Improving graduate education to support a branching career pipeline: recommendations based on a survey of doctoral students in the basic biomedical sciences.

Today's doctoral programs continue to prepare students for a traditional academic career path despite the inadequate supply of research-focused faculty positions. We advocate for a broader doctoral curriculum that prepares trainees for a wide range of science-related career paths. In support of this argument, we describe data from our survey of doctoral students in the basic biomedical sciences at University of California, San Francisco (UCSF). Midway through graduate training, UCSF students are already considering a broad range of career options, with one-third intending to pursue a non-research career path. To better support this branching career pipeline, we recommend that national standards for training and mentoring include emphasis on career planning and professional skills development to ensure the success of PhD-level scientists as they contribute to a broadly defined global scientific enterprise.

Evaluation of the new Vitek 2 GN card for the identification of gram-negative bacilli frequently encountered in clinical laboratories.

The new Vitek 2 GN card (bioMérieux, Marcy-l'Etoile, France) was developed for better identification of fermenting and nonfermenting bacilli. This new card allows the identification of 159 taxa. A total of 426 isolates (331 fermenting and 95 nonfermenting gram-negative bacilli) belonging to 70 taxa covered by the database were evaluated. All isolates were identified in parallel with the ID 32 GN, the API 20E, and the API 20NE methods. The system correctly identified 97.4% (n=415) of the strains. Only 2.1% (n=9) needed additional testing. One strain (0.25%) was misidentified (Klebsiella pneumoniae subsp. pneumoniae), and another one (0.25%) was not identified (Morganella morganii subsp. morganii). The new GN card gives more accurate identifications overall for gram-negative bacilli when compared to the systems described in other similar studies.

[Rhône-Alpes observatory of Streptococcus pneumoniae in 1999: 35 cases of meningitis]. / Observatoire Rhône-Alpes du pneumocoque en 1999: 35 cas de méningites.

In 1999, in Rhône-Alpes region, in a survey of resistance to antibiotics of Streptococcus pneumoniae, 35 cases of meningitis were observed. A retrospectic questionnary was sent to each participant. MICs to Penicillin, Amoxicillin and Cefotaxime were determined with ATB-PNEUMO gallery or E-test and by disk diffusion for the other antibiotics. The results were interpreted according to the recommendations of the CA-SFM. Mean age was 38.1 years (range : 1 month -78 years) and sex-ratio 2/5. Eight patients had previously received antibiotics, 22 patients had risk factors and 23 were transferred in intensive care unit. The patients received C3G + glycopeptide in 15 of 16 children and in 13/19 adults according to the consensus recommendations. Diagnostic was made on the direct examination of CSF in 83%, and blood cultures was positive in 74.3% of cases. The percentage of PRP was 48.6% with 17.1% of intermediate-amoxicilline and 14.3% intermediate-cefotaxime strains. Resistance to trimethoprim-sulfamethoxazole was 45.7%, to chloramphenicol 30% and to fosfomycin 6.9%. All the strains were susceptible to rifampicin and vancomycin. Among the 17 PRP strains, 7 were belonging to serotype 6 (6 in children). The clinical outcome was fatal in 7 male cases (20%), without risk factors in 3 children and 6 of 7 strains were susceptible to penicillin. Six patients (17%) had auditive and/or neurologic sequellaes. This study shows that nearly 50% of strains isolated in meningitis, in Rhône-Alpes region, were not susceptible to penicillin, and confirms the frequency of sequellaes while the mortality is not related with the resistance of strains to the antibiotics.

Comparative in vitro activity of penicillin G, levofloxacin, moxifloxacin, telithromycin, pristinamycin, quinupristin-dalfopristin and linezolid against ofloxacin-intermediate and -resistant Streptococcus pneumoniae.

Screening by ofloxacin disk was carried out on 1158 strains of Streptococcus pneumoniae in order to investigate the in vitro bacteriostatic activity of penicillin G, levofloxacin, moxifloxacin, telithromycin, linezolid, pristinamycin and quinupristin-dalfopristin against ofloxacin-intermediate and -resistant S. pneumoniae strains. It was concluded that these new antimicrobial agents could be useful for the treatment of pneumococcal infections caused by penicillin-sensitive and -resistant S. pneumoniae, and would represent a valid therapeutic option for patients allergic to beta-lactams, should they prove to be potent in vivo.

