Overview of Telemedicine Services in Mongolia

Purpose of Review

To highlight some achievements made through usage of telecommunication technologies in Mongolia as an example of a developing country with remote areas.

Recent Findings

Telemedicine can be implemented not only for remote monitoring, diagnosing, and treating purposes but also can be effectively used for delivering knowledge and consultation services via modern technologies.

Summary

Tele-health services can be successfully added to the traditional approach of physicians, especially in the countries with a vast territory with distant areas.

Mangrove selective logging sustains biomass carbon recovery, soil carbon, and sediment

West Papua's Bintuni Bay is Indonesia's largest contiguous mangrove block, only second to the world's largest mangrove in the Sundarbans, Bangladesh. As almost 40% of these mangroves are designated production forest, we assessed the effects of commercial logging on forest structure, biomass recovery, and soil carbon stocks and burial in five-year intervals, up to 25 years post-harvest. Through remote sensing and field surveys, we found that canopy structure and species diversity were gradually enhanced following biomass recovery. Carbon pools preserved in soil were supported by similar rates of carbon burial before and after logging. Our results show that mangrove forest management maintained between 70 and 75% of the total ecosystem carbon stocks, and 15-20% returned to the ecosystem after 15-25 years. This analysis suggests that mangroves managed through selective logging provide an opportunity for coastal nature-based climate solutions, while provisioning other ecosystem services, including wood and wood products.

Global patterns and drivers of ecosystem functioning in rivers and riparian zones

River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.

Tunneling decay of self-gravitating vortices

We investigate tunneling decay of false vortices in the presence of gravity, in which vortices are trapped in the false vacuum of a theory of scalar electrodynamics in three dimensions. The core of the vortex contains magnetic flux in the true vacuum, while outside the vortex is the appropriate topologically nontrivial false vacuum. We numerically obtain vortex solutions which are classically stable; however, they could decay via tunneling. To show this phenomenon, we construct the proper junction conditions in curved spacetime. We find that the tunneling exponent for the vortices is half that for Coleman-de Luccia bubbles and discuss possible future applications.

Achieving succession planning and implementation: one healthcare network's story

Frequent transitions in leadership can cause inefficiency, inconsistency, and lack of alignment with priorities and strategy. Retaining management talent and collaboratively planning their succession can help ensure organizational survival. Succession planning, in healthcare and other industries, addresses some of these concerns; however, there is a dearth of descriptive articles emphasizing "how to." This article demonstrates one healthcare network's comprehensive system for succession planning and implementation. Leaders looking to plan their human resource processes for organizational sustainability would be able to emulate and adapt practices for their networks.

Complex adaptive strategy to produce capacity-driven financial improvement

Managing capacity in hospitals and emergency departments (EDs) is a global problem. This article demonstrates an efficiency model applied to an acute care hospital facing a budget shortfall as a result of capacity constraints that negatively affected admissions and increased ED diversions. Operating on the hypothesis that reducing inpatient length of stay would allow patients access through all service points and would return the admissions growth rate to budget, a turnaround team was quickly assembled and charged by the chief executive officer to fix the primary cause of financial underperformance--the creeping length of stay--within 60 days. This case study is generalizable to all organizations, regardless of size. Deploying an efficiency model based on the complex adaptive systems approach of "swarmware," the hospital's rapid turnaround efforts produced the results necessary to achieve two established goals: (1) length of stay was decreased to 0.1 days below budget in the 60-day time frame, and (2) all admissions and potential admissions were accepted (saying "yes" to patients) through key points of access in the hospital. Transfer Center denials were reduced to 0 in 19 days, and monthly ED diversions decreased from 110 hours to 20 hours in 60 days. By using a swarmware approach, the hospital created additional bed capacity, allowing for community demand to be accommodated, budgeted admissions target to be exceeded, and market share to be stabilized. This article describes this project's processes and outcomes and the lessons learned and applied, which will assist healthcare leaders who are facing capacity issues in their own organization.

Complicity in contraband: British American Tobacco and cigarette smuggling in Asia

OBJECTIVES

To examine the complicity of British American Tobacco (BAT) in cigarette smuggling in Asia, and to assess the centrality of illicit trade to regional corporate strategy.

METHODS

Analysis of previously confidential documents from BAT's Guildford depository. An iterative strategy combined searches based on geography, organisational structure, and key personnel, while corporate euphemisms for contraband were identified by triangulation.

