Composite 3D printing of biomimetic human teeth.

Human teeth are mechanically robust through a complex structural composite organisation of materials and morphology. Efforts to replicate mechanical function in artificial teeth (typodont teeth), such as in dental training applications, attempt to replicate the structure and morphology of real teeth but lack tactile similarities during mechanical cutting of the teeth. In this study, biomimetic typodont teeth, with morphology derived from X-ray microtomography scans of extracted teeth, were 3D printed using an approach to develop novel composites. These composites with a range of glass, hydroxyapatite and porcelain reinforcements within a methacrylate-based photopolymer resin were compared to six commercial artificial typodont teeth. Mechanical performance of the extracted human teeth and 3D printed typodont teeth were evaluated using a haptic approach of measuring applied cutting forces. Results indicate 3D printed typodont teeth replicating enamel and dentine can be mechanically comparable to extracted human teeth despite the material compositions differing from the materials found in human teeth. A multiple parameter variable of material elastic modulus and hardness is shown to describe the haptic response when cutting through both human and biomimetic, highlighting a critical dependence between the ratio of material mechanical properties and not absolute material properties in determining tooth mechanical performance under the action of cutting forces.

Approaches to 3D printing teeth from X-ray microtomography.

Artificial teeth have several advantages in preclinical training. The aim of this study is to three-dimensionally (3D) print accurate artificial teeth using scans from X-ray microtomography (XMT). Extracted and artificial teeth were imaged at 90 kV and 40 kV, respectively, to create detailed high contrast scans. The dataset was visualised to produce internal and external meshes subsequently exported to 3D modelling software for modification before finally sending to a slicing program for printing. After appropriate parameter setting, the printer deposited material in specific locations layer by layer, to create a 3D physical model. Scans were manipulated to ensure a clean model was imported into the slicing software, where layer height replicated the high spatial resolution that was observed in the XMT scans. The model was then printed in two different materials (polylactic acid and thermoplastic elastomer). A multimaterial print was created to show the different physical characteristics between enamel and dentine. LAY DESCRIPTION: Objectives Trainee dentists practice procedures using artificial teeth that are far from real teeth. Using x-rays and 3D printing technology the project will recreate a real tooth, artificially. Methods X-rays produce a 3D image that can be printed out as a physical replica, after several conversions of files. Different settings can be used to allow the printed model, to be as accurate as possible. Data were collected on the forces from a dental drill on a tooth's surface, to measure hardness and resistance. Results Multiple teeth replicas were printed with a high accuracy. The materials printed did not mimic actual tooth properties, but using the data from real teeth, materials can be tested in future.

Impact of a nutrition and physical activity intervention (ENRICH: Exercise and Nutrition Routine Improving Cancer Health) on health behaviors of cancer survivors and carers: a pragmatic randomized controlled trial.

BACKGROUND: Physical activity and consuming a healthy diet have clear benefits to the physical and psychosocial health of cancer survivors, with guidelines recognising the importance of these behaviors for cancer survivors. Interventions to promote physical activity and improve dietary behaviors among cancer survivors and carers are needed. The aim of this study was to determine the effects of a group-based, face-to-face multiple health behavior change intervention on behavioral outcomes among cancer survivors of mixed diagnoses and carers. METHODS: The Exercise and Nutrition Routine Improving Cancer Health (ENRICH) intervention was evaluated using a two-group pragmatic randomized controlled trial. Cancer survivors and carers (n = 174) were randomly allocated to the face-to-face, group-based intervention (six, theory-based two-hour sessions delivered over 8 weeks targeting healthy eating and physical activity [PA]) or wait-list control (after completion of 20-week data collection). Assessment of the primary outcome (pedometer-assessed mean daily step counts) and secondary outcomes (diet and alcohol intake [Food Frequency Questionnaire], self-reported PA, weight, body mass index, and waist circumference) were assessed at baseline, 8-and 20-weeks. RESULTS: There was a significant difference between the change over time in the intervention group and the control group. At 20 weeks, the intervention group had increased by 478 steps, and the control group had decreased by 1282 steps; this represented an adjusted mean difference of 1761 steps (184 to 3337; P = 0.0028). Significant intervention effects for secondary outcomes, included a half serving increase in vegetable intake (difference 39 g/day; 95 % CI: 12 to 67; P = 0.02), weight loss (kg) (difference -1.5 kg; 95 % CI, -2.6 to -0.3; P = 0.014) and change in body mass index (kg/m(2)) (difference -0.55 kg/m(2); 95 % CI, -0.97 to -0.13; P = 0.012). No significant intervention effects were found for self-reported PA, total sitting time, waist circumference, fruit, energy, fibre, alcohol, meat, or fat consumption. CONCLUSIONS: The ENRICH intervention was effective for improving PA, weight, body mass index, and vegetable consumption even with the inclusion of multiple cancer types and carers. As an example of successful research translation, the Cancer Council NSW has subsequently adopted ENRICH as a state-wide program. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Register identifier: ANZCTRN1260901086257.