[Evaluation of the E-test and the ATB-PNEUMo battery for determining the beta-lactam MIC for Streptococcus pneumoniae in daily practice]. / Evaluation du E-test et de la galerie ATB-PNEUMo dans la détermination des CMI aux bêtalactamines de Streptococcus pneumoniae en pratique quotidienne.

In 1999, during the survey of resistance of Streptococcus pneumoniae to antibiotics by 31 clinical laboratories of Rhône-Alpes area, MIC to penicillin (P), amoxicillin (AMX) and cefotaxime (CTX) of 877 PRP strains or with a diameter of inhibition to oxacillin inferior to 26 mm, were determined by each institution by E-test (n = 220 strains) or ATB-PNEUMO (n = 657 strains). MICs of these three antibiotics were determined by dilution in agar medium by the coordinating center. The essential agreement was respectively for ATB-PNEUMO and E-test 89% versus 84% for P (p > 0.05), of 86% vs 79% for AMX (p < 0.01), and of 91% vs 86% for CTX (p = 0.03). When the strains were classified in clinical category, the differences were significant (p < 0.001) for AMX (85% vs 71%) and for CTX (82% vs 75%) but not for P (73% vs 78%). ATB-PNEUMO method was more sensitive than E-test for the detection of strains susceptible to P (90 vs 73%), to AMX (83 vs 78%) and to CTX (80 vs 72%) and for the strains intermediate to AMX (90 vs 78%). On the contrary, E-test is more specific than ATB-PNEUMO for the detection of P-resistant strains (94 vs 86%). Finally, the specificity of both methods is the same for detection of P-S, AMX-R and CTX-I strains.

Vasopressin mRNA localization in nerve cells: characterization of cis-acting elements and trans-acting factors.

mRNA localization is a complex pathway. Besides mRNA sorting per se, this process includes aspects of regulated translation. It requires protein factors that interact with defined sequences (or sequence motifs) of the transcript, and the protein/RNA complexes are finally guided along the cytoskeleton to their ultimate destinations. The mRNA encoding the vasopressin (VP) precursor protein is localized to the nerve cell processes in vivo and in primary cultured nerve cells. Sorting of VP transcripts to dendrites is mediated by the last 395 nucleotides of the mRNA, the dendritic localizer sequence, and it depends on intact microtubules. In vitro interaction studies with cytosolic extracts demonstrated specific binding of a protein, enriched in nerve cell tissues, to the radiolabeled dendritic localizer sequence probe. Biochemical purification revealed that this protein is the multifunctional poly(A)-binding protein (PABP). It is well known for its ability to bind with high affinity to poly(A) tails of mRNAs, prerequisite for mRNA stabilization and stimulation of translational initiation, respectively. With lower affinities, PABP can also associate with non-poly(A) sequences. The physiological consequences of these PABP/RNA interactions are far from clear but may include functions such as translational silencing. Presumably, the translational state of mRNAs subject to dendritic sorting is influenced by external stimuli. PABP thus could be a component required to regulate local synthesis of the VP precursor and possibly of other proteins.

VP-RBP, a protein enriched in brain tissue, specifically interacts with the dendritic localizer sequence of rat vasopressin mRNA.

The concept of mRNA localization suggests that this process is mediated by sequences residing in the transcript to which proteins specifically bind and ultimately deliver the mRNA along cytoskeletal elements to specific intracellular destinations. The mRNA encoding the vasopressin (VP) precursor protein is localized to the nerve cell processes both in hypothalamic magnocellular neurons and in primary cultured neurons derived from embryonic rat superior cervical ganglia microinjected with a corresponding eukaryotic expression vector. The last 395 nucleotides of the VP mRNA encompassing part of the coding region, as well as the complete 3'-untranslated region, are sufficient to confer dendritic targeting to a normally nonlocalized reporter transcript. Here we report that, by employing in vitro crosslinking analyses with rat brain proteins and radiolabelled VP transcripts, an RNA-binding protein specifically interacts with the dendritic localizer sequence of the VP mRNA. This protein is enriched in nerve cell tissues. Peripheral tissues and various cell lines contain only low amounts of the binding activity. It therefore represents a candidate protein that may be involved in any aspect related to subcellular VP mRNA sorting in nerve cells, including transport and anchoring of the mRNA and possibly its translational control.

[Infection and cancer: general information and specific questions]. / Infection et cancer: notions générales et questions actuelles.

