Efficacy and safety of initial combination treatment with sitagliptin and pioglitazone--a factorial study.

AIM: To evaluate the efficacy and safety of initial combination therapy of sitagliptin 100 mg/day coadministered with all marketed doses of pioglitazone in patients with type 2 diabetes. METHODS: Patients with A1c ≥7.5 and ≤11.0% were randomized among seven arms that received, once daily, 100 mg sitagliptin alone; 15, 30 or 45 mg pioglitazone alone, or 100 mg sitagliptin plus 15, 30 or 45 mg pioglitazone for 54 weeks. The primary endpoint was change from baseline in A1c at week 24. Protocol-specified analyses compared combination therapies with monotherapies at respective dose-strengths and combination of sitagliptin plus pioglitazone 30 mg with pioglitazone 45 mg monotherapy. Post-hoc analyses compared sitagliptin plus pioglitazone 15 mg with pioglitazone monotherapy at the two higher doses. RESULTS: Initial combination therapy with sitagliptin and pioglitazone provided significantly greater reductions in A1c (0.4-0.7% differences) and other glycaemic endpoints than either monotherapy at the same doses. Combining sitagliptin with low-dose pioglitazone generally produced greater glycaemic improvements than higher doses of pioglitazone monotherapy (0.3-0.4% differences in A1c). Combination therapy was generally well tolerated; adverse events (AEs) of hypoglycaemia were reported with similar incidence (7.8-11.1%) in all treatment groups over the 54 weeks of study; oedema was reported in 0.5% of patients in the sitagliptin monotherapy group and 2.7-5.3% among pioglitazone-treated groups. Significant weight gain was observed in all combination-treated groups compared with the sitagliptin monotherapy group. CONCLUSIONS: Initial combination therapy with sitagliptin and pioglitazone provided better glycaemic control than either monotherapy and was generally well tolerated.

Bone loss in the oestrogen-depleted rat is not exacerbated by sitagliptin, either alone or in combination with a thiazolidinedione.

Antihyperglycaemic therapy on bone was evaluated in the ovariectomized (OVX), non-diabetic adult rat. Animals were treated daily for 12 weeks with various doses of sitagliptin, pioglitazone, rosiglitazone, combinations of sitagliptin with pioglitazone or vehicle alone. Sitagliptin target engagement was confirmed by assessing inhibition of plasma dipeptidyl peptidase-4 (DPP-4) and oral glucose tolerance. Parameters related to bone health were evaluated in femur and vertebrae by dual-energy X-ray absorptiometry and histomorphometry. Bone mineral density (BMD) generally did not differ significantly between OVX-sitagliptin-treated animals and OVX-vehicle controls. In lumbar vertebrae, however, there was significantly less BMD loss with increasing sitagliptin dose. Thiazolidinedione (TZD) treatment generally resulted in lower BMD; OVX-TZD-treated (but not OVX-sitagliptin-treated) animals also had lessened cortical thickness in central femur and profoundly greater bone marrow adiposity in lumbar vertebrae. These findings support prior findings with TZDs and suggest a neutral or beneficial impact of DPP-4 inhibition on bone health.

Chronic treatment with a glucokinase activator delays the onset of hyperglycaemia and preserves beta cell mass in the Zucker diabetic fatty rat.

AIMS/HYPOTHESIS: Glucokinase activators (GKAs) are currently being developed as new therapies for type 2 diabetes and have been shown to enhance beta cell survival and proliferation in vitro. Here, we report the effects of chronic GKA treatment on the development of hyperglycaemia and beta cell loss in the male Zucker diabetic fatty (ZDF) rat, a model of type 2 diabetes with severe obesity. METHODS: Cell protection by GKA was studied in MIN6 and INS-1 cells exposed to hydrogen peroxide. Glucose homeostasis and beta cell mass were evaluated in ZDF rats dosed for 41 days with Cpd-C (a GKA) or glipizide (a sulfonylurea) as food admixtures at doses of approximately 3 and 10 mg kg(-1) day(-1). RESULTS: Incubation of MIN6 and INS-1 832/3 insulinoma cell cultures with GKA significantly reduced cell death and impairment of intracellular NADH production caused by exposure to hydrogen peroxide. Progression from prediabetes (normoglycaemia and hyperinsulinaemia) to overt diabetes (hyperglycaemia and hypoinsulinaemia) was significantly delayed in male ZDF rats by in-feed treatment with Cpd-C, but not glipizide. Glucose tolerance, tested in the fifth week of treatment, was also significantly improved by Cpd-C, as was pancreatic insulin content and beta cell area. In a limited immunohistochemical analysis, Cpd-C modestly and significantly enhanced the rate of beta cell proliferation, but not rates of beta cell apoptosis relative to untreated ZDF rats. CONCLUSIONS/INTERPRETATION: These findings suggest that chronic activation of glucokinase preserves beta cell mass and delays disease in the ZDF rat, a model of insulin resistance and progressive beta cell failure.