RESULTS

BAT documents demonstrate the strategic importance of smuggling across global, regional, national, and local levels. Particularly important in Asia, contraband enabled access to closed markets, created pressure for market opening, and was highly profitable. Documents demonstrate BAT's detailed oversight of illicit trade, seeking to reconcile the conflicting demands of control and deniability.

CONCLUSIONS

BAT documents demonstrate that smuggling has been driven by corporate objectives, indicate national measures by which the problem can be addressed, and highlight the importance of a coordinated global response via WHO's Framework Convention on Tobacco Control.

"Almost a role model of what we would like to do everywhere": British American Tobacco in Cambodia

OBJECTIVES

To examine British American Tobacco's (BAT's) renewed interest in Cambodia from the early 1990s, reviewing negotiations to establish a joint venture and the subsequent conduct of BAT Cambodia (BATC).

METHODS

Analysis of previously confidential BAT documents relevant to the Cambodian market.

RESULTS

With the advent of comparative political stability in the early 1990s, BAT was quick to explore the possibilities for investment. The Cambodian government urgently required foreign investment, offering inducements and assistance to investors. In developing a joint venture, BAT saw a cost effective opportunity to dominate the local market and to defend its regional interests, Cambodia being viewed as strategically located to support smuggling. Given minimal advertising regulation, BATC have undertaken wide ranging promotions and sought to prevent advances in tobacco control.

CONCLUSIONS

BATC is presented as a contribution to Cambodia's regeneration, but the documents highlight its exploitation of state incapacity and an escalating threat to public health.

"If we can just 'stall' new unfriendly legislations, the scoreboard is already in our favour": transnational tobacco companies and ingredients disclosure in Thailand

OBJECTIVES

To review the strategies employed by overseas cigarette manufacturers operating in Thailand to obstruct the passage and subsequent enforcement of national public health legislation, specifically the ingredients disclosure provision of the 1992 Tobacco Products Control Act.

METHODS

Analysis of previously confidential tobacco industry documents relevant to non-compliance with the ingredients disclosure legislation.

RESULTS

Requirement for disclosure of ingredients contained in cigarettes contained in the Tobacco Products Control Act was identified by transnational tobacco companies (TTCs) not only as a significant threat to their operations in Thailand, but as a dangerous global precedent. Industry documents reveal a determined campaign to block, stall, or amend the proposed regulation during the legislative process. Industry representatives petitioned the Ministry of Health to revise the requirement from by brand disclosure to a more palatable by company submission. Strategies were adapted in the wake of the passage of the Act. Most significantly, the industry in concert with embassies in Bangkok threatened the Thai government with appeals to international trade bodies on the grounds of violation of international agreements. Industry documents also reveal that as submission of ingredient lists appeared unavoidable, leading companies operating in Thailand endeavoured to confound the disclosure requirement by disguising ingredients and reformulating brand recipes.

CONCLUSIONS

The evidence presented highlights the importance of ingredients regulation and demonstrates how health policy can be transformed during its implementation. A greater understanding of trade agreements emerges as a priority for global tobacco control.

The relationship between socio-economic status, geography, symptomatic carotid territory disease and carotid endarterectomy

OBJECTIVE

recent evidence suggests a strong association between socio-economic status and atherosclerosis. However, little information exists on the relationship between socio-economic status, symptomatic carotid disease and rates of carotid endarterectomy (CEA). The aim was to evaluate the Carstair Deprivation Score (CDS) of (1) patients admitted with symptomatic carotid disease, and (2) those undergoing CEA in one health board.

METHOD

the CDS score was determined from the post-codes of all patients admitted with a diagnosis of transient ischaemic attack (TIA) or stroke due to cerebral infarction (ISD 9 codes 433.1, 433.09, 435, 437.1; ICD-10: 165.2, 163, 163.2, G45.1, G45.3, G45.9) between 1st April 1995 and 31st March 2000. Expected and actual rates for each of the CDS (1 to 7) were determined by direct and indirect methods of standardisation allowing for age and sex. A similar analysis was performed for patients undergoing carotid endarterectomy. Results were analysed using the Mantel-Haenszel test. Only first time admissions and CEA were included.

