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PubMed2000

Serum ferritin concentration and recurrence of colorectal adenoma.

Both body iron stores and dietary iron intake have been reported to increase risk of colorectal neoplasms. We assessed whether serum ferritin concentration was associated with recurrence of colorectal adenomas among 733 individuals with baseline determinations of ferritin as part of a multicenter clinical trial of antioxidant supplements for adenoma prevention. All study participants had at least one adenoma removed within 3 months before enrollment, and 269 of them developed one or more adenomas between follow-up colonoscopies conducted 1 and 4 years after enrollment. Baseline serum ferritin concentrations were analyzed both as a log-transformed continuous variable and as a categorical variable, defined as whether iron stores were nonreplete and low (ferritin < or =30 microg/liter), nonreplete and borderline (31-70 microg/liter), replete and adequate (71-160 microg/liter), or replete and high (>160 microg/liter). Analyses were based on multiple logistic regression models, including age, sex, study center, energy, alcohol, fiber, folate, and total fat intake, number of months between colonoscopic examinations, smoking status, and aspirin use. Overall, there was no statistically significant linear association between log ferritin concentration and adenoma recurrence (P = 0.33). Risk of adenoma recurrence was modestly increased among participants with ferritin concentrations >70 microg/liter relative to those with lower ferritin (odds ratio, 1.39; 95% confidence interval, 0.96-2.02). This result seemed more pronounced among women than men. Dietary intake of iron and red meat was inversely associated with adenoma recurrence among participants with replete iron stores but not consistently associated among those with nonreplete stores. Our findings suggest that any role of iron stores and dietary iron in influencing risk of colorectal adenoma recurrence is likely complex.

Adenoma↗
PubMed2000

[Normal confidence interval for a summary measure].

This paper proposes an approach for calculating the normal confidence interval of a weighted summary measure which requires a particular continuous transformation for its variance estimation. By using the transformation properties and applying the delta method, the variance of transformed measure is easily expressed in terms of the transformed specific measure variances and the squared weights. The confidence limits of the summary measure are easily deduced by inverse transformation of those of transformed measure. The method is illustrated by applying it to some well known epidemiological measures. It seems appropriate for application in stratified analysis context where size allows normal approximation.

Analysis of Variance↗
PubMed1999

On a wing and a prayer: the biomechanics of the Rev. Dr. Samuel Haughton (1821-1897).

In 1873, Samuel Haughton published Principles of Animal Mechanics. Based on research begun in 1862, it was a response to Darwin's The Origin of Species by Means of Natural Selection published three years earlier. In this article, the nature of Haughton's biomechanical researches is described by reviewing and re-analysing some of his original work. He showed how muscles could be seen as designed to carry out the maximum amount of work with the least expenditure of energy. Haughton used the results to argue against Darwin's theory of natural selection, the "unproved hypothesis" as Haughton called it. Despite correspondence with Darwin, Haughton received no scientific rebuttal of his arguements. To this day, it would seem, there is a lack of concordance between the biomechanical view of organic life as "optimised" and the evolutionary view of life under continual transformation as organic forms descended "from a supposed common ancestor."

Biological Evolution↗
PubMed2002

[TNF-related apoptosis-inducing ligand signaling pathway and hematopoietic malignancies].

TNF-related apoptosis-inducing ligand (TRAIL) is a newly identified member of the tumor necrosis factor (TNF) family. TRAIL induces apoptosis by activating caspase cascades, stimulating a loss of mitochondrial membrane potential (Delta Psim) and cytochrome C release in the FADD/caspase-8 dependent pathway. However, TRAIL can also trigger transcriptional activations of the pro-oncogene of c-fos, JNK, and NF-kappaB by other signaling pathways downstream of FADD/caspase-8. MAPK/ERK activation has a dominant protecting effect over apoptotic signaling from the death receptors. The functional expression of TRAIL by leukemic cells may be involved in tumor cells evasion of immunosurveillance. Somatic mutations of TRAIL-R1 and TRAIL-R2 genes may play a role in the pathogenesis of some tumors. TRAIL can induce apoptosis on various continuous transformed cell lines and primary tumor cells, including several of hematopoietic origin, displaying minimal toxic effects on normal tissues. Because of the abilities of induction of both cytotoxic (apoptosis) and cytostatic (cell cycle perturbation) effects on the leukemic cells, TRAIL is currently considered as a potential(co) therapeutic drug against tumors.

