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Results for “Multiple Classification Analysis”

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At least 613 records · Page 34Linked to original sources

PubMed2006

Proposal of a new and simple staging system of colorectal liver metastasis.

AIM: To create a new, simple and useful staging system for colorectal liver metastasis analogous to the Tumor Node Metastasis classification system of International Union Against Cancer. METHODS: A retrospective review was undertaken of 81 consecutive patients who underwent partial hepatectomy for colorectal liver metastases (group 1). Clinical and pathological features of both primary and metastatic liver cancers were entered into a multivariate analysis to determine independent variables helpful in accurately predicting long-term prognosis after hepatectomy. Using selected variables, we created a new staging system like TNM classification. The usefulness of the new staging system was examined in a series of 92 patients from another hospital (group 2). RESULTS: Multivariate analysis showed that 81 patients in group 1 had significant multiple hepatic tumors with the largest tumor being more than 5 cm in diameter, resectable extrahepatic distant metastases, and independent prognostic factors for poor survival after hepatectomy. Using these three variables, we created a new staging system to classify patients with colorectal liver metastases. Finally, our new staging system classified the patients both in group 1 and in group 2. CONCLUSION: Our new staging system of colorectal liver metastasis is simple and useful for staging patients.

Adult↗

PubMed2001

[Posttraumatic retroperitoneal hematoma in injured persons with severe closed multiple and combined abdominal trauma].

The experience of treatment of 69 injured persons with posttraumatic retroperitoneal hematoma suffering severe multiple combined abdominal trauma was analyzed. Application of the classification proposed permits to formulate diagnosis and to choose the tactic of treatment correctly. The intraoperative tactics algorithm was elaborated. It promotes the correct analysis of intraoperative findings and reduction of the diagnostic mistakes frequency as well. In the presence of vast defect, making impossible to suture over the parietal peritoneum, extraperitonization using cerebral dura mater was done. Operative intervention was concluded by drainage with subsequent laserotherapy.

Abdominal Injuries↗

PubMed1998

Standardizing flow cytometry: a classification system of fluorescence standards used for flow cytometry.

The growing number of standards commercially available in the field of flow cytometry makes it difficult to know which standards to use to obtain a desired level of quality assurance. A classification system of fluorescence standards has been developed on the basis of their physical characteristics. In turn, these physical characteristics determine the ability of the specific standards to perform selected functions, such as alignment, target referencing, compensation, and calibration. Knowing the properties and limitations of specific standards will help flow cytometer users to select the appropriate standard for the application that they will be performing, especially in regard to intra- and interlaboratory quality assurance. Common protocols used in conjunction with specific classifications of reference standards can provide unified analysis regions or window of analysis across different instruments and/or laboratories. In addition, specific classifications of calibration standards can help select those standards that will provide independent and direct comparison of instrument performance parameters, especially in studies involving multiple laboratories. Knowledge and understanding of the classification system can guide flow cytometer users in more efficient and accurate instrument setup and quality control when conducting research, as well as clinical applications.

Calibration↗

PubMed2004

UGT1A1*28 polymorphism in ovarian cancer patients.

(Uridino-diphosphate)glucuronosyl-transferase enzyme 1A1 isoform (UGT1A1) is involved in glucuronidation of antineoplastic drugs such as SN38, the active metabolite of irinotecan, as well as estrogens and their metabolites. UGT1A1*28 polymorphism decreases UGT1A1 expression and could alter estrogens disposition influencing tumour growth in hormone sensitive tissues. The UGT1A1*28 distribution among an ovarian cancer patient (OCP) population of 217 mono-institutional individuals was investigated to clarify its possible involvement in the pathogenesis and chemotherapy of ovarian cancer. Data were compared with those of 205 female healthy blood donors. In 160 patients also the tumour tissue was genotyped to describe the occurrence of loss of heterozygosity (LOH). A PCR based assay followed by automated fragment analysis was used. Odds ratios (OR), and 95% confidence intervals (95% CI), were computed by a multiple logistic regression model using as dependent variable in a case-control or in a case-case approach the histological classification. No significant prevalence of the polymorphism was observed in the cases versus controls. In a case-case approach, a higher frequency of the polymorphism was observed in patients with mucinous tumours (6/11, 54.6%) compared to non-mucinous (30/206, 14.6%) (p=0.009, OR=7.20; 95% CI 2.06-25.19). LOH was observed in 12 cases out of 160 (7.5%) and was associated with non-mucinous tumours, 10 (83.3%) cases determined a retention of the wild-type allele. In conclusion, the prevalence of UGT1A1*28 found in mucinous OCP could suggest a role in the development of specific histologic sub-groups and could become a marker to be considered when planning ovarian cancer chemotherapy.

