[Values of carbon dioxide emission from different land-use patterns of alpine meadow]

The value order of carbon dioxide emission from different land-use of alpine meadow was significantly with season changing. It was found that the Potentilla fruticosa shrub meadow(C, 1871.40 g/m2) > Kobresia humilis meadow(A, 1769.63 g/m2) > Degraded Potentilla fruticosa shrub meadow(D, 1495.60 g/m2) > Degraded Kobresia humilis meadow(B, 1191.26 g/m2) during growth season, A(661.46 g/m2) > C(550.90 g/m2) > B(502.50 g/m2) > D (384.50 g/m2) in rest period; and A(2431.09 g/m2) > C(2422.30 g/m2) > D(1880.10 g/m2) > B(1694.06 g/m2) for whole year, separately. This deference not only decided the soil microbial activity and soil characters, but also have the closely relationship to shortage of frozen period.

Useful tests on pleural fluid that distinguish transudates from exudates

We aimed to compare the classic Light's criteria with different testing strategies in an effort to improve the accuracy of pleural fluid (PF) categorization. Thirty-two patients with transudates and 140 with exudates on the basis of their clinical diagnosis were entered into the study. We examined the discriminative properties of 10 analytes in the identification of PF, both singly and in combination with an 'or' rule, to see which was best in distinguishing a transudate from an exudate. A combination of PF lactate dehydrogenase (LD) > 307 U/L (two-thirds of the upper limit of the serum LD reference range) with either PF cholesterol > 1.55 mmol/L or PF to serum protein ratio > 0.5 had a diagnostic accuracy similar to that of Light's criteria. We suggest the use of PF LD and cholesterol in combination as an alternative method for distinguishing pleural transudates from exudates. This test combination avoids the need for venepuncture and the simultaneous collection of a blood sample.

Differential involvement of the hyaluronan (HA) receptors CD44 and receptor for HA-mediated motility in endothelial cell function and angiogenesis

Hyaluronan (HA), an important glycosaminoglycan constituent of the extracellular matrix, has been implicated in angiogenesis. It appears to exert its biological effects through binding interactions with at least two cell surface receptors: CD44 and receptor for HA-mediated motility (RHAMM). Recent in vitro studies have suggested potential roles for these two molecules in various aspects of endothelial function. However, the relative contribution of each receptor to endothelial functions critical to angiogenesis and their roles in vivo have not been established. We therefore investigated the endothelial expression of these proteins and determined the effects of antibodies against RHAMM and CD44 on endothelial cell (EC) function and in vivo angiogenesis. Both receptors were detected on vascular endothelium in situ, and on the surface of cultured EC. Further studies with active blocking antibodies revealed that anti-CD44 but not anti-RHAMM antibody inhibited EC adhesion to HA and EC proliferation, whereas anti-RHAMM but not CD44 antibody blocked EC migration through the basement membrane substrate, Matrigel. Although antibodies against both receptor inhibited in vitro endothelial tube formation, only the anti-RHAMM antibody blocked basic fibroblast growth factor-induced neovascularization in mice. These data suggest that RHAMM and CD44, through interactions with their ligands, are both important to processes required for the formation of new blood vessels.

[Surgical treatment of elderly patients with pancreatic neoplasm]

OBJECTIVE

To further elucidate the clinical feature, treatment and prognosis of pancreatic cancer in elderly patients.

METHODS

Data of 180 elderly patients with pancreatic cancer operated upon during 1990-2000 were analyzed. Postoperative complications and 30-day mortality rates were recorded among the 46 cases subjective to Whipple procedure, including 22 cases undergoing regional pancreatoduodenectomy after intervention therapy. 78 patients received palliative surgery and 50 patients received laparotomy. Follow-up was made for 6 months to 10 years.

RESULTS

All the patients were operated upon successfully. 48 patients underwent radical pancreatectomy with a mortality rate of 6.2 per cent, a complication rate of 20.8 per cent, and a mean survival period of 26 months. The 78 cases undergoing palliative surgery survived for 6 months on average. 54 patients undergoing laparotomy only survived for 3 months on average.

CONCLUSION

Aggressive surgical management helps prolong the survival period and improve the life quality of elderly patients with pancreatic cancer.