RESULTS

1203 patients were admitted with the main diagnosis of symptomatic carotid disease. The admission rate of symptomatic patients was less than expected in the more affluent group (Carstair 1, p < 0.005) and significantly higher in the most deprived group (Carstair 7, p < 0.001). In comparison 192 patients underwent CEA. There were no differences between the expected and actual rates of CEA in each CDS, but the rates tended to be higher in the most affluent group. Geographical variation was also demonstrated with an increased rate of CEA in those patients living in the cities and a reduced rate in those in the rural communities.

CONCLUSION

patients from deprived socio-economic groups had a higher rate of symptomatic carotid disease, but this was not matched by an increased rate of CEA. This suggests that socio-economic inequalities in the prevalence of symptomatic carotid artery disease and treatment exist.

Prophylaxis of radiation-associated mucositis in conventionally treated patients with head and neck cancer: a double-blind, phase III, randomized, controlled trial evaluating the clinical efficacy of an antimicrobial lozenge using a validated mucositis scoring system

PURPOSE

Mucositis occurs in almost all patients treated with radiotherapy for head and neck cancer. The aim of this multicenter, double-blind, prospective, randomized trial was to evaluate the clinical efficacy of an economically viable antimicrobial lozenge (bacitracin, clotrimazole, and gentamicin [BcoG]) in the alleviation of radiation-induced mucositis in patients with head and neck cancer.

PATIENTS AND METHODS

One hundred thirty-seven eligible patients were randomized to treatment with either antimicrobial lozenge (69 patients) or placebo lozenge (68 patients). The primary end point of the study was the time to development of severe mucositis from the start of radiotherapy. Secondary end points included severity and duration of mucositis, pain measurement, radiation therapy interruption, and quality of life. Mucositis was scored using a validated mucositis scoring system.

RESULTS

Toxicity profiles were similar between the two arms of the study. The median time to development of severe mucositis from the start of radiotherapy was 3.61 weeks on BCoG and 3.96 weeks on placebo (P =.61). There were no statistically significant differences between the arms in the extent of severe mucositis as measured by physician, in oral toxicities as recorded by patients, or in radiotherapy delays.

CONCLUSION

This study was conducted on the basis of a pilot study that demonstrated the BCoG lozenge to be tolerable and microbiologically efficacious. A validated mucositis scoring system was used. However, in this group of patients treated with conventional radiotherapy, the lozenge did not impact significantly on the severity of mucositis. Whether such a lozenge would be beneficial in treatment situations where rate of severe mucositis is higher (ie, in patients treated with unconventional fractionation or with concomitant chemotherapy) is unknown.

Alpha-1-antitrypsin and a broad spectrum metalloprotease inhibitor, RS113456, have similar acute anti-inflammatory effects

There is increasing evidence that antiproteases are able to affect the inflammatory response. To further examine this question, we administered human alpha-1-antitrypsin (alpha1AT) or a synthetic metalloprotease inhibitor (RS113456) to C57 mice followed by a single intratracheal dose of quartz, a dust that evokes a marked, lasting, polymorphonuclear leukocyte (PMN) infiltrate. At 2 hours after dust administration, both antiproteases completely suppressed silica-induced PMN influx into the lung and macrophage inflammatory protein-2 (MIP-2)/monocyte chemotactic protein-1 (MCP-1) (neutrophil/macrophage chemoattractant) gene expression, partially suppressed nuclear transcription factor kappaB (NF-kappaB) translocation, and increased inhibitor of NF-kappaB (IkappaB) levels. By 24 hours, PMN influx and connective tissue breakdown measured as lavage desmosine or hydroxyproline were still at, or close to, control levels after antiprotease treatment, and increases in NF-kappaB translocation and MIP-2/MCP-1 gene expression were variably suppressed. At both time points, neither agent prevented silica-induced increases in amount of whole lung MIP-2 or MCP-1 protein, but both did prevent increases in whole lung intercellular adhesion molecule-1 (ICAM-1) at 24 hours. Inactivating the alpha1AT by oxidation to the point that it no longer possessed antiproteolytic properties did not affect its ability to suppress inflammation. Both antiproteases also prevented the silica-induced acute inflammatory response in mice with knocked out genes for macrophage metalloelastase (MME -/-), mice that develop inflammation, but not connective tissue breakdown, and the pattern of alpha1AT breakdown fragments was identical in control and MME -/- animals. These findings suggest that, in this model of acute PMN mediated inflammation, a serine protease inhibitor and a metalloprotease inhibitor have similar anti-inflammatory properties, that inflammation is not mediated by proteolysis with generation of chemotactic matrix fragments, and that classic antiproteolysis (complexing of protease to antiprotease) probably does not play a role in suppression of inflammation. The antiproteolytic effects of these agents do not seem to be mediated by protection of endogenous alpha1AT.

