Medical errors and clinical risk management: state of the art.

Medical errors represent a serious public health problem and pose a threat to patient safety. All patients are potentially vulnerable, therefore medical errors are costly from a human, economic, and social viewpoint. The present report aims not only to provide an overview of the problem on the basis of the published literature, but also to stress the importance of adopting standard terminology and classifications, fundamental tools for researchers to obtain valid and reliable methods for error identification and reporting. In fact, agreement on standard definitions allows comparison of data in different contexts. Errors can be classified according to their outcome, the setting where they take place (inpatient, outpatient), the kind of procedure involved (medication, surgery, etc.) or the probability of occurring (high, low). Error categories are analysed taking into consideration their prevalence, avoidance and associated factors as well as the different strategies for detecting medical errors. Incident reporting and documentation of near-misses are described as useful sources of information, and Healthcare Failure Mode Effect Analysis (HFMEA) and Root Cause Analysis (RCA) are seen as powerful methods for process analysis. Furthermore, means to increase patient safety are considered in the broader context of clinical risk management. New approaches in the field of medical errors are aimed at minimizing the recurrence of avoidable patterns associated with higher error rate. A system approach and a blame-free environment, aimed at better organizational performances, lead to much better results than focusing on individuals. Furthermore, use of technology, information accessibility, communication, patient collaboration and multi-professional team-work are successful strategies to reach the goal of patient safety within healthcare organizations.

[Mandatory or voluntary vaccinations? Juridical and medico-legal aspects]. / Le vaccinazioni tra obbligo e scelta consapevole: aspetti medico-legali e giuridici.

The Italian juridical and legislative aspects of vaccination based on a compulsory system are presented considering the medico-legal questions. The prospective of a voluntary system, as anticipated by many normatives and other official documents, is examined. The experience of some local health authorities on cases of in observance of the vaccinal obligation are detailed Finally professional risks for vaccinal operators are examined and the need of specific guidelines for parents' consent to compulsory vaccination during infancy is prospected.

Involvement of INK4A gene products in the pathogenesis and development of human osteosarcoma.

BACKGROUND: The INK4A tumor suppressor gene plays a crucial role in the regulation of the G1 cell cycle phase. It encodes two transcripts, p16 and p14 alternate reading frame (ARF), involved in retinoblastoma protein (pRb)- and p53- cell growth control pathways, respectively. METHODS: To define the role of gene status and molecule expression involved in the INK4A regulatory system, immunohistochemistry, immunoblotting, and polymerase chain reaction (PCR) analysis were performed on 35 primary high grade osteosarcomas (OS). RESULTS: Although p16 and p14ARF proteins were found negative or weakly detectable in 60% and 57% of the cases respectively, INK4A gene analysis of exons 1alpha, 1beta and 2 did not reveal any deletion or mutation. However, methylation status of the 5'CpG promoter region, assessed by methylation-specific PCR, was found in 12 out of 21 OSs with negative or weak p16 expression. A statistical analysis based on pRb/p16 and p53/p14ARF staining status showed that pRb and p16 co-expression was inversely correlated to tumor relapse and was a marker for a more favorable prognosis. A statistically significant inverse correlation was found between wt-p53 and p14ARF expression. In the group of wt-p53 tumors, the loss of p14ARF was associated with a decreased expression of p21 protein, suggesting a down-regulation of the transcriptional activity of p53. CONCLUSIONS: The current results suggest that, in OS, the altered expression of INK4A products plays a primary role in the deregulation of both pRb and p53 cell growth control pathways, contributing to tumor pathogenesis and development.

Metalloproteinase expression and prognosis in soft tissue sarcomas.