Antineoplastic Agents, Phytogenic↗

PubMedDate not supplied

Acute renal failure in hospitalized patients: part I.

BACKGROUND: Acute renal failure (ARF) is a common condition in hospitalized patients. Morbidity, mortality, and health resource use are considerable, but the true magnitude of the problem is not well described in the literature. OBJECTIVE: To provide a detailed discussion of the epidemiology, economic costs, and classification of ARF. DATA SOURCES: A MEDLINE search (1996-December 2001) was conducted using the search terms kidney and acute kidney failure: epidemiology, etiology, and drug therapy/drug effects. Bibliographies of selected articles were also examined to include all relevant investigations. Economic data were identified using the terms costs and cost analysis and cost of illness. STUDY SELECTION AND DATA EXTRACTION: Review articles, meta-analyses, and clinical trials describing epidemiology and classification of hospital-acquired ARF were identified. Results from prospective, controlled trials were given priority when available. CONCLUSIONS: ARF occurs in up to 25% of critically ill patients, resulting in significant morbidity and high mortality. Characterization of ARF is difficult due to multiple etiologic factors and variable definitions. Limited cost data describe the extensive economic burden associated with the disorder, although further pharmacoeconomic research is needed. Epidemiology and classification of ARF allow prospective management of at-risk patients.

Acute Kidney Injury↗

PubMed2004

High-dose chemotherapy and autologous peripheral blood stem cell transplantation in high-risk multiple myeloma.

We compared the effect of high-dose therapy together with autologous peripheral blood stem cell transplantation (autoPBSCT) in 60 patients with multiple myeloma (MM) with 90 patients who underwent conventional chemotherapy. We scored the prognostic factors according to our reported classification system that includes measurements of serum albumin, serum beta-2-microglobulin, and morphology of myeloma cells selected by multivariate analysis. We separated the patients into three risk groups at stratification level I (low, intermediate and high) and into two risk groups at stratification level II (low and high). AutoPBSCT tended to be as effective for high, as for low-risk patients in level I, and was obviously as helpful for high, as for low-risk patients in stratification II. In conclusion, high-risk patients with MM should be treated with high-dose therapy accompanied with autoPBSCT like low-risk patients.

Adult↗

PubMed1994

The application of a factor evaluation system for community nursing in The Netherlands.

In the literature both advantages and disadvantages are mentioned for factor and prototype patient classification systems. In this study a secondary analysis is used to explore the variance which is explained by a prototype and a factor evaluation classification system of the same patients. In the prototype evaluation system, the care types which were applied resulted in heterogeneous visit times. To explore the factor evaluation system, multiple regression analyses were executed with the average visit time per patient as dependent variable and the activities (separate or aggregated per category) as independent variables. Results show that the activities explain the average visiting time per patient better than the developed care types do.

Aged↗

PubMed2006

High-resolution genomic profiles define distinct clinico-pathogenetic subgroups of multiple myeloma patients.

To identify genetic events underlying the genesis and progression of multiple myeloma (MM), we conducted a high-resolution analysis of recurrent copy number alterations (CNAs) and expression profiles in a collection of MM cell lines and outcome-annotated clinical specimens. Attesting to the molecular heterogeneity of MM, unsupervised classification using nonnegative matrix factorization (NMF) designed for array comparative genomic hybridization (aCGH) analysis uncovered distinct genomic subtypes. Additionally, we defined 87 discrete minimal common regions (MCRs) within recurrent and highly focal CNAs. Further integration with expression data generated a refined list of MM gene candidates residing within these MCRs, thereby providing a genomic framework for dissection of disease pathogenesis, improved clinical management, and initiation of targeted drug discovery for specific MM patients.