The Brugada syndrome--an electrocardiogram with important mortality implications

The electrocardiogram (ECG) is a valuable screening tool for increased risk in underwriting life insurance applicants. This article discusses a recently described ECG pattern associated with a high risk of sudden unexpected death.

The binding of a glycoprotein 120 V3 loop peptide to HIV-1 neutralizing antibodies. Structural implications

The structural and antigenic properties of a peptide ("CRK") derived from the V3 loop of HIV-1 gp120 protein were studied using NMR and SPR techniques. The sequence of CRK corresponds to the central portion of the V3 loop containing the highly conserved "GPGR" residue sequence. Although the biological significance of this conserved sequence is unknown, the adoption of conserved secondary structure (type II beta-turn) in this region has been proposed. The tendency of CRK (while free or conjugated to protein), to adopt such structure and the influence of such structure upon CRK antigenicity were investigated by NMR and SPR, respectively. Regardless of conjugation, CRK is conformationally averaged in solution but a weak tendency of the CRK "GPGR" residues to adopt a beta-turn conformation was observed after conjugation. The influence of GPGR structure upon CRK antigenicity was investigated by measuring the affinities of two cognate antibodies: "5023A" and "5025A," for CRK, protein-conjugated CRK and gp120 protein. Each antibody bound to all the antigens with nearly the same affinity. From these data, it appears that: (a) antibody binding most likely involves an induced fit of the peptide and (b) the gp120 V3 loop is probably conformationally heterogeneous. Since 5023A and 5025A are HIV-1 neutralizing antibodies, neutralization in these cases appears to be independent of adopted GPGR beta-turn structure.

Binding of an antibody mimetic of the human low density lipoprotein receptor to apolipoprotein E is governed through electrostatic forces. Studies using site-directed mutagenesis and molecular modeling

Monoclonal antibody 2E8 is specific for an epitope that coincides with the binding site of the low density lipoprotein receptor (LDLR) on human apoE. Its reactivity with apoE variants resembles that of the LDLR: it binds well with apoE3 and poorly with apoE2. The heavy chain complementarity-determining region (CDRH) 2 of 2E8 shows homology to the ligand-binding domain of the LDLR. To define better the structural basis of the 2E8/apoE interaction and particularly the role of electrostatic interactions, we generated and characterized a panel of 2E8 variants. Replacement of acidic residues in the 2E8 CDRHs showed that Asp(52), Glu(53), and Asp(56) are essential for high-affinity binding. Although Asp(31) (CDRH1), Glu(58) (CDRH2), and Asp(97) (CDRH3) did not appear to be critical, the Asp(97) --> Ala variant acquired reactivity with apoE2. A Thr(57) --> Glu substitution increased affinity for both apoE3 and apoE2. The affinities of wild-type 2E8 and variants for apoE varied inversely with ionic strength, suggesting that electrostatic forces contribute to both antigen binding and isoform specificity. We propose a model of the 2E8.apoE immune complex that is based on the 2E8 and apoE crystal structures and that is consistent with the apoE-binding properties of wild-type 2E8 and its variants. Given the similarity between the LDLR and 2E8 in terms of specificity, the LDLR/ligand interaction may also have an important electrostatic component.

Accelerated radiotherapy with delayed concomitant boost in locally advanced squamous cell carcinoma of the head and neck

PURPOSE

To determine the toxicity, maximum tolerated dose (MTD), and clinical effectiveness of a 5-week course of accelerated radiotherapy with delayed concomitant boost in locally advanced squamous cell carcinoma of the head and neck (SCCHN).

METHODS AND MATERIALS

Thirty-five patients with untreated T3T4NM0 or TN2 (> 3 cm) N3M0 SCC of the oral cavity, oropharynx, hypopharynx, or larynx were entered in the study between January 1994 and October 1997. The initial target volume was treated with conventional daily fractions. A small field boost covering gross disease was added as a second daily fraction during the last 2 weeks of the 5-week schedule, using a minimum interfraction interval of 6 h. The study was initiated using 180-cGy fractions to deliver a total dose of 63 Gy over 33-35 days. A classical dose escalation strategy was planned to increase the delivered dose in steps using minimum cohorts of three patients, up to a maximum of 70 Gy in 200-cGy fractions.