Does routine assessment and real-time feedback improve cancer patients' psychosocial well-being?

This study examined the effectiveness of giving medical oncologists immediate feedback about cancer patients' self-reported psychosocial well-being in reducing those patients' levels of anxiety, depression, perceived needs and physical symptoms. Cancer patients attending one cancer centre for their first visit were allocated to intervention (n = 42) or control (n = 38) groups. All patients completed a computerized survey assessing their psychosocial well-being while waiting to see the oncologist. Intervention patients' responses were immediately scored and summary reports were placed in each patient's file for follow-up. A total of 48 participants (25 intervention and 23 control) completed the survey four times. Intervention patients who reported a debilitating physical symptom at visit 2 were significantly less likely to report a debilitating physical symptom at visit 3 compared with control patients (OR = 2.8, P = 0.04). Reductions in levels of anxiety, depression and perceived needs among intervention patients were not significantly different to control patients. Repeated collection and immediate feedback of patient-reported health information to oncologists has potential to improve patients' symptom control, but has little impact upon emotional well-being, including those at high risk. Future research should consider providing the feedback to other health professionals and patients, and monitor the impact on the process of individual patient care.

Australia's Cancer Helpline--an audit of utility and caller profile.

BACKGROUND: The Cancer Helpline is a telephone information and support service operated throughout Australia. METHODS: Data from all calls received during the months of July, August and September from 2001 to 2003 were collected and analysed. RESULTS: Over 76,000 contacts were made, mostly from women (79%). Almost half of all calls were from people with general inquiries (rather than cancer patients, their families, or health professionals). The most common cancer type discussed was breast cancer, (26% of all calls, 42% of calls from people with cancer). Diagnosed cancer patients most frequently called about treatment/management and practical issues. People with general inquiries called to obtain information about the prevention and early detection of cancer. DISCUSSION: The helpline can complement the role of other information and support providers for people living with or concerned about cancer.

Perceived needs of women diagnosed with breast cancer: rural versus urban location.

OBJECTIVE: To assess the prevalence and predictors of perceived unmet needs among women diagnosed with breast cancer, with a particular focus on the impact of location (rural/urban). METHOD: A random sample of women in NSW diagnosed with breast cancer was surveyed during 1995-96. The Breast Cancer Patients' Needs Questionnaire (BR-CPNQ) explores patients' perceived needs across five domains: psychological, health information, physical/daily living, patient care/support and interpersonal communication. Items assessing breast cancer specific needs and access to services and resources were included. Of 235 eligible rural women, 134 (57%) consented to participate and 129 (55%) returned completed surveys. Of 196 eligible urban women, 102 (52%) consented to participate and 100 (51%) returned completed surveys. RESULTS: For 12 of the 52 items, at least one-third of the sample reported ever having a moderate/high need for help. Of the 15 highest moderate or high unmet needs, 10 related to health information and three to psychological needs. There were few differences in the prevalence of needs reported by rural and urban women. Only in the physical/daily living domain were rural women more likely than urban women to report some need for help (OR = 2.59, 95% CI 1.21-5.52). CONCLUSIONS: Unmet needs, particularly in the information and psycho-social domains, are reported by both rural and urban women with breast cancer, with sub-groups experiencing different types of needs. IMPLICATIONS: There is a need to develop and trial targeted and innovative strategies to meet the health information and psychological needs of women with breast cancer, and the physical/daily living needs of rural women diagnosed with breast cancer.

