychiatric application in children]. / Melatonine. Neurobiologische achtergronden en neuropsychiatrische toepassing bij kinderen.

BACKGROUND: The therapeutic use of melatonin in children is based on research into the properties of the product and on experience gained from its use in specific populations. Our knowledge about melatonin is increasing steadily. AIM: To summarise the state of our knowledge regarding melatonin and to assess the clinical relevance of this knowledge. METHOD: The PsycINFO and Pub Med databases were used to locate and study the relevant literature, using as key words 'melatonin', 'child*' and 'adolescen*'. RESULTS: Melatonin is a fat-soluble neuro-hormone which is produced in the pineal gland and is characterised by a circadian secretion that operates via a feedback circuit. Research has identified various neurobiological mechanisms which have chronobiotic, hypnotic, anticonvulsive, anxiolytic and antioxidant effects. With regard to the use of melatonin for chronobiotic and hypnotic purposes, the literature seems to be unanimous concerning the efficacy and safety of melatonin, at least in the short-term, in cases where the secretion of melatonin is disrupted. In clinical applications the efficacy is assessed by compiling a 24-hour profile within which the moment of the nocturnal increase in secretion is compared to the time at which the patient is expected to fall asleep. So far not enough is known about the effects of long-term use and about the interaction of melatonin with pubertal development. No consensus has yet been reached concerning the role of melatonin in the treatment of affective disorders. Recently there has been increasing interest in the effects of melatonin on seizures and the mechanism involved. CONCLUSION: Melatonin is a product with considerable potential provided it is administered in a controlled manner and the results are assessed accurately. At the moment it seems advisable to use melatonin only in clinical trials.

Is a patient's self-reported health-related quality of life a prognostic factor for survival in non-small-cell lung cancer patients? A multivariate analysis of prognostic factors of EORTC study 08975.

BACKGROUND: The aim of this prognostic factor analysis was to investigate if a patient's self-reported health-related quality of life (HRQOL) provided independent prognostic information for survival in non-small cell lung cancer (NSCLC) patients. PATIENTS AND METHODS: Pretreatment HRQOL was measured in 391 advanced NSCLC patients using the EORTC QLQ-C30 and the EORTC Lung Cancer module (QLQ-LC13). The Cox proportional hazards regression model was used for both univariate and multivariate analyses of survival. In addition, a bootstrap validation technique was used to assess the stability of the outcomes. RESULTS: The final multivariate Cox regression model retained four parameters as independent prognostic factors for survival: male gender with a hazard ratio (HR) = 1.32 (95% CI 1.03-1.69; P = 0.03); performance status (0 to 1 versus 2) with HR = 1.63 (95% CI 1.04-2.54; P = 0.032); patient's self-reported score of pain with HR= 1.11 (95% CI 1.07-1.16; P < 0.001) and dysphagia with HR = 1.12 (95% CI 1.04-1.21; P = 0.003). A 10-point shift worse in the scale measuring pain and dysphagia translated into an 11% and 12% increased in the likelihood of death respectively. A risk group categorization was also developed. CONCLUSION: The results suggest that patients' self-reported HRQOL provide independent prognostic information for survival. This finding supports the collection of such data in routine clinical practice.

Carboplatin and paclitaxol (Taxol) as an induction regimen for patients with biopsy-proven stage IIIA N2 non-small cell lung cancer. an EORTC phase II study (EORTC 08958).

