Application of a portable primary standard level graphite calorimeter for absolute dosimetry in a clinical low-energy passively scattered proton beam.

Objective. A calibration service based on a primary standard calorimeter for the direct determination of absorbed dose for proton beams does not exist. A new Code of Practice (CoP) for reference dosimetry of proton beams is being developed by a working party of the UK Institute of Physics and Engineering in Medicine (IPEM), which will recommend that ionisation chambers are calibrated directly in their clinical beams against the proposed Primary Standard Proton Calorimeter (PSPC) developed at the National Physical Laboratory (NPL). The aim of this work is to report on the use of the NPL PSPC to directly calibrate ionisation chambers in a low-energy passively scattered proton beam following recommendations of the upcoming IPEM CoP.Approach. A comparison between the dose derived using the proposed IPEM CoP and the IAEA TRS-398 protocol was performed, andkQvalues were determined experimentally for three types of chambers. In total, 9 plane-parallel and 3 cylindrical chambers were calibrated using the two protocols for two separate visits.Main results. The ratio of absorbed dose to water obtained with the PSPC and with ionisation chambers applying TRS-398 varied between 0.98 and 1.00, depending on the chamber type. The new procedure based on the PSPC provides a significant improvement in uncertainty where absorbed dose to water measured with a user chamber is reported with an uncertainty of 0.9% (1σ), whereas the TRS-398 protocol reports an uncertainty of 2.0% and 2.3% (1σ) for cylindrical and plane-parallel chambers, respectively. ThekQvalues found agree within uncertainties with those from TRS-398 and Monte Carlo calculations.Significance. The establishment of a primary standard calorimeter for the determination of absorbed dose in proton beams combined with the introduction of the associated calibration service following the IPEM recommendations will reduce the uncertainty and improve consistency in the dose delivered to patients.

Cardiac risk stratification in emergency resection for colonic tumours.

BACKGROUND: Despite advances in perioperative care, the postoperative mortality rate after emergency oncological colonic resection remains high. Risk stratification may allow targeted perioperative optimization and cardiac risk stratification. This study aimed to test the hypothesis that the Revised Cardiac Risk Index (RCRI), a user-friendly tool, could identify patients who would benefit most from perioperative cardiac risk mitigation. METHODS: Patients who underwent emergency resection for colonic cancer from 2007 to 2017 and registered in the Swedish Colorectal Cancer Registry (SCRCR) were analysed retrospectively. These patients were cross-referenced by social security number to the Swedish National Board of Health and Welfare data set, a government registry of mortality, and co-morbidity data. RCRI scores were calculated for each patient and correlated with 90-day postoperative mortality risk, using Poisson regression with robust error of variance. RESULTS: Some 5703 patients met the study inclusion criteria. A linear increase in crude 90-day postoperative mortality was detected with increasing RCRI score (37.3 versus 11.3 per cent for RCRI 4 or more versus RCRI 1; P < 0.001). The adjusted 90-day all-cause mortality risk was also significantly increased (RCRI 4 or more versus RCRI 1: adjusted incidence rate ratio 2.07, 95 per cent c.i. 1.49 to 2.89; P < 0.001). CONCLUSION: This study documented an association between increasing cardiac risk and 90-day postoperative mortality. Those undergoing emergency colorectal surgery for cancer with a raised RCRI score should be considered high-risk patients who would most likely benefit from enhanced postoperative monitoring and critical care expertise.

Self-reported and actual adherence to the Tokyo guidelines in the European snapshot audit of complicated calculous biliary disease.

