Untangle those stethoscopes; never too early to start reflecting! Qualitative review of a reflective practice group for clinical undergraduate medical students

Introduction

Equipping our medical students with as many tools as possible to cope with the challenges that they will inevitably face has never been more important than it is today.

Objectives

The aim of this study was to examine the effectiveness of a reflective practice (RP) group for medical students, particularly with adaptation to COVID-19 and transition to video.

Methods

A pilot programme of RP for 3^rd year medical students commencing their clinical placement was run by the Sligo Medical Academy, NUIG in Ireland between January – April 2020. This group for nine students was initially run face-to-face but pivoted to an online group in March 2020 with the COVID-19 pandemic. Data was collected through one-to-one interviews with all student participants and the facilitator (n=10). Interviews were recorded and transcribed. Data were analysed using thematic content analysis.

Results

Our analysis identified four main discussion themes: transition to clinical environment, gender in the workplace, building professional identity and family and support systems. The students who continued the RP group over zoom during the COVID-19 pandemic particularly identified with the theme of support systems and solidarity. The smooth transition to zoom and its effectiveness in a time of social distancing were discussed. Identified challenges related primarily to timing of the RP group, particularly after a full day of placements or time differences for international students overseas.

Conclusions

Reflective practice programmes are not routinely offered to medical students in Ireland currently and this study gives recommendations on implementing and improving experiences of undergraduate training based on RP.

Disclosure

No significant relationships.

Commentary on "DNA damage response and repair gene alterations are associated with improved survival in patients with platinum-treated advanced urothelial carcinoma."

PURPOSE

Platinum-based chemotherapy remains the standard treatment for advanced urothelial carcinoma by inducing DNA damage. We hypothesize that somatic alterations in DNA damage response and repair (DDR) genes are associated with improved sensitivity to platinum-based chemotherapy.

EXPERIMENTAL DESIGN

Patients with diagnosis of locally advanced and metastatic urothelial carcinoma treated with platinum-based chemotherapy who had exon sequencing with the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) assay were identified. Patients were dichotomized based on the presence/absence of alterations in a panel of 34 DDR genes. DDR alteration status was correlated with clinical outcomes and disease features.

RESULTS

One hundred patients were identified, of which 47 harbored alterations in DDR genes. Patients with DDR alterations had improved progression-free survival (9.3 vs. 6.0 months, log-rank P = 0.007) and overall survival (23.7 vs. 13.0 months, log-rank P = 0.006). DDR alterations were also associated with higher number mutations and copy-number alterations. A trend toward positive correlation between DDR status and nodal metastases and inverse correlation with visceral metastases were observed. Different DDR pathways also suggested variable effect on clinical outcomes.

CONCLUSIONS

Somatic DDR alteration is associated with improved clinical outcomes in platinum-treated patients with advanced urothelial carcinoma. Once validated, it can improve patient selection for clinical practice and future study enrollment.

High-resolution spectroscopy on the laser-cooling candidate La^{-}

The bound-bound transition from the 5d^{2}6s^{2} ^{3}F_{2}^{e} ground state to the 5d6s^{2}6p ^{3}D_{1}^{o} excited state in negative lanthanum has been proposed as a candidate for laser cooling, which has not yet been achieved for negative ions. Anion laser cooling holds the potential to allow the production of ultracold ensembles of any negatively charged species. We have studied the aforementioned transition in a beam of negative La ions by high-resolution laser spectroscopy. The center-of-gravity frequency was measured to be 96.592 80(10) THz. Seven of the nine expected hyperfine structure transitions were resolved. The observed peaks were unambiguously assigned to the predicted hyperfine transitions by a fit, confirmed by multiconfigurational self-consistent field calculations. From the determined hyperfine structure we conclude that La^{-} is a promising laser cooling candidate. Using this transition, only three laser beams would be required to repump all hyperfine levels of the ground state.

Outcome of surgery versus radiotherapy after induction treatment in patients with N2 disease: systematic review and meta-analysis of randomised trials

Objective

Chemoradiotherapy is often considered the ‘standard of care’ for patients with N2 disease. The aim was to evaluate survival outcomes of patients with N2 disease in multimodality trials of chemotherapy, radiotherapy and surgery.

