Impact of loading protocol of a mandibular single implant-supported complete denture on oral health-related quality of life over a period of 5 years: A randomized controlled trial

OBJECTIVES

The aim of the present study was to assess the long-term course of OHRQoL and the impact of the loading protocol in patients receiving a single mandibular implant supporting a complete denture over a period of five years.

METHODS

In this multicenter RCT, a total of 158 edentulous patients were initially included and were randomly allocated immediately after placement of a mandibular midline implant to either immediate loading (IL) or to conventional loading (CL) with submerged healing. The assessment of OHRQoL was performed with the 49-item Oral Health Impact Profile (OHIP) at baseline and 1, 4, 12, 24, and 60 months after loading. At 5-year follow-up, 100 patients (mean age: 69.2 years; 45.0% female) with completed OHIP were available for analyses. A mixed-effects model with patients as random effect and an unstructured covariance matrix was developed to address repeated outcome measurement.

RESULTS

The OHRQoL improved substantially after loading, indicated by a decrease of mean OHIP summary scores from 51.0 points at baseline, by 14.2 (95%-CI: 9.4 - 19.1; p<0.001) points to 37.2 points at 1-month follow-up, and by continuous improvement to 20.4 OHIP points at final follow-up. Considering constant treatment effects, the loading protocol had no significant effect on OHIP scores (-3.7, 95%-CI: -9.4 - 2.2; p = 0.204). Time effect was statistically significant with -0.21 (95%-CI: -0.28 - -0.15; p<0.001) points per month.

CONCLUSION

Both the immediate and conventional loading of a single mandibular midline implant supporting a complete denture offer long-lasting high levels of OHRQoL, with no significant or clinically relevant long-term differences.

CLINICAL SIGNIFICANCE

The study firstly presents long-term data for OHRQoL by investigating the loading protocol of single mandibular implant-supported complete dentures. Since immediate loading has been associated with a reduced implant survival rate for this concept, information on patient benefits is essential for evidence-based decision making.

Do you see what I see? Testing horses' ability to recognise real-life objects from 2D computer projections

The use of 2-dimensional representations (e.g. photographs or digital images) of real-life physical objects has been an important tool in studies of animal cognition. Horses are reported to recognise objects and individuals (conspecifics and humans) from printed photographs, but it is unclear whether image recognition is also true for digital images, e.g. computer projections. We expected that horses trained to discriminate between two real-life objects would show the same learnt response to digital images of these objects indicating that the images were perceived as objects, or representations of such. Riding-school horses (N = 27) learnt to touch one of two objects (target object counterbalanced between horses) to instantly receive a food reward. After discrimination learning (three consecutive sessions of 8/10 correct trials), horses were immediately tested with on-screen images of the objects over 10 image trials interspersed with five real object trials. At first image presentation, all but two horses spontaneously responded to the images with the learnt behaviour by contacting one of the two images, but the number of horses touching the correct image was not different from chance (14/27 horses, p > 0.05). Only one horse touched the correct image above chance level across 10 image trials (9/10 correct responses, p = 0.021). Our findings thus question whether horses recognise real-life objects from digital images. We discuss how methodological factors and individual differences (i.e. age, welfare state) might have influenced animals' response to the images, and the importance of validating the suitability of stimuli of this kind for cognitive studies in horses.

Measuring affect-related cognitive bias: Do mice in opposite affective states react differently to negative and positive stimuli?

Affect-driven cognitive biases can be used as an indicator of affective (emotional) state. Since humans in negative affective states demonstrate greater responses to negatively-valenced stimuli, we investigated putative affect-related bias in mice by monitoring their response to unexpected, task-irrelevant stimuli of different valence. Thirty-one C57BL/6J and 31 DBA/2J females were individually trained to return to their home-cage in a runway. Mice then underwent an affective manipulation acutely inducing a negative (NegAff) or a comparatively less negative (CompLessNeg) affective state before immediately being tested in the runway with either an ‘attractive’ (familiar food) or ‘threatening’ (flashing light) stimulus. Mice were subsequently trained and tested again (same affective manipulation) with the alternative stimulus. As predicted, mice were slower to approach the light and spent more time with the food. DBA/2J mice were slower than C57BL/6J overall. Contrary to predictions, NegAff mice tended to approach both stimuli more readily than CompLessNeg mice, especially the light, and even more so for DBA/2Js. Although the stimuli successfully differentiated the response of mice to unexpected, task-irrelevant stimuli, further refinement may be required to disentangle the effects of affect manipulation and arousal on the response to valenced stimuli. The results also highlight the significant importance of considering strain differences when developing cognitive tasks.