The main risk factors of infectious complications in cancer patients result from immune deficiency more or less related to cancer. Prognosis is related to the type and grade of the underlying disease. Prospective studies should be conducted to update data on the frequency of infections, morbidity and mortality (expert agreement). Prospective studies are needed to follow the epidemiology in cancer patients, particularly in neutropenic patients (expert agreement). Prospective studies should be conducted to determine prognosis factors allowing precise recognition of "low-risk" neutropenic patients with fever who could benefit from home care (expert agreement). When infection is suspected, the first criterion determining the therapeutic attitude concern signs of gravity requiring emergency care (septic shock). Beyond this situation, the first criterion determining the therapeutic attitude is the severity of the neutropenia. Microbial diagnosis is essential for initiating and later adapting anti-infectious treatment as well as for assessing efficacy.

[Standards, options and recommendations for good practice in hemoculture in cancerology]. / Standards, Options et Recommandations pour une bonne pratique des hémocultures en cancérologie.

Excepting emergency and aplasia: two to three blood samples should be draw for culture an hour apart within a 24 period (standard). For emergency or aplasia: two to three blood samples should be drawn for culture before initiating early antibiotic therapy. The delay between samples drawn from different sites should be less than one hour (standard). For patients on antibiotics: four to six blood samples should be drawn for culture within 48 hours, outside ongoing antibiotic administration. If the patient is given corticosteroids, it is recommended to draw two or three blood samples in case of deterioration (agreement of the experts). Rigorous aseptic techniques must be used (standard). Culture media are chosen according to the institution's microbial ecology (standard). The volume of blood drawn should be adapted to the system used (standard). Culture positivity is determined at 24 to 48 hours.

[Standards, Options and Recommendations (SOR) for the surveillance and the prevention of cross infections in oncology. Fédération Nationale des Centres de Lutte Contre le Cancer]. / Standards, Options et Recommandations (SOR) pour la surveillance et la prévention des infections nosocomiales en cancérologie.

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centres (FNCLCC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery. OBJECTIVES: To develop clinical practice guidelines according to the definitions of the Standards, Options and Recommendations project for the prevention and the surveillance of cross infection in oncology. METHODS: Data were identified by searching Medline and the personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to 106 independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: 1) Criteria of infection status and nosocomiality defined by the Centers for Infectious Diseases (CDC) and Prevention and the Superior Council of Public Hygiene (CSHPF) are not adapted and have to be redefined in oncology. 2) The epidemiology of nosocomial infections in oncology is not well known but their incidence seems to be higher. Numerous risk factors of cross infections coexist in cancer patients, among which the duration and depth of neutropenia. 3) Surveillance and prevention of cross infection are compulsory and were taken into account in the accreditation of hospitals. Obligation is expressed in terms of means and results. 4) The objectives of the cross infection surveillance are to detect major problems and critic situations, to guide probabilistic antibiotic therapy and to assess the effectiveness of the infections control. The surveillance means consist in prevalence and incidence survey, punctually and continuously conducted. 5) The three specific behaviors to be adopted to prevent cross infections are to control: all the patients, infected patients carrying multiresistant bacteria, immunodepressed patients. 6) Standards of care have to be applied to a/l patients with cancer. 7) It is necessary to add particular septic cares for the patients infected with micro-organisms indicated on reference lists or carrying multiresistant bacteria. 8) The only objective of the protective isolation of immunodepressed cancer patients is to reduce the cross infection. There is no standard behavior for the indications and the modalities of protective isolation. The prevention behaviors to be taken are defined by expert agreements.

[Intraoperative cholangiography in laparoscopic cholecystectomy for acute cholecystitis]. / Das intraoperative Cholangiogramm bei der laparoskopischen Cholezystektomie wegen akuter Cholezystitis.

In our prospective study we wanted to prove whether the safety of laparoscopic treatment of acute cholecystitis could be improved by intraoperative cholangiography. From July 1993 to June 1998 210 patients with acute cholecystitis underwent a laparoscopic cholecystectomy. In 23 cases (10.9%) a conversion was necessary. 189 patients underwent a laparoscopic cholangiography. In 2 cases (1.1%) an incision of the common bile duct was detected which had been mistaken for the cystic duct. So the cutting of the common bile duct could be prevented. In 12 patients (6.3%) unknown common bile duct stones were found. The complication rate was 9.5% without any mortality or major injury of the common bile duct.