BACKGROUND: Complicated acute biliary calculous disease poses clinical challenges. The European Society of Trauma and Emergency Surgery (ESTES) snapshot audit of complicated biliary calculous disease aims to make novel comparisons between self-reported institutional adherence to the Tokyo guidelines (TG18) and 'real-world' contemporary practice across Europe. METHODS: A preplanned analysis of a prospective observational multicentre audit that captured patients undergoing emergency admission for complicated biliary calculous disease (complicated cholecystitis, biliary pancreatitis, or choledocholithiasis with or without cholangitis) between 1 and 31 October 2018 was performed. An anonymized survey was administered to participating sites. RESULTS: Following an open call for participation, 25 centres from nine countries enrolled 338 patients. All centres completed the anonymized survey. Fifteen centres (60 per cent) self-reported that a minority of patients were treated surgically on index admission, favouring interval cholecystectomy. This was replicated in the snapshot audit, in which 152 of 338 patients (45·0 per cent) underwent index admission cholecystectomy, 17 (5·0 per cent) had interval cholecystectomy, and the remaining 169 (50·0 per cent) had not undergone surgery by the end of the 60-day follow-up. Centres that employed a dedicated acute care surgery model of care were more likely to perform index admission cholecystectomy compared with a traditional general surgery 'on call' service (57 versus 38 per cent respectively; odds ratio 2·14 (95 per cent c.i. 1·37 to 3·35), P < 0·001). Six centres (24 per cent) self-reported routinely performing blood cultures in acute cholecystitis; patient-level audit data revealed that blood cultures were done in 47 of 154 patients (30·5 per cent). No centre self-reported omitting antibiotics in the management of acute cholecystitis, and 144 of 154 (93·5 per cent) of patients in the snapshot audit received antibiotics during their index admission. CONCLUSION: Awareness of TG18 recommendations was high, but self-reported adherence and objective snapshot audit data showed low compliance with TG18 in patients with complicated acute biliary calculous disease.

ANTECEDENTES: La complicación aguda de la litiasis biliar (complicated acute biliary calculous disease, CABCD) plantea retos clínicos. Esta auditoría de la Sociedad Europea de Trauma y Cirugía de Urgencias (European Society of Trauma and Emergency Surgery, ESTES) de la CABCD tuvo como objetivo comparar el conocimiento teórico de las recomendaciones de Tokio (TG18) y la "práctica real" en Europa. MÉTODOS: Se efectuó un análisis pre-establecido de los datos de una auditoría prospectiva, observacional y multicéntrica que incluyó los pacientes ingresados de urgencia por CABCD (es decir, colecistitis complicada, pancreatitis biliar o coledocolitiasis con o sin colangitis) entre el 1 y el 31 de octubre de 2018. Además, se realizó una encuesta anónima en los centros participantes. RESULTADOS: Tras una convocatoria abierta, 25 centros de 9 países incluyeron 338 pacientes. Todos los centros completaron la encuesta anónima. El 60% de los centros reconocieron que trataban en el mismo ingreso una minoría de los pacientes y que favorecían la colecistectomía diferida. Ello se reprodujo en la auditoria, donde a 152/338 (44,9%) de los pacientes se realizó la colecistectomía en el mismo ingreso, a 17/338 (5%) se realizó una colecistectomía diferida y que a 169/338 (50%) todavía no se había realizado ninguna intervención en los 60 días de seguimiento. Los centros que seguían el Modelo de Atención Quirúrgica Urgente tenían mayores probabilidades de realizar la colecistectomía en el mismo ingreso en comparación con un servicio de cirugía general tradicional 'de guardia' (57% versus 38,4%, razón de oportunidades, odds ratio, OR 2,14 (i.c. del 95% 1,37-3,35), P < 0,001)). El 24% de los centros afirmaron realizar hemocultivos de rutina en la colecistitis aguda. Sin embargo, los datos de la auditoría revelaron que solamente 47/154 (30,5%) de los pacientes tenían hemocultivos. Ningún centro declaró no administrar antibióticos en el tratamiento de la colecistitis aguda, mientras que 144/154 (93,5%) de los pacientes de la auditoría no recibieron antibióticos durante el ingreso. CONCLUSIONES: El conocimiento de las recomendaciones de TG18 fue alto. Sin embargo, la observancia reconocida por los centros y los datos objetivos de la auditoría muestran que el cumplimiento en los pacientes con CABCD es bajo.