Social proximity in dairy calves is affected by differences in pessimism

Negative social interactions have been extensively studied in dairy cattle, but little is known about the establishment of positive (preferential) relationships. Adult dairy cows are known to spend more time at close proximity to specific social partners, indicating that they establish stronger bonds with these animals, but few studies have explored what happens in socially housed calves. In this study, we explored whether calves that spent their entire life in the same social group established social preferences (i.e. pairs of individuals that interact more) that are stable over time (two 48-h periods, separated by three days), across two types of behavior (standing and lying) and across contexts (change in environment and housing design). When housed in an open pack, calves showed consistent proximity patterns when standing (but not when lying). These preferential relationships persisted even after calves were moved into a new pen fitted with free stalls. At the individual level, calves varied in how selective they were in their social relationships, with some calves spending much more time with specific partners than did others. This degree of selectivity was not associated to Sociability, marginally associated to Fearfulness, but was associated with Pessimism (more pessimistic calves were more selective in their social relationships). In conclusion, calves can form selective relationships that appeared to be consistent over time and across context, and the degree to which calves were selective varied in relation to individual differences in Pessimism.

Could Greater Time Spent Displaying Waking Inactivity in the Home Environment Be a Marker for a Depression-Like State in the Domestic Dog?

Dogs exposed to aversive events can become inactive and unresponsive and are commonly referred to as being "depressed", but this association remains to be tested. We investigated whether shelter dogs spending greater time inactive "awake but motionless" (ABM) in their home-pen show anhedonia (the core reduction of pleasure reported in depression), as tested by reduced interest in, and consumption of, palatable food (KongTM test). We also explored whether dogs being qualitatively perceived by experts as disinterested in the food would spend greater time ABM (experts blind to actual inactivity levels). Following sample size estimations and qualitative behaviour analysis (n = 14 pilot dogs), forty-three dogs (6 shelters, 22F:21M) were included in the main study. Dogs relinquished by their owners spent more time ABM than strays or legal cases (F = 8.09, p = 0.032). One significant positive association was found between the KongTM measure for average length of KongTM bout and ABM, when length of stay in the shelter was accounted for as a confounder (F = 3.66, p = 0.035). Time spent ABM also correlated with scores for "depressed" and "bored" in the qualitative results, indirectly suggesting that experts associate greater waking inactivity with negative emotional states. The hypothesis that ABM reflects a depression-like syndrome is not supported; we discuss how results might tentatively support a "boredom-like" state and further research directions.

To Group or Not to Group? Good Practice for Housing Male Laboratory Mice

Simple Summary

Wild mice live in territories inhabited by one adult male, several females, and their offspring. This cannot be replicated in the laboratory, so male mice are usually housed in single-sex groups or individually. However, there can be serious animal welfare problems associated with both these approaches, such as lack of social contact when housed individually or aggression between males when kept in groups. Group housing is widely recommended to give male laboratory mice the opportunity to behave as ‘social animals’, but social stress can be detrimental to the welfare of these animals, even without injurious fighting. All of this can also affect the quality of the science, giving rise to ethical concerns. This review discusses whether it is in the best welfare interests of male mice to be housed in groups, or alone. We conclude that it is not possible to give general recommendations for good practice for housing male laboratory mice, as responses to single- and group-housing can be highly context-dependent. The welfare implications of housing protocols should be researched and considered in each case.

Abstract

It is widely recommended to group-house male laboratory mice because they are ‘social animals’, but male mice do not naturally share territories and aggression can be a serious welfare problem. Even without aggression, not all animals within a group will be in a state of positive welfare. Rather, many male mice may be negatively affected by the stress of repeated social defeat and subordination, raising concerns about welfare and also research validity. However, individual housing may not be an appropriate solution, given the welfare implications associated with no social contact. An essential question is whether it is in the best welfare interests of male mice to be group- or singly housed. This review explores the likely impacts—positive and negative—of both housing conditions, presents results of a survey of current practice and awareness of mouse behavior, and includes recommendations for good practice and future research. We conclude that whether group- or single-housing is better (or less worse) in any situation is highly context-dependent according to several factors including strain, age, social position, life experiences, and housing and husbandry protocols. It is important to recognise this and evaluate what is preferable from animal welfare and ethical perspectives in each case.