Methods

Systematic review and meta-analyses (random and fixed effects) were performed. Searches of Medline and Embase (1980–2013) were conducted. Abstracts from thoracic scientific meetings were searched. Reference lists of all relevant studies were reviewed. All studies of patients with N2 disease who received induction chemotherapy or chemoradiotherapy and randomised to surgery or radiotherapy were included. No language restrictions were imposed. The main outcome was overall survival.

Results

805 publications were identified. 519 and 281 were excluded because they were not primary results from randomised trials (or did not include N2 disease) or did not compare surgery with radiotherapy, respectively. The final six trials consisted of 868 patients. In four trials, patients received induction chemotherapy and in two trials patients received induction chemoradiotherapy. The HR comparing patients randomised to surgery after chemotherapy was 1.01 (95% CI 0.82 to 1.23; p=0.954) whereas for patients randomised to surgery after chemoradiotherapy was 0.87 (0.74 to 1.02; p=0.078). The overall HR of all pooled trials was 0.92 (0.81 to 1.04; p=0.179).

Conclusions

In trials where patients received surgery as part of bimodality (with chemotherapy) or trimodality (with chemoradiotherapy) treatment, overall survival was not significantly better than radiotherapy (with chemotherapy) or combination chemoradiotherapy alone.

Extension Education Symposium: The future of biosecurity and antimicrobial use in livestock production in the United States and the role of extension

As the global population continues to grow, food needs will increase as well. The amount of land and other resources devoted to agriculture production is not expected to grow significantly, leading most to agree that the substantial increases in food production to meet food security needs will come through the development of technologies that improve production efficiency. Diseases are constant threats to efficiency in all segments of agriculture. In livestock production, many of the bacterial pathogens that infect food animals are controlled through the use of antimicrobials. Antimicrobials are currently used in the United States not only to treat specific diseases, but also as feed additives to prevent bacterial disease in general or to improve growth performance. In recent years, there have been several proposals in the United States, both at state and federal levels, aimed at curtailing or dramatically reducing the use antimicrobials as feed additives, creating a policy similar to that of the European Union. Here we review the current policies on antimicrobial use in the European Union and their impact on food animal production. In addition, we discuss the future of antimicrobial use in food animal production in the United States and the increasing role of biosecurity programs. Finally, we discuss the role of Cooperative Extension Service in creating improved biosecurity programs and extension programs that provide policy makers and voters information on modern food animal production practices and technologies so that policies and regulations are effective and appropriate.

Dyslipidemia in obese cats

Obesity is an important endocrine disorder in cats and is a risk factor for diabetes similar to humans. The goal of this study was to examine the effect of long-term obesity and different diets (high protein, and high carbohydrate supplemented with saturated fatty acids or n-3 polyunsaturated fatty acids) on plasma lipids in the fasted and fed states in 12 lean (LEAN) and 12 obese (OBESE) cats with ultracentrifugation, and nuclear magnetic resonance spectroscopy. OBESE had higher plasma non-esterified fatty acids and triglycerides, as well as very-low-density-lipoproteins (VLDL) consisting primarily of medium-sized particles. The concentration of low-density-lipoproteins (LDL) was comparable between the groups, although OBESE had mostly very small, whereas LEAN had mostly large particles. The concentration of high-density-lipoproteins (HDL) was lower in OBESE and consisted primarily of small particles. Plasma triglycerides, and triglycerides and cholesterol in all lipoproteins increased postprandially. Different diets had little effect on lipids. Our results show that long-term obese cats develop similar lipoprotein changes to humans, yet, hypertension and atherosclerosis have not been described in obese cats. This suggests that dyslipidemia alone is not sufficient to induce hypertension and atherosclerosis. Other anti-atherogenic factors may be present in the obese, dyslipidemic cat.

Effect of refined coconut oil or copra meal on methane output and on intake and performance of beef heifers

