Effect of Lonicera japonica extract on lactation performance, antioxidant status, and endocrine and immune function in heat-stressed mid-lactation dairy cows.

Here, we examined the effects of Lonicera japonica extract (LJE) on lactation performance, antioxidant status, and endocrine and immune function in heat-stressed mid-lactation dairy cows. Twenty-four healthy Chinese Holstein mid-lactation dairy cows, all with similar milk yield (30.0 ± 1.0 kg/d), parity (2.5 ± 0.3), and days in milk (105 ± 5 d) were allocated to 4 groups using a randomized complete block design: a negative control group (without LJE supplementation; CON) and groups that received LJE at 14, 28, and 56 g/d. The experiment lasted 10 wk over a hot summer, with a pre-feeding period of 2 wk. Cows were exposed to heat stress, as the average temperature-humidity index was greater than 72. The results showed that LJE had no effect on respiration rate; however, it reduced the rectal temperature of dairy cows experiencing heat stress in both a linear and quadratic manner; the lowest (39.03°C) was recorded for the LJE-28 group, lower than the CON group. Supplementation with LJE did not affect dry matter intake, milk yield, or milk composition. The majority of biochemical parameters in serum were unaffected by supplementation with different amounts of LJE; the exception was creatinine, which was reduced quadratically. Compared with the CON group, serum triiodothyronine concentrations increased significantly in the LJE-28 group. Addition of LJE to the diet increased thyroxine concentrations quadratically; values peaked at 18.62 ng/mL in the LJE-28 group. Furthermore, supplementation with increasing amounts of LJE quadratically increased the activity of glutathione peroxidase and total antioxidant capacity in serum but decreased concentration of malondialdehyde. Although we detected no differences in the concentrations of IgA, IgM, or cytokines, dairy cows in the LJE-28 group had higher IgG and IL-4 concentrations than did cows in the CON group. Supplementation with LJE increased concentrations of IgG and IL-4 in the serum quadratically but decreased that of IL-2. Finally, heat shock protein 72 concentrations in the serum tended to fall quadratically as the amount of LJE increased. In summary, LJE had no negative effects on lactation performance but helped to alleviate heat stress by improving antioxidant status and promoting endocrine and immune functions. Supplementation with LJE at 28 g/d is recommended for lactating dairy cows experiencing heat stress during hot summers.

Effects of different types of zinc supplement on the growth, incidence of diarrhea, immune function, and rectal microbiota of newborn dairy calves.

Neonatal diarrhea in dairy calves causes huge economic and productivity losses in the dairy industry. Zinc is an effective anti-diarrheal agent, but high doses may pose a threat to the environment. Therefore, we aimed to evaluate the effects of low-dose zinc supplementation on the growth, incidence of diarrhea, immune function, and rectal microbiota of newborn Holstein dairy calves. Thirty newborn calves were allocated to either a control group (without extra zinc supplementation), or groups supplemented with either 104 mg of zinc oxide (ZnO, equivalent to 80 mg of zinc/d) or 457 mg of zinc methionine (Zn-Met, equivalent to 80 mg of zinc/d) and studied them for 14 d. The rectal contents were sampled on d 1, 3, 7, and 14, and blood samples were collected at the end of the study. Supplementation with ZnO reduced the incidence of diarrhea during the first 3 d of life, and increased serum IgG and IgM concentrations. The Zn-Met supplementation increased growth performance and reduced the incidence of diarrhea during the first 14 d after birth. The results of fecal microbiota analysis showed that Firmicutes and Proteobacteria were the predominant phyla, and Escherichia and Bacteroides were the dominant genera in the recta of the calves. As the calves grew older, rectal microbial diversity and composition significantly evolved. In addition, dietary supplementation with ZnO reduced the relative abundance of Proteobacteria in 1-d-old calves, and increased that of Bacteroidetes, Lactobacillus, and Faecalibacterium in 7-d-old calves, compared with the control group. Supplementation with Zn-Met increased the relative abundance of the phylum Actinobacteria and the genera Faecalibacterium and Collinsella on d 7, and that of the genus Ruminococcus after 2 wk, compared with the control group. Thus, the rectal microbial composition was not affected by zinc supplementation but significantly evolved during the calves' early life. Zinc supplementation reduced the incidence of diarrhea in young calves. In view of their differing effects, we recommend ZnO supplementation for dairy calves during their first 3 d of life and Zn-Met supplementation for the subsequent period. These findings suggest that zinc supplementation may be an alternative to antibacterial agents for the treatment of newborn calf diarrhea.