Survival and Complications of Single Dental Implants in the Edentulous Mandible Following Immediate or Delayed Loading: A Randomized Controlled Clinical Trial

It was the aim of this 24-mo randomized controlled clinical trial to investigate whether the survival of a single median implant placed in the edentulous mandible to retain a complete denture is not compromised by immediate loading. Secondary outcomes were differences in prosthetic complications between the loading principles. Each of the 158 patients who received an implant was randomly assigned to the immediate loading group (n = 81) or the delayed loading group (n = 77). Recall visits were performed 1 mo after implant placement (for only the delayed loading group) and 1, 4, 12, and 24 mo after implant loading. Nine implants failed in the immediate loading group, all within the first 3 mo of implant loading, and 1 implant failed in the delayed loading group prior to loading. Noninferiority of implant survival of the immediate loading group, as compared with the delayed loading group, could not be shown (P = 0.81). Consistent with this result, a secondary analysis with Fisher exact test revealed that the observed difference in implant survival between the treatment groups was indeed statistically significant (P = 0.019). The most frequent prosthetic complications and maintenance interventions in the mandible were retention adjustments, denture fractures, pressure sores, and matrix exchanges. There was only 1 statistically significant difference between the groups regarding the parameter “fracture of the denture base in the ball attachment area” (P = 0.007). The results indicate that immediate loading of a single implant in the edentulous mandible reveals inferior survival than that of delayed loading and therefore should be considered only in exceptional cases (German Clinical Trials Register: DRKS00003730).

Lateralized behaviour as indicator of affective state in dairy cows

In humans, there is evidence that sensory processing of novel or threatening stimuli is right hemisphere dominated, especially in people experiencing negative affective states. There is also evidence for similar lateralization in a number of non-human animal species. Here we investigate whether this is also the case in domestic cattle that may experience long-term negative states due to commonly occurring conditions such as lameness. Health and welfare implications associated with pain in lame cows are a major concern in dairy farming. Behavioural tests combining animal behaviour and cognition could make a meaningful contribution to our understanding of disease-related changes in sensory processing in animals, and consequently enhance their welfare. We presented 216 lactating Holstein-Friesian cows with three different unfamiliar objects which were placed either bilaterally (e.g. two yellow party balloons, two black/white checkerboards) or hung centrally (a Kong™) within a familiar area. Cows were individually exposed to the objects on three consecutive days, and their viewing preference/eye use, exploration behaviour/nostril use, and stop position during approach was assessed. Mobility (lameness) was repeatedly scored during the testing period. Overall, a bias to view the right rather than the left object was found at initial presentation of the bilateral objects. More cows also explored the right object rather than the left object with their nose. There was a trend for cows appearing hesitant in approaching the objects by stopping at a distance to them, to then explore the left object rather than the right. In contrast, cows that approached the objects directly had a greater tendency to contact the right object. No significant preference in right or left eye/nostril use was found when cows explored the centrally-located object. We found no relationship between lameness and lateralized behaviour. Nevertheless, observed trends suggesting that lateralized behaviour in response to bilaterally located unfamiliar objects may reflect an immediate affective response are discussed. Further study is needed to understand the impact of long-term affective states on hemispheric dominance and lateralized behaviour.

Factors Affecting Staff Perceptions of Tele-ICU Service in Rural Hospitals

INTRODUCTION

Telemedicine is designed to increase access to specialist care, especially in settings distant from tertiary-care centers. One of the more established telemedicine applications in hospitals is the tele-intensive care unit (tele-ICU). Perceptions of tele-ICU users are not well studied. Thus, we undertook a study focused on assessing staff acceptance at multiple hospitals that had implemented a tele-ICU system.

MATERIALS AND METHODS

We designed a survey instrument that gathered perceptions on multiple facets of tele-ICU use and administered it to clinical and administrative staff at 28 hospitals that had implemented a tele-ICU system. We also conducted interviews at half of these hospitals to gain a deeper understanding of factors affecting staff perceptions of tele-ICU services.