Evaluating an intensive ward-based writing coach programme to improve nursing documentation: lessons learned.

AIM: This study aimed to develop a ward-based writing coach programme to improve the quality of patient information in nursing documentation. BACKGROUND: Omissions in the patient information make nursing notes an unreliable source for care planning. Strategies to improve the quality of nursing documentation have been unsuccessful. An education programme, with one-to-one coaching in the clinical environment, was tested. METHOD: A concurrent mixed methods approach including a pre-post test intervention and control design for the quantitative component combined with a qualitative approach using a focus group (eight nurses) was used. Healthcare records for 87 patients (intervention) (46 pre and 41 post) and 88 patients (control) (51 pre and 37 post) were reviewed using the Nursing and Midwifery Content Audit Tool for quality nursing documentation. Sixteen nurses from two intervention wards participated in an introductory workshop with 2 weeks of coaching. No intervention was given to the control ward. RESULTS: No significant differences were found between the wards across the 14 criteria representing quality documentation; most criteria were present in 75% or more of the records. Improvements were demonstrated in both the intervention and comparison units. Themes identified from the focus groups included the impact these changes had on nurses and patients, perceived difficulties with nursing documentation, medicolegal aspects and the attributes of an effective writing coach. CONCLUSION: Writing coaching is a supportive approach to improving nursing documentation. Also, regular auditing prompts nurses to improve nursing documentation. Further research using larger sample sizes can further confirm or refute these findings.

Human keratinocytes contain mRNA indistinguishable from monocyte interleukin 1 alpha and beta mRNA. Keratinocyte epidermal cell-derived thymocyte-activating factor is identical to interleukin 1.

Keratinocytes produce an IL-1 like factor termed epidermal cell-derived thymocyte-activating factor (ETAF). In this study, we show that ETAF and IL-1 are identical by the following criteria: Both normal and malignant human keratinocytes contain mRNAs identical to monocytic IL-1 alpha and IL-1 beta mRNA, as determined by an S1 nuclease protection assay; and IL-1 activity in medium conditioned by these cells can be neutralized by antibodies specific for human IL-1. The IL-1 alpha and IL-1 beta mRNAs can be identified in cultured human keratinocytes in the absence of identifiable stimulation; this basal level of mRNA can be further induced to accumulate with certain defined stimuli. Cultured normal human keratinocytes (HFKs) contain 2-4 times more IL-1 alpha than IL-1 beta mRNA; in contrast, human peripheral blood monocytes contain 10-20 times more IL-1 beta than IL-1 alpha mRNA. The IL-1 activity released by these HFK can be neutralized by an antibody that neutralizes both alpha and beta IL-1, but not by an antibody that neutralizes only IL-1 beta. While human monocytes produce a large excess of IL-1 beta after appropriate stimulation, these data suggest that IL-1 alpha is a major (and may be the predominant) form of IL-1 produced by human keratinocytes.

Genome sequence of the emerging pathogen Helicobacter canadensis.

We determined the genome sequence of the type strain of Helicobacter canadensis, an emerging human pathogen with diverse animal reservoirs. Potential virulence determinants carried by the genome include systems for N-linked glycosylation and capsular export. A protein-based phylogenetic analysis places H. canadensis close to Wolinella succinogenes.

Basic fibroblast growth factor from human keratinocytes is a natural mitogen for melanocytes.