Pharmacokinetic interactions of cyclosporine with etoposide and mitoxantrone in children with acute myeloid leukemia.

The purpose of this study was to assess the effect of the multidrug resistance modulator cyclosporine (CsA) on the pharmacokinetics of etoposide and mitoxantrone in children with de novo acute myeloid leukemia (AML). Serial blood samples for pharmacokinetic studies were obtained in 38 children over a 24-h period following cytotoxin treatment with or without CsA on days 1 and 4. Drug concentrations were quantitated using validated HPLC methods, and pharmacokinetic parameters were determined using compartmental modeling with an iterative two-stage approach, implemented on ADAPT II software. Etoposide displayed a greater degree of interindividual variability in clearance and systemic exposure than mitoxantrone. With CsA treatment, etoposide and mitoxantrone mean clearance declined by 71% and 42%, respectively. These effects on clearance, in combination with the empiric 40% dose reduction for either cytotoxin, resulted in a 47% and 12% increases in the mean AUC for etoposide and mitoxantrone, respectively. There were no differences in the rates of stomatitis or infection between the two groups. CsA treatment resulted in an increased incidence of hyperbilrubinemia, which rapidly reversed upon conclusion of drug therapy. The variability observed in clearance, combined with the empiric 40% dose reduction of the cytotoxins, resulted in statistically similar systemic exposure and similar toxicity.

A phase II study of Homoharringtonine for the treatment of children with refractory or recurrent acute myelogenous leukemia: a pediatric oncology group study.

BACKGROUND: Homoharringtonine (HHT) is a plant alkaloid that is derived from a Chinese evergreen tree. Its mechanism of action is thought to be by inhibition of protein, DNA, and RNA synthesis by inhibition of chain initiation. The treatment of acute myelogenous leukemia (AML) in children, has been hampered by few new effective agents developed in the past 30 years. Significant numbers of children still die of this disease. The purpose of this study is to evaluate the efficacy and toxicity of HHT for the therapy of refractory AML in children. PROCEDURE: Patients entered the study and were treated with HHT 7mg/m(2)/day for 10 days. The cycles could be repeated every 21 days depending on recovery from myelosuppression. RESULTS: Thirty-seven patients entered the study, with twenty-eight evaluable for response. Complete response was obtained in four and a partial response in one (response rate 5/28 = 18%). Significant toxicities included prolonged severe myelosuppression in all responsive patients and neuropathogenic pain in two patients. The median duration of response was 62 days with a range of 28-126 days. CONCLUSIONS: HHT has activity against chemotherapy resistant AML in children, with tolerable toxicity. This agent warrants further clinical evaluation in combination with other agents or perhaps biologic response modifiers which will hopefully lead to useful therapeutic options. Med Pediatr Oncol 2001;37:103-107.

Chromosomal abnormalities in 478 children with acute myeloid leukemia: clinical characteristics and treatment outcome in a cooperative pediatric oncology group study-POG 8821.