RESULTS

The 145 survey respondents were generally positive about all facets of the service. Analyses found no significant differences in comparisons between critical access and larger hospitals or between clinical and administrative/managerial respondents, although a few differences between providers and nurses emerged. Respondents at hospitals averaging more tele-ICU use and that had implemented it longer were significantly (p<0.05) more positive in their responses on multiple survey items than other respondents. Interviews corroborated and provided insight into survey responses.

CONCLUSIONS

Tele-ICU was particularly valued when critical access hospitals retained critical care patients during special circumstances and when the tele-ICU hub could monitor patients to provide relief for local providers and nurses. Tele-ICU can aid rural hospitals, but multiple delivery models are warranted to meet disparate needs.

Assessing the TP53 marker type in patients treated with or without neoadjuvant chemotherapy for resectable colorectal liver metastases: a p53 Research Group study

The type of a biomarker - whether it is prognostic or predictive - is frequently not known, although such information is crucial for assessing the clinical value of a marker. In order to evaluate the type of marker TP53 is, we identified a cohort of 76 patients with colorectal liver metastases (CLM), homogeneously staged as resectable, who had been treated either with or without fluorouracil-based neoadjuvant chemotherapy. The TP53 genotype was assessed retrospectively from paraffin-embedded, diagnostic tumour biopsies using a standardised, p53 gene-specific sequencing protocol (mark53(®) kit). The overall median survival was 44.2 months, and the overall TP53 mutation frequency was 55%. A significant interaction was observed between chemotherapy and TP53 status (P = 0.045). To illustrate this effect, the 51 patients with and the 25 patients without neoadjuvant chemotherapy were described separately. In patients with neoadjuvant chemotherapy, mutated TP53 was significantly associated with poor survival (P = 0.0025), resulting in five-year survival rates of 22%, compared to 60% in patients with normal TP53. The hazard ratio was 3.12 (95% confidence intervals (CI): 1.46-6.95) to the disadvantage of TP53-mutated patients and 5.49 (P = 0.0001; 95% CI: 2.28-13.24) after adjustment for known prognostic factors. In patients treated with surgery alone, a mutated TP53 did not have a negative effect on survival (P = 0.54). A mutated TP53 status independently predicted survival disadvantage in CLM patients in the presence, but not in the absence, of neoadjuvant chemotherapy. Our data suggest that TP53 might be a pure predictive marker.

Evaluation strategies for isotope ratio measurements of single particles by LA-MC-ICPMS

Data evaluation is a crucial step when it comes to the determination of accurate and precise isotope ratios computed from transient signals measured by multi-collector-inductively coupled plasma mass spectrometry (MC-ICPMS) coupled to, for example, laser ablation (LA). In the present study, the applicability of different data evaluation strategies (i.e. 'point-by-point', 'integration' and 'linear regression slope' method) for the computation of (235)U/(238)U isotope ratios measured in single particles by LA-MC-ICPMS was investigated. The analyzed uranium oxide particles (i.e. 9073-01-B, CRM U010 and NUSIMEP-7 test samples), having sizes down to the sub-micrometre range, are certified with respect to their (235)U/(238)U isotopic signature, which enabled evaluation of the applied strategies with respect to precision and accuracy. The different strategies were also compared with respect to their expanded uncertainties. Even though the 'point-by-point' method proved to be superior, the other methods are advantageous, as they take weighted signal intensities into account. For the first time, the use of a 'finite mixture model' is presented for the determination of an unknown number of different U isotopic compositions of single particles present on the same planchet. The model uses an algorithm that determines the number of isotopic signatures by attributing individual data points to computed clusters. The (235)U/(238)U isotope ratios are then determined by means of the slopes of linear regressions estimated for each cluster. The model was successfully applied for the accurate determination of different (235)U/(238)U isotope ratios of particles deposited on the NUSIMEP-7 test samples.