Animals↗
PubMed1992

The NZB mouse as a model for chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world and the only leukemia for which a possible genetic component has been described. Analysis of this genetic component has been hindered by the fact that disease onset normally occurs after age 50. We report here the aged NZB mouse as an animal model for CLL. NZB mice have a genetically regulated, age-dependent onset of clonal, aneuploid cells which are IgM+ and Ly1+ (CD5+ B-cells). Peripheral blood smears from old NZB mice show an increase in circulating lymphocytes and "smudged" or ruptured cells, often seen in human CLL. Electron microscopic examination of these cells shows them to be mature lymphocytes. Light microscopy of the spleen shows infiltration of small lymphocytes and is consistent with CLL pathology. These long-lived, CLL-like cells can be serially passaged into recipient animals. This continued passage occasionally results in the development of a large cell lymphoma detectable in the spleen, lymph nodes, and liver. The histology of this lymphoma is quite distinct from that of the CLL-like cells, but the phenotype is that of an aneuploid CD5+, IgM+ cells. This apparently represents a continued transformation of the CLL-like clone similar to the development of Richter's syndrome in human CLL. Therefore, the NZB mouse can be a valuable tool for the determination of the genetic basis of CLL ontogeny and the conversion of CLL into Richter's syndrome.

Age Factors↗
PubMed2004

The challenge of leadership in technology and education.

The leadership qualities necessary today in technology, education, and other modern organizations include the ability to recognize rapid changes in organizational environments and ensure continuous transformation and adaptability to that change. The important skills of such leaders include understanding their own business, articulating vision, creating a positive culture, communicating effectively, and measuring results. Rapidly emerging technology is prone to misunderstanding by those who mistake the surface features of how technology works with the functional opportunities it provides. Organizations that transform processes in parallel by adopting new technologies can expect much larger productivity gains than can those who merely insert technology. The problems of memory, speed, and cost have been addressed; the new challenge of technology is making it universal. Education in America is in danger. The infrastructure is outdated and it is not oriented toward change. Jobs will follow competence. Although the challenges of leadership today, especially in technology and education, are great, so is the opportunity for impact and the excitement of bringing diverse skills to bear.

Administrative Personnel↗
PubMed2005

The revolution in advanced wound-care converting.

In the advanced wound-care sector, there is an accelerating trend away from serial batch production towards transformational, continuous and integrated process lines. This is creating new standards and challenges in converting processes, which run faster, produce less waste and require fewer operators to run them. This article identifies those challenges and highlights the increasing importance of the relationship between wound-care manufacturer, materials science and the design of the converting process.

Bandages↗
PubMed1991

The ability of the epithelium of diencephalic origin to differentiate into cells of the ocular lens.

After the discovery that in adult salamanders following lentectomy a new, functional lens develops by transdifferentiation (cell-type conversion) of previously depigmented epithelial cells of the iris (Wolffian lens regeneration), this phenomenon has been intensively studied by various experimental approaches. During the last two decades it was shown that pleiomorphic aggregates of atypical lens cells (lentoids) differentiated in reaggregates of dissociated cells of the chick neural retina and in spread cell cultures of the pigmented epithelium of the iris and retina, of the neural retina and the pineal gland of the chick embryo. The neural retina of human fetuses and adults also displayed this capacity. We showed that lentoids developed at a low incidence in renal isografts of rat embryonic shields or isolated embryonic ectoderm and of lentectomized eyes of rat fetuses, as well as in organ cultures of rat embryonic shields in chemically defined media. The addition of transferrin significantly increased the incidence of differentiation of lentoids in explants. In both renal isografts and explants in vitro a continuous transformation of retinal epithelial cells into atypical lens cells was observed. In renal isografts lentoids were also observed to originate from the ependyma of the brain ventricle. All tissues having the capacity to convert into lens cells belong to the diencephalon in a broad sense. Evolutionary aspects of this feature are discussed.

Animals↗
PubMed1990

Self-analysis: a fool for a patient?

In this paper I first reviewed the scanty publications on the subject of self-analysis. Although it was recommended by Freud as early as 1910 for every analyst, self-analysis turns out to have many pitfalls and to be quite a complicated and controversial procedure. There is no agreement on the proper technique of self-analysis in the literature, nor is there any discussion of the determinants of the particular choice of technique of self-analysis that is employed, nor even of the reasons why some analysts do not engage in it at all. Using clinical data gathered from written material of many years of self-analysis following the termination of a successful training psychoanalysis, I have attempted to elucidate some of the problems posed by this procedure. These problems are in some ways similar to formal psychoanalysis, but are in some ways contingent on the fact that it is basically a different technique. It is a solitary occupation and therefore suffers from the dangers of disintegration into autism, narcissism, and obsessional rumination. There is no living presence of an analyst to serve either as a transference figure or to make interpretations and stimulate the production of material. The identification with the analyst's analyzing function is far from simple in self-analysis because of the complex nature of the various internalizations of the analyst that take place over years of a formal training analysis. Thus, Ticho (1967) is correct when she claimed that self-analysis is a skill that the analysand has to acquire by himself or herself. An important phase of the beginning of self-analysis involves the working through of the separation from the psychoanalyst and the re-evaluation of the analyst and the analytic process. This results in a heightened sense of independence and autonomy, increased cohesion of the self, and maturation--which is manifested by greater autonomous ego functioning, a more mature sense of identity, and continued transformations of narcissism which highly valuable goals, on the basis of the data I have presented, can be approached through the process of self-analysis. Above all this stands the most important goal of self-analysis, the understanding of one's countertransference reactions. This is especially important in the treatment of seriously disturbed patients who become disruptive, and thus get labeled borderline, often as a response to unconscious countertransference manifestations from the analyst which are then experienced in the self-object transference as failures in empathy.(ABSTRACT TRUNCATED AT 400 WORDS)