BACKGROUND: Degradation of extracellular matrix by tumor-associated proteases can promote cell invasion and metastasis. This study assessed the prognostic role of MMP2, MMP9 metalloproteinases, and of the metalloproteinase inhibitor TIMP2, related to disease-free survival (DFS), in soft tissue sarcoma (STS) patients. MATERIALS AND METHODS: Level and distribution of MMP2, MMP9, and TIMP2 expression were evaluated on 73 biopsies by immunohistochemistry and immunoblotting. Biopsies included 29 liposarcomas, 29 synovial sarcomas, and 15 malignant peripheral nerve sheath tumors (MPNST). Association between DFS and overall survival with different variables was assessed. RESULTS: In terms of DFS, increased MMP2 reactivity and lack of TIMP2 expression were significant for poor prognosis in all samples (P = 0.0005 and P = 0.006 respectively). MMP2 correlated to histologic grade (P = 0.005). Lack of TIMP2 expression was a poor prognostic factor for DFS in synovial sarcoma (P = 0.009), while MMP2 and MMP9 correlated with metastasis (P = 0.008 and P = 0.005, respectively) and grade (P = 0.001 and P = 0.04 respectively) in liposarcoma. CONCLUSIONS: These prognostic markers that influence growth and spread of tumor cells might be useful to define tumor aggressiveness and risk of the metastasic event.

Osteosarcoma in blood relatives.

Osteosarcoma is an uncommon tumor. Family occurrence of osteosarcoma is even rarer. Four cases of osteosarcoma in two siblings and in a father and son treated at our Institute with surgery and chemotherapy are reported. These patients had no other tumors in their family history, and had negative p53 mutations in exons 5-9 by SSCP analysis. RB, CDK4, MDM2, c-myc, c-fos, and p53 gene expression, which are the major genes involved in osteosarcoma susceptibility, were studied. Our results revealed an inactive form of p53 sporadically seen in the samples, a total loss of Rb protein expression, an increased expression of Cdk4, MDM2, c-fos, and c-myc proteins which literature currently reports being the principal alterations found in osteosarcoma. These findings confirm that specific genetic alterations occur in osteosarcoma pathogenesis.

Analysis of 12q13-15 genes in parosteal osteosarcoma.

The region q13-15 of chromosome 12 frequently is altered in human sarcomas, and several genes, such as SAS, CDK4, and MDM2, have been found to be amplified in bone and soft tissue sarcomas. These genes and their products were studied by quantitative polymerase chain reaction and immunohistochemical analysis in 25 parosteal osteosarcoma samples (22 Grades I or II, three dedifferentiated) to evaluate if the possible alterations detected of the genes on chromosome 12 could have a role in the development of this rare bone tumor. Immunohistochemical analysis was performed on formalin fixed, paraffin embedded tumor sections to evaluate CDK4 and MDM2 protein expression. To measure the degree of SAS and CDK4 gene amplification, quantitative polymerase chain reaction was done on deoxyribonucleic acid derived from the same samples. The results showed that CDK4 protein was expressed in 92% of the cases. Strong and uniform CDK4 and MDM2 immunoreactivity was found respectively in three of three and two of three dedifferentiated parosteal osteosarcomas. SAS and CDK4 genes were found to be amplified fourfold in two Grade II tumors and in one dedifferentiated tumor. These findings, which should be investigated further, might suggest a possible role of the chromosome 12 genes in the pathogenesis of parosteal osteosarcoma.

Presence and expression of the simian virus-40 genome in human giant cell tumors of bone.

SV40 DNA sequences have been found in human tumors, such as mesotheliomas, ependymomas, and bone tumors, suggesting that SV40 may be involved in their etiology. The FOS oncogene could play an important role in bone development because SV40 is able to induce FOS in cell culture. In this study, the presence of SV40 sequences, large T antigen (Tag), and FOS protein expression were investigated in 120 giant cell tumors (GCTs), moderately benign bone tumors that in some cases can progress to a malignant phenotype. Polymerase chain reaction (PCR), using primers that amplify the RB1 pocket binding domain and the intron of Tag, was used to analyze GCT for the presence of SV40 DNA. Tag and FOS protein expression was evaluated by immunohistochemistry. SV40 sequences were found in 30/107 GCTs, and of these, 22/30 samples expressed Tag protein (73%) and 15/30 overexpressed the FOS oncogene (50%). FOS was undetectable in 77 SV40-negative GCTs. Sequence analysis of the amplified DNAs confirmed that the amplified sequences corresponded to SV40 DNA. The correlation between FOS overexpression and SV40-positive GCTs was highly statistically significant (P < 0.001). These results show that SV40 DNA sequences and SV40 Tag are present in GCTs and might induce FOS activity. These data suggest that SV40 might play a role in the development and progression of some GCTs.

