Surface modification of an experimental silicone rubber aimed at reducing initial candidal adhesion

Silicone rubber, which is a widely used biomaterial, is often used to make soft liners for permanent denture. Colonization of denture soft lining materials by Candida albicans can result in clinical problems. The aim of this study was to chemically modify the surface of an experimental silicone rubber in order to produce a silicone that was less susceptible to candidal colonization. Surface modification was carried out with the use of argon-plasma bombardment followed by silane treatment, which caused the incorporation of either hydrophilic or hydrophobic functional groups onto the surface. Changes in water contact angles and chemical analysis of the materials with scanning ion mass spectroscopy confirmed surface changes. In vitro assays were carried out using C. albicans to measure levels of adherence to the surface-modified silicone after 1 h. C. albicans exhibited very low adherence to all silane-treated surfaces, whether hydrophobic or hydrophilic. This led to the conclusion that incorporated long-chain functional groups were inhibiting the adherence of the yeast, possibly by the formation of a barrier between the surface of the material and the yeast. In conclusion, silane surface treatment of an experimental silicone rubber has been successful in reducing candidal adherence.

Risk identification, assessment and management in public health practice: a practical approach in one public health department

BACKGROUND

The continuing identification, assessment and management of risks are key themes for clinical governance. These themes are being integrated into both primary and secondary care practice; however, integration into public health practice appears much slower. This paper describes the recent approach that we have taken in Sheffield, and proposes a model for public health departments to identify, assess and manage risks, which complements other risk management processes and is transferable to other settings. It assumes that public health practice is not a risk-free activity and holds that the process of identifying, assessing and managing risks is a key component to raising standards.

METHODS

A number of risk 'management' models were reviewed and a primary care approach was applied to public health practice. A list of potential risks was identified using a number of methods including reflective practice, information from complaints and/or critical incidents. Risks were assessed by likelihood and impact, and were captured in a risk framework.

RESULTS

By March 2002, 21 risks had been identified and characterized, and progress had been made to manage 11 of these risks.

CONCLUSION

This process, and the development of a risk framework, was useful in identifying a prioritized work programme to improve standards of public health practice in this department. This model can also be used not only for planning risk management activities, continual identification and assessment of risks but also to provide inspiration for other clinical governance activities including public health audit.

Ethnic intermixture of migrants and indigenous peoples in Australia

"Claims concerning the size of ethnic and indigenous communities need to be considered in the light of intermixture with other communities. Intermixture levels are in fact high for most of Australia's ethnic and indigenous peoples."

Sequence of Plasmodium falciparum chromosomes 1, 3-9 and 13

Since the sequencing of the first two chromosomes of the malaria parasite, Plasmodium falciparum, there has been a concerted effort to sequence and assemble the entire genome of this organism. Here we report the sequence of chromosomes 1, 3-9 and 13 of P. falciparum clone 3D7--these chromosomes account for approximately 55% of the total genome. We describe the methods used to map, sequence and annotate these chromosomes. By comparing our assemblies with the optical map, we indicate the completeness of the resulting sequence. During annotation, we assign Gene Ontology terms to the predicted gene products, and observe clustering of some malaria-specific terms to specific chromosomes. We identify a highly conserved sequence element found in the intergenic region of internal var genes that is not associated with their telomeric counterparts.

Phase I study of weekly oxaliplatin plus irinotecan in previously treated patients with metastatic colorectal cancer

BACKGROUND

In vitro synergy between Oxal (oxaliplatin) and CPT-11 (irinotecan) has been reported. Oxaliplatin exerts its antineoplastic activity through the formation of platinum-DNA adducts. Resistance to oxaliplatin is through repair of these adducts, which is inhibited by irinotecan.

PATIENTS AND METHODS

Oxaliplatin and irinotecan were administered weekly for 4 weeks followed by a 2-week rest period. The dose of oxaliplatin was escalated first, starting at 30 mg/m(2). Once a dose of 60 mg/m(2) was attained, the weekly dose of irinotecan was escalated, from 40 mg/m(2) to 85 mg/m(2). A total of 49 previously treated patients with metastatic colorectal cancer were entered in order to establish the maximum tolerated dose. Pharmacokinetics of oxaliplatin and irinotecan were analyzed.