Conflict, Psychological↗
PubMed1987

[Human papillomavirus infection and carcinogenesis of cancer of the uterine cervix. I. Pathomorphology of 357 cervical tissues].

Human papillomavirus (HPV) infection in the cervix was studied by pathomorphology for the first time in China according to Meisels and Fortin's criteria. Cervical condyloma was found in 257 out of 357 (71.99%) cervical tissues. 141 were simple condyloma, 50 dysplasia with condyloma and 66 carcinoma with condyloma. A zone of continuous transformation was observed between the condyloma and dysplasia or carcinoma. 141 simple condylomas were initially diagnosed as chronic cervicitis in 94 (66.67%) and as dysplasia in 29 (20.57%). The pathomorphologic features of condyloma have not been fully recognized before. In carcinogenesis of the cervical carcinoma, the fact that condyloma associated becomes severer in extent but less in incidence, conforms well to Meisels' view that condyloma is the precursor of carcinoma in situ. It is suggested that HPV infection is closely related to cervical carcinoma.

Biopsy↗
PubMed1987

[Human papillomavirus infection and carcinogenesis of cancer of uterine cervix. II. Immunoperoxidase localization of papilloma-virus antigen in tissues of the uterine cervix].

244 cervical tissue specimens with different diagnoses were stained by peroxidase-anti-peroxidase technique (PAP) for assay of the human papillomavirus (HPV) genus-specific antigen, the first of its kind performed in China. HPV antigen was detected in 41.93% of simple condyloma group, in 35.29% of dysplasia with condyloma and in 27.27% of carcinoma with condyloma. There was no positive in the control, dysplasia or carcinoma groups. The antigen positive nuclei were found in the koilocytes or parakeratosis cells in the upper layers of the epithelium. The severer the condyloma, the higher the positive rate of antigen. In the severe condyloma group, the positive rate was as high as 64.71%. The koilocytes were observed in every HPV antigen positive section. In view of the coexistence and continuous transformation of condyloma, dysplasia and carcinoma in pathomorphology, these results provide an important evidence to the further studies on the relation between HPV infection and carcinogenesis of cancer of uterine cervix.

Antigens, Viral↗
PubMed1994

A cultured malignant B-1 line serves as a model for Richter's syndrome.

Human chronic lymphocytic leukemia (CLL) is a malignancy of B-1 cells characterized by the accumulation of mature appearing, long lived, slow growing B-1 cells in peripheral blood. CLL occasionally evolves into an aggressive large cell lymphoma termed Richter's syndrome. NZB mice can be used to model the early stage of CLL because aged NZB mice can spontaneously develop slow growing malignant B-1 cell clones. The malignant NZB B-1 clones fail to grow in culture and are typically carried in vivo as passaged lines. During serial passage, an aggressive lymphoma developed as a result of a continued transformation of the original B-1 clone, similar to the development of Richter's syndrome. An in vitro cell line was established from the aggressive lymphoma, which was stromal dependent and could rapidly metastasize when passaged into recipient animals. Analysis of adhesion molecules did not reveal any consistent characteristics that could account for the metastatic potential of the Richter's-like cells. In addition, the aggressive in vitro line had the identical heavy chain sequence as the slow growing NZB malignant B-1 clones. The in vitro and in vivo aggressive B-1 cells had very high levels of IL-10 message, and underwent more apoptosis in response to anti-IgM than did nonaggressive B-1 clones. Taking these characteristics together, we have composed a comprehensive animal model system for human CLL that includes both the aged NZB mice for the early stage and the recipients of the in vitro B-1 line for the late stage or Richter's syndrome. This model system can be used to study, not only the ontogeny and genetic linkage of CLL, but also the regulatory factors involved in transformation and growth both in vivo and in vitro.

Animals↗
PubMed1993

[Interaction of the world of dreams and wakefulness].