Evaluation of an instrument to assess the needs of patients with cancer. Supportive Care Review Group.

BACKGROUND: This study aimed to assess the face, content, and construct validity and the internal reliability of a tool for assessing the generic needs of patients with cancer (the Supportive Care Needs Survey). METHODS: A total of 1,492 consecutive patients attending the surgical, radiation, or medical oncology departments of 9 cancer treatment centers in New South Wales, Australia, were asked to participate. Of the 1,370 eligible patients, 1,354 (99%) consented to participate and 888 (65%) completed the survey. Eligible consenting patients were given a Supportive Care Needs Survey to complete at home and return by mail within 7 days. RESULTS: In the assessment of construct validity, the principal components method of factor analysis identified 5 factors with eigenvalues greater than 1, which together accounted for 64% of the total variance (patients' needs in the domains of psychologic, health system and information, physical and daily living, patient care and support, and sexuality). Face and content validity were found to be high following pilot tests and tests of reading ease. Internal reliability coefficients (Cronbach alpha) of all 5 factor-based scales were found to be substantial, ranging from 0.87 to 0.97. CONCLUSIONS: These findings suggest that the Supportive Care Needs Survey provides a reliable and valid index of the global needs of oncology patients. The standardized and widespread application of this instrument is recommended following further refinement and evaluation.

The unmet supportive care needs of patients with cancer. Supportive Care Review Group.

BACKGROUND: The aim of this study was to determine the prevalence and predictors of the perceived unmet needs of cancer patients undergoing treatment for their disease at public treatment centers. METHODS: A total of 1,492 consecutive patients attending the surgical, radiation, or medical oncology departments of 9 major public cancer treatment centers in New South Wales, Australia, were asked to participate. Of the 1,370 eligible patients, 1,354 (99%) consented to participate and 888 (65%) returned completed surveys. Eligible consenting patients were given a Supportive Care Needs Survey to complete at home and return by mail within 7 days. RESULTS: Patients' perceived needs were assessed across the following five areas: psychologic, health system and information, physical and daily living, patient care and support, and sexuality. Patients' perceived needs were highest in the psychologic, health system and information, and physical and daily living domains. Logistic regression modeling revealed subgroups of patients with different types of needs. The significant predictors of reporting some unmet need for help varied according to the domain examined. CONCLUSIONS: This statewide study shows that cancer patients experience high levels of unmet needs across the range of domains examined. The study provides information that may be valuable in identifying areas where interventions could be tested and evaluated in an attempt to address the unmet needs of people living with cancer.

A gene cluster encoding steps in conversion of naphthalene to gentisate in Pseudomonas sp. strain U2.