To survive and proliferate in pure culture, human melanocytes require basic fibroblast growth factor (bFGF) and cAMP. Without these factors, even in the presence of serum, the cells die. Melanocytes cultured in the presence of keratinocytes, however, survive for weeks without added bFGF and cAMP. We show here that the growth factor for melanocytes produced by human keratinocytes is bFGF because its activity can be abolished by neutralizing antibodies to bFGF and by a bFGF synthetic peptide that inhibits the binding of the growth factor to its receptor. The melanocyte mitogen in keratinocytes is cell associated and increases after irradiation with ultraviolet B. Northern blots reveal bFGF gene transcripts in keratinocytes but not melanocytes. These studies demonstrate that bFGF elaborated by keratinocytes in vitro sustains melanocyte growth and survival, and they suggest that keratinocyte-derived bFGF is the natural growth factor for normal human melanocytes in vivo.

Treatment preference and recruitment to pediatric RCTs: A systematic review.

BACKGROUND: Recruitment to pediatric randomised controlled trials (RCTs) can be a challenge, with ethical issues surrounding assent and consent. Pediatric RCTs frequently recruit from a smaller pool of patients making adequate recruitment difficult. One factor which influences recruitment and retention in pediatric trials is patient and parent preferences for treatment. PURPOSE: To systematically review pediatric RCTs reporting treatment preference. METHODS: Database searches included: MEDLINE, CINAHL, EMBASE, and COCHRANE.Qualitative or quantitative papers were eligible if they reported: pediatric population, (0-17 years) recruited to an RCT and reported treatment preference for all or some of the participants/parents in any clinical area. Data extraction included: Number of eligible participants consenting to randomisation arms, number of eligible patients not randomised because of treatment preference, and any further information reported on preferences (e.g., if parent preference was different from child). RESULTS: Fifty-two studies were included. The number of eligible families declining participation in an RCT because of preference for treatment varied widely (between 2 and 70%) in feasibility, conventional and preference trial designs. Some families consented to trial involvement despite having preferences for a specific treatment. Data relating to 'participant flow and recruitment' was not always reported consistently, therefore numbers who were lost to follow-up or withdrew due to preference could not be extracted. CONCLUSIONS: Families often have treatment preferences which may affect trial recruitment. Whilst children appear to hold treatment preferences, this is rarely reported. Further investigation is needed to understand the reasons for preference and the impact preference has on RCT recruitment, retention and outcome.

Deficient neurogenesis in forebrain-specific presenilin-1 knockout mice is associated with reduced clearance of hippocampal memory traces.

To examine the in vivo function of presenilin-1 (PS1), we selectively deleted the PS1 gene in excitatory neurons of the adult mouse forebrain. These conditional knockout mice were viable and grew normally, but they exhibited a pronounced deficiency in enrichment-induced neurogenesis in the dentate gyrus. This reduction in neurogenesis did not result in appreciable learning deficits, indicating that addition of new neurons is not required for memory formation. However, our postlearning enrichment experiments lead us to postulate that adult dentate neurogenesis may play a role in the periodic clearance of outdated hippocampal memory traces after cortical memory consolidation, thereby ensuring that the hippocampus is continuously available to process new memories. A chronic, abnormal clearance process in the hippocampus may conceivably lead to memory disorders in the mammalian brain.

A qualitative study of nurses' perceptions of a behavioural strategies e-learning program to reduce interruptions during medication administration.

OBJECTIVES: We sought to evaluate the perceptions of nurses of an e-learning educational program to encourage the use of behavioural strategies-blocking, engaging, mediating, multitasking, and preventing-to reduce the negative effects of interruptions during medication administration. DESIGN: A qualitative design was used to evaluate the impact of this e-learning educational intervention on nurses' behaviour. SETTINGS: Two wards (palliative care and aged care) from two different hospitals within a large local health service within Sydney Australia, were included in the study. These wards were also involved in a cluster randomised trial to test the effectiveness of the program. PARTICIPANTS: A purposive sample participated comprising nine registered and enrolled nurses certified to conduct medication administration, who had reviewed the educational modules. METHODS: Two focus groups were conducted and these sessions were digitally recorded and transcribed verbatim. Thematic analysis identified seven themes. RESULTS: The major themes identified included: perceptions of interruptions, accessing the program, content of the program, impact, maintaining good practice and facilitators and barriers to changing behaviour. CONCLUSIONS: The use of embedded authentic images of patient interruptions and management strategies increased some nurses' perceived use of strategies to manage interruptions. Nurses varied in their perception as to whether they could change their behaviour with some describing change at the individual and ward team levels, while others described patient caseload and other health professionals as a barrier. The use of this innovative educational intervention is recommended for staff orientation, student nurses, medical officers and allied health staff. Further research is required in how this e-learning program can be used in combination with other effective interventions to reduce interruptions.