RESULTS

Forty-nine patients were evaluable for toxicity. The recommended phase II doses for this combination are oxaliplatin 60 mg/m(2) and irinotecan 50 mg/m(2), weekly x 4 q 6 weeks. Diarrhea was the most common dose-limiting toxicity. No pharmacological interactions were noted between oxaliplatin and irinotecan. Twelve of the 47 evaluable patients (26%) achieved a partial response.

CONCLUSION

Weekly combination of oxaliplatin and irinotecan appears to be a well tolerated and active regimen in patients previously treated for metastatic colorectal cancer. Further investigations of this regimen are warranted.

Combination of electroporation and DNA/dendrimer complexes enhances gene transfer into murine cardiac transplants

Electroporation is a new gene delivery method to increase gene transfer and expression in vivo. Starburst polyamidoamine dendrimers have been demonstrated to augment gene expression in vitro and in vivo. We hypothesized that the combination of electroporation and dendrimer could enhance the gene transfer and gene expression in cardiac transplants. After immersion in DNA/dendrimer complexes or intracoronary transfer of DNA/dendrimer complexes, both nonvascularized and vascularized syngeneic cardiac grafts, respectively, were subjected to serial electrical pulses before transplantation. beta-Galactosidase reporter gene expression in the graft was determined by X-Gal staining. Gene expression was enhanced 10- to 45-fold in grafts immersed in DNA/dendrimer complexes, or after intracoronary transfer of DNA/dendrimer complexes, and subjected to 20 square wave 25-ms pulses with a strength of 200 V/cm. The combination of electroporation and DNA/dendrimer complexes may provide a novel approach to enhance gene transfer and gene expression ex vivo.

Structure of TCTP reveals unexpected relationship with guanine nucleotide-free chaperones

The translationally controlled tumor-associated proteins (TCTPs) are a highly conserved and abundantly expressed family of eukaryotic proteins that are implicated in both cell growth and the human acute allergic response but whose intracellular biochemical function has remained elusive. We report here the solution structure of the TCTP from Schizosaccharomyces pombe, which, on the basis of sequence homology, defines the fold of the entire family. We show that TCTPs form a structural superfamily with the Mss4/Dss4 family of proteins, which bind to the GDP/GTP free form of Rab proteins (members of the Ras superfamily) and have been termed guanine nucleotide-free chaperones (GFCs). Mss4 also acts as a relatively inefficient guanine nucleotide exchange factor (GEF). We further show that the Rab protein binding site on Mss4 coincides with the region of highest sequence conservation in the TCTP family. This is the first link to any other family of proteins that has been established for the TCTP family and suggests the presence of a GFC/GEF at extremely high abundance in eukaryotic cells.

A report of an outbreak of Shigellosis in a primary school in Staffordshire

This paper describes the management of an outbreak of Shigellosis, reported in the national media, in a village school in Staffordshire. The issues encountered by the outbreak team during the management of this incident have re-affirmed the need for public and environmental health departments to work closely with educational bodies to develop clear and consistent action plans for the management of communicable disease outbreaks. The management of communicable disease in schools, the workplace and other settings should be addressed, possibly as a component of local health improvement plans.

Support of clinician image-related workflow by a user-edited, web-based patient list manager

Clinician efficiency can be enhanced by worklists that compile useful data for rapid access at the time of need. The authors report development of a web-based, user-edited "Patient List Manager" for the Clinical Image Management System (CIMS). The CIMS List Manager interfaces with the CIMS Archive to provide the user with available studies. It has tools that let the user build personal lists from the available studies. Listed studies are moved from the archive to the cache for rapid access at the time of need. Users can build/edit the list through a browser (without viewing pictures) or from within the image viewer. In this way, the List Manager distributes list building into knowledgeable hands. This is particularly valuable at the current time when health system patient registries are not mature enough to reliably support building build anticipatory patient lists.

The Digital Imaging and Communications in Medicine (DICOM) archive is a dynamic component of a clinician image-related workflow solution

The authors investigated clinician transactions against the Digital Imaging and Communications in Medicine (DICOM) archive within a clinical image management system (CIMS) in support of patient care. A Neurosurgical Oncology practice was audited for image utilization. There were 400 requests for 233 image studies during 297 sessions. Fifty percent were for current studies, and 50% were for historical studies. Current studies alone were requested in 37% of the sessions, current plus historical in 31%, and historical alone in 32% of the sessions. Seventy percent of studies were within 8 weeks old and were rapidly available from the CIMS disk cache without an archive image transaction. Conversely, 30% were older than 8 weeks, requiring a clinician transaction against the archive for image retrieval. Approximately 25% of studies were older than 3 months and 10% older than 6 months. Clinician image needs are complex and any CIMS solution must include a DICOM archive that can support clinician-based transactions.