Changes of the p16 gene but not the p53 gene in human chondrosarcoma tissues.

The role of two important tumour suppressor genes, p16 and p53, was evaluated in cartilaginous tumour tissues. Genomic DNA from 22 chondrosarcomas, 5 benign chondroid tumours, 1 sample of reactive proliferative cartilage and 2 samples of normal cartilage were analysed using polymerase chain reaction, single strand conformational polymorphism, DNA sequencing and methylation-specific polymerase chain reaction. The p16 gene was found to be partly methylated in 5 high-grade chondrosarcomas and homozygously deleted in 1 chondrosarcoma. Moreover, a polymorphism was detected in 3 malignant tumours, but not in benign tumours or normal cartilage. Analysis of the p53 gene revealed an unchanged structure in all samples. These findings show a role for p16, but not p53, in chondrosarcoma.

Incidence of xenobiotics among drivers killed in single-vehicle crashes.

The authors have performed a study of single-vehicle crashes (SVCs) in order to verify a correlation between the loss of vehicle control and the presence of drugs in the body. Overall, 129 cases were recorded and occurred in the catchment area of the Institute of Legal Medicine in Milan between 1986 to 1996. Among the 129 cases under study, respectively 121 men and eight women, 101 were car-drivers and 28 motor-cyclists. The median age was equal to 29 years, while the average age to 32.0 years (range 15-65 years). Fifty eight cases (45.0%) were "positive" for the presence of ethanol > or = 0.8 g/l or other drugs. The sample of "positive cases" was studied according to sex, age, day, hour and type of vehicle. Considering the cases with presence of ethanol, although under the legal limit (20 cases), the total amount of cases (78) becomes even more consistent. The amount of ethanol was found to be respectively 0.34 g/l in daily drivers and 0.87 g/l in nightly drivers (p < 0.01). Our considerations confirm the importance of toxicological analyses in the forensic investigation of traffic deaths being the sample under study recorded following criteria which minimised other possible factors effecting road accidents.

Prevalence of HIV and hepatitis C markers among a cadaver population in Milan.

AIMS: To examine the distribution of serological markers for HIV and hepatitis C virus (HCV) infection in a medicolegal population; to compare prevalence of HIV and HCV markers and cause of death; and to evaluate the risk of potential infection to personnel involved in medicolegal incidents and procedures. METHODS: Blood samples were collected at necropsy from 328 males and 69 females, aged 16 to 50 years at time of death, and tested for antibodies to HIV and HCV. The individuals were classified according to cause of death and whether there was known antemortem risk of infection. RESULTS: Overall, 134 subjects gave positive test results: 20 for anti-HIV, 69 for anti-HCV, and 45 for both. By cause of death, the total number of positives (and negatives) with the pairs of figures referring, respectively, to patients with and without known antemortem risks were: natural causes 3 (1), 8 (32); AIDS 2 (0), 0 (0); homicide 0 (2), 5 (24); suicide 3 (0), 9 (69); road traffic accidents 1 (0), 9 (81); other accidents 2 (3), 1 (12); drug overdose 74 (17), 7 (9); unknown causes 3 (2), 7 (11). CONCLUSIONS: The cases tested represented a predominantly young male population with a high prevalence of serological markers for HIV and HCV infection. The distribution of HIV and HCV positivity varied with the cause of death, probably reflecting the known association between high risk behaviour and infection. However, a substantial number of cases with no known risks also had markers for HIV and HCV, suggesting that there is a large unrecognised pool of potential infection in medicolegal practice.

Alteration of pRb/p16/cdk4 regulation in human osteosarcoma.