An experiment was conducted to establish the effect of feeding either refined coconut oil (CO) or copra meal containing CO to beef heifers on DMI, animal performance, enteric CH4 emissions, diet digestibility, and the fatty acid profile of the resulting meat. Forty-one Charolais and Limousin crossbred beef heifers (474 +/- 29 kg; 661 +/- 89 d of age) were blocked by BW before being assigned in a randomized complete block design to 1 of 3 experimental treatments (n = 12) or to a pretrial slaughter group (n = 5) used to determine the initial carcass weight. The experimental period lasted for 93 d. Enteric CH4 output was recorded for 2 periods of 5 consecutive days from d 14 to 18 and from d 70 to 74. The 3 dietary treatments were 1) control, a barley/soybean meal-based concentrate with 0 g of CO/ d; 2) RCO, a barley/soybean meal-based concentrate with 250 g of CO/d from refined coconut oil; and 3) CM, a copra meal-based concentrate with 250 g of CO/d from copra meal. Each diet had a 50:50 forage:concentrate using grass silage as the forage source. There was no effect of diet on DMI (P = 0.734) or GE intake (P = 0.486). The addition of RCO increased ADG (P < 0.05) compared with the control treatment. The CM treatment decreased (P < 0.05) average daily carcass gain compared with the RCO treatment only. There was a decrease (P < 0.05) in the digestibility of the DM, OM, CP, and GE fractions of the diet only with the CM treatment. Both the RCO and CM concentrates decreased (P < 0.001) daily enteric CH4 output when expressed in terms of liters per day, liters per kilogram of DMI, percentage of GE intake, liters per kilogram of ADG, and liters per kilogram of average daily carcass gain. The RCO treatment produced the greatest numerical response for all measures. Ruminal protozoa numbers on the RCO treatment were lower (P < 0.05) than on the control treatment. The concentrations of the fatty acid methyl esters, lauric (P < 0.001) and myristic (P < 0.002) acids, were increased in muscle when either of the CCO treatments was compared with the controls, but the differences were of a magnitude unlikely to influence human health status. Although the CM concentrate decreased CH4 comparable with the RCO concentrate, decreased performance resulted in an extended finishing time with implications for lifetime CH4 emissions.

Salmonella surveillance in raw and cooked meat and meat products in the Republic of Ireland from 2002 to 2004

The food industry, under the regulation of the Department of Agriculture and Food (DAF) in the Republic of Ireland, is required to undertake all microbiological testing in relation to zoonoses control, in laboratories approved by DAF. These laboratories submit a monthly report of all tests undertaken, together with all presumptive Salmonella isolates for confirmation, typing and storage to the Central Veterinary Research Laboratory (CVRL). Details of Salmonella tests on 110,229 raw and 25,189 cooked meat samples from 25 laboratories were recorded over the 3-year period 2002-2004. Salmonella spp. were isolated from 1.0% of the 110,229 raw meat samples and 0.1% of the 25,189 cooked meat samples tested. The percentage of raw meat samples contaminated with Salmonella decreased over the three-year period from 1.2% to 0.9%. There was no seasonal trend in the isolation of Salmonella from any of the meats or meat products. Recoveries of the organism were highest for turkey and chicken meats at 3.1% and 2.8%, respectively, followed by porcine meats at 2.1%. The recoveries were much lower for ovine meats and meat products at 0.2% and bovine meat and meat products at 0.16%.

Effect of refined soy oil or whole soybeans on intake, methane output, and performance of young bulls

An experiment was conducted to establish the effects of feeding refined soy oil (RSO) or whole soybeans (WSB) containing soy oil on DMI, animal performance, and enteric methane (CH4) emissions in young bulls. Thirty-six Charolais and Limousin cross-bred, young beef bulls (338 +/- 27 kg of BW, 218 +/- 17 d of age at the beginning of the experiment) were blocked by BW, age, and breed before being assigned in a randomized complete block design to 1 of 3 experimental treatments (n = 12). The experimental period lasted for 103 d, with enteric CH4 output recorded for 2 periods of 5 consecutive days on d 37 to 41 and d 79 to 83. The 3 dietary treatments consisted of a barley/soybean meal-based concentrate with 0 g/d of RSO; oil from WSB as 6% of DMI (WSB treatment); and oil from RSO as 6% of DMI (RSO treatment). Each diet had a 10:90 forage:concentrate ratio, using barley straw as the forage source. Diet affected DMI (P < or = 0.001) and GE intake (P < 0.05 during the CH4 measurement periods), with the WSB treatment producing the lowest values. The addition of WSB decreased ADG (P < 0.05) compared with the RSO treatment. The WSB treatment also decreased (P < 0.05) average daily carcass gain (ADCG). Both the RSO and WSB concentrates decreased (P < 0.05 to P < 0.001) daily enteric CH4 output when expressed in terms of liters per day, liters per kilogram of DMI, percentage of GE intake, liters per kilogram of ADG, and liters per kilogram of ADCG. Diet had no effect (P = 0.557) on ruminal protozoal numbers. The reductions in enteric CH4 were achieved at relatively high oil inclusion levels. Such oil levels have previously been reported to decrease DMI of high-forage diets, although no effect on DMI was noted with the low-forage diets fed in this experiment. This impact on DMI of high-forage diets may limit the range of diets for which this CH4 reduction strategy may be applicable. The inclusion level of WSB in the current experiment (27%) was beyond the palatability threshold of the bulls used and resulted in a marked decline in intake and performance. Therefore, WSB may have a role to play in ruminant diets, but only at a reduced inclusion rate.