The aim of this study was to document the activity and toxicity of paclitaxel (Taxol)/carboplatin when used as induction chemotherapy in patients with stage IIIA N2 non-small cell lung cancer (NSCLC) prior to definitive local treatment within a large, ongoing comparative study (EORTC 08941). 52 eligible, consenting, chemotherapy-naïve patients with NSCLC, median age of 60 years, stage IIIA N2 disease and the ability to tolerate a pneumonectomy received paclitaxel 200 mg/m2 as a 3-h infusion followed by carboplatin at an area under the concentration curve (AUC) of 6 every 3 weeks for three courses. Most patients received three courses. No grade 3/4 anaemia or thrombocytopenia was documented. Over all of the cycles, 6% (3 patients) experienced grade 3 leucopenia while 63% (32/51 patients) experienced grade 3-4 neutropenia. There was 1 patient (2%) with febrile neutropenia, no early or toxic deaths and no hypersensitivity reactions. Severe non-haematological toxicity was uncommon, with the exception of grade 3 alopecia in 39%, lethargy in 8% and myalgia in 6%. Of the eligible patients (n=52), there was one complete response (CR) and 32 partial responses (PR), resulting in a response rate of 64% (95% Confidence Interval (CI) 49%-76%). Of the 15 eligible patients randomised to surgery after induction chemotherapy, 3 patients did not receive surgery and 2 patients (n=12) had no tumour in the mediastinal nodes (17%). Resections were considered complete in 2 of the 12. Median survival for all eligible patients (n=52) was 20.5 months (95% CI 16.1-31.2), with an estimated 1-year survival rate of 68.5% (95% CI 55.2-81.7). In patients with N2 stage IIIA NSCLC, paclitaxel/carboplatin is an active and very well-tolerated induction regimen.

Temozolomide in patients with advanced non-small cell lung cancer with and without brain metastases. a phase II study of the EORTC Lung Cancer Group (08965).

This study was performed to evaluate the activity of single-agent temozolomide in two groups of chemotherapy-naïve non-small cell lung cancer (NSCLC) patients, with (12 patients) and without (13 patients) brain metastases (BM). Patients in both groups were treated with temozolomide 200 mg/m(2)/day, administered orally for 5 consecutive days of a 28-day cycle. Treatment was continued for up to six cycles, disease progression or unacceptable toxicity. The median number of received cycles was only one in the group with and two in the group without BM, and early disease progression was the main reason for treatment discontinuation. Toxicity was moderate-in the group of patients with BM, the most frequently observed grade 3 or 4 side-effects included thrombocytopenia (17%), granulocytopenia (17%), lethargy (17%); other neurological (17%) and other genitourinary toxicity (17%). Patients without BM experienced anaemia (15%), thrombocytopenia (23%), nausea (15%) and lethargy (15%). This trial was designed according to Simon one-sample two-stage testing procedure and both groups of patients were assessed separately. No objective response was observed in either group and the study was closed after the first step of accrual with the conclusion of a lack of therapeutic activity of single-agent temozolomide in patients with stage IV NSCLC.

The activity of raltitrexed (Tomudex) in malignant pleural mesothelioma: an EORTC phase II study (08992).

We investigated the activity and toxicity of raltitrexed (Tomudex) as a single agent treatment in patients with Malignant Pleural Mesothelioma (MPM) in a multicentre phase II European Organization for Research and Treatment of Cancer (EORTC) study. This study enrolled chemonaíve patients with histologically-confirmed measurable MPM. Raltitrexed was administered at the dose of 3 mg/m(2) intravenous (i.v.) bolus on an outpatient basis every 3 weeks. A maximum of eight cycles was planned in cases with an absence of progression or unacceptable toxicity. 24 patients received a total of 104 courses. 5 patients (20.8%, 95% confidence interval (CI) 7.1-42.2%) had a partial response (PR), which was confirmed by an independent radiology committee. Toxicity was mild, with diarrhoea, nausea, vomiting, fatigue and neutropenia as the major side-effects, but not exceeding grade 3 toxicity. We conclude that raltitrexed has activity as a single agent in the treatment of MPM, and that further studies with this drug in MPM are warranted.

Economic evaluation of antibiotic prophylaxis in small-cell lung cancer patients receiving chemotherapy: an EORTC double-blind placebo-controlled phase III study (08923).