Autism, early psychosis, and social anxiety disorder: understanding the role of social cognition and its relationship to disability in young adults with disorders characterized by social impairments.

Impairments in social cognition are believed contribute to disability, particularly for disorders characterized by difficulties in social interaction. There has been little transdiagnostic investigation of this across social cognition domains in young adults. A total of 199 young adults diagnosed with autism spectrum disorder (ASD; N = 53), early psychosis (EP; N = 51), and social anxiety disorder (SAD; N = 64) were compared against neurotypical controls (NT; N = 31) on a battery of lower and higher-order and self-report social cognition measures. For both ASD and EP, participants showed impaired performance on all lower-order emotion recognition tasks and one higher-order social cognition test. Self-reports of empathy were reduced in all clinical groups and particularly in ASD. For SAD, despite showing no objective social cognition impairment, self-reported empathy was reduced to the same level as EP. Discriminant analysis revealed that self-reported empathy and lower-order emotion recognition tests provide best capacity to differentiate groups. Regressions predicting disability revealed depression as the strongest predictor across all disability measures. Empathy provided additional predictive value for social disability and social interaction anxiety. Overall, results support a similar social-cognitive development profile across ASD and EP. While self-reported empathy differentiated between groups, discrepancy between objective social cognition test performance and self-reported empathy in the SAD group suggests probable threat-related self-monitoring report biases that likely further influence all group outcomes. As depression and empathy were the most important predictors of disability, regardless of diagnostic group, research is required to explore targeted interventions for difficulties in these domains to reduce disability.

Belief-bias reasoning in non-clinical delusion-prone individuals.

BACKGROUND AND OBJECTIVES: It has been proposed that people with delusions have difficulty inhibiting beliefs (i.e., "doxastic inhibition") so as to reason about them as if they might not be true. We used a continuity approach to test this proposal in non-clinical adults scoring high and low in psychometrically assessed delusion-proneness. High delusion-prone individuals were expected to show greater difficulty than low delusion-prone individuals on "conflict" items of a "belief-bias" reasoning task (i.e. when required to reason logically about statements that conflicted with reality), but not on "non-conflict" items. METHODS: Twenty high delusion-prone and twenty low delusion-prone participants (according to the Peters et al. Delusions Inventory) completed a belief-bias reasoning task and tests of IQ, working memory and general inhibition (Excluded Letter Fluency, Stroop and Hayling Sentence Completion). RESULTS: High delusion-prone individuals showed greater difficulty than low delusion-prone individuals on the Stroop and Excluded Letter Fluency tests of inhibition, but no greater difficulty on the conflict versus non-conflict items of the belief-bias task. They did, however, make significantly more errors overall on the belief-bias task, despite controlling for IQ, working memory and general inhibitory control. LIMITATIONS: The study had a relatively small sample size and used non-clinical participants to test a theory of cognitive processing in individuals with clinically diagnosed delusions. CONCLUSIONS: Results failed to support a role for doxastic inhibitory failure in non-clinical delusion-prone individuals. These individuals did, however, show difficulty with conditional reasoning about statements that may or may not conflict with reality, independent of any general cognitive or inhibitory deficits.

Belief-bias reasoning in non-clinical delusion-prone individuals.