Chromosomes, Human↗

PubMed1999

A staging system for multiple myeloma based on the morphology of myeloma cells.

The morphology of myeloma cells is reported to be one of the prognostic factors in multiple myeloma (MM) patients. We analyzed the prognostic factors, including morphological classification, in 292 patients with MM in order to select poor-risk patients who should be considered candidates for early intensive chemotherapy, including stem cell transplantation. Multivariate analysis was applied to 90 patients diagnosed between 1989 and 1996, because serum beta-2-microglobulin (beta2M) has been measured regularly since 1989, and showed that serum albumin, serum beta2M, and the morphology of myeloma cells predicted survival. According to these factors, patients were divided into 3 risk groups; a high-risk group (14%), a intermediate-risk group (46%) and a low-risk group (40%). There were significant differences between survival times in these 3 groups (median survival: high-risk, 16; intermediate-risk, 22; and low-risk, 44 months).

Aged↗

PubMed2005

Use of the Radiation Therapy Oncology Group recursive partitioning analysis classification system and predictors of survival in 19 women with brain metastases from ovarian carcinoma.

BACKGROUND: Brain metastases are an uncommon complication in women with primary ovarian carcinoma; thus, little is known about whether the Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) prognostic classification system is valid in this patient population. METHODS: From September 1985 to June 2002, 19 patients with brain metastases resulting from primary ovarian carcinoma underwent treatment at the Cleveland Clinic Foundation. The medical records of these patients were retrospectively reviewed. RESULTS: At the time of data analysis, all 19 women had died. The median age at diagnosis of primary ovarian carcinoma and brain metastasis was 51 and 54 years of age, respectively. Fifteen patients presented with a Karnofsky performance status (KPS) of 70 or higher. Seven patients had a single brain lesion and 12 had multiple lesions. All RTOG RPA prognostic classes were represented, with median survivals of 24.7, 8.9, and 2.6 months for Classes I, II, and III, respectively (P = 0.31). Patients who underwent surgical resection survived longer than those who did not (33.7 vs. 7.4 mos). The presence of multiple lesions was adversely related to survival on multivariate analysis (P = 0.03). Primary control was an important predictor of survival on multivariate analysis as well (P = 0.01) and was achieved in 15 of the 19 women. CONCLUSIONS: This is the first study to support the prognostic usefulness of the RTOG RPA classification for ovarian carcinoma patients with metastasis to the brain. The number of metastatic intracranial lesions should be included when determining the prognosis.

Adult↗

PubMedDate not supplied

From cognition to the system: developing a multilevel taxonomy of patient safety in general practice.

The paper describes the process of developing a taxonomy of patient safety in general practice. The methodologies employed included fieldwork, task analysis and confidential reporting of patient-safety events in five West Midlands practices. Reported events were traced back to their root causes and contributing factors. The resulting taxonomy is based on a theoretical model of human cognition, includes multiple levels of classification to reflect the chain of causation and considers affective and physiological influences on performance. Events are classified at three levels. At level one, the information-processing model of cognition is used to classify errors. At level two, immediate causes are identified, internal and external to the individual. At level three, more remote causal factors are classified as either 'work organization' or 'technical' with subcategories. The properties of the taxonomy (validity, reliability, comprehensiveness) as well as its usability and acceptability remain to be tested with potential users.

Classification↗

PubMed2006

Bifurcation and singularity analysis of a molecular network for the induction of long-term memory.