BACKGROUND: To determine whether the cost of prophylactic antibiotics during chemotherapy is offset by cost savings due to a decreased incidence of febrile leukopenia (FL). PATIENTS AND METHODS: Small-cell lung cancer (SCLC) patients were randomised to standard or intensified chemotherapy with granulocyte colony-stimulating factor to assess the impact on survival (n = 244). In addition, patients were randomised to prophylactic ciprofloxacin and roxithromycin or placebo to assess the impact on FL (n = 161). The economic evaluation examined the costs and effects of patients taking antibiotics versus placebo. Medical resource utilisation was documented prospectively, including 33 patients from one centre in The Netherlands (NL) and 49 patients from one centre in Germany (GE). The evaluation takes the perspective of the health insurance systems and of the hospitals. Sensitivity analyses were performed. RESULTS: In the main trial, prophylactic antibiotics reduced the incidence of FL, hospitalisation due to FL and use of therapeutic antibiotics by 50%. In GE, the incidence of FL was not reduced by prophylaxis. This resulted in an average cost difference of only 35 Euros [95% confidence interval (CI) (-)1.713-2.263] in favour of prophylaxis (not significant). In NL, prophylaxis reduced the incidence of FL by nearly 50%, comparable with the results of the main trial, resulting in a cost difference of 2706 Euros [95% CI 810-5948], demonstrating savings in favour of prophylactic antibiotics of nearly 45%. Sensitivity analyses indicate that with an efficacy of prophylaxis of 50%, and with expected costs of antibiotic prophylaxis of 500 Euros or less, cost savings will incur over a broad range of baseline risks for FL; that is, a risk >10-20% for FL per cycle. CONCLUSIONS: Giving oral prophylactic antibiotics to SCLC patients undergoing chemotherapy is the dominant strategy in both GE and NL, demonstrating both cost-savings and superior efficacy. The sensitivity analyses demonstrate that, due to the efficacy of prophylactic antibiotics and their low unit cost, cost savings will incur over a broad range of baseline risks for FL. We recommend the use of prophylactic antibiotics in patients at risk for FL during chemotherapy.

A phase II EORTC study of temozolomide in patients with malignant pleural mesothelioma.

The aim of this study was to investigate the anti-tumour activity of temozolomide in patients with malignant pleural mesothelioma. 27 chemotherapy-naïve patients with histologically-proven malignant mesothelioma were treated with temozolomide 200 mg/m2/day, given orally on days 1-5 of each 28-day cycle. Therapy continued up to 10 cycles unless disease progression or excessive toxicity mandated discontinuation. Toxicity, symptom improvement and pain intensity were regularly assessed. With a median relative dose intensity of 97%, toxicity was moderate with grade 3 or more nausea, vomiting, thrombocytopenia, leucocytopenia, neutropenia, febrile leucocytopenia, arthralgia, infection and fever with infection occurring in 13, 13, 10, 3, 7 and 3% of patients for the remaining events, respectively. Overall, 1 objective response was observed (response rate 4%, 95% Confidence Interval (CI): 0.1-19). Median survival was 8.2 months. Symptom assessment showed no improvement and an increase of pain was observed during the study. Thus, oral temozolomide is an inactive agent in malignant mesothelioma.

From chemoprevention and organ preservation programmes to postoperative management: major achievements and strategies of the EORTC Head and Neck Cancer Group.

The purpose of this article is to review the most significant results of the clinical studies conducted in the past two decades by the EORTC Head and Neck Cancer Group (HNCG). As for phase III trials, the HNCG investigated, besides the efficacy of chemopreventive drugs, the impact of cytostatic agents on various therapeutic targets, in combination or not with surgery and chemotherapy. These targets were: (a) chemo-prevention in curatively treated early stage disease; (b) organ preservation programmes in patients with operable tumour, comparing immediate surgery versus first-line chemotherapy; (c) postoperative management of locally advanced tumours, comparing radio-chemotherapy versus radiotherapy alone. Other phase II and phase III studies were also completed to investigate drug activity in advanced and/or recurrent head and neck squamous cell and adenoid cystic carcinomas. The present article will also analyse the strategies developed within the Group in the field of translational research.

