Caregivers of frail elderly and medically fragile children: perceptions of ability to continue to provide home health care

The purposes of this study were to compare the characteristics and support systems of caregivers of frail elderly and medically fragile children and to determine what factors discriminated between caregivers who could (and could not) continue to provide home health care. Caregivers of children were significantly more likely (chi 2 = 52.30)2), p = < .0000) to report that they were managing OK than caregivers of frail elderly. They also reported receiving more support and assistance from formal and informal sources, although in general, less than 30% of the caregivers received any help. Five variables (Mental impairment of the elder, poor physical and mental health of the caregiver, high monthly caregiving-related expenses, and use of paid in-home assistance) explained 35% of the variance between caregivers of frail elderly who were managing OK and those who were unable to continue to manage. Six variables (physical and mental impairment of the child, physical health of the caregiver, feeling like there were no alternative providers, time demand and lack of assistance from others) explained 26.57% of the variance between caregivers of children who were managing OK and those who were unable to continue to manage. The findings suggest that a strong objective stressor, combined with a lack of personal and social resources are associated with caregivers' perceptions that they cannot continue to manage home health care.     

Lack of microsatellite instability in human prostate-cancer

DNA replication errors are especially frequent in repetitive DNA sequences, including microsatellites. Thus, microsatellites are sensitive indicators of the genetic instability observed in many types of human cancers, particularly colorectal cancer. We tested prostate carcinomas for the presence of microsatellite alleles not present in normal tissue from the same individuals. Analysis of 7 microsatellites in each of 30 patients revealed instability at only one microsatellite in one tumor. This level of microsatellite instability, considerably lower than that reported previously, may reflect differences in patient pools. We discuss the implications of the genetic stability of prostate cancers relative to other cancers.     

Phenotypes of invasion in sporadic colorectal carcinomas related to aberrations of the adenomatous polyposis coli (APC ) gene

AIMS: To determine whether the dissociation of tumour cells from neoplastic glands in colorectal carcinomas is caused by disruption of the wnt-signalling pathway and whether the adenomatous polyposis coli (APC) protein is implicated in this. METHODS AND RESULTS: In a series of 99 clinically sporadic colorectal carcinomas, APC exon 15 mutations, loss of heterozygosity (LOH) and promoter methylation were found in 49, 20 and 23 cases, respectively. Singly, these APC aberrations were not associated with the degree of tumour cell dissociation, but dissociation was higher for the cases with combined APC mutation and LOH. Immunohistochemical beta-catenin translocation to the nucleus correlated with APC aberrations. Tumour growth pattern (expansive/infiltrative/diffuse) and tumour stroma (desmoplastic common-type versus keloid-like) showed a statistically significant association with tumour cell dissociation and with beta-catenin translocation. Of other molecular alterations tested (p53 mutation; LOH at 17p13, 18q, 9p21; CpG island methylator phenotype), only the highly microsatellite unstable status (n = 11) was negatively associated. CONCLUSIONS: In colorectal carcinomas, wnt dysregulation relates to APC aberrations, but wnt dysregulation and APC aberrations are not strictly required for tumour cell dissociation, and additional and/or alternative factors must play a role. Of these, outside-in signalling by cancer cell-matrix interactions, as partially mirrored in histomorphological features, could be important.     

High-degree tumor budding and podia-formation in sporadic colorectal carcinomas with K-ras gene mutations

In vitro ras activation enhances the epithelial-mesenchymal transition of colorectal carcinoma cells. But ras effects are known to be highly dependent on cell types and the tissue context. Therefore, this study was made to test the hypothesis that in clinical colorectal carcinoma specimens, aggressive invasion phenotypes, specifically tumor budding and podia formation, would correlate with K-ras gene mutations. In a series of 95 clinically sporadic primary colorectal carcinomas collected ad hoc, tumor budding and podia formation were counted using pan-cytokeratin immunohistochemistry, and K-ras gene mutations in codons 12 and 13 were determined. Consistent with the hypothesis, tumor budding and podia formation were observed to be significantly higher in the 32 (34.7%) of the tumors with K-ras gene mutations (29 mutations in codon 12, 3 in codon 13), and this correlation was observed independent of the patterns of invasion (expansive versus infiltrative). Microsatellite status, numbers of losses of heterozygosity, adenomatous polyposis coli and p53 gene mutations, and degree of promoter methylations (CIMP status) were not associated with K-ras gene mutations. Besides their effects on the tumor cell cycles, oncogenic K-ras gene mutations in colorectal carcinomas could be important for aggressive tumor invasion. This may be important in metastasizing disease and could provide a rationale for developing drugs that interrupt ras-signaling cascades.