BACKGROUND AND OBJECTIVES: It has been proposed that people with delusions have difficulty inhibiting beliefs (i.e., "doxastic inhibition") so as to reason about them as if they might not be true. We used a continuity approach to test this proposal in non-clinical adults scoring high and low in psychometrically assessed delusion-proneness. High delusion-prone individuals were expected to show greater difficulty than low delusion-prone individuals on "conflict" items of a "belief-bias" reasoning task (i.e. when required to reason logically about statements that conflicted with reality), but not on "non-conflict" items. METHODS: Twenty high delusion-prone and twenty low delusion-prone participants (according to the Peters et al. Delusions Inventory) completed a belief-bias reasoning task and tests of IQ, working memory and general inhibition (Excluded Letter Fluency, Stroop and Hayling Sentence Completion). RESULTS: High delusion-prone individuals showed greater difficulty than low delusion-prone individuals on the Stroop and Excluded Letter Fluency tests of inhibition, but no greater difficulty on the conflict versus non-conflict items of the belief-bias task. They did, however, make significantly more errors overall on the belief-bias task, despite controlling for IQ, working memory and general inhibitory control. LIMITATIONS: The study had a relatively small sample size and used non-clinical participants to test a theory of cognitive processing in individuals with clinically diagnosed delusions. CONCLUSIONS: Results failed to support a role for doxastic inhibitory failure in non-clinical delusion-prone individuals. These individuals did, however, show difficulty with conditional reasoning about statements that may or may not conflict with reality, independent of any general cognitive or inhibitory deficits.

Immunological evidence that band 3 is the major glucose transporter of the human erythrocyte membrane.

We have previously reported that human erythrocyte band 3 contains 90-95% of the reconstitutable glucose transport activity of the erythrocyte membrane (Shelton, R.L. and Langdon, R.G. (1983) Biochim. Biophys. Acta 733, 25-33). We have now found that monoclonal and polyclonal antibodies to epitopes on band 3 specifically removed band 3 and more than 90% of the reconstitutable glucose transport activity from unfractionated octylglucoside extracts of erythrocyte membranes; nonimmune serum removed neither. Western blots of whole membrane extracts revealed that the polyclonal antibody to band 4.5 used to isolate cDNA clones presumed to code for the transporter (Mueckler, M., Caruso, C., Baldwin, C.A., Pancio, M., Blench, J., Morris, H.B., Allard, W.J., Lienhard, G.E. and Lodish, H.F. (1985) Science 229, 941-945) reacts strongly with six discrete bands in the 4.5 region. A monoclonal antibody to band 3 also reacts with a Mr 55,000 component of band 4.5. We conclude that band 3 contains the major glucose transporter of human erythrocytes, and that the transport activity in band 4.5 might be attributable to a band 3 fragment. Band 3 is probably a multifunctional transport protein responsible for transport of glucose, anions, and water.

Reconstitution of glucose transport using human erythrocyte band 3.

Band 3 and the diffuse component of zone 4.5, designated band 4.5.B, have been separately prepared from human erythrocyte membranes and incorporated into the membranes of 150 nm 1-palmitoyl-2-oleoyl phosphatidylcholine vesicles. The rates of glucose influx into these vesicles were measured under zero-trans conditions. Both sets of vesicles exhibited substrate-saturable transport which was inhibited by phloretin. However, the specific activity of the band 3 vesicles, 292 mumol X min-1 X (mg protein)-1, was more than twice that of the band 4.5.B vesicles, and the turnover number of transporters in the band 3 vesicles was at least 4-fold greater than those in the 4.5.B vesicles. Very little background density was visible in the band 4.5 region of erythrocyte membranes protected from degradation. In unprotected membranes, band 4.5.B was abundantly present, could be purified, and had glucose transport activity. Previously we have shown (Biochemistry 19, 1205 (1980] that maltosyl isothiocyanate, an affinity label for the glucose transporter, labelled a single 100 000 Mr protein of the intact erythrocyte membrane. Based upon the results of both affinity labelling and reconstitution we suggest that the native glucose transporter is a component of band 3, and that band 4.5.B contains a partially active fragment of the native transporter.

Reconstitution of the glucose transport activity of rat adipocytes.