Overview of past, present and future of the EORTC Lung Cancer Group. European Organisation for Research and Treatment of Cancer.

The EORTC Lung Cancer Group (LCG) is a multidisciplinary international group of experts performing clinical research in lung cancer since 1962. Originally, the group consisted mainly out of French and Belgian investigators and expanded gradually into a wide range of investigators from all European Union countries, as well as some investigators from Switzerland, Poland, Czech Republic, Egypt, Slovenia, South Africa, Peru, Brazil and Cyprus. Despite the wide collaboration, it remains a difficult task to perform high quality large clinical research trials to answer important scientific questions in the treatment of lung cancer. For this reason, the EORTC Lung Cancer Group has invested a lot of efforts in promoting worldwide, randomised phase III studies in collaboration with other Groups. Furthermore, the LCG promotes small phase II trials of new drugs or treatments for lung cancer and stimulates the investigation of new strategies and treatments for rare intrathoracic malignancies.

Reduction of chemotherapy-induced febrile leucopenia by prophylactic use of ciprofloxacin and roxithromycin in small-cell lung cancer patients: an EORTC double-blind placebo-controlled phase III study.

BACKGROUND: CDE (cyclophosphamide, doxorubicin, etoposide) is one of the standard chemotherapy regimens in the treatment of small-cell lung cancer (SCLC), with myelosuppression as dose-limiting toxicity. In this trial the impact of prophylactic antibiotics on incidence of febrile leucopenia (FL) during chemotherapy for SCLC was evaluated. PATIENTS AND METHODS: Patients with chemo-naïve SCLC were randomized to standard-dose CDE (C 1,000 mg/m2 day 1, D 45 mg/m2 day 1, E 100 mg/m2 days 1-3. i.v., q 3 weeks, x5) or to intensified CDE chemotherapy (125% dose, q 2 weeks, x4, with filgrastim 5 microg/kg/day days 4-13) to assess the impact on survival (n = 240 patients). Patients were also randomized to prophylactic antibiotics (ciprofloxacin 750 mg plus roxithromycin 150 mg, bid. days 4-13) or to placebo in a 2 x 2 factorial design (first 163 patients). This manuscript focuses on the antibiotics question. RESULTS: The incidence of FL during the first cycle was 25% of patients in the placebo and 11% in the antibiotics arm (P = 0.010; 1-sided), with an overall incidence through all cycles of 43% vs. 24% respectively (P = 0.007; 1-sided). There were less Gram-positive (12 vs. 4), Gram-negative (20 vs. 5) and clinically documented (38 vs. 15) infections in the antibiotics arm. The use of therapeutic antibiotics was reduced (P = 0.013; 1-sided), with less hospitalizations due to FL (31 vs. 17 patients, P = 0.013: 1-sided). However, the overall number of days of hospitalization was not reduced (P = 0.05; 1-sided). The number of infectious deaths was nil in the antibiotics vs. five (6%) in the placebo arm (P = 0.022; 2-sided). CONCLUSIONS: Prophylactic ciprofloxacin plus roxithromycin during CDE chemotherapy reduced the incidence of FL, the number of infections, the use of therapeutic antibiotics and hospitalizations due to FL by approximately 50%, with reduced number of infectious deaths. For patients with similar risk for FL, the prophylactic use of antibiotics should be considered.

Gemcitabine and cisplatin as induction regimen for patients with biopsy-proven stage IIIA N2 non-small-cell lung cancer: a phase II study of the European Organization for Research and Treatment of Cancer Lung Cancer Cooperative Group (EORTC 08955).