Caspase-activated DNase/DNA fragmentation factor 40 mediates apoptotic DNA fragmentation in transient cerebral ischemia and in neuronal cultures

Nuclear changes, including internucleosomal DNA fragmentation, are characteristic features of neuronal apoptosis resulting from transient cerebral ischemia and related brain insults for which the molecular mechanism has not been elucidated. Recent studies suggest that a caspase-3-mediated mechanism may be involved in the process of nuclear degradation in ischemic neurons. In this study, we cloned from rat brain a homolog cDNA encoding caspase-activated deoxyribonuclease (CAD)/DNA fragmentation factor 40 (DFF40), a 40 kDa nuclear enzyme that is activated by caspase-3 and promotes apoptotic DNA degradation. Subsequently, we investigated the role of CAD/DFF40 in the induction of internucleosomal DNA fragmentation in the hippocampus in a rat model of transient global ischemia and in primary neuronal cultures under ischemia-like conditions. At 8-72 hr after ischemia, CAD/DFF40 mRNA and protein were induced in the degenerating hippocampal CA1 neurons. CAD/DFF40 formed a heterodimeric complex in the nucleus with its natural inhibitor CAD (ICAD) and was activated after ischemia in a delayed manner (>24 hr) by caspase-3, which translocated into the nucleus and cleaved ICAD. Furthermore, an induced CAD/DFF40 activity was detected in nuclear extracts in both in vivo and in vitro models, and the DNA degradation activity of CAD/DFF40 was inhibited by purified ICAD protein. These results strongly suggest that CAD/DFF40 is the endogenous endonuclease that mediates caspase-3-dependent internucleosomal DNA degradation and related nuclear alterations in ischemic neurons.

Adenovirus-mediated interferon-beta gene therapy suppresses growth and metastasis of human prostate cancer in nude mice

The purpose of this study was to determine the effects of interferon-beta (IFN-beta) gene transfer on the growth of PC3MM2 human prostate cancer cells in nude mice. Intralesional delivery of an adenoviral vector encoding murine IFN-beta (AdIFN-beta), but not a vector encoding bacterial beta-galactosidase (AdLacZ), suppressed PC3MM2 tumors in a dose-dependent manner. At the highest dose (2x10(9) plaque-forming units, PFU), a single injection of AdIFN-beta (but not AdLacZ) suppressed orthotopic PC3MM2 tumors and development of metastasis by 80%, and eradicated the tumors in 20% of mice. Immunohistochemical staining showed that AdIFN-beta-treated tumors contained fewer microvessels, fewer proliferating cells, and more apoptotic cells than did the control tumors. Compared with controls, tumors injected with AdIFN-beta expressed higher levels of IFN-beta and inducible nitric oxide synthase (iNOS) and lower levels of basic fibroblast growth factor (bFGF) and transforming growth factor beta1 (TGF-beta1). In vitro analysis indicated that expression of bFGF and TGF-beta1 in PC3MM2 cells could be suppressed by the nitric oxide donor sodium nitroprusside. These data suggest that intratumoral delivery of the IFN-beta gene with adenoviral vectors could be an effective therapy for prostate cancer and that tumor suppression by AdIFN-beta correlated with up-regulation of iNOS and down-regulation of angiogenesis.

bcl 10 gene mutation in hepatocellular carcinoma

OBJECTIVE

To detect the mutation frequency of the bcl 10 gene in the early and advanced stages of hepatocellular carcinoma (HCC).

METHODS

Genome DNA samples were extracted from 46 cases of fresh HCC tumor tissues and their non-tumor adjacent tissues. Polymerase chain reaction-single strand conformation polymorphism method was used to detect point mutations of the three exons of the bcl 10 gene. For each individual exon, six random samples from those showing abnormal DNA bands were sequenced to verify those mutations. The relationship between serum alpha-fetoprotein (AFP) level and bcl 10 mutation, between the tumor size and bcl 10 mutation was also analyzed.

RESULTS

Among the 46 samples, 26 cases (56.5%) were found to have mutations in exon 1, 5 out of the 6 cases were shown to have 5744 C-->G mutation by sequencing; 25 cases (54.3%) were found to have mutations in exon 2, 4 out of the 6 cases were shown to have 11,311 T deletion mutation by sequencing. Twenty-one cases (45.7%) were found to have mutations in exon 3, all of the 6 cases selected for sequencing were shown to have 14,116 C-->T mutation. Statistical analysis showed that neither serum alpha-fetoprotein level nor the size of hepatocellular carcinoma has a significant relationship with bcl 10 mutation.