Oxygenation status and tumor response during fractionated irradiation in two murine tumor cell lines of same origin but different intrinsic radiosensitivities.

Two murine tumor cell lines derived from the same origin and having different intrinsic radiosensitivities, one radiosensitive, SHA3K4-Ic (Ic), and the other relatively radioresistant, SHA3K4-III19 (III19), were compared in vivo regarding oxygenation, proliferation, and tumor response during fractionated irradiation. Tumors transplanted into nude mice were irradiated five times a week with a fraction size of 3 Gy up to a total dose of 30 Gy. Oxygenation status was analyzed using a non-invasive system with near infrared reflection spectroscopy. Proliferation status was quantified as the percentage of bromodeoxyuridine-labelled tumor cells and the percentage of necrotic area. All parameters were compared between untreated and irradiated tumors of the two lines. The oxygenation status in the untreated tumors did not correlate with tumor response. However, for the radioresponsive line, Ic, O2 saturation was significantly higher in irradiated than in untreated tumors, suggesting the existence of reoxygenation following fractionated irradiation. On the other hand, oxygenation status remained almost unchanged for the non-radioresponsive line, III19. Proliferation status did not correlate with tumor response. The results indicate that comprehensive investigations, including oxygen measurements, are necessary to understand the various intrinsic and extrinsic factors determining in vivo tumor radioresponse.

Occult hypoglycemia caused by hemodialysis.

BACKGROUND: Previous studies have ignored hypoglycemia in patients undergoing hemodialysis. The fall in plasma glucose may not have been considered to be clinically relevant because the patients were asymptomatic. The present study was designed to assess the effect of hemodialysis on plasma glucose, insulin, glucagon, cortisol and catecholamines in non diabetic patients. METHODS: 21 non diabetic patients with chronic renal failure were hemodialyzed using a glucose-free dialysis fluid. They did not take any medication prior to dialysis and were asked not to eat during the first hour on hemodialysis. Blood and dialysate fluid was sampled at regular intervals during the first hour of dialysis for analysis. RESULTS: Plasma glucose fell below 4.0 mmol/l (72 mg/dl) in 9 of the 21 patients, below 3.5 mmol/l (63 mg/dl) in 6 and below 3.0 mmol/l (54 mg/dl) in 3. The lowest recorded value was 2.1 mmol/l (38 mg/dl). The mode glucose loss in the waste dialysate fluid was 6 g/h. In the group of 9 patients whose plasma glucose fell below 4.0 mmol/l (72 mg/dl), no symptoms of hypoglycemia were shown but 4 of the 7 patients who felt very hungry and ate were in this group. When 7 patients from this group were subsequently dialysed with a dialysis fluid containing 5.5 mmol/l (100 mg/dl) glucose, their plasma glucose became stabilized within the fasting reference range. There were no significant hormonal changes during the dialysis or between euglycemic and hypoglycemic patients. CONCLUSIONS: Patients undergoing hemodialysis may become hypoglycemic and not be aware of it. There is no hormonal imbalance causing the hypoglycemia and the hormonal response to the hypoglycemia is blunted. Patients with an initial plasma glucose of 4.5 mmol/l (81 mg/dl) or less who are hemodialyzed and who do not eat during dialysis may be particularly at risk. They should be dialysed with a dialysis fluid containing at least 5.5 mmol/l (100 mg/dl) glucose.

[Pneumococcus observatory data in the Rhône-Alps region. Results from 1996]. / Observatoire du pneumocoque en région Rhône-Alpes. Résultats de l'année 1996.