Tailored ultrasound learning for acute care surgeons: a review of the MUSEC (Modular UltraSound ESTES Course) project.

PURPOSE: The European Society for Trauma and Emergency Surgery (ESTES) identified the need for general and trauma surgeons involved in the management of critically ill surgical patients to embrace and learn both basic and advanced US skills. A steering group was created to address this deficit. METHODS: Modular UltraSound ESTES Course (MUSEC) is a modular blended-learning course. It incorporates pre-test/post-test examinations, pre-course online materials, didactic and interactive lectures, interactive case scenarios discussion with pathological US clips, hands-on practice on healthy volunteer models, and on original phantoms for simulating both pathological US findings and practicing US-guided interventional maneuvers. Four independent modules were provided. Surgical decision-making didactics were also included in the course curriculum. Learning gain (Δ of the rating of pre-test and post-test) was calculated for each module. An anonymous post-course satisfaction survey was also administered (16 questions with a Likert's 5-point scale of evaluation). RESULTS: Twenty-three MUSEC Courses were run in a 30 months period, training 416 doctors from 29 countries. A total of 52 modules were delivered. The mean pre-test and post-test grades were 8.3/12 and 10.7/12, respectively, yielding a significant mean learning gain of 28.9 % (p = 0.001). Post-course satisfaction survey got an overall ranking of 4.5/5. CONCLUSIONS: MUSEC is an effective and original educational format, enjoyed by candidates, that fills an educational gap for tailored US education as a procedural skill to acute care surgeons. Ongoing revisions should reduce the current limitations and increase the educational value, in terms of number of modules and post-course credentialing.

A comparison of clinical-pathological characteristics between symptomatic and interval breast cancer.

BACKGROUND: An association between interval breast cancers (cancer detected after a normal mammogram and before the next scheduled mammogram) and tumour aggressiveness has been postulated which may reflect their relatively poor overall prognosis. The aim of this study was to evaluate known prognostic features of screen detected breast cancers compared to interval breast cancers. METHODS: Patients diagnosed with breast cancer between January 2010 and 2013 at a single unit of the National Breast Screening Program (NBSP) in Ireland and those between the ages of 50 and 65 diagnosed at a symptomatic breast clinic were included in the study. Patients who had not had a screening mammogram within the proceeding two years or had a previous history of breast cancer were excluded. Data were retrospectively collected on patient demographics, tumour type, grade, hormone receptor status and stage of disease at presentation. RESULTS: There were 915 patients included in the study, with 92% (n = 844) diagnosed through the NBSP. Ductal carcinoma in-situ accounted for 19% (n = 160) of screen-detected breast cancers but only 2.8% of interval cancers (p < 0.05). The most common type of invasive cancer was invasive ductal carcinoma. Tumour grade was significantly higher in interval breast cancers (p < 0.05). Interval cancers were identified at a significantly higher stage (Stage 1 versus 2; p < 0.001) than screen-detected cancers. Interval breast cancers were less likely to be ER positive (76% versus 81%; p < 0.05) and significantly more likely to over-express HER2 (20% vs 10%, p < 0.05) than screen-detected cancers. CONCLUSION: This study highlights the fact that interval cancers appear to have a number of adverse prognostic markers for overall breast cancer survival when compared to women with screen-detected breast cancers. Interval cancers were more likely to be invasive, of a higher grade and stage and with a greater predominance of HER2 and triple negative molecular subtypes. Therefore this heterogeneous group of tumours may be biologically more aggressive and account disproportionately to overall breast cancer mortality.

Penetrating stab injuries at a single urban unit: are we missing the point?

