Effects of dietary supplementation with copper sulfate or tribasic copper chloride on broiler performance, relative copper bioavailability, and oxidation stability of vitamin E in feed

An experiment was conducted using a total of 420, 1-d-old, Arbor Acres commercial male chicks to compare copper sulfate and tribasic copper chloride (TBCC) as sources of supplemental copper for broilers. Chicks were randomly allotted to 1 of 7 treatments for 6 replicates of 10 birds each and were fed a basal corn-soybean meal diet (11.45 mg/kg copper) supplemented with 0, 150, 300, or 450 mg/kg copper from copper sulfate or TBCC for 21 d. Chicks fed 450 mg/kg copper as copper sulfate had lower (P < 0.01) average daily feed intake and average daily gain than those consuming other diets. Feeding supplemental copper increased linearly (P < 0.0001) liver copper concentrations regardless of copper source. The slopes of regressions of log10 liver copper on different independent variables used in regressions differ (P < 0.05) between the 2 copper sources. Linear regression over nonzero dietary levels of log10 transformed liver copper concentration on added copper intake resulted in a slope ratio estimate of 109.0 +/- 3.4% (with a 95% confidence interval from 102.2 to 115.8) for bioavailability of copper from TBCC compared with 100 for that in copper sulfate. When the feeds were stored at room temperature for 10 or 21 d, the vitamin E content in the feed fortified with 300 mg/kg copper as TBCC was higher (P < 0.01) than that in the feed added with 300 mg/kg copper as CuSO4. The vitamin E contents in liver and plasma of broilers given TBCC were also higher (P < 0.01) than those of birds fed copper sulfate. The results from this study indicate that TBCC is a safer product and more available to broilers than copper sulfate, and it is chemically less active than copper sulfate in promoting the oxidation of vitamin E in feed.

Changes in weight and composition in various tissues of pregnant gilts and their nutritional implications1

The objectives of this study were to characterize the quantitative changes in various body tissues of high-lean type gilts during gestation and to determine the protein needs of pregnant gilts based on changes in tissue contents. Thirty-five gilts (158.2 +/- 8.3 kg) were housed in individual gestation crates with six unbred gilts randomly selected and slaughtered to provide data for d 0 of gestation. The remaining gilts were bred and assigned randomly to one of six slaughter groups: d 45, 60, 75, 90, 102, and 112. Gilts were fed 2 kg (as-fed basis) of gestation diet daily (3.1 Mcal/kg of ME and 0.56% lysine). Carcass soft tissue, bone, gastrointestinal tract, spleen, pancreas, kidney, liver, uterus, fetus, mammary gland, and the remaining viscera were separated and weighed. Carcass soft tissue, liver, remaining viscera, uterus, and gastrointestinal tract were ground, freeze-dried, and analyzed for composition. Body weights of the gilts increased quadratically (P < 0.001) during gestation. Weights of carcass soft tissue and uterus, including placenta, increased linearly (P < 0.001) during gestation. Weights of individual fetuses, fetal litters, individual mammary glands, and the entire mammary glands increased cubically (P < 0.001) during gestation. Crude protein in carcass soft tissue increased cubically (P < 0.01), whereas DM and ether extract (EE) in carcass soft tissue increased linearly (P < 0.01). The DM, CP, and EE in the entire mammary glands increased quadratically (P < 0.001) during gestation. The DM, CP, and EE in fetal litter increased cubically (P < 0.01) as gestation progressed. The accretion rates of the conceptus, fetal litter, individual fetus, individual mammary gland, and CP in fetal litter differed (P < 0.05) before and after d 70 of gestation. The CP daily gain from all maternal and fetal tissues was 40 and 103 g/d before and after d 70 of gestation, respectively, suggesting that pregnant gilts may require different quantities of dietary protein during gestation. Based on the maintenance requirement, maternal tissue gain, and conceptus gain, pregnant gilts require 6.8 and 15.3 g/d of true ileal-digestible lysine (or 147 and 330 g/d of true ileal-digestible protein) before and after d 70 of gestation, respectively, to support their true biological needs.