Cell-cycle regulation depends on a fine balance between cyclin-cyclin-dependent kinase complexes and a family of kinase inhibitors that bind cyclin-cdk complexes and block their activity. To investigate the role of mechanisms regulating cell-cycle progression in human osteosarcomas (OS), pRb/p16/cdk4 expression was analyzed in 39 high-grade OS; 19 of these developed metastasis during follow-up. Positive reaction for functional pRB was shown by 18/39 (46%) OS, while 21/39 (54%) were negative. A higher probability of metastasis was seen in patients with negative pRb expression (p < 0.05). Furthermore, while functional pRb and D1 expression are inversely associated to metastasis occurrence, the presence of D1/cdk4 complex in our study was related to poor prognosis. We found that 10/18 pRb-positive and 14/21 pRb-negative tumors were p16-positive. No significant correlation was found between pRb and p16 expression. On the other hand, high cdk4 levels in p16-positive tumors as compared with p16-negative tumors resulted in a positive association between p16 and cdk4 expression (Chi squared = 5.98; p = 0.01). No extensive p16INK4A genomic alterations were found in tumors lacking p16-protein expression. To determine which mechanisms are involved in the down-regulation of p16 protein, the methylation status of the p16INK4 gene was evaluated on the 15 p16-negative tumors: 8 samples showed 5' CpG-island methylation; 4/8 had a complete methylation status, while in the remaining 4 the gene was only partially methylated. These data confirm the role of the pRb/p16/cdk4 pathway in OS development.

Increased c-myc oncogene expression in Ewing's sarcoma: correlation with Ki67 proliferation index.

AIMS AND BACKGROUND: Ewing's sarcoma is a highly malignant musculoskeletal tumor composed of small round cells. Although important results have been achieved with surgery associated with chemotherapy, recurrent disease is still a major problem. In order to define new prognostic factors useful for therapeutic decision-making, we conducted a study on 38 Ewing's sarcoma samples in which c-myc oncogene expression and Ki67 proliferation index were correlated with clinical outcome. METHODS AND STUDY DESIGN: Nineteen patients developed metastases during follow-up and 10 of these patients died. C-myc and Ki67 protein expression was evaluated by immunohistochemistry performed on 5 microm formalin-fixed and paraffin-embedded sections, while the c-myc mRNA transcript was localized using in situ hybridization. RESULTS: A statistically positive correlation was found between c-myc protein and Ki67 (P = 0.001) and c-myc mRNA and Ki67 expression (P = 0.047). The 38 patients were divided into two groups using as the cutoff 50% of Ki67-positive cells. The disease-free survival and overall survival estimates were 68% and 90%, respectively, in the group of patients with a percentage of Ki67-positive cells <50%, and 25% and 50%, respectively, in the group with a percentage of Ki67-positive cells > or = 50%. The difference between the survival curves was statistically significant (P <0.05 and P <0.01). Furthermore, relapsed patients had a high and uniform expression of c-myc protein and mRNA compared to disease-free patients. CONCLUSION: These results suggest a possible role of the c-myc oncogene and Ki67 antigen in the malignant progression of Ewing's sarcoma.

Expression of G1 phase regulators in MG-63 osteosarcoma cell line.

Cyclins and cyclin-dependent kinases (cdks) form complexes that govern transitions during cell cycle phases. In this study we characterized a human osteosarcoma cell line, MG-63, for the expression level of cyclin D1, cyclin E, cdk4, cdk2, and cell cycle inhibitors pRb and p21. To investigate the role of these proteins we treated MG-63 cells with tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Cell proliferation analysis demonstrated an increased proliferation of MG-63 cells with IL-6, while TNF-alpha acted as an anti-proliferative agent. Immunoblotting revealed an increased expression of p21 with TNF-alpha and its complex with cdk2. TNF-alpha reduced the expression of the cyclin E-cdk2 complex. TNF-alpha did not affect the amount of cyclin D1, cyclin E, cdk4, cdk2, and of cyclin D1-cdk4 complex. IL-6 decreased p21 expression and its complex with cdk2, while it increased the cyclin E-cdk2 complex. Cyclin D1 and cdk4 expression and their complex did not change after IL-6 treatment, nor did cyclin E and cdk2 protein expression. Hyperphosphorylated/dephosphorylated Rb protein ratio was reduced with TNF-alpha whereas it increased with IL-6. These results may suggest an important role of p21 and of cyclin E-cdk2 complex in the G1 phase regulation through pRb phosphorylation in MG-63 cells.