BACKGROUND: Penetrating trauma--the classical presentation of disorganised crime--can pose a challenge in their management due to their complexity and unpredictability. AIM: We examined the experience of one urban unit in the management of penetrating injuries to draw conclusions pertinent to other Irish centres. METHODS: A retrospective study was performed of all penetrating injuries presenting to the Emergency Department (ED) of Connolly Hospital, Dublin between January 2009 and December 2012. Information was collected from the Hospital Inpatient Enquiry database, theatre logbooks and ED records. RESULTS: One hundred and four patients presented with penetrating injuries in the given period. Four mortalities were recorded. Abdominal injury was recorded in 22% of patients; 26% had multiple injuries not involving the abdomen; 11% had an isolated thoracic injury. Fifty-seven percent required surgery, of which 40% required emergency or early surgical intervention. Laparotomy and laparoscopy were required in 14 and 7%, respectively; 5% required thoracotomy of which two had penetrating cardiac injuries, both of whom survived. CONCLUSIONS: Although many patients with penetrating trauma can be safely managed conservatively, our study shows that over half required surgical intervention. These data highlight the need for a trauma team in each Irish centre receiving trauma with a clear need for general surgeons on emergency on-call rotas to be experienced in trauma management. There is an urgent need to centralise the management of trauma to a limited number of designated trauma centres where expertise is available by surgeons with a special interest in trauma management.

Malignant melanoma: factors affecting the surgical interval from excision biopsy to definitive surgical management.

INTRODUCTION: Surgery remains the mainstay of treatment for malignant melanoma. Despite previous studies examining the surgical interval (SI) between the diagnostic excision biopsy (DEB) and definitive surgical management there remains few guidelines regarding an optimal time interval. The aim of this study was to determine the SI between DEB and definitive surgery and elucidate factors associated with delays in management of malignant melanoma. METHODS: A retrospective study of 107 consecutive patients who had a DEB and subsequent wide local excision between January 2011 and June 2012 was performed. Mode of referral and dates of diagnostic biopsy/definitive surgery were documented. Patient demographics and tumour characteristics were reviewed. RESULTS: The mean age was 59.6 years, and male:female ratio was 1:1.3. Median duration of the SI was 41 ± 27 days (range 6-137 days). The SI was increased when dermatologists performed the DEB as opposed to general surgeons (p = 0.035). The anatomic location of the lesion predicted the SI, with lesions of the head/neck undergoing definitive excision 48 ± 32.3 days after DEB vs. 37.5 ± 22.6 days for all other sites (p = 0.001). Neither demographic factors nor histopathological prognostic features affected the SI. Reasons for a prolonged SI included referrals to different services and time for pre-operative planning. CONCLUSIONS: Significant variations were noted in the SI predominantly accounted for by mode of referral and location of the malignant melanoma. Further investigation is required to elucidate factors affecting the SI and its subsequent effect on patient outcomes.

High-dose carmustine, etoposide and melphalan ('BEM') with autologous stem cell transplantation: a dose-toxicity study.

We have investigated the toxicity of dose-escalation of BCNU, etoposide and melphalan ('BEM') chemotherapy with autologous stem cell transplantation in patients with haematological malignancies. Seventy-two patients with haematological malignancies were treated with BCNU (600 mg/m2, 450 mg/m2 or 300 mg/m2), etoposide 2 g/m2 and melphalan 140 mg/m2 followed by autologous bone marrow transplantation (ABMT), n = 51, or autologous peripheral blood progenitor cell transplantation (APBPCT), n = 21. Liver and pulmonary function was monitored pretransplant and at regular intervals post-transplant. Mucositis was graded daily during in-patient stay. There was a significantly higher incidence of symptomatic pulmonary toxicity in the patients who received BCNU at 600 mg/m2 than in the other two groups, and there was a significant increase in the incidence of asymptomatic decrease in carbon monoxide (KCO) in the patients who received BCNU 450 mg/m2. There was no significant difference between the three groups in the incidence and severity of mucositis or in the incidence of transiently abnormal liver function. We conclude that etoposide at 2 g/m2 can be used without unacceptable mucositis. BCNU at 600 mg/m2 is associated with an unacceptably high incidence of lung toxicity, but at 450 mg/m2 there is minimal symptomatic lung toxicity.