Growth and compositional changes of fetal tissues in pigs1

Three hundred twenty fetuses were obtained from 33 pregnant gilts (Camborough-22, Pig Improvement Co.) to determine rates of nutrient deposition in fetal tissues and to estimate nutrient requirements for fetal growth. Pregnant gilts were fed an equal amount of a gestation diet (2.0 kg/d; as-fed basis), and were slaughtered at d 0, 45, 60, 75, 90, 102, or 110 of gestation (n = 3 to 6 per day). Fetuses were dissected into carcass and individual tissues (including gastrointestinal tract, liver, lung, heart, kidney, spleen [> or = d 75]), and partial placental collection was made for chemical analysis. Fetal tissues were weighed and analyzed for DM, ash, CP, and crude fat. Regression equations were obtained to explain the weight and compositional changes of individual tissues during gestation. Weights of the fetus, carcass, gastrointestinal tract, liver, heart, lung, and kidney increased cubically (P < 0.001), whereas brain weight increased linearly (P < 0.001) as gestation progressed. Fetal protein and fat contents increased quadratically (P < 0.001) as gestation progressed (R2 = 0.906 and 0.904, respectively). Changes in fetal protein and fat contents fit a multiphasic regression that consisted of two linear equations (P < 0.001, R2 = 0.988 and P < 0.001, R2 = 0.983, respectively), indicating that protein and fat growth accelerated after d 69 of gestation. Fetal protein and fat accretions were 0.25 and 0.06 g/d (P < 0.001) before d 69 of gestation, and increased to 4.63 and 1.09 g/d (P < 0.001) after d 69 of gestation. Protein needs for tissue protein gains increased 19-fold after d 69 of gestation. Results of this study indicate that the growth of the fetus and fetal tissues occurs at different rates during gestation and support the practice of a two-phase feeding strategy (before and after approximately d 70 of gestation) for pregnant gilts.

[Morpholgical, histological and histochemical observations on the effect of albendazole on encysted larvae of Trichinella spiralis in mice]

AIM

To study the mechanism of action of albendazole on encysted larvae of Trichinella spiralis in mice.

METHODS

Twelve Kunming strain mice each infected with 200 T. spiralis larvae were equally divided into two groups. Six mice of the treatment group were treated with 30 mg of albendazole/kg daily for 5 days. Morphological, histological and histochemical methods were used.

RESULTS

The encysted larvae of albendazole-treated group became significantly damaged, most worms were shrunken and surrounded by inflammatory cells. Histochemical study demonstrated that the glycogen and RNA content of the larvae in the treated group was decreased, the activities of SDH, ATPase, ACP were lower than those of the control group.

CONCLUSION

Albendazole can affect the physiological function of Trichinella spiralis.

Studies on a soft glycopyrrolate analog, SG-1

A short-acting soft drug analog (SG-1) of glycopyrrolate (G) was developed by retrometabolic design in order to minimize systemic side effects and optimize the therapeutic index. SG-1,3-(1'-hydroxycyclopentyl)phenylacetoxy-1-methyl-1- methoxycarbonylpyrrolidinium bromide, was synthesized by: (a) esterification of phenylacetic acid with N-methyl-3-pyrrolidinol by DCC to obtain N-methyl-3-pyrrolidinyl phenylacetate; (b) reaction of lithium salt of above phenylacetates with cyclopentanone to obtain N-methyl-3-pyrrolidinyl 3-(1'-hydroxycyclopentyl)phenylacetate; and (c) quarternization with methyl bromoacetate in acetonitrile to give the designed product. To evaluate the pharmacological effect of SG-1, its mydriatic activity in rabbit eyes was compared to that of glycopyrrolate. At the pharmacodynamically equivalent doses (the lowest dose that induces the maximum response) of SG-1 (1%) and glycopyrrolate (0.1%), the mydriatic activities lasted for 5 and 100 h, respectively. Compared to glycopyrrolate, the intrinsic pupil dilation potency of SG-1 was lower (approximately 1/10th) but the duration of action was much shorter (< 1/20th) as SG-1 is susceptible to facile enzymatic hydrolysis/deactivation in the rabbit eyes. In vitro metabolism and stability investigations further supported this finding. In vitro half lives of SG-1 in rat plasma, blood, and 20% liver and lung tissue homogenates were 15.62, 53.86, 263.43, and 318.35 min, respectively. In human plasma and blood, half-lives were 19.93 and 88.32 min, respectively. SG-1 was relatively stable under acidic conditions (pH 5 and lower). SG-1 is a promising, clinically useful short acting anticholinergic.