A prospective study of the interaction between p53 genotype and overall survival in patients with colorectal cancer liver metastases (CRCLM) with and without neoadjuvant therapy (oxaliplatin and capecitabine/5-FU): A p53 research group study

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Background: Mutations in the p53 gene have been suggested as both a marker of tumour aggressiveness and a means of predicting response to chemotherapy. Unfortunately, there remains no clear evidence that p53 gene mutation affects cancer survival rates. Methods: We sought to evaluate whether mutation in the p53 gene is a marker of more aggressive tumours or of chemotherapeutic failure. Between 2001 and 2003 we collected data prospectively on 76 patients with CRCLM at a single institution. Patients considered to be technically operable were included. 51 patients received preoperative therapy with oxaliplatin plus 5-FU or capetcitabine and 25 were treated with surgery only. Treatment decision was based on the preference of the surgeon or the patient. The groups did not differ in age, chronicity of CRCLM, staging and grading of the primary colorectal cancer. The p53 gene was assessed in all tumours through complete direct gene sequencing (Exon 2–11 including splice sites). Results: For entire cohort the p53 gene mutation rate was 55%, and the median survival was 44.2 months. The overall death rate was 51%. There were 14 (41%) deaths in patients with a normal p53 gene compared to 25 (60%) deaths in patients with mutations in this gene (Logrank P=0.079). For patients that received only surgical treatment the overall death rate was 48% and was unaffected by the presence of p53 gene mutation (Logrank P=0.54). For patients who received neoadjuvant chemotherapy, median survival was 44 months if they had a normal p53 gene compared to only 20 months in patients with p53 gene mutations. The unadjusted hazard ratio for death was 3.24 in the p53 mutation group compared those with a normal p53 gene (95 percent confidence interval 1.5 to 7.0; P=0.045). The adjusted hazard ratio for death in patients with a p53 gene mutation receiving neoadjuvant chemotherapy was 5.5 (95% CI 2.3 to 13.2; P=0.0042). Conclusions: In CRCLM patients receiving neoadjuvant chemotherapy, the p53 gene mutation predicts overall survival. Our data suggests an interaction between the p53 gene and chemotherapy in patients with colorectal liver metastasis.

No significant financial relationships to disclose.

p53 adapted neoadjuvant therapy for esophageal cancer: Pilot study

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Background: Randomized trials could not yet prove clinical efficacy of neoadjuvant chemotherapy for esophageal cancer. A survival benefit could be shown for treatment responders only. Using platinum based regimen, yet about 20 % of patients can achieve pathological complete remission which translates in reported 3-year survival rates of 64% in this group. Factors identifying this subgroup of responders and selecting optimal drugs for non responders could dramatically enhance treatment efficacy. Several studies suggest that mutations in the p53 gene may induce drug resistance especially for agents whose effect is based on apoptosis induction, like Cisplatin. Methods: In order to test the hypothesis that the p53 genotype is predictive for chemotherapy response, a prospective study was conducted. Thirty-eight patients with potentially respectable esophageal cancer were evaluated for the relation between p53 genotype and response to two different neoadjuvant treatments. P53 gene mutations were assessed by complete direct sequencing of DNA extracted from diagnostic biopsies. Response to neoadjuvant chemotherapy was assessed pathohistologically in the surgical specimen. Results: 20 squamous cell carcinoma and 18 adenocarcinoma were included. Overall the p53 mutation rate was 58% (22/38), with 66 % for squamous cell and 53% for adenocarcinomas, respectively. 30 patients received CIS/5FU (cisplatin 80mg/m2 d1 5-FU 1,000mg/m2 d 1–5, q21,2 cycles), 8 received docetaxel (75mg/m2, q21,2 cycles). The overall response rate was 48% (18/38). Patients with p53 mutation did not respond to CIS/5-FU (0/16), while all mutant patients responded to docetaxel (6/6). The overall response to p53 adapted neoadjuvant therapy was 94%. P53 adapted treatment was associated with a significant survival advantage (p=0,042) after a median follow up of 15,4 months. Conclusions: A prospective randomized trial was initiated to test the interaction between the predictive marker p53 and response to CIS/5-FU and Docetaxel, respectively.

[Table: see text]

No significant financial relationships to disclose.

Functional categories of TP53 mutation in colorectal cancer: results of an International Collaborative Study

BACKGROUND

Loss of TP53 function through gene mutation is a critical event in the development and progression of many tumour types including colorectal cancer (CRC). In vitro studies have found considerable heterogeneity amongst different TP53 mutants in terms of their transactivating abilities. The aim of this work was to evaluate whether TP53 mutations classified as functionally inactive (< or=20% of wildtype transactivation ability) had different prognostic and predictive values in CRC compared with mutations that retained significant activity.

MATERIALS AND METHODS

TP53 mutations within a large, international database of CRC (n = 3583) were classified according to functional status for transactivation.