CONCLUSION

The bcl 10 gene has a high mutation frequency in liver cancer.

Characteristics of dorsal lingual papillae of the Bactrian camel (Camelus bactrianus)

The morphology of dorsal lingual papillae of the Bactrian camel (Camelus bactrianus) was studied by using light and scanning electron microscopy. Filiform and lenticular papillae were considered as mechanical papillae but fungiform and vallate papillae were considered as gustatory papillae. Filiform papillae were distributed mostly in the anterior two-thirds region of the tongue. Each filiform papilla consisted of one primary papilla and a few smaller secondary papillae. Lenticular papillae were distributed on the torus linguae. The larger papillae were arranged in two parallel lines medially whereas the smaller papillae were laterally located. Most of the fungiform papillae were found on the lateral margins of the anterior two-thirds of the tongue. These papillae were small and round. Intra-epithelial taste buds were located on the dorsal surface of each papilla. The vallate papillae were arranged in two rows on each rim of the torus linguae. Each round- and flat-shaped vallate papilla was surrounded by a prominent gustatory groove and an annular pad. A few taste buds were observed in the lateral epithelium of the papillae. The keratinization of the covering stratified squamous epithelium of the mechanical lingual papillae was relatively thicker than those of the gustatory papillae. The lingual papillae of the Bactrian camel exhibited some different characteristics from other domestic ruminants. These morphological characteristics of the tongue of the Bactrian camel might have evolved to assist the camel in prehension and manipulating of the inorganic stiff plants that grow in its environment and therefore might relate to the feed and feeding habits of the animal.

[Randomized controlled trial for the effect of amrinone and aprotinin on proinflammatory cytokine release in patients with prosthetic valve replacement during perioperative period]

OBJECTIVE

To explore the effect of amrinone and aprotinin on whole-body inflammatory response in the patients with prosthetic valve replacement during perioperative period.

METHODS

24 patients undergoing prosthetic valve replacement were randomized to control group (group A, n = 8), aprotinin group (group B, n = 8) and amrinone combined with aprotinin group (group C, n = 8). In the aprotinin group, 3 x 10(6) of aprotinin was added to the priming solution of the extracorporeal circulation (ECC). In the amrinone combined with aprotinin group 3 x 10(6) of aprotinin was added to the priming solution of the ECC and amrinone began with a bolus of 1 mg/kg followed by a maintenance infusion of 8 micrograms/(kg.min). The control group received an equivalent prime volume without aprotinin. Venous blood samples were drawn before the operation, at the end of ECC, 1 hour after the end of ECC, and one day after the operation respectively. Enzyme-linked immunosorbent assay techniques were used to measure each of the cytokines.

RESULTS

Before ECC, there were no differences of the levels of IL-6 and IL-8 among groups (P > 0.05). After ECC, the levels of IL-6 and IL-8 increased significantly in all groups (P < 0.05). The levels on day one after the operation were still higher than those before the operation in all groups (except the level of IL-8 in group C), but no statistical significance was observed. (P > 0.05). At 1 hour after the end of ECC, the level of IL-6 in group B was lower than that in group A, and the level of IL-6 in group C was lower than that in group B, but there was no statistically significant difference (P > 0.05); At the end of ECC, the level of IL-8 in group B was lower than that in group A and the level of IL-8 in group C was lower than that in group B, but no significant difference was noted (P > 0.05). It was also observed that the level of IL-8 was lower in group C than group A or B at 1 hour after the end of ECC.

CONCLUSION

Although amrinone and aprotinin have antiinflammatory activity, but pump prime only aprotinin or aprotinin combined with amrinone may fall in preventing proinflammatory cytokine release (IL-6, IL-8) completely in patients with prosthetic valve replacement during ECC perioperative period.

Recent changes in the health status of the older U.S. population: findings from the 1984 and 1994 supplement on aging

OBJECTIVES

To examine the changes in the use of health care services, physical functioning, disability, and other aspects of health status in the older U.S. population between 1984 and 1994.

