Insulin lispro lowers postprandial glucose in prepubertal children with diabetes.

OBJECTIVE: This study compared the glucose-lowering effect of insulin lispro, given before or after meals, with regular human insulin given before meals in prepubertal children with diabetes. RESEARCH DESIGN AND METHODS: A 3-way crossover, open-label study involving 61 prepubertal children (ages 2.9-11.4 years) with type 1 diabetes. The children were randomly assigned to receive regular human insulin 30 to 45 minutes before meals, insulin lispro within 15 minutes before or immediately after meals, combined with basal insulin. Each treatment lasted 3 months. Hemoglobin A(1c) levels and home glucose monitoring profiles were measured at the end of each treatment period. RESULTS: Treatment with insulin lispro before breakfast resulted in lower 2-hour postprandial glucose values than regular human insulin (11.7 +/- 4.4 mmol/L vs 15.0 +/- 5.4 mmol/L). Similarly, insulin lispro given before dinner resulted in lower blood glucose values 2 hours postprandially (8.8 +/- 5.0 mmol/L vs 10.8 +/- 5.4 mmol/L) than regular human insulin. When insulin lispro was administered after meals, the 2-hour glucose levels were between those seen with either insulin lispro or regular human insulin given before meals. The number and types of adverse events, the rates of hypoglycemia, and the HbA(1c) levels did not differ among the 3 therapies. CONCLUSIONS: In prepubertal children, insulin lispro given before meals is safe and significantly lowers postprandial glucose levels after breakfast and dinner compared with regular human insulin, and insulin lispro given after the meal provides similar benefits as regular human insulin before the meal.

Safety of insulin lispro: pooled data from clinical trials.

The safety of insulin lispro was compared with that of regular human insulin of recombinant DNA origin (Humulin R, Lilly), with special emphasis on the development and progression of the chronic complications of diabetes mellitus in relation to insulin therapy. Ten clinical trials of 3634 patients with type 1 and type 2 diabetes mellitus were analyzed. The primary focus was treatment-emergent adverse events, and the secondary focus was the development and progression of the chronic complications of diabetes. The evaluations were based on pertinent laboratory values, predetermined disease-specific COSTART (coding symbol and thesaurus for adverse event terminology) terms, physician evaluations of patients, and physical examinations. There were no clinically or statistically significant differences in the frequency of treatment-emergent adverse events or progression of retinopathy, neuropathy, or cardiovascular disease reported with each therapy. There was no difference between insulin lispro and Humulin R in the occurrence and progression of kidney disease as measured by changes in serum creatinine levels. Pooled data from clinical studies show that insulin lispro has a safety profile comparable to that of Humulin R.

Health-related quality-of-life results from multinational clinical trials of insulin lispro. Assessing benefits of a new diabetes therapy.

OBJECTIVE: To compare health-related quality of life (HRQOL) in patients with diabetes receiving insulin lispro with patients receiving regular human insulin (Humulin R). RESEARCH DESIGN AND METHODS: We performed two randomized comparative studies over a 6-month period (3 months per treatment). Primary analyses used crossover baseline to 3-month changes in HRQOL scores. Ninety-three principal investigators in Canada, France, Germany, and the U.S. participated in these studies. One HRQOL crossover study included 468 patients with type I diabetes; the other HRQOL crossover study included 474 patients with type II diabetes. In both studies, patients were taking insulin at least 2 months before enrollment. Primary outcomes included two generic HRQOL domains, energy/fatigue and health distress, and two diabetes-specific domains, treatment satisfaction and treatment flexibility. Thirty secondary outcomes included both generic and diabetes-specific measures. Secondary outcome domains were controlled for multiplicity in the analyses. RESULTS: Primary analyses showed that treatment satisfaction scores (P < 0.001) and treatment flexibility scores (P = 0.001) were higher for insulin lispro in type I diabetic patients. No other significant treatment differences were detected using the data from these 6-month crossover studies. CONCLUSIONS: Treatment satisfaction and treatment flexibility were significantly improved in patients with type I diabetes using insulin lispro. Other HRQOL findings were comparable for insulin lispro and regular human insulin. Insulin lispro appears to have a measurable impact on lifestyle benefits in patients with type I diabetes, as demonstrated by increased treatment satisfaction and treatment flexibility.