We determined the type and frequency of chromosomal aberrations in leukemic cells of 478 children diagnosed with acute myeloid leukemia and enrolled in the Pediatric Oncology Group study 8821. Of the 478 cases, 109 (22.8%) had normal karyotypes. Chromosomal abnormalities of 280 patients (58.6%) were classified into subgroups: 11q23 abnormalities (n = 88, 18.4%), t(8;21) (n = 56, 11.7%), t(15;17) (n = 55, 11.5%), inv(16)/t(16;16) (n = 28, 5.9%), trisomy 8 alone (n = 10, 2.1%), monosomy 7 (n = 9, 1.9%), non-Down-associated trisomy 21 alone (n = 7, 1.5%), and rare recurrent chromosomal translocations (n = 27, 5.6%). The remaining 89 patients (18.6%) had miscellaneous clonal abnormalities. Overall, 84.9% of the children achieved a complete remission; the 4-year event-free survival (EFS) estimate was 33.8% +/- 2.4%. Remission rates were significantly higher (96.4%, P =.011) for patients with t(8;21) and inv(16)/t(16;16) but significantly lower (74.5%, P =.022) for those with t(15;17). The 4-year survival rate for all patients was 43.5% +/- 2.4%; for those with an inv(16)/t(16;16), 75.0% +/- 8.6%; a normal karyotype, 53.8% +/- 4.9%; a t(8;21), 51.6% +/- 7.3%; a t(15;17), 39.8% +/- 6.9%; and an 11q23 abnormality, 32.9% +/- 5.1%. Four-year EFS estimates for patients with inv(16)/t(16;16) (58.2% +/- 10.9%, P =.007), t(8;21) (45.1% +/- 7.7%, P =.014), or normal karyotypes (43.1% +/- 5.0%, P =. 012) were higher than the 4-year EFS estimate for all patients, but EFS estimates for patients with t(15;17) (19.6% +/- 8.0%, P =.033) or 11q23 abnormalities (23.8% +/- 4.8%, P =.0013) were lower. EFS estimates did not differ significantly among 11q23 subgroups. Limited analysis suggested that patients with inv(16) can be salvaged better following relapse than those with t(8;21). Thus, patients with an inv(16)/t(16;16) may have high survival rates when treated with chemotherapy alone.

Expression of chromosome 21-localized genes in acute myeloid leukemia: differences between Down syndrome and non-Down syndrome blast cells and relationship to in vitro sensitivity to cytosine arabinoside and daunorubicin.

The high event-free survival rates of Down syndrome (DS) children with acute myeloid leukemia (AML) are due, in part, to increased in vitro sensitivity of DS myeloblasts to cytosine arabinoside (ara-C) and daunorubicin and the greater generation of ara-C triphosphate (ara-CTP) from ara-C compared with myeloblasts from non-DS patients (Taub et al, Blood 87:3395, 1996). This study further explores the molecular basis of chemotherapy sensitivity of DS AML patients by examining the expression of chromosome 21-localized genes in myeloblasts from newly diagnosed AML patients. Transcript levels of two chromosome 21-localized genes, cystathionine-beta-synthase (CBS) and superoxide dismutase (SOD), measured by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), were 12.0- and 3. 8-fold higher in DS compared with non-DS myeloblasts (P <.0001 and P <.0001, respectively). Conversely, there were no significant increases in transcripts for 2 other chromosome 21-localized genes, carbonyl reductase and the reduced folate carrier. CBS transcript levels correlated with both in vitro ara-C sensitivity measured by the 3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium-bro mid e (MTT) assay (P =.003) and the generation of (3)H-ara-C triphosphate (ara-CTP) after in vitro incubations with 5 micromol/L (3)H-ara-C (P =.0003). Transcripts of deoxycytidine kinase were 2.6-fold higher in DS compared with non-DS cells and may be a factor in the enhanced metabolism of ara-C in DS cells. There was no significant correlation of SOD transcripts with in vitro ara-C and daunorubicin sensitivities. Increased CBS transcripts could result in elevated CBS activity, which modulates ara-C metabolism by altering reduced folate pools, deoxycytidine triphosphate pools, S-adenosylmethionine levels, and/or methylation of the deoxycytidine kinase gene. The further identification of the molecular mechanisms of chemotherapy sensitivity of DS AML patients may lead to significant improvements in the treatment and cure of AML.

Group sequential designs for phase II trials with historical controls.

Two-step tests based on historical control data are proposed for detecting different means when experimental and control populations are normally distributed with possibly different known variances. The results readily extend to the case where the control and experimental data are dichotomous. Provisions for early acceptance and early rejection are included.