RESULTS

Inactive TP53 mutations were found in 29% of all CRCs and were more frequent in rectal (32%) than proximal colon (22%) tumours (P < 0.001). Higher frequencies of inactive TP53 mutations were also seen in advanced stage tumours (P = 0.0003) and in tumours with the poor prognostic features of vascular (P = 0.006) and lymphatic invasion (P = 0.002). Inactive TP53 mutations were associated with significantly worse outcome only in patients with Dukes' stage D tumours (RR = 1.71, 95%CI 1.25-2.33, P < 0.001). Patients with Dukes' C stage tumours appeared to gain a survival benefit from 5-fluorouracil-based chemotherapy regardless of TP53 functional status for transactivation ability.

CONCLUSIONS

Mutations that inactivate the transactivational ability of TP53 are more frequent in advanced CRC and are associated with worse prognosis in this stage of disease.

Contralateral breast cancer: molecular differentiation between metastasis and second primary cancer

Previous cancer in one breast is a strong known risk factor for cancer in the contralateral breast. Differences in tumor histology and nuclear grading are applied to distinguish between a metastatic spread and a second primary cancer, although cancers of the breast often share the same histological features. Comparison of genetic alterations in paired tumors may provide the most reliable approach for discerning clonal relationships, hence uncovering the presence or absence of multiple primary cancers. We compared tumors from 33 patients with cancer in both breasts for mutations in the p53 gene. With this molecular approach, we were able to define the relationship within paired tumors in 13 patients. The paired tumors of two patients shared the same mutation, revealing the second lesion in one case as a contralateral metachronous lymph node metastasis appearing 29 months after first surgery, and in the other as a spread to the opposite breast. In 11 patients, mutations were either discordant or solely present in one of the lesions, confirming the diagnosis of bilateral breast cancer. Histopathological evaluation had failed to provide firm diagnosis in nine out of 11 instances on account of concordances in pathological parameters such as histological type and grading. In our study, we could show that bilateral breast malignancies most frequently represent two primary breast cancers. We could also demonstrate that contralateral breast cancer spread does occur. Standard pathological assessment allowed a firm diagnosis only in the presence of different histological types.

Interleukin-10-deficient mice and inflammatory bowel disease associated cancer development

Interleukin-10-deficient mice develop colitis and colorectal cancer similar to the inflammatory bowel disease associated cancer in humans. The aim of this study was to identify possible mutations of oncogenes and tumour suppressor genes involved in tumorigenesis in Interleukin-10 (IL-10)-deficient mice. Twenty colon carcinomas from IL-10-deficient mice were screened for mutations in the K-ras and p53 genes by 'cold' single-strand-conformation polymorphism. Immunohistochemical staining was performed to detect mutations in the proteins P53, APC and MSH2, and the transforming growth factor beta type II receptor. Microsatellite instability was analysed at eight chromosomal loci and plasma levels of transforming growth factor beta1 (TGF-beta1) were also measured. At 9 weeks, 14% of the animals developed colorectal cancer, and at 10-31 weeks the incidence of carcinoma was 65%. No mutations were detected in the analysed oncogene and tumour suppressor genes. Plasma TGF-beta1 levels in IL-10-deficient mice 10-31 weeks old were higher than in wild-type littermates e.g. 45.7 +/- 4.6 ng/ml versus 19.8 +/- 4.5 ng/ml (P<0.01). No alterations in K-ras, p53, APC: and Msh2 genes suggests that other genes are involved in the development of these tumours. Elevated TGF-beta1 plasma levels correspond to the high incidence of dysplasia and cancer. Normal expression of the TGF-beta II receptors hints at genetic alterations in other members of the TGF-beta receptor signal transduction pathway.