The cellular YY1 transcription factor binds a cis-acting, negatively regulating element in the Epstein-Barr virus BRLF1 promoter.

Disruption of Epstein-Barr virus latency is induced by expression of either the BZLF1 (in B cells and epithelial cells) or BRLF1 (in epithelial cells only) immediate-early protein. Regulation of BZLF1 and BRLF1 transcription may therefore modulate the stringency of viral latency. The cellular transcription factor YY1 negatively regulates BZLF1 transcription. Here we show that the BRLF1 promoter (Rp) sequences from -206 to -227 (relative to the mRNA start site) and from -7 to +6 are directly bound by YY1. Mutation of the upstream YY1 binding site increases constitutive Rp activity in epithelial cells and B cells, while mutation of the downstream YY1 binding site does not significantly affect Rp activity. Negative regulation of BZLF1 and BRLF1 transcription by YY1 may act to maintain viral latency.

Epstein-Barr viral latency is disrupted by the immediate-early BRLF1 protein through a cell-specific mechanism.

Epstein-Barr virus (EBV), the causative agent of infectious mononucleosis, is a human herpesvirus associated with epithelial cell malignancies (nasopharyngeal carcinoma) as well as B-cell malignancies. Understanding how viral latency is disrupted is a central issue in herpesvirus biology. Epithelial cells are the major site of lytic EBV replication within the human host, and viral reactivation occurs in EBV-associated nasopharyngeal carcinomas. It is known that expression of a single viral immediate-early protein, BZLF1, is sufficient to initiate the switch from latent to lytic infection in B cells. Cellular regulation of BZLF1 transcription is therefore thought to play a key role in regulating the stringency of viral latency. Here we show that, unexpectedly, expression of another viral immediate-early protein, BRLF1, can disrupt viral latency in an epithelial cell-specific fashion. Therefore, the mechanisms leading to disruption of EBV latency appear to be cell-type specific.

Functional and physical interactions between the Epstein-Barr virus (EBV) proteins BZLF1 and BMRF1: Effects on EBV transcription and lytic replication.

The Epstein-Barr virus (EBV) proteins BZLF1 and BMRF1 are both essential for lytic EBV replication. BZLF1 is a transcriptional activator which binds directly to the lytic origin of replication (oriLyt) and plays a critical role in the disruption of viral latency. The BMRF1 protein is required for viral polymerase processivity. Here we demonstrate that the BMRF1 gene product functions as a transcriptional activator and has direct (as well as indirect) interactions with the BZLF1 gene product. The BMRF1 gene product activates an essential oriLyt promoter, BHLF1, but does not activate two other early EBV promoters (BMRF1 and BHRF1). Direct interaction between the BMRF1 and BZLF1 gene products requires the first 45 amino acids of BMRF1 and the bZip domain of BZLF1. The effect of the BZLF1-BMRF1 interaction on early EBV transcription is complex and is promoter specific. The oriLyt BHLF1 promoter is activated by either the BZLF1 or BMRF1 gene product alone and is further activated by the combination of the BZLF1 and BMRF1 gene products. Enhanced activation of BHLF1 transcription by the BMRF1-BZLF1 combination does not require direct interaction between these proteins. In contrast, BZLF1-induced activation of the BMRF1 promoter is inhibited in the presence of the BMRF1 gene product. A point mutation in the BZLF1 protein (amino acid 200), which prevents in vitro interaction with the BMRF1 protein but which does not reduce BZLF1 transactivator function, allows the BZLF1 protein to activate the BMRF1 promoter equally well in the presence or absence of the BMRF1 gene product. Therefore, direct interaction between the BZLF1 and BMRF1 proteins may inhibit BZLF1-induced transcription of the BMRF1 promoter. BZLF1 mutated at amino acid 200 is as efficient as wild-type BZLF1 in promoting replication of an oriLyt plasmid. However, this mutation reduces the ability of BZLF1 to induce lytic replication of the endogenous viral genome in D98/HE-R-1 cells. Our results indicate that functional and physical interactions between the BMRF1 and BZLF1 proteins may modulate the efficiency of lytic EBV infection. The BMRF1 gene product clearly has a transcriptional, as well as replicative, role during lytic EBV infection.