Modelling cure rates using the Gompertz model with covariate information.

We extend the modified Gompertz hazard function, first used by Cantor and Shuster for estimation of cure rates from pediatric clinical trials, by including covariate effects. The extended model provides a convenient method for estimation of the cure rate as a function of treatments and covariates.

Novel cytokine release inhibitors. Part I: Triterpenes.

Tripterine and closely related triterpenoid derivatives as IL-1 beta release inhibitors are discussed.

Autologous bone marrow transplantation versus intensive consolidation chemotherapy for acute myeloid leukemia in childhood. Pediatric Oncology Group.

BACKGROUND: The value of autologous bone marrow transplantation in the treatment of children with acute myeloid leukemia (AML) is unknown. We compared autologous bone marrow transplantation with intensive consolidation chemotherapy as treatments for children with AML in first remission. METHODS: We induced remission with one course of daunorubicin, cytarabine, and thioguanine, followed by one course of high-dose cytarabine (3 g per square meter of body-surface area for six doses). Patients in remission after the second course of induction therapy were eligible for randomization. Between June 1988 and March 1993, 552 of 649 enrolled patients who could be evaluated (85 percent) entered remission. A total of 209 patients were not eligible for randomization; of the remaining 343 patients, 232 were randomly assigned to receive six courses of intensive chemotherapy (117 patients) or autologous transplantation (115 patients). Of the original 649 patients, 189, including 21 with Down's syndrome, were nonrandomly assigned to receive intensive chemotherapy. RESULTS: The rates of event-free survival and overall survival for the entire group at three years were 34 +/- 2.5 percent and 42 +/- 2.6 percent, respectively. For patients who were randomly assigned to one of the two treatment groups, the mean (+/- SE) rates of event-free survival three years after randomization were not significantly different in the two groups when examined by intention-to-treat analysis: 36 +/- 5.8 percent for the intensive-chemotherapy group as compared with 38 +/- 6.4 percent for the autologous-transplantation group; and the relative risk of treatment failure for the chemotherapy group as compared with the autologous-transplantation group was 0.81 (P = 0.20 by the log rank test; 95 percent confidence interval, 0.58 to 1.12). Overall survival at three years followed a similar pattern. There was a lower relapse rate (31 percent vs. 58 percent, P < 0.001) but a higher rate of treatment-related mortality (15 percent vs. 2.7 percent, P = 0.005) in the group treated with autologous transplantation than in the intensive-chemotherapy group. The event-free survival at three years for the nonrandomized intensive-chemotherapy group was 39 +/- 5.1 percent, and for a contemporaneous group of patients each of whom received a histocompatible bone marrow transplant from a sibling, it was 52 +/- 8.0 percent. CONCLUSIONS: Treatment of children with AML in first remission with either autologous bone marrow transplantation or intensive chemotherapy prolongs event-free survival equally.

Inhibition of IL-1 release from human monocytes and suppression of streptococcal cell wall and adjuvant-induced arthritis in rats by an extract of Tripterygium wilfordii Hook.

1. It was investigated whether an extract of Tripterygium wilfordii Hook f (TW) inhibits IL-1 production by monocytes and suppresses the development of IL-1-dependent arthritis induced in rats with streptococcal cell wall and adjuvant. 2. TW preferentially inhibited IL-1 alpha and IL-1 beta production by bacterial lipopolysaccharide (LPS)-stimulated human monocytes with IC50 of approximately 1 microgram/ml. 3. Oral administration of TW dose-dependently suppressed joint swelling and structural damage in streptococcal cell wall-induced arthritis (ED50 = 20 mg/kg/day) and in adjuvant-induced arthritis (ED50 = 46 mg/kg/day for developing and 8 mg/kg/day for established arthritis).

Interim analysis for randomized clinical trials: simulating the predictive distribution of the log-rank test statistic.

This paper presents an analog to stochastic curtailment, where the simulation of the remaining trial data from interim analysis is constructed using the existing data, rather than the design planning parameters. The nonparametric approach for the predictive distribution as proposed by Berliner and Hill (1988, Journal of the American Statistical Association 83, 772-779) forms the basis of the procedure. The methods are applied retrospectively to a clinical trial in childhood cancer.

