Evaluation of noncytotoxic DNMT1-depleting therapy in patients with myelodysplastic syndromes.

BACKGROUND: Mutational inactivation in cancer of key apoptotic pathway components, such as TP53/p53, undermines cytotoxic therapies that aim to increase apoptosis. Accordingly, TP53 mutations are reproducibly associated with poor treatment outcomes. Moreover, cytotoxic treatments destroy normal stem cells with intact p53 systems, a problem especially for myeloid neoplasms, as these cells reverse the low blood counts that cause morbidity and death. Preclinical studies suggest that noncytotoxic concentrations of the DNA methyltransferase 1 (DNMT1) inhibitor decitabine produce p53-independent cell-cycle exits by reversing aberrant epigenetic repression of proliferation-terminating (MYC-antagonizing) differentiation genes in cancer cells. METHODS: In this clinical trial, patients with myelodysplastic syndrome (n=25) received reduced decitabine dosages (0.1-0.2 mg/kg/day compared with the FDA-approved 20-45 mg/m2/day dosage, a 75%-90% reduction) to avoid cytotoxicity. These well-tolerated doses were frequently administered 1-3 days per week, instead of pulse cycled for 3 to 5 days over a 4- to 6-week period, to increase the probability that cancer S-phase entries would coincide with drug exposure, which is required for S-phase-dependent DNMT1 depletion. RESULTS: The median subject age was 73 years (range, 46-85 years), 9 subjects had relapsed disease or were refractory to 5-azacytidine and/or lenalidomide, and 3 had received intensive chemoradiation to treat other cancers. Adverse events were related to neutropenia present at baseline: neutropenic fever (13 of 25 subjects) and septic death (1 of 25 subjects). Blood count improvements meeting the International Working Group criteria for response occurred in 11 of 25 (44%) subjects and were highly durable. Treatment-induced freedom from transfusion lasted a median of 1,025 days (range, 186-1,152 days; 3 ongoing), and 20% of subjects were treated for more than 3 years. Mutations and/or deletions of key apoptosis genes were frequent (present in 55% of responders and in 36% of nonresponders). Noncytotoxic DNMT1 depletion was confirmed by serial BM γ-H2AX (DNA repair/damage marker) and DNMT1 analyses. MYC master oncoprotein levels were markedly decreased. CONCLUSION: Decitabine regimens can be redesigned to minimize cytotoxicity and increase exposure time for DNMT1 depletion, to safely and effectively circumvent mutational apoptotic defects. TRIAL REGISTRATION: Clinicaltrials.gov NCT01165996. FUNDING: NIH (R01CA138858, CA043703); Department of Defense (PR081404); Clinical and Translational Science Award (CTSA) (UL1RR024989); and the Leukemia and Lymphoma Society (Translational Research Program).

Getting the measure of the patient experience.

Enhanced recovery uses evidence-based interventions to improve the perioperative care of patients undergoing major surgery. Due to the relative lack of research into patient experience, Central Manchester Foundation Trust distributed a questionnaire to measure the experience of patients cared for on a colorectal ER pathway. Overall, results were favourable, and described good pain management and high-quality care provided by the enhanced recovery team. This article describes how the results will be used to shape services in the future.

Tributyltin and the obesogen metabolic syndrome in a salmonid.

We conducted a dietary feeding study with juvenile chinook salmon (Oncorhynchus tshawytscha) to assess the potential for tributyltin (TBT) to elicit the obesogen response that has been described for mammals. The results show increases in whole-body lipid content, which is consistent with the obesogen response; however, we also observed associated parameters that were dissimilar. We found increases in body mass and alterations to several physiological parameters at doses between 0.4 and 3.5 ng/g fish/day (1.4-12 pmol/g fish/day) and reduced body mass at the highest dose after 55 days of exposure. Lipid related plasma parameters (plasma triacylglycerols, cholesterol, and lipase) exhibited monotonic increases over all doses while other values (glucose and insulin-like growth factor (IGF)) exhibited increases only for the low-dose treatments. The increases noted for several parameters in fish were opposite to those reported for the obesogen metabolic syndrome, which is characterized by a reduction in serum glucose, free fatty acids, and triglycerides. This is the first report of growth stimulation resulting from low-dose exposure to this pesticide, which is an unusual response for any animal exposed to an organic or organometallic xenobiotic. Because a number of environmental contaminants act as metabolic disruptors at very low doses, these results are noteworthy for a variety of species. Intuitively, enhanced growth and lipid storage may appear beneficial; however, for salmonids there are numerous potentially negative consequences for populations.