A comparison of CD34+ cell selected and unselected autologous peripheral blood stem cell transplantation for multiple myeloma: a case controlled analysis.

Following ASCT for multiple myeloma, it is unclear whether relapse is due solely to the presence of residual myeloma cells after myeloablation, or whether it is in part attributable to contamination of the stem cell harvest with viable malignant cells. Positive selection of CD34+ cells markedly reduces plasma cell contamination. We performed a case controlled analysis in which 15 patients with myeloma who underwent autologous PBSCT with CD34+cell selection using the Ceprate System (index group), were compared with 15 matched controls. All subjects received an identical preparative regimen. The median times to neutrophils >/=0.5 x 10(9)/l and unsupported platelets >/=50 x 10(9)/l were 14 and 23 days for the CD34+cell selected group and 11 (P = 0.03) and 14 (P = 0.029) for the case controls. Median follow-up of purged patients from autologous PBSCT was 32 months (range 18-43). At 36 months, the probability of PFS was 47 +/- 14% and 46 +/- 14% in the index and control groups (P = 0.44). The 3 year probability of OS was 69 +/- 13% for the CD34+ cell selected arm and 66 +/- 12.4% in unpurged patients (P = 0.91). Median PFS for the cell selected group is 24 months (CI 19.1-36.0), and 29 months for controls (CI 7.1-50.9). Eleven patients undergoing cell selection remain alive, seven of whom are progression free. At the same time-point after unpurged autologous PBSCT, the corresponding figures are 12 patients alive, with seven remaining progression free. Autologous PBSCT with CD34+ cell selection is both feasible and safe, but results in delayed engraftment as compared to case controls. The 3 year probability of PFS and OS in the cell selected arm was similar to that of the unpurged controls. Our findings indicate that autologous PBSCT with CD34+ cell selection appears not to have any favourable effect on disease progression. However, the results of this case controlled analysis should be cautiously interpreted, and the role of CD34+ selection in autologous PBSCT should be further investigated by large randomised trials.

The minimum CD34 threshold depends on prior chemotherapy in autologous peripheral blood stem cell recipients.

We analysed 57 patients with non-myeloid malignancies who received a non-purged autologous PBSCT. All had similar mobilisation and conditioning regimens. A high prior chemotherapy score and the number of chemotherapy lines used (P = 0.015 and P = 0.01, respectively) were adverse predictors of CD34 cell yields. Lower CD34 values (P = 0.002) were seen in patients treated with potent stem cell toxins (BCNU, melphalan, CCNU and mustine), designated toxicity factor 4 agents (TF4). All patients infused with grafts containing CD34 cell doses between 1.0 and 2.0 x 10(6)/kg (range 1.25-1.90) engrafted by day 51. The only variable associated with slow platelet recovery was exposure to TF4 (P = 0.007). The majority of patients with CD34 >1.0 x 10(6)/kg achieved rapid and sustained engraftment and the only predictive factor of delayed recovery is prior exposure to stem cell toxins. Potential PBSCT candidates should if possible avoid first line and salvage chemotherapy containing TF4 drugs. We therefore advocate a minimum CD34 threshold of >1.0 x 10(6)/kg in patients without extensive prior chemoradiotherapy, and > or = 2.0 x 10(6)/kg in all other patients.

A trend towards an increased incidence of chronic graft-versus-host disease following allogeneic peripheral blood progenitor cell transplantation: a case controlled study.