Chronic phase lipids in sera of chronic fatigue syndrome (CFS), chronic ciguatera fish poisoning (CCFP), hepatitis B, and cancer with antigenic epitope resembling ciguatoxin, as assessed with MAb-CTX

Clinical reports and descriptions of chronic fatigue syndrome (CFS) and chronic ciguatera fish poisoning (CCFP) show great similarities in clinical symptomology. These similarities in the literature suggested the exploration of lipids in sera of CFS, CCFP, and other diseases with the membrane immunobead assay (MIA), which is typically used for screening ciguateric ocean fish. Sera from patients with other diseases, including hepatitis B, cancer, and diabetes, were included to assess the degree of specificity involved. Sera were treated with acetone in a ratio of 1 part serum to 4 parts acetone. The suspension was centrifuged, and the acetone layer was evaporated. The residue was weighed and redissolved in 1.0 mL methanol and tested by the MIA, undiluted and titered to 1:160. The undiluted acetone fraction of the 37 normal showed +/- activity to +activity with 16 no titer, 15 with 1:5 titer and two with 1:10 titer, and four with > or =1:40 titers. One hundred fifteen CFS sera showed 1 with 1+ and 114 with 2+ activity in the undiluted samples, 1 with 1:10 titer, 3 with 1:20 titer, 31 with 1:40 titer, 50 with 1:80 titer, and 30 with 160 titer. Thus 95.6% of the samples had > or =1:40 titer. Eight hepatitis B sera samples had > or =1:40 titers. Four CCFP samples had > or =1:40 titers. Three of 16 cancer samples had 1:40 titer. These data are summarized in Fig. 1. As shown in Table 1, a significant increase (P<0.001) in the chronic phase lipids (CPLs) was shown relative to the normal group. A preliminary chemical study in C18 octadecylsilyl columns showed all fractions (100% chloroform, 9:1 chloroform : methanol, 1:1 chloroform : methanol, and 100% methanol) to contain lipids reactive to MAb-CTX with different intensities. Prostaglandins were shown in 100% methanol fraction. Competitive MIA with crude fish ciguatoxin and CFS with synthetic JKLM ciguatoxin epitope suggested similarities in structure with ciguatoxin. This was compatible with the neuroblastoma assay demonstrated in the C(18) column fractions 9:1 and 1:1, chloroform : methanol solvents.

An action plan for mouse genomics

The mouse has become the leading animal model for studying biological processes in mammals. Creation of additional genomic and genetic resources will make the mouse an even more useful model for the research community. On the basis of recommendations from the scientific community, the National Institutes of Health (NIH) plans to support grants to generate a 'working draft' sequence of the mouse genome by 2003, systematic mutagenesis and phenotyping centres, repositories for mouse strain maintenance, distribution and cryopreservation and training fellowships in mouse pathobiology.

[Merkel cell carcinoma of the auricle]

A case of a 80-year-old woman suffering from Merkel cell carcinoma of the auricle with regional cervical lymph nodes metastases has been described. Surgical treatment (tumour and regional lymph nodes dissection) was applied at first. Metastasis to one lymph node was established in postoperative histological examination. Chemotherapy (farmorubicin, cyclophosphamide, vincristine) in 3 cycles was applied within 2 months. In spite of the above, 4 months after tumour excision, metastatic lymph node manifested in the neck. Combined treatment, radical neck dissection and radiotherapy was applied then.