Design, pharmacokinetic, and pharmacodynamic evaluation of soft anticholinergics based on tropyl alpha-phenylcyclopentylacetate

Four new soft anticholinergic agents based on tropyl alpha-phenylcyclopentylacetate, 15a, 15b, 18a, and 18b, were designed and synthesized. Receptor binding studies on the cloned human muscarinic receptors indicated that the new soft anticholinergic agents possessed moderate potency as pKi ranged from 6.7 to 7.6. Mydriatic studies in rabbit eyes revealed that the duration of the action of the new soft anticholinergics (8.5-11.0 h) were shorter than that of atropine (about 24 h) under pharmacodynamic equivalent dose, and one of them, 18a, showed even shorter than that of tropicamide. In addition, after unilateral administration, significant dilation of pupil in the control eyes was observed with tropicamide and atropine but not with soft drugs, suggesting the systemic activity of soft drugs was minimal. With their soft nature, the new soft anticholinergics displayed much shorter protective effect against carbachol-induced bradycardia (about 30 min) than atropine (at least 60 min) in rats. In vitro and in vivo pharmacokinetic studies demonstrated that the soft anticholinergics were rapidly hydrolyzed into the corresponding inactive metabolites once they were introduced into the systemic circulation.

Soft cannabinoid analogues as potential anti-glaucoma agents

Cannabinoids are able to reduce elevated intraocular pressure; however, their use in glaucoma treatment is not approved due to severe systemic side effects. New cannabinoid derivatives have been designed based on a retrometabolic/soft drug approach; they were expected to have local effect, but not systemic side effects. Lead compounds and soft analogues were prepared using Pechmann condensation. In agreement with the SAR hypothesis used for the present soft drug design, all the compounds that were successfully synthesized had IOP lowering effect, but the common metabolite of soft analogues that was found to be inactive. Accordingly, when the soft analogue 8 was administered i.v., its biological effect lasted just for 15 minutes; nevertheless, when administered topically, its effect lasted significantly longer. Its metabolite, though, was inactive when applied either i.v. or topically. Thus, the designed soft analogues proved to be good candidates for topical control of glaucoma without producing systemic side effects. The preliminary i.v. experimental data could be successfully described by an indirect response PK/PD model.

A hypercycle theory of proliferation of viruses and resistance to the viruses of transgenic plant

A set of dynamical equations for the proliferation of two typical viruses TMV and PVY has been derived from the reaction equations describing their replication, assembly and translation. These equations can be seen as the generalization of hypercycle theory to the system. The quantitative explanation on the phenomena of proliferation of plant virus and the mechanism of resistance to the disease of transgenic plant is offered. The phenomenon of specific cessation of minus-strand RNA accumulation in the proliferation of TMV, the cross-protection of plant viruses and the mechanism of resistance to viruses of transgenic plant are discussed based on the computer simulation of the proliferation of viruses and the prediction of the secondary structure of the genomic RNA.

Soft cannabinoid analogues as potential anti-glaucoma agents

Cannabinoids have intraocular pressure (IOP) lowering effects, thus, they have a therapeutic potential in the treatment of glaucoma. Unfortunately, in the same time, they show CNS and cardiovascular effects as well. Our aim was to develop a safer, cannabinoid type anti-glaucoma agent, a topically applied soft analogue, that has local, but no systemic effect. The lead compound chosen was a nitrogen-containing cannabinoid analogue that was shown to have IOP lowering activity. A full library of possible soft drugs was generated and the structures were ranked based on the closeness of calculated properties to those of the lead compound. The lead compound has been synthesized, and a preliminary pharmacological study was performed. The structure-activity relationship and pharmacological results indicate a good possibility for the development of a safe, soft anti-glaucoma agent.

Design, synthesis, and pharmacological evaluation of soft glycopyrrolate and its analog

Glycopyrrolate is a quaternary anticholinergic drug. Like for other anticholinergics, the usefulness of this agent is limited by its side effects. In this study, based on the structure of glycopyrrolate, we designed a soft drug, methoxycarbonylphenyl-cyclopentylacetoxy-N,N-dimethyl-3-p yrrolidinium methyl sulfate (SG), and its analog, methoxycarbonylphenylcyclopentyl-acetoxyethyl-N,N,N-trimethylammon ium methyl sulfate (SGA). These soft drugs are expected to be locally active, but systemically inactive in order to increase therapeutic index. SG and SGA were synthesized by (i) carboxylation of methyl phenylcyclopentylacetate, (ii) esterification with N-methyl-3-pyrrolidinol (for SG) or 2-chloro-N,N-dimethylaminoethane (for SGA), and (iii) quarternization with dimethyl sulfate. Receptor binding studies demonstrate that SG has muscarinic subtype selectivity (m3/m2). Guinea pig ileum pA2 assay indicates that activity of SG is moderate, and SG is about ten times more potent than SGA. The in vivo characterization of SG and SGA, both in mydriasis tests and in prevention of carbachol induced bradycardia, supported its soft nature. Applying SG or SGA into rabbit eyes, the dilation of the contralateral (water-treated) pupils was not observed. Glycopyrrolate application, however, caused dilation of the contralateral pupil, indicating a systemic effect of this drug. Cardiac studies were carried out by evaluating the protective effect of soft anticholinergics against carbachol induced bradycardia. The results indicate that SG and SGA were as potent as atropine-MeBr in preventing carbachol induced bradycardia in the rat; however, their durations of action were significantly shorter. In conclusion, the newly synthesized SG and SGA showed soft nature in the body. They are anticholinergics with subtype selectivity and moderate potency, and can be used as topical antiperspirants.