DESIGN AND SETTING

The 1984 and 1994 National Health Interview Survey Supplements on Aging, which were national probability samples of the civilian, noninstitutionalized population age 70 and older.

PARTICIPANTS

A total of 7,541 and 9,447 persons, representing the 17.3 million and 21.8 million U.S. population age 70 and older in 1984 and 1994, respectively.

MEASUREMENTS

Annual bed-limitation days, doctor visits, episodes and days of hospital stays, limitation in 10 measures of physical performance, disability in seven activities of daily living (ADLs) and six instrumental activities of daily living (IADLs), and participation in social activities and exercise.

RESULTS

The annual bed-limitation days and hospital stays declined significantly in both men and women between 1984 and 1994. There was a large decrease in the prevalence of limitation in physical performance and a smaller decrease in disability of IADLs. The changes were greater in women than in men. The prevalence of disability in ADLs was not changed in women in general and increased somewhat in men. Significant increases in the proportion of persons participating in certain social activities and regular exercise were found in both men and women. Jointly considering the indicators, including annual bed days and hospital stays, physical performance, ADLs, and IADLs, 4.2% more men and 3.1% more women were physically robust in 1994 than in 1984. Approximately 420,000 more older people would have lived in a severely restricted and disabled state in 1994 if the rate of limitation had not declined.

CONCLUSION

This study provides evidence of an overall improvement in the health status of older Americans but inconsistency in the trends existed for different disability measures and for population subgroups.

Anthocyanins are absorbed in glycated forms in elderly women: a pharmacokinetic study

BACKGROUND

Anthocyanins are potent antioxidants that are widely distributed in fruit, vegetables, and red wines. Anthocyanin products are also prescribed as medicines in many countries for treating various diseases. However, the pharmacokinetics of dietary anthocyanins are not known in humans because these glycosides were long considered nonabsorbable.

OBJECTIVE

The objective of this study was to determine whether anthocyanins can be absorbed as glycosides and to evaluate their pharmacokinetics in humans.

DESIGN

Four healthy elderly women consumed 720 mg anthocyanins. A series of blood and urine samples were collected before and after consumption of the anthocyanins. Anthocyanins were measured in plasma and urine by combining an octadecylsilane solid-phase extraction for sample preparation and an HPLC system with diode array for anthocyanin separation and detection. The structures of anthocyanins as glycosides in plasma and urine were further confirmed by using liquid chromatography-mass spectrometry.

RESULTS

Anthocyanins were detected as glycosides in plasma and urine. The maximum plasma concentration of total anthocyanins varied from 55.3 to 168.3 nmol/L, with an average of 97.4 nmol/L, and was reached within 71.3 min. The elimination of plasma anthocyanins appeared to follow first-order kinetics. The elimination half-life of plasma total anthocyanins was calculated to be 132.6 min. Most anthocyanin compounds were excreted in urine during the first 4 h. The excretion rate of total anthocyanins was 77 microg/h during the first 4 h and 13 microg/h during the second 4 h.

CONCLUSION

Anthocyanins are absorbed in their unchanged glycated forms in elderly women.

Single-dose pharmacokinetics of atrasentan, an endothelin-A receptor antagonist

The pharmacokinetics of 1, 10, 23.25, and 139.5 mg doses of atrasentan was assessed in a placebo-controlled, double-blind, single oral dose study in 24 healthy male subjects. Atrasentan was well tolerated. Atrasentan pharmacokinetics was linear in the 1 to 23.25 mg dose range, with some dose dependency in the highest dose group. Harmonic mean terminal half-life was similar across all dose groups (20-25 h). Apparent oral clearance was low (12 L/h) for the highest dose group compared with the other three dose groups (21-27 L/h). The apparent volume of distribution was large (approximately 6 L/kg), consistent with extensive tissue distribution.

[Analysis and expression of Hyphantria cunea nuclear polyhedrosis virus sod gene]

The sequencing results indicated that Hyphantria cunea nuclear polyhedrosis virus (HcNPV) sod gene open reading frame of 456 nt encoding protein of 151 amino acid, was identified to that of Bombyx mori nuclear polyhedrosis virus (BmNPV), and exhibited 97.2% homology at nucletde level to that of Autographa californica nuclear polyhedrosis virus (AcNPV), three amino acid residues difference in amino acid level with AcNPV sod. The essential amino acid residues for the construction and active could be detected in HcNPV sod. Activity of the SOD is 147.09 U per milliliter E. coli.