Allogeneic peripheral blood progenitor cell transplantation (alloPBPCT) is increasingly used as an alternative to bone marrow transplantation (alloBMT). Early data suggest that the incidence and severity of acute graft-versus-host disease (GVHD) following alloPBPCT is no higher than that seen with alloBMT, despite the increased number of cytotoxic T cells infused with mobilised blood. We compared 12 patients undergoing alloPBPCT with 12 well-matched alloBMT controls. All patients received identical GVHD prophylaxis. No T cell depletion or CD34 purification was performed. Median engraftment times for neutrophils >0.5 x 10(9)/l and platelets >20 x 10(9)/l were 14 and 12 (alloPBPCT) and 21 and 23 days (alloBMT), respectively (P = 0.0035 and P = 0.002). There was no difference in antibiotic requirements (P = 0.83), platelet support (P = 0.59) or days in hospital (P = 0.51). After alloPBPCT, five patients developed > or =grade II acute GVHD vs five patients after alloBMT (P = 0.99). There was one death (alloBMT) at 100 days and three at 1 year (all due to relapse). There was one death at 100 days with alloPBPCT, and 11 patients remain alive (range 9-21 months) to date. Chronic GVHD occurred in five patients in the PBPC arm and one patient in the BM arm (P = 0.14). This case-controlled analysis indicates that alloPBPCT results in more rapid engraftment kinetics but in no significant difference in transplant-related morbidity or mortality. There is no difference in the incidence of acute GVHD. However, there is a trend towards increased incidence of chronic GVHD in patients allografted with PBPC. Prospective randomised trials are required to determine further the role of alloPBPCT.

Autografting for multiple myeloma: a 5-year experience at a single institution.

Over a 5-year period, we have performed 33 autologous bone marrow or PBPC transplantations for multiple myeloma. Nine patients were in complete remission and 24 in partial remission at time of transplantation. Conditioning regimens were BEM (BCNU, etoposide and melphalan) in 29, busulphan and cyclophosphamide in three and melphalan alone in one. Two patients (6%), died within 3 months of transplant-related mortality, seven (21.3%), died of disease progression at a median follow-up of 11 months (range 4-24). Twenty-four patients (72.7%) are alive at a median follow-up of 15 months (range 4-61). Of nine patients transplanted in CR, four have relapsed and are alive and five remain in CR. Of 24 patients transplanted in PR, nine have died, six remain in PR, eight achieved CR and one has progressive disease. The overall median progression-free survival (PFS) is 31 months (95% CI = 20-42). For patients transplanted in PR the median PFS is 24 months (95% CI = 22-26), the median PFS for patients transplanted in CR has not yet been reached. The median PFS for patients achieving CR pre- or post-transplantation was better than for patients neither achieving CR pre- nor post-transplantation (P = 0.05). The median PFS was also significantly improved for patients requiring only primary therapy, compared to patients needing second-line therapy to achieve CR or stable PR prior to transplantation (31 vs 11 months, P = 0.02).

High-dose therapy and autologous stem cell rescue for poor risk and refractory lymphoma: a single centre experience of 123 patients.

Over an 8-year period we autografted 123 patient with poor-risk lymphoma. Sixty-three patients had Hodgkin's disease (HD) and 60 non-Hodgkin's lymphoma (NHL). Of the patients with HD, 45 had responsive and 18 resistant disease prior to high-dose therapy. Fifty-three patients with NHL had responsive and seven had resistant disease at the time of transplantation. Seventy-seven patients received autologous bone marrow (BM) rescue, 39 autologous peripheral blood progenitor cell (PBPC) rescue, and seven combined BM and PBPC rescue. High-dose chemotherapy was BEM in 67, BEAM in 39, TBI and cyclophosphamide or etoposide or BCNU in 10, etoposide/mitozantrone in six and etoposide/melphalan in one. There was eight (6.5%) deaths due to treatment-related toxicity, within the first 100 days post-transplantation. Of the patients with HD 41 (65%) are alive at a median follow-up of 39 months (range 2-94). Thirty-three (52%) patients remain in CR. The median DFS of the 63 patients with HD is 34 months (95% CI 7-61). The median DFS for patients transplanted with responsive disease was significantly better than for those transplanted with refractory disease (61 vs 21 months P < 0001). Thirty-five (58%) of the patients with NHL are alive, and 20 (33%) remain in CR. The median DFS for patients transplanted with responsive and refractory disease was 11 months (95% CI 3-19) and 4 months (95% CI 0-9; P = NS) respectively. The median DFS for patients transplanted with HD was significantly better than for patients transplanted with NHL (34 vs 8 months, P < 0.002). In both groups there was no significant difference in DFS in patients receiving one, two, three or more lines of therapy prior to transplantation. In summary, in patients with poor-risk lymphoma who have responsive disease high-dose therapy may result in durable CRs. Conversely, only a small proportion of patients with HD or NHL with resistant disease achieve CR after autologous stem cell rescue.