Rat epididymal fat cell membrane proteins were extracted from adipocyte ghosts with octylglucoside and incorporated by detergent dialysis into unilamellar phosphatidylcholine vesicles approx. 200 nm in diameter. The rate of glucose transport into the vesicles under zero-trans conditions was substrate dependent, saturable and inhibited by phloretin and cytochalasin B. Their maximum specific transport activity was 35.6 mumol/min per mg protein, and their half saturation constant for glucose was 15 mM. Glucose transport into the reconstituted vesicles was inhibited by only those sugars which competitively inhibited glucose transport into intact adipocytes. A major protein component of the vesicles was a 100 kDa protein which we had previously found to react with the affinity label maltosyl isothiocyanate (Malchoff, D.M., Olansky, L., Pohl, S. and Langdon, R.G. (1981) Fed. Proc. 40, 1893). Removal of adipocyte ghost membrane extrinsic proteins with dimethylmaleic anhydride followed by extraction of the resulting membrane pellet with octylglucoside yielded a solution which contained two major proteins, of Mr 100 000 and 85 000, with very small quantities of lower Mr proteins. Vesicles into which these proteins were incorporated had average specific transport activities of 624 mumol/min per mg protein and half saturation constants of 22 mM. Our results strongly indicate that the native glucose transporter of the rat adipocyte, like that of the human erythrocyte (Shelton, R.L. and Langdon, R.G. (1983) Biochim. Biophys. Acta 733, 25-33), is a 100 kDa protein.

Randomized, surgical adjuvant clinical trial of recombinant interferon alfa-2a in selected patients with malignant melanoma.

PURPOSE: We conducted a randomized prospective trial in selected patients with fully resected high-risk stage I and II malignant melanoma. PATIENTS AND METHODS: Interferon alfa-2a (IFN-alpha 2a) 20 x 10(6) U/m2 was administered three times each week for 12 weeks by the intramuscular route. Both the treatment group (n = 131) and the control group (n = 131) were evenly balanced with regard to relevant prognostic discriminants. RESULTS: The median disease-free survival (DFS) time was 2.4 years for the IFN-alpha 2a group and 2.0 years for the observation group (log-rank P = 0.19). The median survival times were 6.6 years for IFN-alpha 2a and 5.0 years for observation (log-rank P = .40). For stage I patients (n = 102), there was no apparent therapeutic advantage from IFN-alpha 2a therapy. The DFS for stage II patients was a median of 10.8 months in the control group versus 17 months in the treatment group. The overall survival time was 4.1 years for the treatment group versus 2.7 years for the control group. The differences in DFS for stage II patient were significant in a Cox model. These results must be interpreted cautiously because of subset analysis. A severe flu-like toxicity occurred in 44% of patients, 13% lost at least 10% of their baseline weight, and 45% experienced a worsening of Eastern Cooperative Oncology Group (ECOG) performance score. CONCLUSION: Our findings indicate trends that suggest a possible benefit for selected patients with high-risk malignant melanoma. The results will require further study in a larger patient population for confirmation.

American Society of Clinical Oncology clinical practice guidelines for the use of chemotherapy and radiotherapy protectants.