Throughout 1996, 22 hospital-based laboratories in the Rhône-Alpes region of France collected pneumococcal strains and used a standardized protocol to record the following data; patient age and sex; type of specimen; and determination of susceptibility to at least the following antibiotics: oxacillin 1 microgram and 5 micrograms, erythromycin (Ery), tetracycline (Tet), chloramphenicol (Chl), rifampin (Rmp), and loracarbef. For penicillin-nonsusceptible strains (PNSSs), which were identified based on results with oxacillin, MICs for penicillin G, amoxicillin (Amx), and cefotaxime (Ctx) were determined using the E Test, at the study site and agar dilution at the coordinating center. Of the 1153 strains, 65.5% were from adults and 31.8% from children; patient age was unknown in 2.7% of cases. PNSPs (MIC > 0.06 mg/l) contributed 32.9% of strains (I: 23.3%; R: 9.6%) and were more common in children (41.1%) than in adults (28.1%). The frequency of PNSSs varied across specimen types: 27.9% in blood cultures (305 strains), 15.6% in cerebrospinal fluid (32), 38.7% in protected bronchopulmonary specimens (31), 31.5% in unprotected bronchopulmonary specimens (434), 50.8% in acute otitis media (118), and 34.4% in other specimens (221). Among PNSSs, nonsusceptibility (I + R) to other antibiotics was variable: Ery, 62.1%; Tet, 41.5%; Chl, 40.4%; Rmp, 1.1%. Corresponding figures for the overall strain population were Ery, 33.3%; Tet, 22.7%; Chl, 22.8%; Rmp, 0.9%. In addition, 56.5% of PNSSs exhibited multiple drug resistance. Resistance to amoxicillin (MIC > 2 mg/l) was demonstrated for only 5 strains. No strains were resistant to loracarbef or cefotaxime. Serotypes of the 379 PNSSs were as follows: 23F, 26.6%; 14 (25.6%); 9V (18.2%), 6 (8.7%), 15 (5%), 19 (4.5%).

Cefepime versus imipenem-cilastatin as empirical monotherapy in 400 febrile patients with short duration neutropenia. CEMIC (Study Group of Infectious Diseases in Cancer).

This open, comparative, randomized, multicentre equivalence study compared cefepime 2 g bd and imipenem-cilastatin 1 g tds (50 mg/kg/day) as empirical monotherapy for febrile episodes in a homogeneous cohort of cancer patients with short duration neutropenia following chemotherapy for solid tumour, lymphoma or myeloma. The study was conducted in 17 French anti-cancer centres in 1995 and 1996. Response to monotherapy was assessed 7 days after treatment and was based on resolution of fever and signs and symptoms, eradication of pathogens, absence of new infection, relapse, and death of infectious origin, without addition of other antibiotics. Patients were treated for a minimum of 4 days. Of the 400 episodes randomized, 344 (86%) were evaluable for efficacy. Patient characteristics were comparable between treatment groups. Success of monotherapy was observed in 79% of episodes with cefepime and 72% with imipenem-cilastatin (equivalence, P <0.0001). The response rate for microbiologically documented infections was 66% with cefepime and 61% with imipenem-cilastatin (bacteraemic episodes: 63% for cefepime; 44% for imipenem-cilastatin). A second antibiotic (usually a glycopeptide) was added in 20% and 21% of the cases, respectively. Overall, the response to therapy, with or without an additional antibiotic, was 95% (cefepime) and 90% (imipenem-cilastatin). Survival was similar in both groups (95% and 98%, respectively). Cefepime treatment was better tolerated, with 9% of the patients experiencing related intercurrent events compared with 19% in the imipenem-cilastatin group (P = 0.003). Nausea/vomiting was significantly more frequent in the imipenem-cilastatin group (15%) than in the cefepime group (5%; P = 0.001). Cefepime monotherapy was as effective as, and better tolerated than, imipenem-cilastatin in the empirical treatment of fever during short duration neutropenia.

[Comparison of the results of the Etest and the method for determining minimum inhibitory concentrations in solid media for penicillin G, amoxicillin, and cefotaxime for S. pneumoniae. A multicenter study]. / Comparaison des résultats du Etest et de la méthode de détermination des concentrations minimales inhibitrices en milieu solide pour la pénicilline G, l'amoxicilline et le céfotaxime chez S. pneumoniae. Une étude multicentrique.

In 1996-1997 a multicentre study was carried out on 450 Streptococcus pneumoniae strains to compare the MICs and susceptibility categories obtained with the Etest (AB Biodisk) used under routine conditions in 22 hospital laboratories in the Rhône-Alpes region, France, with those obtained by the reference technique of agar dilution performed in a single coordinating centre. Each laboratory detected penicillin resistant pneumococci (PRP) by the oxacillin disk method (1 microgram and 5 micrograms) and determined the MICs of penicillin G (PG), amoxycillin (AMX) and cefotaxime (CTX) by the Etest. All the PRP strains were collected in the coordinating centre where MICs were carried out. The strains were classified as susceptible (S), intermediate (I) and resistant (R) according to the CASFM criteria (Comité de l'Antibiogramme de la Société Française de Microbiologie). The concordance results based on susceptibility categories are as follows: PG = 67.6%, AMX = 63.6%, CTX = 71.5%. Minor errors are as follows: PG = 31.2%, AMX = 36%, CTX = 28.5%. Major and very major errors are rare (0% to 0.6%). Agreement within 1 log2 dilution was obtained for about 80% of the strains. The minor errors results from strains clustering near the breakpoints 1 mg/l (PG) and 0.5 mg/l (AMX, CTX), and from practical difficulties in routine use of the Etest. These discrepancies may result in severe therapeutic problems. This study confirms the limits of the Etest. The authors insist on standardization and rigorous use of the Etest under routine conditions.