New goals for the U.S. Human Genome Project: 1998-2003

The Human Genome Project has successfully completed all the major goals in its current 5-year plan, covering the period 1993-98. A new plan, for 1998-2003, is presented, in which human DNA sequencing will be the major emphasis. An ambitious schedule has been set to complete the full sequence by the end of 2003, 2 years ahead of previous projections. In the course of completing the sequence, a "working draft" of the human sequence will be produced by the end of 2001. The plan also includes goals for sequencing technology development; for studying human genome sequence variation; for developing technology for functional genomics; for completing the sequence of Caenorhabditis elegans and Drosophila melanogaster and starting the mouse genome; for studying the ethical, legal, and social implications of genome research; for bioinformatics and computational studies; and for training of genome scientists.

[Regarding assessment of changes in the larynx after radiation according to RTOG/EORTC classification]

The authors discuss the classification of changes in reactions occurring during and after radiotherapy of the laryngeal cancer adopted in 1987 by Radiation Therapy Oncology Group and European Organisation for Research and Treatment of Cancer (RTOG/EORTC). The above classification is not based on uniform criteria. The authors express the opinion that is extremely difficult to distinguish between chondritis, chondronecrosis of high intensity and necrosis without microscopic examination and limiting oneselves to the subjective symptoms only. In they opinion the classification of the post-radiation reaction should take into account the clinical assessment of the state of the larynx as well as the subjective elements of the examination. The authors have their findings on their own clinical and microscopic research as well as on the date accessible in the relevant literature.

Pregnancy after cardiac transplantation: principles of nursing care

The number of cardiac transplants for chronic end-stage disease, congenital heart disease, and primary pulmonary hypertension has increased during the past 20 years. Decreased symptoms, decreased incidence of rejection, and greater tolerance of medical regimens have improved the quality of life for heart transplant recipients. Women of childbearing age who have undergone cardiac transplantation may now consider pregnancy. The principles of nursing care for pregnant women who have undergone heart transplantation are presented in this article. A case report of pregnancy after cardiac transplantation is included.

Phase I and pharmacokinetic study of recombinant human granulocyte-macrophage colony-stimulating factor given in combination with fluorouracil plus calcium leucovorin in metastatic gastrointestinal adenocarcinoma

PURPOSE

To determine the toxicities and potential for dose escalation of intravenous (IV) bolus fluorouracil (5-FU) given with 500 mg/m2/d leucovorin (LCV) and granulocyte-macrophage colony-stimulating factor (GM-CSF).

PATIENTS AND METHODS

Thirty-seven patients received escalating doses of 5-FU/LCV on days 1 to 5 with subcutaneous GM-CSF either 5 or 10 micrograms/kg/d starting on day 6 or 3 micrograms/kg/d starting on day 1. 5-FU was escalated from 370 mg/m2/d by 15% increments between patient cohorts and within patients according to tolerance.

RESULTS

With GM-CSF starting on day 6, dose-limiting toxicity occurred during cycle no. 1 in all three patients entered at 5-FU 490 mg/m2/d. However, individual patients tolerated 5-FU doses up to 644 mg/m2/d. When all cycles were analyzed, grade 3 to 4 mucositis and grade 4 granulocytopenia complicated < or = 15% and < or = 6% of cycles with 5-FU doses < or = 560 mg/m2/d (115 cycles). With GM-CSF starting on day 1, dose-limiting granulocytopenia occurred during cycle no. 1 in five of 10 patients entered at 5-FU 490 mg/m2/d. Although the granulocyte nadirs were significantly lower at each 5-FU dose level with the concurrent GM-CSF schedule (eg, 490 mg/m2/d: median, 879/microL v3,286/microL; two-tailed P [P2] < .001), dose-limiting granulocytopenia complicated < or = 16% of cycles with 5-FU < or = 560 mg/m2/d (99 cycles); > or = grade 3 mucositis occurred in < or = 20% of cycles. Grade 3 to 4 diarrhea was unusual with either GM-CSF schedule. Most patients treated with GM-CSF > or = 5 micrograms/kg/d required dose reductions for constitutional toxicity; 3.0 to 3.8 micrograms/kg/d was better tolerated. Venous thrombosis occurred in 17% of patients (concurrent v sequential GM-CSF, 29% v 5%; P2 = .08). The median delivered 5-FU dose-intensity for GM-CSF starting either on day 6 or on day 1 was 615 and 647 mg/m2/wk (P2 = .41), respectively. Pharmacologic exposure to 5-FU increased with higher doses of 5-FU, and concurrent GM-CSF administration did not affect 5-FU clearance.