Reduction in burden of illness: a new efficacy measure for prevention trials.

A new efficacy measure is developed for use in prevention trials of interventions which may affect both disease incidence and disease severity. We assign a severity score to each incident case and sum severity scores over all incident cases within each treatment group to create a burden-of-illness score for each treatment group. Efficacy is evaluated by the difference between the burden-of-illness per randomized subject in the two randomized treatment groups. Since the numbers of summands in each burden-of-illness score is a random variable, standard methods of analysis are not directly applicable. The asymptotic distribution and sampling properties of the net reduction in the burden-of-illness score are derived for trials designed to stop either after a fixed length of follow-up or after the occurrence of a fixed number of cases. We illustrate the method with data from a clinical trial of a human rotavirus vaccine.

Metabolism of the platelet-activating factor antagonist (+/-)-trans-2-(3'-methoxy-5'-methylsulphonyl-4'-propoxyphenyl)-5-(3",4" ,5"- trimethoxyphenyl)tetrahydrofuran (L-659,989) in rhesus monkeys.

1. The plasma concentration, main route of metabolism and excretion of 3H-L-659,989 were studied in male and female rhesus monkeys by dosing either i.v. or orally at 10 mg/kg. 2. The percentage of the AUC for the plasma radioactivity concentration-time curve of oral vs i.v. dosed monkeys was 78% for males and 90% for females, indicating that the dose was well absorbed. 3. The bioavailability of the drug was low (less than or equal to 10%) for all monkeys, probably due to rapid first pass metabolism. The drug was metabolized-predominantly at the C-4'-propoxy side-chain. The two major plasma metabolites were identified as the 4'-2-(hydroxy)propoxy metabolite (3H-trans-4'-HP) and the 4'-hydroxy metabolite (3H-4'-hydroxy) which was isolated as a 2:1 mixture of (+/-)trans: (+/-)cis. 4. Approx. 80% of the radiolabelled dose was excreted equally in the urine and faeces in 96 h, with the largest percentage of the tritiated dose (31 +/- 4%) in the 0-24 h urine. 5. The major metabolites in the excreta were the (+/-)trans/(+/-)cis mixture of 3H-4'-hydroxy and the glucuronide conjugate of 3H-trans-4'-hydroxy. The glucuronide conjugate of 3H-trans-4'-hydroxy was excreted in the urine of i.v. and orally dosed monkeys and represented an average of 21% and 5.1% of the dose, respectively. 3H-4'-Hydroxy was excreted in both the urine and faeces, accounting for less than or equal to 0.1% and 7.4% of the dose in i.v. and orally dosed monkeys, respectively.

A stochastic model for analyzing prevalence surveys of hepatitis A antibody.

Epidemiologic surveys of the age-specific prevalence of antibody to hepatitis A virus (anti-HAV) provide information on the spread of infection such as the infection rate and age-dependent characteristics. However, the data on prevalence are confounded with the mortality and diminished immunity of surveyed individuals. Through modeling, the age-specific prevalence of an individual can be separated from these confounding factors. A Markov chain is used to model the process of acquisition of anti-HAV by an individual and to derive the age-specific prevalence. Data from Frösner et al. [Am. J. Epidemiol. 110:63-69 (1979)] are used for illustration and estimation of parameters. The model offers an explanation of the well-known phenomenon of a decline in prevalence in older age. In addition to hepatitis, the framework of the model can be adapted to analyzing seroepidemiologic surveys of other diseases.

Antioxidant-based inhibitors of leukotriene biosynthesis. The discovery of 6-[1-[2-(hydroxymethyl)phenyl]-1-propen-3-yl]-2,3-dihydro-5- benzofuranol, a potent topical antiinflammatory agent.