Intracellular Bax translocation after transient cerebral ischemia: implications for a role of the mitochondrial apoptotic signaling pathway in ischemic neuronal death

Activation of terminal caspases such as caspase-3 plays an important role in the execution of neuronal cell death after transient cerebral ischemia. Although the precise mechanism by which terminal caspases are activated in ischemic neurons remains elusive, recent studies have postulated that the mitochondrial cell death-signaling pathway may participate in this process. The bcl-2 family member protein Bax is a potent proapoptotic molecule that, on translocation from cytosol to mitochondria, triggers the activation of terminal caspases by increasing mitochondrial membrane permeability and resulting in the release of apoptosis-promoting factors, including cytochrome c. In the present study, the role of intracellular Bax translocation in ischemic brain injury was investigated in a rat model of transient focal ischemia (30 minutes) and reperfusion (1 to 72 hours). Immunochemical studies revealed that transient ischemia induced a rapid translocation of Bax from cytosol to mitochondria in caudate neurons, with a temporal profile and regional distribution coinciding with the mitochondrial release of cytochrome c and caspase-9. Further, in postischemic caudate putamen in vivo and in isolated brain mitochondria in vitro, the authors found enhanced heterodimerization between Bax and the mitochondrial membrane permeabilization-related proteins adenine nucleotide translocator (ANT) and voltage-dependent anion channel. The ANT inhibitor bongkrekic acid prevented Bax and ANT interactions and inhibited Bax-triggered caspase-9 release from isolated brain mitochondria in vitro. Bongkrekic acid also offered significant neuroprotection against ischemia-induced caspase-3 and caspase-9 activation and cell death in the brain. These results strongly suggest that the Bax-mediated mitochondrial apoptotic signaling pathway may play an important role in ischemic neuronal injury.

Pharmacokinetics and tolerability of extended-release clarithromycin

BACKGROUND

Clarithromycin is a semisynthetic macrolide that exhibits broad-spectrum activity against gram-positive, gram-negative, and atypical respiratory tract and skin/skin structure pathogens, Mycobacterium species, and Helicobacter pylori. It is indicated for the treatment of a wide variety of respiratory and dermatologic infections in children and adults as well as prophylaxis and treatment of Mycobacterium avium complex infection and peptic ulcers due to H. pylori.

OBJECTIVE

In this article, we review the results of 3 studies of the steady-state pharmacokinetic profiles of clarithromycin and 14(R)-hydroxy-clarithromycin after multiple oral once-daily doses of 500-mg extended-release (ER) clarithromycin tablets. We also review the drug tolerability in 2 phase III comparative clinical trials of immediate-release (IR) and ER clarithromycin conducted in adults with acute maxillary sinusitis (AMS) and acute exacerbation of chronic bronchitis (AECB).

METHODS

In the 3 pharmacokinetic studies, multiple-dose regimens of clarithromycin IR (one 250-mg or 500-mg tablet twice daily) and clarithromycin ER (one or two 500-mg tablets once daily), administered to healthy male and female volunteers, were evaluated. The effect of administration in nonfasting versus fasting conditions was assessed as well. Tolerability information was collected from each adult patient enrolled in phase III efficacy studies conducted to support the application for US Food and Drug Administration approval for the treatment of AMS and AECB. Regimens evaluated were 500 mg IR clarithromycin tablets twice daily or 1000 mg (2 x 500 mg) ER clarithromycin tablets once daily for 7 days (AECB) or 14 days (AMS).

RESULTS

Bioavailability of the ER clarithromyin tablet administered with food was equivalent to that of the reference IR tablet, based on area under the plasma concentration-time curve (AUC) for both parent compound and active metabolite. The bioavailability of the ER tablet was 30% lower (based on clarithromycin AUC) when administered under fasting versus nonfasting conditions. Compared with the IR tablet, administration of the ER tablet resulted in significantly lower (P < 0.05) clarithromycin peak plasma concentration (Cmax), delayed time to Cmax, and lower degree of concentration fluctuation, confirming its in vivo extended-release characteristics. The most frequently reported adverse events (AEs) in the phase III clinical trials were diarrhea, abnormal taste, and nausea and were generally mild or moderate. The incidence of AEs was comparable for the 2 formulations. The severity of gastrointestinal AEs was significantly less for the ER formulation than for the IR formulation (P = 0.018), as was the frequency of premature study discontinuation due to gastrointestinal AEs or abnormal taste (P = 0.004).