CONCLUSION

A starting dose of 425 mg/m2/d of 5-FU with LCV on days 1 to 5 could be safely combined with GM-CSF starting either on day 1 or day 6, with further 5-FU dose escalation according to individual tolerance.

Energy costs of manual therapy: effects of plinth height and an assistive device

The purpose of this investigation was to examine the metabolic and cardiopulmonary responses of an experienced therapist (8 years experience) performing manual therapy at standard (S) plinth height (31 in), elevated (E) plinth height (38 in), and standard (SMTH) and elevated (EMTH) plinth height wearing a manual therapy harness (MTH). The MTH, developed by one of the investigators (J.L.S.), is a vestlike device worn by the therapist, which, when attached to the patient, can be used to distract articular surfaces. The MTH allows the therapist more freedom of hand movement and use of body weight to help provide joint distraction. Inferior glide (Grade 3-Maitland) was provided to the lift hip of 12 individuals at a rate of 20 oscillations per minute for 4 minutes, continuously, so that steady-rate metabolic conditions could be established. Mean body mass and height for the 12 individuals was 70±10.5 kg and 174.5±13 cm, respectively. The therapist's heart rate returned to resting levels between each of the randomly assigned treatments. One subject was treated daily. The therapist (age 32) was chosen because of his clinical experience, similar height (172 em) and weight (73 kg) to the average adult American male, and excellent intra- and interday (5%≤ METs, 5%≤ HR) reproducibility. Metabolic equivalents (METs), heart rate (HR), and rate of perceived exertion (RPE) were measured and averaged for the last 2 minutes of each treatment condition. The therapist was unaware of day-to-day test results except for RPE. Mean METs were 3. 7,3.2,2.6, and 2.4 for S, E, SMTH, and EMTH, respectively. Mean HRs were .117, 110, 104, and 93 beats/min for S, E, SMTH, and EMTH, respectively. RPE was 11. 0,8.7, 7.9, and 7.3jorS, E, SMTH, and EMTH, respectively. Repeated-measures analysis of variance (Scheffé F-test) revealed that SMTH and EMTH METs were similar, and significantly different (p≤0.05) from Sand E. METs for E were significantly different and lower than for S. HRs were significantly greater during E than the SMTH condition. RPE for S was significantly greater than SMTH, E, or EMTH. It can be concluded that the MTH significantly reduced the physiologic cost of providing manual therapy at either standard or elevated plinth height. further studies on these types of assistive devices and the effects of health status of the therapist on the provision of manual therapy treatments at various plinth heights are needed.

Phase II study of fluorouracil, leucovorin, and interferon alfa-2a in metastatic colorectal carcinoma

PURPOSE

To test the activity of a regimen of interferon alfa-2a (IFN alpha-2a) 5 x 10(6) U/m2 subcutaneously (SC) days 1 through 7 combined with leucovorin 500 mg/m2/d intravenously (IV) over 30 minutes and fluorouracil (5-FU) 370 mg/m2/d through IV push 1 hour after leucovorin days 2 through 6 in a phase II study.

PATIENTS AND METHODS

Forty-six patients with a good performance status (PS) with measurable colorectal cancer and no prior therapy for metastatic disease were entered. Cycles were repeated at 3-week intervals if toxicity had resolved. The 5-FU dose was increased by 15% if toxicity was mild, and decreased by 15% for grade 3 to 4 nonhematologic or grade 4 hematologic toxicity.

RESULTS

Three complete responses (CRs) and 21 partial responses (PRs) were seen among 44 assessable patients (54%; 95% confidence interval, 39% to 70%). A moderately strong association was noted between PS and response: PS O (n = 26), two CRs and 15 PRs (65%); PS 1 (n = 13), one CR and six PRs (54%); PS 2 (n = 5), zero CRs and zero PRs (0%; two-tailed P = .026). With a median follow-up duration of 18.8 months, the median time to treatment failure (TTF) and survival were 7.8 months and 16.3 months, respectively. Doses were escalated to 425 mg/m2/d 5-FU in 10 patients, but only four tolerated the higher dose. When expressed as the most severe degree of toxicity experienced by each patient across all cycles, grade 3 to 4 toxicity of the following types was observed; mucositis, 37%; diarrhea, 40%; rash, 7%; fatigue, 14%; granulocytopenia, 13%. Dose-limiting toxicity at 370 mg/m2/d 5-FU eventually occurred in 28 patients (61%). Twelve patients (26%) required an IFN alpha-2a dose reduction for constitutional toxicity.