The leukotrienes, metabolites of arachidonic acid produced through the action of the enzyme 5-lipoxygenase, are important mediators of immediate hypersensitivity and inflammation. Among the variety of diseases in which the leukotrienes may play a symptomatic or causative role is the dermatological condition psoriasis, a chronic proliferative disease of the skin. This study reports the synthesis and comparative biological activities of various ortho-substituted phenols including 4-methoxyphenols, 6-hydroxy-1,2,3,4-tetrahydrobenzopyrans, 2,3-dihydro-5-benzofuranols, and 5-benzofuranols. The phenols prepared in this study were evaluated for their ability to inhibit the production of leukotriene B4(LTB4) in isolated human polymorphonuclear leukocytes (PMNs) and to inhibit a topical inflammatory response in the topical mouse ear (TME) model. In the former case, when the log IC50 was plotted versus the log of the octanol/water partition coefficient (log P), to eliminate the effect of lipophilicity, the 2,3-dihydro-5-benzofuranol ring system was shown to be more potent than the other ring systems examined throughout the range of partition coefficients studied. The ability to inhibit leukotriene production in vitro in human PMNs can be rationalized on the basis of a model that suggests that the observed inhibition is dependent on the kinetic ability of the inhibitor to reduce a radical species and on the fraction of inhibitor that is partitioned into the cell membrane. While the in vivo antiinflammatory activity as measured by the TME did not correlate with the in vitro data, it was felt that the TME represented a valuable measure of the ability of a compound to penetrate the skin to the site of an ongoing inflammatory response. Of the compounds synthesized in this study, 6-[1-[2-(hydroxymethyl)phenyl]-1-propen-3-yl]-2,3-dihydro-5-benzof uranol (1, L-651896) was chosen for further development.

The inhibition of cytoplasmic acetoacetyl-CoA thiolase by a triyne carbonate (L-660, 631).

The compound L-660, 631 (2-oxo-5-(1-hydroxy-2,4,6-heptatriynyl)-1,3-dioxolane-4 heptanoic acid), a natural product isolated from an Actinomycete culture, was found to inhibit rat liver cytosolic acetoacetyl-CoA thiolase, the first step in the cholesterol biosynthesis pathway, with an IC50 of 1.0 x 10(-8) M. The inhibitor had no effect on other sulfhydryl containing enzymes of lipid synthesis such as HMG-CoA synthase, HMG-CoA reductase, and fatty acid synthase. When tested in cultured human liver Hep G2 cells the compound inhibited the incorporation of 14C-acetate and 14C-octanoate into sterols 56% and 48% respectively at 3 x 10(-6) M with no effect on fatty acid synthesis. No noticeable effect was seen on fatty acid biosynthesis. This strongly suggests that the locus of inhibition of acetate incorporation into sterols found with this compound is the acetoacetyl-CoA thiolase step in the cholesterol biosynthesis pathway.

The bias of the sample proportion following a group sequential phase II clinical trial.

Group sequential testing procedures have seen wide use in Phase II clinical trials. The sample proportion p of responders is the commonly used estimator for the binomial response probability p. It can be shown that p is the maximum likelihood estimator (MLE) of p. It is well known that MLE can be in general (Whitehead) and p in particular (Dupont) biased estimators, if ther computation follows a group sequential procedure. In this paper we numerically investigate the bias of p. We find that the magnitude of the bias of p is less than 0.025 in all cases we investigated. We apply the idea in Whitehead to propose a bias-adjusted estimator that reduces the bias substantially and reduces the mean square error as well in a certain range of p. We also evaluate the uniformly minimum variance unbiased (UMVU) estimator. If one does not mind a bias of 0.025, one may find the sample proportion a suitable estimator for p because of its simplicity and easy explanation. If one is concerned with bias, the bias-adjusted estimator may be a good choice.

Confidence intervals for a normal mean following a group sequential test.

This paper presents methodology based on the likelihood-ratio test, developed for construction of confidence intervals for a normal mean, following a group sequential test. Examples show that the confidence intervals produced by this method have accurate nominal probability of coverage and have generally shorter average length than that produced by Tsiatis, Rosner, and Mehta (1984, Biometrics 40, 797-803).