PURPOSE: Our objective was to better define the activity/feasibility of gemcitabine/cisplatin (GC) as induction chemotherapy in patients with stage IIIA N2 non-small-cell lung cancer (NSCLC) followed by surgery or radiotherapy within a large, ongoing comparative study (EORTC 08941). PATIENTS AND METHODS: Forty-seven chemotherapy-naive patients with NSCLC, median age of 58 years, stage IIIA N2 disease, World Health Organization performance status of 0 or 1, and the ability to tolerate a pneumonectomy received gemcitabine 1,000 mg/m(2) on days 1, 8, and 15 and cisplatin 100 mg/m(2) on day 2, every 4 weeks. Patients received induction chemotherapy (three cycles) before re-evaluation and randomization to surgery or radiotherapy. RESULTS: Grade 3/4 thrombocytopenia, the main hematologic toxicity, occurred in 60% of patients but was not associated with bleeding. Full-dose gemcitabine was given in 48% of the courses. Severe nonhematologic toxicity was uncommon. Two patients with preexisting, autoimmune pulmonary fibrosis had deterioration of pulmonary function after radiotherapy. Thirty-three (70.2%; 95% confidence interval, 55.1% to 82.7%) of the 47 eligible patients had objective responses (three complete responses and 30 partial responses). Mediastinal nodes were tumor-free after induction therapy in 53% of cases. Resections were considered complete in 71% of the patients who underwent thoracotomy after induction therapy. Median survival for all recruited patients (N = 53) was 18.9 months, with an estimated 1-year survival rate of 69%. CONCLUSION: In patients with N2 stage IIIA NSCLC, GC is a highly active and well-tolerated induction regimen. GC should be explored in combination with surgery or radiotherapy in stage I and II patients.

A Phase II study of gemcitabine in patients with malignant pleural mesothelioma. European Organization for Research and Treatment of Cancer Lung Cancer Cooperative Group.

BACKGROUND: Gemcitabine has shown activity in patients with less chemosensitive solid tumors. Phase II screening of novel drugs is an accepted method with which to investigate new therapies in malignant mesothelioma. The European Organization for Research and Treatment of Cancer-Lung Cancer Cooperative Group has performed several sequential Phase II trials of new agents for the treatment of mesothelioma over the last 10 years. METHODS: Twenty-seven chemotherapy-naive patients with histologically proven malignant mesothelioma were treated with gemcitabine as a 30-minute intravenous administration of 1250 mg/m2 on Days 1, 8, and 15 of a 28-day cycle. Therapy continued for up to ten cycles unless disease progression or excessive toxicity mandated discontinuation. RESULTS: With a median relative dose intensity of 96%, toxicity was mild and neutropenia of > or = Grade 3 (according to National Cancer Institute criteria) occurred in 30% of patients, without episodes of febrile neutropenia. One case of hemolytic-uremic syndrome, most likely related to gemcitabine use, was observed. Overall, 2 objective responses were observed (response rate of 7%; 95% confidence interval, 1-24%). The median survival was 8 months. CONCLUSIONS: At the prescribed dosage and schedule, single agent gemcitabine appears to have limited activity in chemotherapy-naive patients with malignant pleural mesothelioma.

Randomized study of paclitaxel-cisplatin versus cisplatin-teniposide in patients with advanced non-small-cell lung cancer. The European Organization for Research and Treatment of Cancer Lung Cancer Cooperative Group.