While we are dreaming the dream is the world. This reality is extinguished when we wake up. At the same time we recognize parts of the world of wakefulness in the things we dreamed about. Both worlds merge, and each in doing so interprets the other. Interpreting dreams is like drawing out these perspectives. This is shown here with examples from a series of dreams. They are woven into the biography of the dreamer and continually transform the traces of his world. The illustrations serve to visualize the elements of the world of wakefulness and of history, which reappear in a changed form in the dream.

Dreams↗
PubMed1996

[What does health care mean?].

The important problem of the contemporary health care is the financial and organizational coping with the continuing transformation of the society as a whole. There is no doubt that from the long term point of view, the questions concerning the ethos of health care are essential, are worth asking, and should become a matter of interest for health professionals and the public.

Czech Republic↗
PubMed1998

Transient patterns of organization of the human fetal brain.

Fetal development of the human brain is characterized by continuous transformations and reorganization of the fetal telencephalic wall which consists of transient, cytoarchitectonically defined cellular compartments, the so-called embryonic/fetal zones. The cellular and fiber content of these zones is permanently changing, so that fetal neuronal circuitry elements (afferent fibers, synapses, and postsynaptic neurons) display transient patterns of areal, laminar, and modular organization. In the late human fetus and preterm infant, transient patterns of structural and physiological organization form the basis of transient behavioral states and patterns of activity. The transient subplate zone is a key compartment for transient fetal neuronal circuitry, and competitive cellular interactions within the subplate zone are crucial for the areal specification of the cerebral cortex and the formation of cortical connectivity. The subplate zone may also have a key role in cortical repair and plasticity after perinatal brain lesions.

Brain↗
PubMed2006

Improved peak detection in mass spectrum by incorporating continuous wavelet transform-based pattern matching.

MOTIVATION: A major problem for current peak detection algorithms is that noise in mass spectrometry (MS) spectra gives rise to a high rate of false positives. The false positive rate is especially problematic in detecting peaks with low amplitudes. Usually, various baseline correction algorithms and smoothing methods are applied before attempting peak detection. This approach is very sensitive to the amount of smoothing and aggressiveness of the baseline correction, which contribute to making peak detection results inconsistent between runs, instrumentation and analysis methods. RESULTS: Most peak detection algorithms simply identify peaks based on amplitude, ignoring the additional information present in the shape of the peaks in a spectrum. In our experience, 'true' peaks have characteristic shapes, and providing a shape-matching function that provides a 'goodness of fit' coefficient should provide a more robust peak identification method. Based on these observations, a continuous wavelet transform (CWT)-based peak detection algorithm has been devised that identifies peaks with different scales and amplitudes. By transforming the spectrum into wavelet space, the pattern-matching problem is simplified and in addition provides a powerful technique for identifying and separating the signal from the spike noise and colored noise. This transformation, with the additional information provided by the 2D CWT coefficients can greatly enhance the effective signal-to-noise ratio. Furthermore, with this technique no baseline removal or peak smoothing preprocessing steps are required before peak detection, and this improves the robustness of peak detection under a variety of conditions. The algorithm was evaluated with SELDI-TOF spectra with known polypeptide positions. Comparisons with two other popular algorithms were performed. The results show the CWT-based algorithm can identify both strong and weak peaks while keeping false positive rate low. AVAILABILITY: The algorithm is implemented in R and will be included as an open source module in the Bioconductor project.

Algorithms↗
PubMedDate not supplied

[Inhibitory effect of remantadine hydrochloride on oncornavirus production and transformation of a continuous culture of mouse leukemia cells].

20-methylcholantrene in a concentration of 5 micrograms/ml and exposure for 72 hours as well as in a concentration of 2.5 micrograms/ml and exposure for 72 and 240 hours caused transformation of a continuous mouse leukemia cell culture producing Rauscher leukemia virus. Remantadine hydrochloride in non-toxic concentrations (12.5 and 6.25 micrograms/ml) decreased infectious virus production by cells of this culture and prevented its transformation by 20-methylcholantrene for 6 months.

Adamantane↗
PubMed1983

Long-term cultivation of amphibian melanophores. In vitro ageing and spontaneous transformation to a continuous cell line.

Pure melanophore populations isolated from the tail skin of the tadpole, Rana catesbeiana, were mass cultured for a period of 2-3 years. All cell lines of amphibian melanophores studied exhibited growth crisis (in vitro ageing) followed by spontaneous transformation to a continuous cell line, as shown by changes in growth characteristics in mass culture and in clone culture, by the appearance of the cells, and by measurements of cell volumes. Even after becoming a continuous cell line, amphibian melanophores continued to have a diploid chromosome number (2n = 26) in three of four cell lines examined. The chromosome mode in one cell line, however, changed to thirty. Measurement of melanin dispersion after the addition of alpha-melanocyte-stimulating hormone suggested that the mechanism for melanin dispersion in melanophores changed during in vitro ageing.

Adrenocorticotropic Hormone↗