CONCLUSIONS

The results from the 3 pharmacokinetic studies reviewed demonstrate the bioequivalence of the ER and IR formulations and support the use of this clarithromycin ER formulation in a once-daily dosing regimen in phase III clinical trials. The ER tablet should be taken with food to maximize bioavailability. The results of 2 phase III comparative clinical efficacy and safety trials of clarithromycin ER tablets versus IR tablets in AMS and AECB confirm the good tolerability of the ER formulation.

Identification of procyanidins and anthocyanins in blueberries and cranberries (Vaccinium spp.) using high-performance liquid chromatography/mass spectrometry

Blueberries and cranberries were analyzed for procyanidins using normal-phase HPLC/MS. Monomers, identified as (+)-catechin and (-)-epicatechin, and a series of oligomers were detected in blueberries, and MS data confirmed that the oligomers consisted of (epi)catechin units that were exclusively singly linked (B-type). The procyanidin "fingerprints" were similar for Tifblue and Rubel but higher than that for lowbush blueberries. In whole cranberries, (-)-epicatechin was present, along with a complex series of oligomers. Both A-type (contained only one double linkage per oligomer) and B-type oligomers were present. Two commercial cranberry juices exhibited similar procyanidin profiles, except that one contained increased quantities. There were processing effects on the procyanidin content of cranberry extract and juices when compared to those of the unprocessed fruits. Monomer, dimers, and A-type trimers were the primary procyanidins, with only trace levels of the B-type trimers and A-type tetramers and with an absence of the higher oligomers in cranberry extract and juices.

Gene therapy for hepatocellular carcinoma based on tumour-selective suicide gene expression using the alpha-fetoprotein (AFP) enhancer and a housekeeping gene promoter

The aim of this study was to examine whether the human alpha-fetoprotein (AFP) enhancer could be used to induce hepatocellular carcinoma (HCC)-selective expression of the herpes simplex virus thymidine kinase (HSV-tk) gene which is under the control of the phosphoglycerate kinase (pgk) promotor. The human AFP enhancer was linked with the non-tissue-specific, human housekeeping pgk promoter in a retroviral vector. AFP-producing HCC cells infected with retroviruses carrying the HSV-tk gene under the control of the AFP enhancer/pgk promoter were much more susceptible to the prodrug, ganciclovir (GCV), than those infected with the same retroviruses without the AFP enhancer. Non-HCC cells infected with retroviruses carrying the HSV-tk gene under the control of the AFP enhancer/pgk promoter exhibited profoundly increased resistance to GCV compared with those infected with the same retroviruses without the AFP enhancer. Northern blot analysis revealed that the AFP enhancer caused enhanced HSV-tk expression in AFP-producing HCC cells and suppressed HSV-tk expression in non-HCC cells. Our results indicate that the AFP enhancer could give HCC selectivity to the pgk promoter, and that this novel strategy may be useful for HCC-selective cancer gene therapy.

The role of the membrane-spanning domain of type I signal peptidases in substrate cleavage site selection

Type I signal peptidase (SPase I) catalyzes the cleavage of the amino-terminal signal sequences from preproteins destined for cell export. Preproteins contain a signal sequence with a positively charged n-region, a hydrophobic h-region, and a neutral but polar c-region. Despite having no distinct consensus sequence other than a commonly found c-region "Ala-X-Ala" motif preceding the cleavage site, signal sequences are recognized by SPase I with high fidelity. Remarkably, other potential Ala-X-Ala sites are not cleaved within the preprotein. One hypothesis is that the source of this fidelity is due to the anchoring of both the SPase I enzyme (by way of its transmembrane segment) and the preprotein substrate (by the h-region in the signal sequence) in the membrane. This limits the enzyme-substrate interactions such that cleavage occurs at only one site. In this work we have, for the first time, successfully isolated Bacillus subtilis type I signal peptidase (SipS) and a truncated version lacking the transmembrane domain (SipS-P2). With purified full-length as well as truncated constructs of both B. subtilis and Escherichia coli (Lep) SPase I, in vitro specificity studies indicate that the transmembrane domains of either enzyme are not important determinants of in vitro cleavage fidelity, since enzyme constructs lacking them reveal no alternate site processing of pro-OmpA nuclease A substrate. In addition, experiments with mutant pro-OmpA nuclease A substrate constructs indicate that the h-region of the signal peptide is also not critical for substrate specificity. In contrast, certain mutants in the c-region of the signal peptide result in alternate site cleavage by both Lep and SipS enzymes.