CONCLUSION

This regimen has promising activity in advanced colorectal cancer, particularly in patients with an Eastern Cooperative Oncology Group (ECOG) PS of 0 to 1.

[Detection and quantitative determination of lectins and viscotoxins in mistletoe preparations]

Mistletoe lectins and viscotoxins, which up to now have been isolated only from plant material, were detected and quantitatively determined in the mistletoe preparation Iscador and in a fermented mistletoe extract. Lectins were isolated by affinity chromatography and analyzed by isoelectric focussing. Thus, in Iscador and in the fermented mistletoe extract only the mistletoe lectins ML II/III were found whereas typical proteins of the ML I complex were missing. The lectin content of the preparation and the extract was determined by "single radial immunodiffusion" (SRID). For identification and quantitative determination of viscotoxins, a HPLC method was designed.

A bacteriophage RNA polymerase transcribes through a Xenopus 5S RNA gene transcription complex without disrupting it

Conditions are described for programming with active transcription complexes essentially all the Xenopus 5S RNA genes added to an extract of Xenopus oocyte nuclei. We call this rate enhancement. Transcription by SP6 RNA polymerase of either strand of a Xenopus 5S RNA gene is unimpeded by the presence of a complete transcription complex associated with the internal control region of the gene. Furthermore, the transcription complex remains stably associated with the 5S RNA gene following multiple transits by the prokaryotic polymerase.

Studies on the standardization of mistletoe preparations

The newly isolated phenylpropanoids syringin, syringenin-apiosylglucoside, eleutheroside E and the high molecular lectins and viscotoxins were selected for a standardization of mistletoe extracts and drug preparation. The phenylpropanoids found in all alcoholic and aqueous extracts were suitable for an HPLC fingerprint analysis, and for quantitative determination. The lectin content of the drug preparations was determined by single radial immunodiffusion. As shown by the isoelectric focussing method, Iscador and fermented mistletoe extracts contain only the mistletoe lectins ML II/III, whereas the proteins of the ML I complex are missing. For identification and quantitative determination of viscotoxins, an HPLC method was designed.

Structure and properties of polysaccharides from Viscum album (L.)

Polysaccharides are possibly involved in the pharmacological effects of Viscum album (mistletoe) extracts, which are used in cancer therapy. Therefore the water-soluble polysaccharides of the fresh plant and the fermented proprietary preparation Iscador were isolated and characterized inter alia by methylation analysis, partial hydrolysis and C-13-NMR spectroscopy. The main polysaccharide of the green parts of Viscum is a highly esterified galacturonan whereas in Viscum 'berries' a complex arabinogalactan is predominant. Both types of these constituents were found in Iscador but with definite changes in molecular weight and structure. An interaction between the arabinogalactan and the galactose-specific lectin (ML I) in Viscum could be demonstrated. In three immunological tests (granulocyte, chemiluminescence, carbon clearance test) the polysaccharides failed to increase phagocytic activity of granulocytes and macrophages.

Intermolecular and intramolecular transposition and transposition immunity in Tn3 and Tn2660

Intermolecular transposition of Tn2660 into pCR1 was measured at 30 degrees C in recA- and recA+ hosts as between 2.6 and 5.5 X 10(-3), a similar value to that previously found for Tn3. No cointegrate structures were found under conditions where 10(4) transposition events occurred. Immunity to intermolecular transposition of Tn2660, similar to that found for Tn3 was demonstrated by showing that the above transposition frequency was reduced by a factor of between 10(-3) and 10(-4) when a mutant Tn2660 (resulting in the synthesis of a temperature-sensitive beta-lactamase) was present in the recipient plasmid. Intramolecular transposition of Tn3 was found to occur under the same conditions as previously demonstrated for Tn2660 giving rise to similar end products, in which the newly introduced Tn3 is oriented inversely to the resident Tn3 and the DNA sequence between the two transposons has been inverted. Thus, in all respects functional identity of the transposition activities of Tn3 and Tn2660 is shown, thereby identifying characteristics of intramolecular transposition that are not readily accommodated by current models of transposition.