RESULTS

In the dose escalation study, 4 patients were entered at level 1 (63 Gy), 9 at level 2 (65 Gy), and 8 at level 3 (67 Gy). One patient was withdrawn at level 2 because of unstable angina, and 1 at level 3 because of uncontrolled diabetes. One patient at level 3 failed to complete treatment because of radiation toxicity. RTOG Grade 3 mucositis, dermatitis, or pharyngitis was documented in 1 (25%), 5 (63%), and 7 (100%) evaluable patients at levels 1, 2, and 3, respectively. Grade 4 reactions were documented in 1 patient at each level. One patient at level 3 died 5 weeks post-treatment of unknown causes. Two additional patients at level 3 died of progressive disease and RT toxicity. Sixty-five Gy (level 2) was chosen as the MTD. In the MTD study, 14 additional patients were entered at level 2, providing a total of 22 evaluable patients with a median follow-up of 21 months (range 12-41 months). Grade 3 mucositis, dermatitis, or pharyngitis were documented in 11 (50%), 8 (36%), and 6 (27%) patients, respectively. One patient developed Grade 4 mucositis. A complete response was recorded in 16 (77%). Three of 5 patients with uncontrolled disease and 3 of 3 patients with recurrent disease underwent salvage surgery with no postoperative complications. Radiotherapy controlled disease above the clavicles in 14 (68%). Ultimate locoregional control was achieved in 17 (77%). The disease-free, overall, and cause-specific survival of all patients entered at level 2 was 56%, 76%, and 80%, respectively, at 2 years. Late complications have been limited to 3 patients (trismus, chronic mucosal ulcer, and soft tissue necrosis).

CONCLUSION

A 5-week course of accelerated radiotherapy with delayed concomitant boost can deliver 65 Gy with acceptable toxicity, encouraging rates of complete response, and locoregional control, and no compromise of salvage surgery in patients with locally advanced SCCHN. The regimen is worthy of further study in a Phase III trial.

Patterns of p53 gene mutations in head and neck cancer: full-length gene sequencing and results of primary radiotherapy

p53 gene alterations are common in head and neck cancers, but their prognostic value has not been clearly established. Despite evidence in other cancers that sequencing of the entire p53 coding region provides prognostic information, full-length p53 gene sequencing has rarely been performed in head and neck cancers. In this study, p53 was assessed in a series of 42 pretreatment biopsies from patients with laryngeal carcinomas by full-length gene sequencing and by immunohistochemistry (IHC). Associations among p53 genotype, protein expression, and local recurrence were assessed in 35 irradiated patients followed for a minimum of 5 years. DNA was extracted from formalin-fixed, paraffin-embedded biopsies, and exons 2-11 of the p53 gene were individually amplified by PCR and then directly sequenced. IHC was performed to detect mutant and wild-type p53 protein using the DO7 monoclonal antibody. p21 protein expression was assessed using the EA1 monoclonal antibody. Twenty genetic alterations were observed in 42 tumors (48%). Four of these alterations (20%) occurred outside exons 5-8. There was a significant association between p53 gene and protein status (chi2 = 4.18, P = 0.04), although the correlation was weak (phi coefficient = -0.327). Although local relapse following radiation was significantly associated with nodal status, no correlations were observed between p53 status (gene or IHC) and local recurrence following radiation therapy, based on the Kaplan-Meier method. These results show that p53 mutations are common in laryngeal carcinomas and that a proportion occur outside traditionally examined regions. The lack of correlation between p53 status and local control suggests that this marker is not as powerful as traditional prognostic factors, such as lymph node status.