Peripheral blood progenitor cell transplantation: a single centre experience comparing two mobilisation regimens in 67 patients.

Between June 1991 and January 1995 we performed 67 peripheral blood progenitor cell transplants (PBPCT). Ten patients (group 1) were mobilised with 7 gm/m2 of cyclophosphamide followed by daily G-CSF injections (5 micrograms/kg, subcutaneously). When the white cell count reached 1 x 10(9)/1 they were leukapheresed for 5 days. After stem cell infusion they received G-CSF (10 micrograms/kg/day) until the neutrophil count reached 1.5 x 10(9)/1. Fifty-six patients had PBPCs mobilised with 3 gm/m2 of cyclophosphamide followed by daily subcutaneous G-CSF (5 micrograms/kg) and PBPCs were harvested on 2 consecutive days, when the white cell count rose to 4 x 10(9)/1. After stem cell infusion this group did not receive G-CSF. In 47 of the 56 patients (group 2) adequate MNC (> or = 4 x 10(8)/kg) and/or CFU-GM (> or = 10 x 10(4)/kg) were obtained. Insufficient MNC and/or CFU-GM were obtained in 10 patients. They were therefore transplanted using a combination of bone marrow and peripheral blood progenitor cells (group 3). Overall 64 patients successfully engrafted. Median days to neutrophils > or = 0.5 x 10(9)/1 were 9 (range 8-13), 12 (range 8-25) and 11 (range 9-16) and to platelets > or = 50 x 10(9)/1 were 11 (range 9-23), 13 (range 9-90) and 16 (range 13-99) in groups 1, 2 and 3 respectively. Patients in group 1 had a faster neutrophil recovery than patients in group 2 (P = 0.0002). The three patients who failed to engraft all received a combination of autologous peripheral blood and bone marrow cells.

Autologous bone marrow transplantation for Hodgkin's disease--a five-year single centre experience.

The results from 40 patients who have undergone autologous bone marrow transplantation (ABMT) for relapsed or refractory Hodgkin's disease between March 1988 and September 1992 have been analysed. In contrast to our results in patients with relapsed HD, our results in patients with refractory HD are comparatively poor. Conventional salvage chemotherapy also seems inappropriate in these patients and we therefore believe they should be offered high-dose chemotherapy before their disease becomes refractory to conventionally scheduled regimens. Peripheral blood stem cell (PBSC) transplant now offers an attractive alternative to ABMT and may replace both intensive salvage chemotherapy and ABMT as the optimum treatment for patients who fail to respond to conventional chemotherapy regimens.

Structure-activity studies on inhibition of Streptococcus mutans by long-chain aliphatic diamines.

A series of long-chain aliphatic diamines, R1R2N(CH2)mNR3-CnH2n+1' was tested for in vitro inhibition of Streptococcus mutans. In general, high activity was found for all analogs with alkyl chains containing 14 to 18 carbons. The nature of the substituents on the remainder of the alkylenediamine were of secondary importance. N-hydroxyethyl substituents tend to decrease activity. Good correlations of activity with quadratic functions of diamine critical micelle concentrations were obtained.