Withdrawal reflexes of the mollusk Aplysia exhibit sensitization, a simple form of long-term memory (LTM). Sensitization is due, in part, to long-term facilitation (LTF) of sensorimotor neuron synapses. LTF is induced by the modulatory actions of serotonin (5-HT). Pettigrew et al. developed a computational model of the nonlinear intracellular signaling and gene network that underlies the induction of 5-HT-induced LTF. The model simulated empirical observations that repeated applications of 5-HT induce persistent activation of protein kinase A (PKA) and that this persistent activation requires a suprathreshold exposure of 5-HT. This study extends the analysis of the Pettigrew model by applying bifurcation analysis, singularity theory, and numerical simulation. Using singularity theory, classification diagrams of parameter space were constructed, identifying regions with qualitatively different steady-state behaviors. The graphical representation of these regions illustrates the robustness of these regions to changes in model parameters. Because persistent protein kinase A (PKA) activity correlates with Aplysia LTM, the analysis focuses on a positive feedback loop in the model that tends to maintain PKA activity. In this loop, PKA phosphorylates a transcription factor (TF-1), thereby increasing the expression of an ubiquitin hydrolase (Ap-Uch). Ap-Uch then acts to increase PKA activity, closing the loop. This positive feedback loop manifests multiple, coexisting steady states, or multiplicity, which provides a mechanism for a bistable switch in PKA activity. After the removal of 5-HT, the PKA activity either returns to its basal level (reversible switch) or remains at a high level (irreversible switch). Such an irreversible switch might be a mechanism that contributes to the persistence of LTM. The classification diagrams also identify parameters and processes that might be manipulated, perhaps pharmacologically, to enhance the induction of memory. Rational drug design, to affect complex processes such as memory formation, can benefit from this type of analysis.

Algorithms↗

PubMed2005

[Application of Excel Visual Basic for efficiently complete statistic analysis].

OBJECTIVE: In order to analyze multiple statistic tables more efficiently Excel Visual Basic for Application (VBA) was introduced through the use of an example of calculating standardized mortality rates (SMRs). METHODS: Mortality data of cancer and cardiovascular diseases, by sex and age, have been collected from 1991 to 2003 by the Center for Disease Control and Prevention of Shanghai Huangpu District. Standard population composition was defined as Chinese census statistics in 2000. The male's SMRs were calculated, using Excel VBA for each year and classification of cancers. RESULTS: The male's SMRs were obtained by year and different cancers. At the same time, the results were listed in the cancer's SMRs table for male. CONCLUSIONS: Excel is more flexible than general database on the combination of data and annotation. Excel VBA is better than the basic Excel in operating multiple tables simultaneously and man-machine conversation. Statistic analysis can be efficiently completed by using Excel VBA.

Age Factors↗

PubMedDate not supplied

Observing structure, function and assembly of single proteins by AFM.

Single molecule experiments provide insight into the individuality of biological macromolecules, their unique function, reaction pathways, trajectories and molecular interactions. The exceptional signal-to-noise ratio of the atomic force microscope allows individual proteins to be imaged under physiologically relevant conditions at a lateral resolution of 0.5-1nm and a vertical resolution of 0.1-0.2nm. Recently, it has become possible to observe single molecule events using this technique. This capability is reviewed on various water-soluble and membrane proteins. Examples of the observation of function, variability, and assembly of single proteins are discussed. Statistical analysis is important to extend conclusions derived from single molecule experiments to protein species. Such approaches allow the classification of protein conformations and movements. Recent developments of probe microscopy techniques allow simultaneous measurement of multiple signals on individual macromolecules, and greatly extend the range of experiments possible for probing biological systems at the molecular level. Biologists exploring molecular mechanisms will benefit from a burgeoning of scanning probe microscopes and of their future combination with molecular biological experiments.

Biophysical Phenomena↗

PubMed1983

[Studying pulmonary mechanics in intensive care].

Assessing pulmonary function in critically ill patients is difficult, mainly because of lack of cooperation, artificial ventilation and jeopardized vital functions. We describe bedside methods and mobile equipment used to measure lung volumes, static pulmonary and thoracic compliance. The analysis of single and multiple-breath nitrogen washout curves allows an estimation of closing volume and an assessment of the inhomogeneity of ventilation. The use of a microcomputer facilitates recording, calculation, reproduction and classification of the data; it also permits the collection of more information in a shorter time, allowing the adjustment of mechanical ventilation to the underlying pulmonary disease.

Critical Care↗

PubMed2005

Impact of age on both BIS values and EEG bispectrum during anaesthesia with sevoflurane in children.