GABA and histogenesis in fetal and neonatal mouse brain lacking both the isoforms of glutamic acid decarboxylase

Recent in vitro investigations have suggested that GABA is involved in the development of the mammalian central nervous system. To evaluate the roles of GABA in neurogenesis in vivo, we generated mice lacking both the isoforms of glutamic acid decarboxylase (GAD), GAD65 and GAD67, by mating GAD65- and GAD67-mutant mice generated by homologous recombination in this laboratory. Similar to GAD67-deficient mice, the GAD65/67-deficient mice did not survive after birth because of cleft palate. We thus analyzed these mice at the fetal and newborn stages. GABA was scarcely detectable in the GAD65/67-deficient brains, indicating that the GAD-independent GABA synthetic pathway was not active. The activity of ornithine decarboxylase, which is possibly involved in such a pathway, did not increase with the GAD deficiency. Histological and immunohistochemical studies of the GAD65/67-deficient brain did not reveal any discernible disorders of histogenesis. The discrepancy between the results of previous in vitro investigations, performed mostly on rat tissue, and those of the present analysis on mutant mice may be attributed to the different species used or to the possibility that other mediators can compensate for GABA functions in vivo.

Development of the GABA system in organotypic culture of hippocampal and cerebellar slices from a 67-kDa isoform of glutamic acid decarboxylase (GAD67)-deficient mice

Mice lacking glutamic acid decarboxylase 67kDa (GAD67) are born with much reduced GABA contents but do not survive after birth. To estimate the subsequent development of GAD67-deficient neural tissue, the hippocampal and cerebellar slices were prepared while the mice were alive, and subjected to organotypic culture. Although GABA contents were initially less than 5%, they were markedly increased, and GABA-containing fiber networks were well developed during the culture, indicating that GAD65, the other GAD isoform, largely compensates for the lack of GAD67. Cerebellar Purkinje cells developed similarly in culture.

The preferential mode analysis of DNA sequence

After reviewing approaches to the nucleotide correlation of DNA sequences the preferential mode analysis method is emphasized and discussed in detail. The preferred modes and poor modes in coding regions, as well as in introns, 5'-caps and 3'-tails are found through the statistical analysis of sequence data of all kinds of species in GenBank. The relation between the preferential mode analysis and informational parameter method is deduced. It is discovered that in higher species the coding sequences preferentially use the strong-weak bond (strong bond=C,G; weak bond=A, T) language and many noncoding regions (introns, 5'-caps, 3'-tails) use purine-pyrimidine language. The application of different languages in coding and noncoding sequences is a result of evolution, and it may be related to the functional differences in these two regions. Furthermore, we find that many preferential triplets in coding sequences can be expressed in a form of (* W S) (W=A,T; S=C,G), which may be explained by its relation to t-RNA abundance. The systematic change of some mode contents with evolution has also been found.

[A dynamic study of the cytotoxic effects of hyperthermia combined with cis-diaminedichlorolplatinum (DDP) on human gastric cancer cell lines MKN28 and MKN45 in vitro]

Cytotoxic effects of hyperthermia combined with DDP on MKN28 and MKN45 cells were studied by MTT assay according to a nested design. The rusults showed: hyperthermia alone above 43 degrees C for 30 min was cytotoxic; hyperthermia at temperature lower than 43 degrees C for 30 min could increase sensitivity of cancer cells to DDP. The cytotoxic effect of simultaneous use of hyperthermia and DDP was more marked than that of sequential use of the 2 treatments. Hyperthermia combined with DDP could inhibit growth of human gastric adenocarcinoma cells regardless of their degree of differentiation.

Fuzzy classification of nucleotide sequences and bacterial evolution

A new method for reconstructing evolutionary relationship among bacteria by use of rRNA sequence data is proposed. The method is based on the concept of fuzzy classification of probabilities p(i), p(i/j) and p(i/j*) (i = A, G, C, U) of each sequence. The resulting partition tree shares common features of previous works but has some new peculiarities.