Expression and characterisation of human and rat CRF2alpha receptors

Rat and human CRF2alpha receptors were expressed in CHO-pro5 cells and stable cell lines generated. Each receptor was characterised using [125I][tyr0]sauvagine and results compared to CRF1 receptors expressed in the same parental cell line. Under identical assay conditions, [125I][tyr0]sauvagine labelled both CRF1 and CRF2alpha receptors with high affinity. The level of expression varied from 103 fmol/mg membrane protein to 1842 fmol/mg membrane protein (rat CRF1 receptors and rat CRF2 receptors, respectively). It was possible to establish robust scintillation proximity assays (SPA) using wheat germ agglutinin (WGA) SPA beads to trap membrane protein. The success of the SPA assay format was dependent on the level of receptor expression observed. The rank order of affinities of a series of peptide CRF receptor agonists and antagonists was similar to that described in the literature for the two receptor subtypes as determined using radioligand binding and cAMP accumulation. No pharmacological differences were apparent between rat and human cloned receptors with the exception of alpha-helical CRF-(9-41). This peptide exhibited 10-fold higher affinity for rat CRF2alpha receptors as compared to human CRF2alpha receptors. PD 173307, PD 173602 and PD 174239 exhibited high affinity and selectivity for human CRF1 receptors, and as such represent useful tools for probing CRF receptor function.

The role of valency in the selection of anti-carbohydrate single-chain Fvs from phage display libraries

Several strategies were investigated for phage display of anti-carbohydrate single-chain Fvs (scFvs) using the anti-Salmonella Se155-4 scFv as a model system. All were based on the knowledge that panning V(H) CDR libraries displayed in a standard pIII phagemid/helper phage format against immobilized multivalent carbohydrate antigens selects almost solely for mutants with higher yields of soluble product or scFvs that form dimers or higher oligomers even when the linker length is chosen to give monomeric molecules. Construction of scFv libraries, in a phagemid vector, with mutations that already provide higher yields and/or short linkers to promote dimeric display greatly reduced these undesired selection pressures. However. the panning of an error-prone library of the entire scFv in a short linker format yielded two mutants that existed partially in higher oligomeric forms, indicating that dimeric display did not entirely eliminate the selection pressure problem. In one mutant a Ser75Gly mutation led to the formation of greater amounts of dimeric, trimeric and tetrameric scFv and surface plasmon resonance analysis of these different forms gave quantitative data for the functional affinity of these different scFv forms. Finally, a phage vector was constructed and the original V(H) CDR library was transferred to this vector. This display format, in which scFv is displayed on all three to five copies of pIII, seemed to be superior in terms of selection on the basis of binding site affinity and as a display mode for scFvs with low intrinsic affinity. While the use of the phage vector did not lead to the isolation of higher affinity binders from the library employed here, it did almost entirely remove the undesired selection pressures in that there was selection for the wild-type sequence. It is suggested that the multivalency of display provided by phage vectors is preferable to any phagemid vector strategy for the de novo isolation of anti-carbohydrate antibodies from phage libraries.

Pyrazolo[1,5-a]pyrimidine CRF-1 receptor antagonists

A series of 3-phenylpyrazolo[1,5-a]pyrimidines was prepared and found to have affinity for the human CRF-1 receptor. The 3-dimensional structure of one of the most potent analogs in this series, 10d, was determined by X-ray crystallography and suggests the spatial requirements for potent CRF-1 receptor binding affinity in this series.

Randomized trial of intensive cyclophosphamide, epirubicin, and fluorouracil chemotherapy compared with cyclophosphamide, methotrexate, and fluorouracil in premenopausal women with node-positive breast cancer. National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To determine the relative efficacy of an intensive cyclophosphamide, epirubicin, and fluorouracil (CEF) adjuvant chemotherapy regimen compared with cyclophosphamide, methotrexate, and fluorouracil (CMF) in node-positive breast cancer.

PATIENTS AND METHODS

Premenopausal women with node-positive breast cancer were randomly allocated to receive either cyclophosphamide 100 mg/m2 orally days 1 through 14; methotrexate 40 mg/m2 intravenously (i.v.) days 1 and 8; and fluorouracil 600 mg/m2 i.v. days 1 and 8 or cyclophosphomide 75 mg/m2 orally days 1 through 14; epirubicin 60 mg/m2 i.v. days 1 and 8; and fluorouracil 500 mg/m2 i.v. days 1 and 8. Each cycle was administered monthly for 6 months. Patients administered CEF received antibiotic prophylaxis with cotrimoxazole two tablets twice a day for the duration of chemotherapy.