Postprandial changes in plasma growth hormone, insulin, insulin-like growth factor (IGF)-I, and IGF-binding proteins in coho salmon fasted for varying periods.

We examined postprandial changes in circulating growth hormone (GH), insulin, insulin-like growth factor (IGF)-I, and IGF-binding proteins (IGFBPs) in yearling coho salmon under different feeding regimes. Fish were initially fasted for 1 day, 1 wk, or 3 wk. Fasted fish were then fed, and blood was collected at 4-h intervals over 26 h. After the various periods of fasting, basal levels of insulin were relatively constant, whereas those of IGF-I, IGFBPs and GH changed in proportion to the duration of the fast. A single meal caused a rapid, large increase in the circulating insulin levels, but the degree of the increase was influenced by the fasting period. IGF-I showed a moderate increase 2 h after the meal but only in the regularly fed fish. Plasma levels of 41-kDa IGFBP were increased in all groups within 6 h after the single meal. The fasting period did not influence the response of 41-kDa IGFBP to the meal. IGFBP-1 and GH decreased after the meal to the same extent among groups regardless of the fasting period. The present study shows that insulin and IGF-I respond differently to long (weeks)- and short (hours)-term nutritional changes in salmon; insulin maintains its basal level but changes acutely in response to food intake, whereas IGF-I adjusts its basal levels to the long-term nutritional status and is less responsive to acute nutritional input. IGFBPs maintain their sensitivity to food intake, even after prolonged fasting, suggesting their critical role in the nutritional regulation of salmon growth.

Androgen effects on plasma GH, IGF-I, and 41-kDa IGFBP in coho salmon (Oncorhynchus kisutch).

Among many species of salmonids, fast growing fish mature earlier than slow growing fish, and maturing males grow faster than non-maturing ones. To study the potential endocrine basis for this reciprocal relationship we examined the in vivo effects of the androgens, testosterone (T) and 11-ketotestosterone (11-KT), on plasma growth hormone (GH), insulin-like growth factor-I (IGF-I) and 41-kDa IGF binding protein (41-kDa IGFBP) (putative IGFBP-3) in coho salmon, Oncorhynchus kisutch. Immature male and female, two-year old fish (avg. wt. 31.7 +/- 0.63 g) were injected with coconut oil containing T or 11-KT at a dose of 0.1, 0.25, or 1 microg/g body weight. Blood samples were taken 1 and 2 weeks postinjection, and analyzed by immunoassay for T, 11-KT, GH, IGF-I, and 41-kDa IGFBP. Steroid treatments elevated the plasma T and 11-KT levels to physiological ranges typical of maturing fish. Plasma IGF-I and 41-kDa IGFBP levels increased in response to both T and 11-KT in a significant and dose-dependent manner after 1 and 2 weeks, but GH levels were not altered. These data suggest that during reproductive maturation, in addition to the previously demonstrated effects of the IGFs on steroidogenesis, the gonadal steroids may in turn play a significant role in regulating IGF-I and its binding proteins in fish. The interaction between the reproductive and growth axes may provide a regulatory mechanism for bringing about the dimorphic growth patterns observed between maturing and non-maturing salmonids and other species of fish.

Response of the somatotropic axis of juvenile coho salmon to alterations in plane of nutrition with an analysis of the relationships among growth rate and circulating IGF-I and 41 kDa IGFBP.