PURPOSE: To compare two cisplatin based chemotherapy schedules in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: A total of 332 patients with advanced NSCLC were randomized to receive cisplatin 80 mg/m2 on day 1 either in combination with teniposide 100 mg/m2 on days 1, 3, and 5 (arm A) or paclitaxel 175 mg/m2 by 3-hour infusion on day 1 (arm B); cycles were repeated every 3 weeks. RESULTS: Fifteen patients were ineligible; patient characteristics were well balanced between the two arms: 71% were male, 71% had less than 5% weight loss, 89% had a World Health Organization (WHO) performance status of 0 to 1, 51% had adenocarcinoma, and 61% had stage IV disease. Hematologic toxicity was significantly more severe in arm A (leukopenia, neutropenia, and thrombocytopenia grade 3 or 4: 66% v 19%, 83% v 55%, 36% v 2% in arms A and B, respectively), which resulted in more febrile neutropenia (27% v 3% in arms A and B, respectively), dose reductions, and treatment delays. There were a total of nine toxic deaths, six due to neutropenic sepsis: five in arm A and one in arm B. In contrast, arthralgia/myalgia (grade 2 or 3, 4% v 17%), peripheral neurotoxicity (grade 2 or 3, 6% v 29%), and hypersensitivity reactions (1% v 7%, all grades) were significantly more frequent in arm B. The frequency and severity of other toxicities were comparable between the two arms. Responses were one complete and 44 partial on arm A (28%) and two complete and 61 partial (41%) on arm B (P = .018). There was no significant difference in survival, with median and 1-year survivals 9.9 versus 9.7 months and 41% versus 43%, respectively in arm A and B. Progression-free survival was 4.9 and 5.4 months in arm A and B, respectively. Selected centers participated in a quality-of-life (QoL) assessment, which was performed by the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 and LC-13 administered at baseline and every 6 weeks thereafter. Arm B achieved a better score at week 6 for emotional, cognitive and social functioning, global health status, fatigue, and appetite loss, which was lost at 12 weeks. In conclusion, arm B appears superior to arm A with regard to response rate, side effects, and QoL. CONCLUSION: Although survival was not improved, arm B offers a better palliation for advanced NSCLC patients than arm A.

Cisplatin/paclitaxel vs cisplatin/teniposide for advanced non-small-cell lung cancer. The EORTC Lung Cancer Cooperative Group. The European Organization for Research and Treatment of Cancer.

A total of 332 patients with advanced non-small-cell lung cancer were randomized by the European Organization for Research and Treatment of Cancer Lung Cancer Cooperative Group (EORTC) to receive one of two cisplatin (Platinol)-based chemotherapy regimens: Paclitaxel (Taxol) 175 mg/m2 given by 3-hour infusion followed by cisplatin 80 mg/m2 on day 1; Or cisplatin 80 mg/m2 on day 1, followed by teniposide (Vumon) 100 mg/m2 given on days 1, 3, and 5. Cycles were repeated every 3 weeks. Preliminary analysis of the results of this phase III trial shows that hematologic toxicity was decidedly more severe in the group treated with cisplatin/teniposide than in those given paclitaxel/cisplatin. Of 264 patients evaluable so far, responses have been observed in 47% of those given paclitaxel and in 29% of those treated with teniposide. However, extramural radiologic response evaluation is still under way, so these figures are expected to change somewhat. It appears clear that the paclitaxel-based therapy affords a benefit in terms of response and toxicity, but survival results are premature and any definite conclusions await final analysis.

Results of the phase II EORTC study comparing paclitaxel/cisplatin with teniposide/cisplatin in patients with non-small cell lung cancer. EORTC Lung Cancer Cooperative Group.

Toxicity and response rates are evaluated in a randomized phase II study comparing paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ)/cisplatin with teniposide/cisplatin in the treatment of non-small cell lung cancer to decide whether this study should continue as a phase III trial. A response was seen in 26% (10 of 38) of the patients receiving teniposide/cisplatin and in 40% (14 of 35) of those receiving paclitaxel/cisplatin. Overall, evidence of toxicity was more severe in the cisplatin/teniposide group, especially with regard to myelotoxicity. Grade 4 neutropenia was seen in 66% of patients receiving teniposide compared with 29% of those treated with paclitaxel/cisplatin. The study is to continue as a phase III trial, with 150 patients expected to participate in each treatment group.