A phase I trial of amsalog (CI-921) administered by intravenous infusion using a 5-day schedule

PURPOSE

Amsalog, a derivative of 9-aminoacridine, is an inhibitor of topoisomerase II. Early studies of intravenous amsalog administered either once weekly, or daily for 3 days repeated every 3 weeks, showed that myelosuppression is the dose-limiting toxicity (DLT). Phase II studies showed only limited activity in breast, head and neck, and non-small-cell lung cancer. The activity of other topoisomerase inhibitors is schedule-dependent. We therefore performed a phase I study to evaluate the use of amsalog on a more prolonged schedule.

METHODS

A group of 19 patients with refractory malignancies were treated in six cohorts using 2-h infusions of amsalog daily for 5 days, repeated every 3 weeks.

RESULTS

Myelosuppression was seen as DLT at 200 mg/m2 per day. Other toxicities included nausea and vomiting, fatigue, and, when administered via a peripheral venous line, severe phlebitis necessitating administration via an indwelling central venous catheter for doses greater than 100 mg/m2. Pharmacokinetic studies showed a linear relationship between Cmax and AUC, and dose. The terminal half-life was 2 h, consistent with previous studies.

CONCLUSION

We conclude that amsalog can be safely given on a 5-day schedule every 3 weeks at doses up to 200 mg/m2. The dose recommended for further studies is 180 mg/m2 per day for 5 days repeated every 3 weeks. However, in view of the phlebitis, which necessitated the use of central venous catheters for administration, other routes of administration, for example oral formulations, should be explored.

Multicenter study of obstetric admissions to 14 intensive care units in southern England

OBJECTIVES

To identify pregnant and postpartum patients admitted to intensive care units (ICUs), the cause for their admission, and the proportion that might be appropriately managed in a high-dependency environment (HDU) by using an existing database. To estimate the goodness-of-fit for the Simplified Acute Physiology Score II, the Acute Physiology and Chronic Health Evaluation (APACHE) II, and the APACHE III scoring systems in the obstetrical population.

DESIGN

Retrospective analysis of demographic, diagnostic, treatment, and severity of illness data.

SETTING

Fourteen ICUs in Southern England.

PATIENTS

Pregnant or postpartum (<42 days) admissions between January 1, 1994, and December 31, 1996.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified 210 patients, constituting 1.84% (210 of 11,385) of all ICU admissions and 0.17% (210 of 122,850) of all deliveries. Most admissions followed postpartum complications (hypertensive disease of pregnancy [39.5%] and major hemorrhage [33.3%]). Seven women were transferred to specialist ICUs. There was considerable variation between ICUs with respect to the number and type of interventions required by patients. Some 35.7% of patients stayed in ICU for <2 days and received no specific ICU interventions; these patients might have been safely managed in an HDU. There were seven maternal deaths (3.3%); fetal mortality rate was 20%. The area under the receiver operator characteristic curve and the standardized mortality ratio were 0.92 (confidence interval [CI], 0.85-0.99) and 0.43 for the Simplified Acute Physiology Score II, 0.94 (CI, 0.86-1.0) and 0.24 for APACHE II, and 0.98 (CI, 0.96-1.0) and 0.43 for APACHE III, respectively.

CONCLUSIONS

Existing databases can both identify critically ill obstetrical patients and provide important information about them. Obstetrical ICU admissions often require minimal intervention and are associated with low mortality rates. Many might be more appropriately managed in an HDU. The commonly used severity of illness scoring systems are good discriminators of outcome from intensive care admission in this group but may overestimate mortality rates. Severity of illness scoring systems may require modification in obstetrical patients to adjust for the normal physiologic responses to pregnancy.