Analysis of SAS gene and CDK4 and MDM2 proteins in low-grade osteosarcoma.

The region q13-15 of chromosome 12 contains SAS, CDK4, and MDM2 genes that are rearranged or amplified in a variety of human sarcomas. This study evaluated SAS gene amplification, and MDM2 and CDK4 protein expression in 20 tumor samples of central low-grade osteosarcoma (16 primary, 3 recurrences, 1 lung metastasis). SAS amplification was analyzed by quantitative polymerase chain reaction (PCR), while from the same paraffin-embedded samples, MDM2 and CDK4 protein expression was evaluated by immunohistochemistry. MDM2 and CDK4 proteins were found strongly expressed in 35% and 65%, respectively, of the samples. SAS was found amplified in 15% of the samples. These findings indicate that these genes may be involved in tumorigenesis and progression of low-grade osteosarcoma.

C-myc and c-fos in human osteosarcoma: prognostic value of mRNA and protein expression.

The c-myc and c-fos proto-oncogenes have several putative functions, including regulation of cell growth. In many neoplasms c-myc overexpression has been linked to poor prognosis. In order to study the role of c-myc and c-fos expression on the tumorigenesis, and the metastatic spread of osteosarcoma, frozen and paraffin-embedded tissue 38 primary osteosarcoma and 10 lung metastases were analyzed. The mRNA analysis was performed by quantitative reverse transcription-polymerase chain reaction and in situ hybridization. The protein expression was studied by Western blot analysis and immunohistochemistry. C-myc and c-fos were found overexpressed in a high percentage of the relapsed tumors and of the metastases, and overexpression of both oncogenes in the same tumor was strongly correlated to the development of metastases (p < 0.05), as 6 of the 7 primary tumors overexpressing both the oncogenes gave metastases. In conclusion, both c-myc and c-fos are involved in the growth and spread of osteosarcoma and a synchronous overexpression of both oncogenes is highly significant for a metastatic potential of a primary tumor.

Adhesion molecules in high-grade soft tissue sarcomas: correlation to clinical outcome.

The extracellular matrix (ECM) forms a framework for cell adhesion, but it also regulates growth and differentiation. Normal and malignant cells interact with the ECM via specific receptors, the integrins. To explore the mechanisms of growth and spread in soft tissue sarcomas the expression of the major ECM molecules and their corresponding integrin receptors were studied by immunohistochemistry in high-grade soft tissue sarcomas: malignant fibrous histiocytoma (20 cases), malignant peripheral nerve sheath tumour (17 cases) and synovial sarcoma (21 cases). The expression pattern was compared with cell proliferation and clinical outcome. Integrins were found to be expressed according to histological pattern. In synovial sarcomas, the epithelial component showed a high alpha 2 but negative or minimal detection of alpha 5 expression, while a weak alpha 2 expression and a moderate alpha 5 expression were found in the spindle cell component. No alpha 2 expression was detected in malignant fibrous histiocytoma, and minimal alpha 5 expression was detected in malignant schwannoma. The alpha 6 expression levels were positively correlated with the occurrence of metastases in all types of sarcomas studied. The expression of ECM molecules was downregulated and irregular in most tumours. In conclusion, the divergent integrin expression pattern could be useful in the diagnosis and classification of soft tissue sarcomas. Furthermore, since high laminin receptor expression correlates with occurrence of metastases, it could become a useful prognostic marker.

Prognostic significance of cyclin expression in human osteosarcoma.

To evaluate the distribution of cyclin protein expression, in relation to cell proliferation rate and clinical behavior, an immunohistochemical study was performed on 92 tumor samples of patients with high grade osteosarcoma (OS). A large cyclin A- and cyclin E-positive fraction was found respectively in 59% and 47% of the osteosarcomas, while immunostaining for cyclin D1 was weak or absent in most tumor samples. A positive, statistically significant correlation was found between A and E cyclins and Ki67 expression (p<0.001). Disease-free survival (DFS) analysis included 69 of the 92 patients. A significantly higher probability of metastasis was seen in patients lacking cyclin D1 compared to those in which cyclin D1 was positive (p<0.01). Conversely, patients with >40% of cyclin A-positive cells relapsed more frequently than those with <40% of cyclin A-positive cells (p<0.05). The multivariate analysis demonstrated that cyclin A had a lower predective risk in terms of disease-free survival as opposed to the loss of cyclin D1 that is considered a powerful prognostic factor.