Pseudomonas sp. strain U2 was isolated from oil-contaminated soil in Venezuela by selective enrichment on naphthalene as the sole carbon source. The genes for naphthalene dioxygenase were cloned from the plasmid DNA of strain U2 on an 8.3-kb BamHI fragment. The genes for the naphthalene dioxygenase genes nagAa (for ferredoxin reductase), nagAb (for ferredoxin), and nagAc and nagAd (for the large and small subunits of dioxygenase, respectively) were located by Southern hybridizations and by nucleotide sequencing. The genes for nagB (for naphthalene cis-dihydrodiol dehydrogenase) and nagF (for salicylaldehyde dehydrogenase) were inferred from subclones by their biochemical activities. Between nagAa and nagAb were two open reading frames, homologs of which have also been identified in similar locations in two nitrotoluene-using strains (J. V. Parales, A. Kumar, R. E. Parales, and D. T. Gibson, Gene 181:57-61, 1996; W.-C. Suen, B. Haigler, and J. C. Spain, J. Bacteriol. 178:4926-4934, 1996) and a naphthalene-using strain (G. J. Zylstra, E. Kim, and A. K. Goyal, Genet. Eng. 19:257-269, 1997). Recombinant Escherichia coli strains with plasmids carrying this region were able to convert salicylate to gentisate, which was identified by a combination of gas chromatography-mass spectrometry and nuclear magnetic resonance. The first open reading frame, designated nagG, encodes a protein with characteristics of a Rieske-type iron-sulfur center homologous to the large subunits of dihydroxylating dioxygenases, and the second open reading frame, designated nagH, encodes a protein with limited homology to the small subunits of the same dioxygenases. Cloned together in E. coli, nagG, nagH, and nagAb, were able to convert salicylate (2-hydroxybenzoate) into gentisate (2,5-dihydroxybenzoate) and therefore encode a salicylate 5-hydroxylase activity. Single-gene knockouts of nagG, nagH, and nagAb demonstrated their functional roles in the formation of gentisate. It is proposed that NagG and NagH are structural subunits of salicylate 5-hydroxylase linked to an electron transport chain consisting of NagAb and NagAa, although E. coli appears to be able to partially substitute for the latter. This constitutes a novel mechanism for monohydroxylation of the aromatic ring. Salicylate hydroxylase and catechol 2,3-dioxygenase in strain U2 could not be detected either by enzyme assay or by Southern hybridization. However growth on both naphthalene and salicylate caused induction of gentisate 1,2-dioxygenase, confirming this route for salicylate catabolism in strain U2. Sequence comparisons suggest that the novel gene order nagAa-nagG-nagH-nagAb-nagAc-nagAd-++ +nagB-nagF represents the archetype for naphthalene strains which use the gentisate pathway rather than the meta cleavage pathway of catechol.

PEAPS-Q: a questionnaire to measure the psychosocial effects of having an abnormal pap smear. Psychosocial Effects of Abnormal Pap Smears Questionnaire.

We have developed the Psychosocial Effects of Abnormal Pap Smears Questionnaire (PEAPS-Q) which measures distress experienced by women undergoing follow-up investigation after an abnormal Pap smear result. A thorough literature review and qualitative research resulted in the development of a questionnaire which was tested on 350 women attending a Family Planning New South Wales (FPNSW) clinic. This sample included women at different stages of management after detection of a cervical abnormality: 93 first colposcopy clients and 257 follow-up colposcopy clients. Factor analysis identified four dimensions of distress: experience of medical procedures, beliefs/feelings about cervical abnormality and changes in perception of oneself, worry about infectivity and effect on sexual relationships. Repeatability of the PEAPS-Q was indicated by intra-class correlations of 0.88 overall and at least 0.60 for each scale. Internal consistency was shown by Cronbach's alpha of 0.84 overall and at least 0.72 for each scale. Validity was demonstrated by the correlation of scale scores with the 12-item General Health Questionnaire (GHQ) score of 0.32 (95% CI 0.22-0.41). The PEAPS-Q is a valid, reliable and multidimensional instrument for quantifying distress experienced by women with abnormal Pap smears.

Repetition of overdose: a retrospective 5-year study.

This study investigated the number, timing and disposal (admission or discharge) of patients repeating an overdose who attended the accident and emergency department of a district general hospital during a 5-year period. There was a total of 1958 overdoses by 1597 individuals over the 5-year period. Overdoses were repeated by 12% (n = 191) of patients and accounted for 552 of the total overdoses (representing 361 repeats). First repeats were found to occur more frequently in the 3 months following the original overdose for 43% of patients, 70% of repetitions occurring within a year. The distribution of first repeats showed a similar pattern for males and females. During the 5-year period 49% of all repetitions occurred within 3 months. Almost one-fifth of repeaters were discharged, irrespective of whether it was the patient's 'index' (first overdose within the study period) or a repeat overdose. Within the repeater population, 31% of overdoses occurred on a Friday, Saturday and on, or immediately prior to, a Bank Holiday. Since there was no on-site psychiatric service available at such times, those patients had to wait until the next working day for assessment. The study recommends that all overdose patients should receive psychiatric assessment, and therefore on-site psychiatric services should be available for accident and emergency patients.