TP53 mutation and p53 overexpression for prediction of response to neoadjuvant treatment in breast cancer patients

The value of p53 to predict the cytotoxic effect of two commonly used chemotherapy regimens was assessed in patients with advanced breast cancer. Response to a DNA-damaging combination therapy [fluorouracil, epirubicin, cyclophosphamide (FEC] considered to induce p53-dependent apoptosis was compared with a microtubule stabilizing therapy (paclitaxel) expected to be independent of p53 function. The p53 status of the patients' breast tumors was assessed using both immunohistochemistry (IHC) and direct sequencing of the entire p53 gene. p53 findings were correlated with treatment response, and linkage between p53 function and cellular response was assessed by terminal deoxynucleotidyl transferase-mediated nick end labeling assay. In a series of 67 breast tumors, 19% had TP53 gene mutations, 40% had a positive p53 IHC, and 12% had both. In the FEC group, treatment failure was related to both the presence of TP53 gene mutations (P = 0.0029) and a positive IHC (P < 0.0001). Apoptosis was almost exclusively found in tumors having normal p53 in both parameters (P < 0.0001). In the paclitaxel group, treatment response was neither related to apoptosis nor to normal p53. Combination of sequencing and IHC results revealed a significant association between abnormal p53 and response to paclitaxel (P = 0.011). We found TP53 mutations, as well as p53 protein overexpression, to be associated with response to chemotherapy. Whereas clinical response to FEC was found to be dependent on normal p53, the cytotoxicity of paclitaxel was related to defective p53. The efficiency of paclitaxel during mitosis might be supported by lack of G1 arrest due to p53 deficiency. Therefore, patients with p53-deficient tumors may benefit from paclitaxel.

The TP53 genotype but not immunohistochemical result is predictive of response to cisplatin-based neoadjuvant therapy in stage III non-small cell lung cancer

BACKGROUND

The cytotoxic effects of cisplatin and anthracyclins have been attributed to apoptosis induction, which has been recognized as a major function of the TP53 gene. The TP53 gene appears to be mutated in about 50% of cases of non-small cell lung cancer. A possible dependence of chemotherapy response on TP53 genotype was evaluated retrospectively in a group of patients with advanced non-small cell lung cancer and induction treatment.

METHODS

Patients with complete or partial remission were compared with those with stable or progressive disease with respect to TP53 genotype and overall survival. Mutations in the TP53 gene were detected by complete direct sequencing (exons 2-11).

RESULTS

A normal TP53 genotype proved to be significantly associated with major response to chemotherapy (P <.001). Overall, no association was found between p53 protein expression and TP53 genotype. A normal TP53 genotype was found to be highly sensitive in predicting response to treatment, whereas a mutant genotype was revealed to be specific in predicting lack of response. The difference in overall length of survival was significant between patients exhibiting a normal TP53 genotype (corresponding to those whose disease responded to chemotherapy) and patients showing mutant TP53 genotype (corresponding to those who had disease resistant to chemotherapy, P =.027).

CONCLUSIONS

In a small cohort of patients with advanced non-small cell lung cancer we found a direct link between normal TP53 genotype and response to cisplatin-based induction treatment and also between mutant genotype and resistance to treatment, whereas p53 immunohistochemical result was predictive of neither.

AIDS knowledge and attitudes among adults in Vermont

To design a statewide educational campaign, the Vermont Department of Health attempted to measure knowledge about AIDS among residents of the State. During the period November 1986 through January 1987, the authors conducted a telephone survey of noninstitutionalized residents ages 18 and over. The results were examined in relation to age and education. The most accurate answers were given by respondents less than 45 years. In terms of educational attainment, respondents with less than a high school education had an average score of 61.4 and those with a college degree averaged 85.0. When the authors examined responses to individual questions, it became apparent that respondents were more knowledgeable about ways the virus could be transmitted than about ways it could not. A more comprehensive education program must reduce fear. One component of the current AIDS campaign in Vermont is an advertisement that addresses unfounded concern about casual transmission of AIDS.

Drinking-water-induced copper intoxication in a Vermont family

Three of four family members reported recurrent episodes of gastrointestinal illness while residing in a house in a small northwestern Vermont village. The father and two daughters repeatedly experienced episodes of emesis and abdominal pain after drinking water drawn from their kitchen faucet. One early-morning water sample taken from the family household contained a copper level of 7.8 mg/L, which is above the standard for drinking water (1.0 mg/L). Values for the second daughter's copper in hair analysis (1,200 micrograms/g) and copper in nail analysis (100 micrograms/g) were elevated (normal range 11 to 53 micrograms/g). The household was at the end of a 3/4-in (19.05-mm) copper main, and it is suspected that copper levels increased in water when the water remained stagnant in the main. All symptoms of the family resolved when they stopped drinking water in their home. This is the first report of copper-induced gastrointestinal illness attributable to a public supply of drinking water.