Prognostic relevance of C-myc gene expression in giant-cell tumor of bone.

Giant-cell tumor is a primary bone tumor, of uncertain origin, with the potential capacity to metastasize. To study the role of c-myc and c-fos oncogene overexpression in the tumorigenesis and metastatic spread of giant-cell tumors, 32 primary tumors were collected; of these, 19 remained disease-free and 13 metastasized to the lung. Samples of lung metastasis from these 13 patients were also available for study. The expression of c-myc and c-fos mRNA was studied by reverse transcription-polymerase chain reaction and by in situ hybridization. The expression of protein was studied by Western blot analysis and by immunohistochemistry. C-myc mRNA was overexpressed in 12 (38%) of the 32 primary tumors. Thirteen primary tumors metastasized to the lung; in nine (69%) of these, c-myc mRNA was overexpressed. The c-myc protein was overexpressed in seven (54%) of the 13 tumors that metastasized to the lung. C-fos was overexpressed in only one lung metastasis. A strong correlation between the overexpression of c-myc, and the occurrence of metastases was found: thus, c-myc seems a powerful prognosticator in giant-cell tumor. C-myc was overexpressed both in giant cells and in mononuclear cells, suggesting that both cell types are involved in the progression of this tumor.

[Anesthesiologic incidents from esophageal intubation. Presentation of three cases and medico-legal evaluation]. / Incidenti anestesiologici da intubazione esofagea. Presentazione di tre casi clinici e valutazione medico-legale.

Undiagnosed esophageal intubation is still prominently in anesthesia-related morbidity and mortality. Three cases of undiagnosed esophageal intubation taken into consideration for possible anesthesiologic malpractice are presented. A review of the international anesthetic-related morbidity and mortality statistics indicates that this misadventure remains a problem even among anesthesia personnel, a medical population specifically trained in such a procedure. It is not only the frequency of this misadventure but the potential catastrophic consequences for the patient that underline the importance of being able to recognise and correct an esophageal intubation. The reliability of commonly prescribed methods of assessing tracheal tube position is reviewed and the conclusion is drawn that continuous end-tidal carbon dioxide measurement during anesthesia is perhaps the most reliable means under all circumstances for determining proper tube position and should be employed routinely whenever possible.

Altered G1 phase regulation in osteosarcoma.

Alterations in the normal cell cycle lead to abnormal cell proliferation and to tumor development. To explore the role of the cyclin D/Cdk4 complex and the retinoblastoma protein (pRb) in the growth and spread of osteoblastic osteosarcoma (OS), 40 tumor samples were selected. In 17 of these cases, lung metastases occurred during follow-up. Expression of pRb, cyclin D1 and its catalytic subunit, Cdk4, was studied by immunohistochemistry and immunoblotting. As controls, non-neoplastic tissues surrounding the tumor were used. The expression level and pattern were compared to clinical outcome. Cdk4 was over-expressed in 80% of OS, independently of clinical outcome, and showed an intense and uniform distribution in tumor cells compared to normal cells. However, co-immunoprecipitation of Cdk4 with cyclin D1 revealed low levels of cyclin D/Cdk4 complex; 20 of 40 OS examined had a negative or minimal immunostaining for active pRb. The probability of relapse was significantly higher in pRb-negative than in the -positive patients (p < 0.05). The ratio of unphosphorylated/hyperphosphorylated pRb was lower in relapsed patients than in patients with no evident disease, though the difference was not statistically significant. High levels of pRb/cyclin D1 were found in all samples exhibiting functional pRb expression. Our results show that G1 phase deregulation is involved in formation and development of OS. The expression levels of both pRb and cyclin D1 had a clear correlation with clinical outcome, suggesting that these parameters could be used as prognostic markers.