Characterization of the rat DNA fragmentation factor 35/Inhibitor of caspase-activated DNase (Short form). The endogenous inhibitor of caspase-dependent DNA fragmentation in neuronal apoptosis

Nuclear changes, including internucleosomal DNA fragmentation, are classical manifestations of apoptosis for which the biochemical mechanisms have not been fully elucidated, particularly in neuronal cells. We have cloned the rat DNA fragmentation factor 35/inhibitor of caspase-activated DNase (short form) (DFF35/ICAD(S)) and found it to be the predominant form of ICAD present in rodent brain cells as well as in many other types of cells. DFF35/ICAD(S) forms a functional complex with DFF40/caspase-activated DNase (CAD) in the nucleus, and when its caspase-resistant mutant is over-expressed, it inhibits the nuclease activity, internucleosomal DNA fragmentation, and nuclear fragmentation but not the shrinkage and condensation of the nucleus, in neuron-differentiated PC12 cells in response to apoptosis inducers. DFF40/CAD is found to be localized mainly in the nucleus, and during neuronal apoptosis, there is no evidence of further nuclear translocation of this molecule. It is further suggested that inactivation of DFF40/CAD-bound DFF35 and subsequent activation of DFF40/CAD during apoptosis of neuronal cells may not occur in the cytosol but rather in the nucleus through a novel mechanism that requires nuclear translocation of caspases. These results establish that DFF35/ICAD(S) is the endogenous inhibitor of DFF40/CAD and caspase-dependent apoptotic DNA fragmentation in neurons.

Combinatorial synthesis of novel and potent inhibitors of NADH:ubiquinone oxidoreductase

BACKGROUND

NADH:ubiquinone oxidoreductase (complex I) is the first of three large enzyme complexes located in the cell's inner mitochondrial membrane which form the electron transport chain that carries electrons from NADH to molecular oxygen during oxidative phosphorylation. There is significant interest in developing small molecule inhibitors of this enzyme for use as biological probes, insecticides and potential chemopreventive/chemotherapeutic agents. Herein we describe the application of novel natural product-like libraries to the discovery of a family of potent benzopyran-based inhibitors.

RESULTS

Initially a combinatorial library of benzopyrans, modeled after natural products, was synthesized using a solid phase cycloloading strategy. Screening of this diversity oriented library for inhibitory potency against NADH:ubiquinone oxidoreductase activity in vitro using bovine heart electron transport particles provided several lead compounds which were further refined through a series of focused libraries.

CONCLUSIONS

Using this combinatorial library approach, a family of potent 2,2-dimethylbenzopyran-based inhibitors was developed with IC(50) values in the range of 18-55 nM. Cell-based assays revealed that these inhibitors were rather non-cytotoxic in the MCF-7 cell line; however, they were quite cytostatic in a panel of cancer cell lines suggesting their potential as chemotherapeutic/chemopreventive candidates.

Effect of long-term dietary antioxidant supplementation on influenza virus infection