The Zif268 cellular transcription factor activates expression of the Epstein-Barr virus immediate-early BRLF1 promoter.

The Epstein-Barr virus immediate-early protein BZLF1 mediates the switch from latent to lytic infection. BZLF1 transcription can be derived from either the BZLF1 promoter or the BRLF1 promoter (Rp). Productive viral infection of EBV-infected B cells can be induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment, as well as cross-linking of surface immunoglobulin with antiimmunoglobulin antibody. Both TPA and antiimmunoglobulin antibody are known to activate expression of the cellular transcription factor Zif268 in B cells. In this study, we have examined the regulation of BZLF1 transcription by Zif268. We show that Rp (but not the BZLF1 promoter) is activated by Zif268. Bacterially synthesized Zif268 binds strongly to an upstream sequence in the Rp promoter (located from -131 to -123 relative to the start site) and more weakly to a proximal sequence (-49 to -40). Zif268 activation of Rp requires these two Zif268 binding sites. TPA treatment of B cells induces the expression of Zif268 protein, which binds to Rp. Furthermore, TPA activation of Rp requires the upstream Zif268 site. These findings indicate that Zif268 can activate a critical Epstein-Barr virus immediate-early promoter and, therefore, may play a key role in the regulation of viral latency.

The Epstein-Barr virus immediate-early promoter BRLF1 can be activated by the cellular Sp1 transcription factor.

Disruption of viral latency in Epstein-Barr virus-infected cells is mediated through the activation of the BZLF1 (Z) immediate-early gene product. The Z protein can be derived from either of two promoters: the BZLF1 promoter, which directs transcription of a 1.0-kb mRNA encoding the Z gene product alone, or the upstream BRLF1 promoter, which directs transcription of a 2.8-kb bicistronic mRNA encoding the BRLF1 and BZLF1 immediate-early proteins. In this study we have examined the regulation of the BRLF1 promoter by viral and cellular factors. We found that the BRLF1 promoter is autoregulated by the BRLF1 transactivator through a nonbinding mechanism. We show that the BRLF1 (but not the BZLF1) promoter is highly responsive to the Sp1 transcription factor. Sp1 activation of the BRLF1 promoter is mediated through a consensus Sp1-binding site located from -39 to -44 (relative to the mRNA start site). We demonstrate that the BRLF1 promoter has high constitutive activity in C-33 cells (an epithelial cell line) and that the proximal Sp1-binding site is required for this activity. Despite the ubiquitous presence of Sp1 in many cell types, we found that the BRLF1 promoter has essentially no activity in lymphoid cell lines, suggesting that factors other than Sp1 may negatively regulate the BRLF1 promoter in these cells. Our findings demonstrate that the two potential promoters directing BZLF1 transcription are differentially regulated and that Sp1 can activate the BRLF1 promoter but not the BZLF1 promoter.

Ascorbic acid concentration of human fetal tissues in relation to fetal size and gestational age.

1. Studies were carried out on the distribution of ascorbic acid in human fetal tissues with the progress of gestation. 2. Fetuses and stillborn babies varying in gestational age from 12 to 38 weeks were obtained from various Baroda hospitals. Ascorbic acid levels were determined in selected tissues: brain, adrenal, liver, kidney, lung, heart and placenta. 3. Ascorbic acid concentration in the brain was higher than that in the adrenal at all gestational ages, suggesting the importance of this vitamin in brain development. The concentrations of this vitamin in liver, kidney, lung and placenta were comparable, but that in the heart tended to be lower. In all the tissues, there was a fall in ascorbic acid during late gestation. However, the levels in tissues of stillborn babies were higher than those reported for adults.

Ascorbic acid and reduced glutathione concentration of human fetal tissues in relation to gestational age, fetal size and maternal nutritional status.

Studies were carried out on ascorbic acid and glutathione concentration in human fetal tissues with the progress of gestation. The glutathione concentration in human fetal liver and adrenal showed a decline during late gestation, the decline in the brain being earlier. This is consistent with the fall in ascorbic acid concentration in all tissues during late gestation. Glutathione concentration and glutathione/ascorbic acid ratio was significantly lower in the low income group than the high income group, confirming previous observations that state of nutrition may influence cellular glutathione.