PURPOSE: Because toxicities associated with chemotherapy and radiotherapy can adversely affect short- and long-term patient quality of life, can limit the dose and duration of treatment, and may be life-threatening, specific agents designed to ameliorate or eliminate certain chemotherapy and radiotherapy toxicities have been developed. Variability in interpretation of the available data pertaining to the efficacy of the three United States Food and Drug Administration-approved agents that have potential chemotherapy- and radiotherapy-protectant activity-dexrazoxane, mesna, and amifostine-and questions about the role of these protectant agents in cancer care led to concern about the appropriate use of these agents. The American Society of Clinical Oncology sought to establish evidence-based, clinical practice guidelines for the use of dexrazoxane, mesna, and amifostine in patients who are not enrolled on clinical treatment trials. METHODS: A multidisciplinary Expert Panel reviewed the clinical data regarding the activity of dexrazoxane, mesna, and amifostine. A computerized literature search was performed using MEDLINE. In addition to reports collected by individual Panel members, all articles published in the English-speaking literature from June 1997 through December 1998 were collected for review by the Panel chairpersons, and appropriate articles were distributed to the entire Panel for review. Guidelines for use, levels of evidence, and grades of recommendation were reviewed and approved by the Panel. Outcomes considered in evaluating the benefit of a chemotherapy- or radiotherapy-protectant agent included amelioration of short- and long-term chemotherapy- or radiotherapy-related toxicities, risk of tumor protection by the agent, toxicity of the protectant agent itself, quality of life, and economic impact. To the extent that these data were available, the Panel placed the greatest value on lesser toxicity that did not carry a concomitant risk of tumor protection. RESULTS AND CONCLUSION: Mesna: (1) Mesna, dosed as detailed in these guidelines, is recommended to decrease the incidence of standard-dose ifosfamide-associated urothelial toxicity. (2) There is insufficient evidence on which to base a guideline for the use of mesna to prevent urothelial toxicity with ifosfamide doses that exceed 2.5 g/m(2)/d. (3) Either mesna or forced saline diuresis is recommended to decrease the incidence of urothelial toxicity associated with high-dose cyclophosphamide use in the stem-cell transplantation setting. Dexrazoxane: (1) The use of dexrazoxane is not routinely recommended for patients with metastatic breast cancer who receive initial doxorubicin-based chemotherapy. (2) The use of dexrazoxane may be considered for patients with metastatic breast cancer who have received a cumulative dosage of 300 mg/m(2) or greater of doxorubicin in the metastatic setting and who may benefit from continued doxorubicin-containing therapy. (3) The use of dexrazoxane in the adjuvant setting is not recommended outside of a clinical trial. (4) The use of dexrazoxane can be considered in adult patients who have received more than 300 mg/m(2) of doxorubicin-based therapy for tumors other than breast cancer, although caution should be used in settings in which doxorubicin-based therapy has been shown to improve survival because of concerns of tumor protection by dexrazoxane. (5) There is insufficient evidence to make a guideline for the use of dexrazoxane in the treatment of pediatric malignancies, with epirubicin-based regimens, or with high-dose anthracycline-containing regimens. Similarly, there is insufficient evidence on which to base a guideline for the use of dexrazoxane in patients with cardiac risk factors or underlying cardiac disease. (6) Patients receiving dexrazoxane should continue to be monitored for cardiac toxicity. Amifostine: (1) Amifostine may be considered for the reduction of nephrotoxicity in patients receiving cisplatin-based chemoth

Epidermal growth factor stimulates ornithine decarboxylase activity in cultured mammalian keratinocytes.

The influence of epidermal growth factor (EGF) on ornithine decarboxylase has been examined in cultured bovine keratinocytes. Keratinocyte ornithine decarboxylase activity was maximal at pH 6.3 in MES buffer in the presence of dithiothreitol and EDTA. When cultured cells, deprived of serum, were exposed to EGF, the activity of ornithine decarboxylase was stimulated severalfold. Enzyme activity increased in a dose-dependent manner with EGF. The time course of this stimulation is unlike any previously reported in cultured cells. The increase in activity was maximal by 8 h. A small dip in activity was seen between 8 and 12 h. Increased activity was sustained for as long as 24 h after exposure to EGF. The prolonged increased in enzyme activity was reduced by actinomycin D. When cycloheximide was added 1 h before EGF, ornithine decarboxylase activity was obliterated. This is the first demonstration of ornithine decarboxylase stimulation following exposure to EGF in cultured keratinocytes. The prolonged duration of ornithine decarboxylase stimulation is unexplained but may be related to processing of EGF by the keratinocytes.

In vitro reconstitution of skin: fibroblasts facilitate keratinocyte growth and differentiation on acellular reticular dermis.

Extensive full-thickness burns require replacement of both epidermis and dermis. We have described a method in which allogeneic dermis from engrafted cryopreserved cadaver skin was combined with cultured autologous keratinocytes. In the present study we combined human keratinocytes and fibroblasts, and acellular human dermis in vitro and transplanted this "reconstituted skin" into athymic mice. Both human papillary dermis in which the basement membrane zone has been retained and human reticular dermis that has been repopulated with human dermal fibroblasts are good substrates for keratinocyte attachment, stratification, growth, and differentiation. Both of these dermal preparations can be lyophilized and stored at room temperature without losing their ability to support keratinocyte growth. In contrast, human papillary dermis that has been treated with trypsin lacks laminin and collagen type IV in the BMZ and supports keratinocyte attachment and differentiation less well.