RESULTS

The median follow-up was 59 months. One hundred sixty-nine of the 359 CMF patients developed recurrence compared with 132 of the 351 CEF patients. The corresponding 5-year relapse-free survival rates were 53% and 63%, respectively (P = .009). One hundred seven CMF patients died compared with 85 CEF patients. The corresponding 5-year actuarial survival rates were 70% and 77%, respectively (P = .03). The rate of hospitalization for febrile neutropenia was 1.1% in the CMF group compared with 8.5% in the CEF group. There was one case of congestive heart failure in a patient who received CMF compared with none in the CEF group. Acute leukemia occurred in five patients in the CEF group.

CONCLUSION

The results of this trial show the superiority of CEF over CMF in terms of both disease-free and overall survival in premenopausal women with axillary node-positive breast cancer.

The prognostic significance of tracheostomy in carcinoma of the larynx treated with radiotherapy and surgery for salvage

PURPOSE

To determine retrospectively the prognostic significance of airway compromise necessitating tracheostomy in carcinoma of the larynx managed with radical radiotherapy and surgery for salvage (RRSS).

METHODS AND MATERIALS

The charts of 270 patients managed with RRSS at the Toronto-Sunnybrook Regional Cancer Centre between June 1980 and December 1990 were reviewed. Airway compromise necessitating tracheostomy was documented in 26 patients prior to radiotherapy and 3 patients during radiotherapy. Of 29, 27 had T3T4 primaries. Patients have been followed for a median of 5 years.

RESULTS

Patients managed without tracheostomy had a 2-year disease-free survival of 74% compared to 41% for those managed with tracheostomy. The adverse impact of airway compromise was more marked in patients with glottic primaries (78% vs. 32%, p = 0.0001) than those with supraglottic primaries (64% vs. 47%, p = 0.18). Tracheostomy was identified in univariate analysis, but not in multivariate analysis, as having a statistically significant impact on local control and local-regional control. Radiotherapy controlled disease above the clavicles in 185 of 267 (69%) evaluable patients. 83% of isolated local-regional failures underwent salvage surgery. Among those managed without tracheostomy, ultimate local-regional control (LRC) was achieved in 161 (94%) of 172 glottic primaries and 54 (81%) of 67 supraglottic primaries. Among those managed with tracheostomy, ultimate LRC was achieved in 9 (69%) of 13 glottic primaries and 12 (80%) of 15 supraglottic primaries. In a subset analysis of 76 patients with T3T4 primaries, there was no statistically significant difference in larynx preservation, disease-free survival, or cause-specific survival between those managed with and without tracheostomy.

CONCLUSION

Airway compromise necessitating tracheostomy is an adverse prognostic factor in patients with carcinoma of the larynx. However, larynx preservation is possible in over 40% of those undergoing tracheostomy and radiotherapy with no compromise of cause-specific survival. The need for pretreatment tracheostomy should not rule out the possibility of RRSS.

A kinetics approach to the characterization of an IgM specific for the glycolipid asialo-GM1

The unique features of protein recognition of membrane-anchored glycolipids were investigated by surface plasmon resonance (SPR) monitoring of antibody interactions with glycolipids contained in liposomes. Several positive hybridomas belonging to the IgM and IgG classes were identified when tested for binding to the glycosphingolipid asialo-GM1 (Gal beta1-3GalNAcl beta1-4Gal beta1-4Glc beta1-1-Ceramide). Preliminary screening by enzyme immunoassay and thin layer chromatography (TLC) followed by immunostaining indicated that only those of the IgM type showed specificity for this glycosphingolipid. One of the IgMs, H2G10, was purified and further characterized using a SPR technique that involved antibody binding to liposomal asialo-GM1. This method generated kinetic and affinity constants for the interaction and confirmed the specificity of H2G10 for the terminal galactose of asialo-GM1. Interestingly, inhibition of antibody binding to asialo-GM1 liposomes by the asialo-GM1 tetrasaccharide reduced the total amount of bound antibody but increased the affinity of the antigen-antibody interaction due to an inverse relationship between tetrasaccharide concentration and the H2G10 dissociation rate constant. We believe that this effect is due to the selective inhibition of lower valency binding by the tetrasaccharide which, in turn, promotes higher avidity antibody-carbohydrate interactions. The observation that slower dissociation rate constants were also observed at high antigen to antibody ratios supports this interpretation. These results highlight the insight that kinetic data can provide in efforts to promote and inhibit high avidity interactions such as those involving proteins and carbohydrates.