The effect of different feeding levels on plasma levels of insulin-like growth factor-I (IGF-I), 41 kDa insulin-like growth factor binding protein (41 kDa IGFBP), and growth hormone (GH) were assessed in post-smolt coho salmon. Fish were fed at either stable (1 and 2% body weight/day) or varying (1-0.5-1%, 2-0.5-2% body weight/day) feeding rates and plasma was sampled from 10 fish/treatment at 2-3 week intervals over five dates from June to September, resulting in a total of 200 samples. Fish fed at higher rates grew faster and had higher plasma IGF-I and 41 kDa IGFBP levels. Plasma GH levels were variable but generally showed an inverse relationship to feeding rate. Both plasma IGF-I and 41 kDa IGFBP increased seasonally, average IGF-I levels doubled from June to September, regardless of feeding rate. On any one date both IGF-I and 41 kDa IGFBP were highly related to growth rate with regression coefficients ranging from 0.36 to 0.68 (IGF-I) and from 0.33 to 0.70 (41 kDa IGFBP). No relationship was found between IGF-I:41 kDa IGFBP ratio and individual growth rate. Overall, both feeding rate and date were important in explaining variation in IGF-I and 41 kDa IGFBP levels.

Microarray screening of lymphocyte gene expression differences in a multiplex schizophrenia pedigree.

In order to help prioritize the selection of candidate genes and to study possible trait and not state related changes in gene expression, we compared lymphocytic gene expression patterns of five individual family members with schizophrenia and nine unaffected individuals from a large multiplex high density pedigree. We screened gene expression by microarray consisting of 1128 brain focused genes. Three criteria for selection of microarray gene differences between schizophrenia and unaffected family members were employed: a significant t-test, expression in a majority of subjects, and fold change magnitude. Gene expression levels were significantly different for nine genes between individuals with schizophrenia compared to unaffected controls, and two genes were validated by real-time PCR. The expression of the neuropeptide Y receptor Y1 gene (NPY1R localized at 4q31.3-q32) and the human guanine nucleotide-binding regulatory protein Go-alpha (GNAO1 localized at 16q13) was significantly decreased in individuals with schizophrenia compared to unaffected family controls by microarray and real-time PCR. The cytosolic malate dehydrogenase gene (MDH1 localized at 2p13.3) was also significantly increased by microarray analysis and showed a trend for increase by real-time PCR. The significant genes are discussed in terms of proximity to linkage regions, prior association studies of schizophrenia, and other reports of microarray screening of schizophrenia tissue. Evidence from these studies taken together with the present study suggests critical pathways in schizophrenia may be studied in peripheral tissue as part of the strategy in functional genomic convergence. This preliminary study needs to be repeated by screening a larger set of genes in additional families with schizophrenia. The present study offers support for examination of gene expression patterns using lymphocytic RNA for complex neuropsychiatric disorders from large cohorts of patients.

Improving the health and well-being of adolescent boys.

Adolescent men are at risk of having significant unmet health care needs. Like adolescent girls, they have complex health care needs and are more likely than younger children to be to be uninsured. They are less likely than women and other age groups to seek medical attention from traditional sources of care. Because of inadequate youth-oriented services, as well as teens' developmental stage, they have a tendency to receive care that is brief and problem oriented [20]. Such care is not likely to address complex problems that may be related to risk behaviors. Adolescent boys are also more concerned with the skills of the provider offering services than with the system in which the provider functions. Opportunities for outreach to adolescent men exist within many institutions. Nurses as advocates, educators, counselors, and providers of preventive health care have a creative opportunity for enhancing services to the teenage boy. The school is a natural place to begin as adolescents spend a significant part of each day there. Family planning and STI clinics are a source of care that are not well used by adolescent males, but when they do attend it is an opportunity to identify problems, provide counseling and referrals, and offer continuity. These health care institutions are not often welcoming or comfortable for the male youth. Use of these clinics will be enhanced by providers demonstrating increased acceptance of the adolescent when he attends as well as actively requesting that he attend with his partner. The most unusual but sorely needed outreach must be made to incarcerated and delinquent adolescent male. Residential facilities for delinquent youth need to be encouraged to provide a multidisciplinary comprehensive medical, mental health, and social services model. This approach will not only benefit the adolescent but the youth's community as well. Emergency rooms represent another crucial, missed opportunity to connect with young men. With some forethought and follow-up, emergency departments must become connected to appropriate and accessible adolescent primary care resources in the community. Finally, adolescent men are an underinsured population. Nurses can be important advocates of available state insurance funds, sliding scale or free services to youth, and must be a voice in youth policy-making.