[Standards, Options, and Recommendations for the management of brief neutropenias. Fedération Nationale des Centres de Lutte Contre le Cancer]. / Standards, Options et Recommandations pour la prise en charge des neutropénies courtes.

CONTEXT: The "Standards, Options and Recommendations" (SOR), initiated in 1993, is a collaborative project between the Federation of the French Cancer Centres (FNCLCC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcomes for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary experts group, with feedback from specialists in cancer care delivery. OBJECTIVE: To develop a clinical practice guideline for the management of neutropenic cancer patients (excluding prolonged neutropenia). METHODS: Data have been identified by literature search using Medline and Current Contents (up to February 1997) and personal reference lists. The main end points considered were mortality, morbidity, risk factors, fever, source of infection, microbiological documentation, incidence and length of hospital stays, quality of life, efficacy of treatment, safety and costs. Once the guideline was defined, the document was submitted to 48 reviewers for peer review and to the medical committees of the 20 French Cancer Centres for review and agreement. RESULTS: The key recommendations are: 1) before receiving cytotoxic chemotherapy, patients must be informed of potential risks and precautions to observe; 2) non-febrile neutropenic patients can be followed at home (except specific context); antibiotic prophylaxis is not recommended; 3) initial empirical antibiotic therapy for febrile patients is mandatory, whether associated beta-lactam and aminoglycoside, or monotherapy with a broad-spectrum beta-lactam (except in case of septic shock or pneumopathy). A glycopeptide can be added in case of overt catheter-related or cutaneous infection, in case of microbiologically documented infection with a oxacillin-resistant Gram positive bacteria, or in case of persistent fever in a clinically deteriorating patient; 4) at the present time, there is insufficient evidence to recommend the management of febrile neutropenic patients at home. We recommend participation in studies to identify predicting factors of low-risk patients and to assess the feasibility and safety of early discharge and home therapy.

Radiosensitivity of normal fibroblasts from breast cancer patients assessed by the micronucleus and colony assays.

PURPOSE: To investigate whether radiation-induced micronucleus formation as expressed by the cytochalasin-blocked Mn-assay correlates with cellular radiosensitivity measured by a colony assay in primary fibroblast cultures from cancer patients. MATERIALS AND METHODS: Studies were made on skin fibroblasts from 36 breast cancer patients. The micronucleus assay was performed using treatment with cytochalasin-B to create binucleate cells. Response was scored in terms of the percentage of binucleate cells with micronuclei, also as the number of micronuclei per binucleate cell. The data were related to previously published results of cell survival measurements on these cell lines. RESULTS: Neither endpoint for micronucleus formation showed a correlation with radiosensitivity by the colony assay. The fraction of fibroblasts that reach mitosis without micronuclei also failed to correlate with cell survival. CONCLUSIONS: Among these primary fibroblast cell lines radiation-induced micronucleus formation was not associated with radiosensitivity as measured by a colony assay.

Evaluation of boron neutron capture effects in cell culture using sulforhodamine-B assay and a colony assay.

PURPOSE: The purpose of this study was to find an in vitro method for determining the cytotoxicity of boronated drugs as well as their potential suitability for neutron capture therapy. MATERIALS AND METHODS: The survival of human melanoma cells has been determined by a colony assay and the sulforhodamine-B assay after X-irradiation and irradiation with fast d(14) + Be-neutrons using the boronated compound borocaptate sodium (BSH). The cytotoxic effects of BSH have been studied using both methods. RESULTS: Under well-defined experimental conditions, and after a sufficient amount of time for the expression of radiation damage, the results of the sulforhodamine-B assay are qualitatively comparable with the results of the colony assay. CONCLUSION: The sulforhodamine-B assay is suitable for the screening of compounds for potential use in neutron capture therapy because it is a fast and efficient method that is reproducible and technically advantageous.