Paclitaxel for malignant pleural mesothelioma: a phase II study of the EORTC Lung Cancer Cooperative Group.

The EORTC Lung Cancer Cooperative Group undertook a phase II study of paclitaxel in 25 chemotherapy-naive patients with malignant pleural mesothelioma. Paclitaxel was given intravenously at a dose of 200 mg m-2 as a 3 h infusion every 3 weeks, after standard premedication with corticosteroids and antihistamines. This regimen was well tolerated, with < 4% of cycles resulting in severe toxicity. No major objective responses were observed and ten patients had stable disease. Median survival time was 39 weeks and the 1 year survival rate was 30%. In conclusion, paclitaxel at the dose and schedule investigated in this trial had no major activity in the treatment of malignant pleural mesothelioma.

Intraobserver variation in the radiological measurement of the anorectal angle.

Seven experts drew the rectal axes of 18 representative proctographic images on two occasions, with a 1-year interval, in order to assess intraobserver variation in the determination of the anorectal angle (ARA). Intraobserver variation (6%) and interobserver variation (17%) were smallest when the central rectal axis was used to determine the ARA. A strong relation was found between inter- and intraobserver variation (r = 0.77). Intraobserver variation tended to be rather small for pictures made during straining, but a relation with the magnitude of the ARA was not found. Although none of the seven experts could reproduce the rectal axes with less than or equal to 10% variation in all 18 pictures, redrawing of the central rectal axis delivered less than or equal to 10% variation in 86% of determinations. It is concluded that intraobserver variation is influenced by the expertise of the investigator, the method of analysis, and the anorectal configuration to be analyzed. Radiologic assessment of the ARA may yield reliable data on the dynamics of the anorectum if performed by a single investigator on x-ray films that allow confident analysis.

Observer variation in the radiological measurement of the anorectal angle.

Determination of the anorectal angle (ARA) and the position of the pelvic floor is, theoretically, very important in understanding the mechanisms of anorectal continence and defaecation. The variability in the measurement of the ARA was analyzed. Nine experts drew ther rectal axis either as a line along the posterior wall of the distal rectum or as the central axis of the rectal lumen on the outlines of 18 representative proctographic images. The standard deviations and ranges of the mean values of each ARA were comparable but large in both methods. On average, the S.D. was 8 degrees and the range value about 23 degrees. Inter-observer variation was not related to the magnitude of the ARA, but rather to the anorectal configuration. Drawing a line along the posterior distal rectal wall is difficult when it is irregular or when the puborectalis impression is indistinct. The central rectal axis is difficult to draw when the junction between the upper and lower rectum is ill defined or when the outlines of the distal rectum are asymmetric e.g. by the presence of a rectocele. Thus, the variability of both methods was not strongly interrelated (r = 0.68 for the median values). It is concluded that, in general, radiologic assessment of the ARA is not reliable enough for comparative investigation of the dynamics of the anorectum.

Purification and properties of coffee-bean alpha-D-galactosidase.

A purification method for alpha-D-galactosidase from Coffea canephora is described. Two enzymes, alpha-D-galactosidases I and II, having molecular weights of 28,000 and 36,500, respectively, were found and extensively purified. The reaction mechanism of alpha-D-galactosidase II was studied. The enzyme hydrolyzed aryl and alkyl alpha-D-galactopyranosides and was severely inhibited by excess of these substrates. No inhibition occurred with raffinose. The influence of para substituents on the reaction rate of phenyl alpha-D-galactopyranosides, the effect of added alcohols, and the non-competitive inhibition by methyl alpha-D-galactopyranoside were investigated. A two-step mechanism with the formation of an enzyme-galactosyl complex is proposed. With aryl galactopyranosides, the reaction of the enzyme-galactosyl complex with water is rate-limiting. Influences of the substituents on the inhibition constant were investigated by linear free-energy relationships, and significant correlations between this constant and electronic parameters could be calculated. The influence of pH on the reaction is complex.