BACKGROUND: The aim of this study was to evaluate the potential relationship between age, BIS (Aspect), and the EEG bispectrum during anaesthesia with sevoflurane. METHODS: BIS and raw EEG were recorded at a steady state of 1 MAC in 100 children, and during a decrease from 2 to 0.5 MAC in a sub-group of 29 children. The bispectrum of the EEG was estimated using MATLAB software. For analysis, the bispectrum was divided into 36 frequencies of coupling (P(i))--the MatBis. A multiple correspondence analysis (MCA) was used to establish an underlying structure of the pattern of each individual's MatBis at 1 MAC. Clustering of children into homogeneous groups was conducted by a hierarchical ascending classification (HAC). The level of statistical significance was set at 0.05. RESULTS: At 1 MAC, the BIS values for all children ranged from 20 to 74 (median 40). Projection of both age and BIS value recorded at 1 MAC onto the structured model of the MCA showed them to be distributed along the same axis, demonstrating that the different values of BIS obtained in younger or older children are mainly dependent on their MatBis. At 1 MAC, six homogeneous groups of children were obtained through the HAC. Groups 5 (30 months; range 23-49) and 6 (18 months; range 6-180) were the younger children and Group 1 (97 months; range 46-162) the older. Groups 5 and 6 had the highest median values of BIS (54; range 50-59) (55; range 26-74) and Group 1 the lowest values (29; range 22-37). CONCLUSION: The EEG bispectrum, as well as the BIS appeared to be strongly related to the age of children at 1 MAC sevoflurane.

Adolescent↗

PubMedDate not supplied

Spiritual care activities of nurses using Nursing Interventions Classification (NIC) labels.

PURPOSE: To describe the spiritual care activities of nurses as subsequently identified in the Nursing Interventions Classification (NIC) labels. METHODS: Data were taken from a larger study that used a multiple triangulation research design to describe spiritual perspectives, interventions, and attitudes of 1,000 Sigma Theta Tau International members. Data analysis included descriptive and multivariate statistics for quantitative items, and content analysis for responses to questions. FINDINGS: 97 respondents reported providing 32 spiritual care activities. Ten NIC labels actually mapped the nurses' spiritual care activities. CONCLUSIONS: Spiritual care activities involve a broad spectrum of interventions that may be unique to each patient. The 32 spiritual care activities described by the nurses provide new knowledge regarding core spiritual care activities. The use of NIC labels can facilitate documentation of spiritual care activities in diverse practice settings. PRACTICE IMPLICATIONS: This study supports greater specificity in describing spiritual care interventions to a level that allows replication and advancement of knowledge.

Adult↗

PubMed1996

Caliber estimation from cranial entrance defect measurements.

Caliber estimation from entrance defects has long been rejected by forensic scientists. This appears to be a consequence of soft tissue perspective of forensic pathologists. This study examined the relation between caliber and cranial entrance defects and maximum cranial thickness. The calibers considered in this inquiry were .22, .25, .32, and .38. The sample consisted of 73 specimens obtained at autopsy (thirty-seven of .22 caliber, five of .25, six of .32, and twenty-five of .38). To test the strength of the relation between caliber, minimum diameter, and maximum thickness Pearson correlation coefficients were conducted. The strongest relationship was observed between caliber and minimum diameter. A relationship between minimum diameter and maximum thickness was also observed. To test the null hypothesis that the mean minimum diameter is not significantly different between calibers an analysis of variance procedure was performed. The ANOVA yielded a strong relationship between dependent variable minimum diameter and caliber. Multiple regression analysis measuring the association between minimum diameter, caliber, and maximum thickness was also conducted. The Pr > F .0001 suggests that the overall model is significant. Discriminant functions and canonical variables were obtained. Classification was first performed by using two values small and large calibers. The large caliber group consisted of .38, while the small caliber group included .22, .25, and .32. The correct classification rate using crossvalidation for large caliber is 86.96%, and 93.33% for the group small caliber. A narrower classification was also performed by using three values, .23 caliber (.22 and .25 calibers grouped), .32, and .38 as the criterion variable groups also using minimum diameter and maximum thickness as predictors. The correct classification rate using crossvalidation is 82.02% for .23 caliber, 73.94% for .38 caliber, and 16.67% for .32 caliber defects. The discriminant functions can be used with appropriate caution to classify observations into groups defined by caliber using minimum diameter and maximum thickness as the predictors. Caution is suggested when attempting to estimate caliber from defects that are not produced from the perpendicular entrance of a bullet.

Analysis of Variance↗