Macrochelation, cyclometallation and G-quartet formation: N3- and C8-bound PdII complexes of adenine and guanine

The reactions of Pd(II) ions with a series of chelate-tethered derivatives of adenine and guanine have been studied and reveal a difference in the reactivity of the purine bases. Reactions of [PdCl2(MeCN)2] and A-alkyl-enH x Cl (alkyl = propyl or ethyl, A adenine, en = ethylenediamine) yield the monocationic species [PdCl(A-N3-Et-en)]+ (1) and [PdCl(A-N3-Pr-en)]+ (2). Both involve co-ordination at the minor groove site N3 of the nucleobase as confirmed by single-crystal X-ray analysis. Reactions with the analogous G-alkyl-enH x Cl derivatives (G=guanine, alkyl = ethyl or propyl) were more complex with a mixture of species being observed. For G-Et-en HCI a product was isolated which was identified as [PdCl(G-C8-Et-en)]+ (3). This compound contains a biomolecular metal-carbon bond involving C8 of the purine base. Crystallography of a product obtained from reaction of G-Pr-enH x Cl and [Pd(MeCN)4][NO3]2 reveals an octacationic tetrameric complex (4), in which each ligand acts to bridge two metal ions through a combination of a tridentate binding mode involving the diamine and N3 and monodentate coordination at N7.

Identification without naming: a functional neuroimaging study of an anomic patient

The neural correlates of identification and name retrieval have proved difficult to characterise because both occur highly automatically in normal language processing. Thus, although some evidence points to the left anterior temporal cortex (ATC) as a brain region underlying these functions, its relative role in semantic and lexical retrieval processes is still a matter of debate. Positron emission tomography (PET) was used to measure regional cerebral blood flow responses to famous and non-famous visually presented faces and buildings in a severely anomic patient and in six control subjects, while they were performing a same-different matching task. Because the patient was able to identify the stimuli that he could not name, it was possible to investigate whether the left ATC would respond when identification occurred without name retrieval. Both the patient and the controls activated the left ATC when famous stimuli were compared with non-famous stimuli. This result supports the hypothesis of a predominantly semantic function of the left ATC.

Mapping between SNOMED RT and Clinical terms version 3: a key component of the SNOMED CT development process

SNOMED RT and Clinical Terms Version 3 are two large, controlled medical terminologies that are being merged to form a new work titled SNOMED Clinical Terms (SNOMED CT). One of the first steps in this process was to create maps between semantically equivalent and proximate concepts in the two terminologies. Same-as and is-a relationships were used to map the descriptions from one terminology to concepts in the other terminology. The objectives were to identify semantically equivalent concepts in the two terminologies, to find the most semantically proximate is-a relationships for non-equivalent concepts, and to evaluate the synonymy in the source terminologies. The results suggest that the rate of semantic overlap between descriptions in SNOMED RT and CTV3 is approximately 28%. This article discusses the methodology, issues, and findings of the description mapping process.

SNOMED clinical terms: overview of the development process and project status

Two large health care reference terminologies, SNOMED RT and Clinical Terms Version 3 , are in the process of being merged to form a comprehensive new work referred to as SNOMED Clinical Terms. The College of American Pathologists and the United Kingdom s National Health Service have entered into a collaborative agreement to develop this new work. Both organizations have extensive terminology development and maintenance experience. This paper discusses the process and status of SNOMED CT development and how the resources and expertise of both organizations are being used to develop this new terminological resource. The preliminary results of the merger process, including mapping, the merger of upper levels of each hierarchy, and attribute harmonization are also discussed.

Sensitometric evaluation of a new F-speed dental radiographic film

OBJECTIVE

To compare a new experimental Kodak (Eastman Kodak, Rochester, NY, USA) F-speed dental X-ray film with Ektaspeed Plus and Ultra-speed.

METHODS

The three types of film were exposed and processed under standardized conditions. Values of base plus fog, speed, and film contrast were derived. Resolution was compared by a line-pair plate.

RESULTS

Under these experimental conditions, the speed of the new film was just into the F-speed range, and a little over twice as fast as Ultra-speed. The Ektaspeed Plus emulsion was somewhat slower than previously recorded when it was first introduced, but around the centre of the E-speed range. Ektaspeed Plus and the new F-speed film had almost identical film contrasts, the F-speed film having slightly greater contrast in the higher density range. Ultra-speed contrast was marginally greater in the lower density range, but was overtaken by both of the other emulsions at higher densities. All three emulsions had low values of base plus fog. Both E- and F-speed films resolved 10 line-pairs per millimetre well, though both emulsions were inferior to Ultra-speed.

CONCLUSIONS

The new F-speed film, since marketed as Insight, provides a further saving in radiation exposure, with no evident deterioration in film contrast or resolution.