This study compared the effect of vitamin E on the course of influenza infection with that of other antioxidants. (In a previous study we showed that short-term vitamin E supplementation significantly decreased pulmonary viral titer in influenza-infected old mice). Eighteen-month-old C57BL/6NCrlBR mice were fed one of the following semisynthetic diets for 6 months: control, vitamin E supplemented, glutathione supplemented, vitamin E and glutathione supplemented, melatonin supplemented, or strawberry extract supplemented. After influenza virus challenge, mice fed vitamin E-supplemented diet had significantly lower pulmonary viral titers compared to those fed the control diet (10(2.6) vs 10(4.0), p < .05) and were able to maintain their body weight after infection (1.8+/-0.9 g weight loss/5 days postinfection in vitamin E group vs 6.8+/-1.4 g weight loss/5 days postinfection in control group, p < .05). Other antioxidants did not have a significant effect on viral titer or weight loss. There was a significant inverse correlation of weight loss with food intake (r = -.96, p < .01), indicating that the observed weight changes were mainly due to decreased food intake. Pulmonary interleukin (IL)-6, IL-1beta, and tumor necrosis factor (TNF)-alpha levels increased significantly postinfection. The vitamin E group had lower lung IL-6 and TNF-alpha levels following infection compared to the control group. In addition, there was a significant positive correlation between weight loss and lung IL-6 (r = .77, p < .01) and TNF-alpha (r = .68, p < .01) levels. Because IL-6 and TNF-alpha have been shown to contribute to the anorexic effect of infectious agents, the prevention of weight loss by vitamin E might be due to its reduced production of IL-6 and TNF-alpha following infection. Thus, among the antioxidants tested, only vitamin E was effective in reducing pulmonary viral titers and preventing an influenza-mediated decrease in food intake and weight loss. Other dietary antioxidant supplementations that reduced one or more measures of oxidative stress (4-hydroxynonenal, malondialdehyde, and hydrogen peroxide) did not have an effect on viral titer, which suggests that, in addition to its antioxidant activity, other mechanisms might be involved in vitamin E's beneficial effect on lowering viral titer and preventing weight loss.

The effects of a multivitamin/mineral supplement on micronutrient status, antioxidant capacity and cytokine production in healthy older adults consuming a fortified diet

BACKGROUND

Inadequate micronutrient intake among older adults is common despite the increased prevalence of fortified/enriched foods in the American diet. Although many older adults take multivitamin supplements in an effort to compensate, studies examining the benefits of this behavior are absent.

OBJECTIVE

To determine whether a daily multivitamin/mineral supplement can improve micronutrient status, plasma antioxidant capacity and cytokine production in healthy, free-living older adults already consuming a fortified diet.

METHODS

An eight-week double-blind, placebo-controlled clinical trial among 80 adults aged 50 to 87 years (mean = 66.5 +/- 8.6 years).

RESULTS

Multivitamin treatment significantly increased (p<0.01, compared to placebo) plasma concentrations of vitamins D (77 to 100 nmol/L), E (27 to 32 micromol/L), pyridoxal phosphate (55.1 to 75.2 nmol/L), folate (23 to 33 nmol/L), B12 (286 to 326 pmol/L)), C (55 to 71 micromol/L), and improved the riboflavin activity coefficient (1.23 to 1.15), but not vitamins A and thiamin. The multivitamin reduced the prevalence of suboptimal plasma levels of vitamins E (p=0.003), B12 (p=0.004), and C (p=0.08). Neither glutathione peroxidase activity nor antioxidant capacity (ORAC) were affected. No changes were observed in interleukin-2, -6 or -10 and prostaglandin E2, proxy measures of immune responses.

CONCLUSIONS

Supplementation with a multivitamin formulated at about 100% Daily Value can decrease the prevalence of suboptimal vitamin status in older adults and improve their micronutrient status to levels associated with reduced risk for several chronic diseases.

[Distribution of peptidergic neurons in the rat suprachiasmatic nucleus]

The distribution of the peptidergic neurons in the suprachiasmatic nucleus(SCN) in five adult male SD rats was examined by multi-immunolabelling for vasoactive intestinal polypeptide(VIP), arginine vasopressin (AVP) and somatostatin(SOM). The immunoreactions were visualized with an Elite ABC Kit(Vector Lab). The substrates in the peroxidase reaction were diaminobenzidine(DAB), tetramethylbenzidine(TMB) and 4-chloro-1-naphtol. The results showed that the differences in distribution and population of VIP-, AVP- and SOM-like neurons existed in the rostral, intermediate and caudal regions of the SCN and these neurons were overlapped and SOM-like neurons were scattered among them in the area between VIP- and AVP-like neurons. These findings may provide new morphologic evidences for explaining the functional mechanism in the SCN.

Postprandial increases in serum antioxidant capacity in older women

Eight women were recruited for studying the effects of a meal on overall antioxidant status. Subjects resided in a metabolic research unit for two 36-h periods. During period A, subjects fasted overnight (12 h) and were then given a breakfast, a lunch, a snack, and a dinner. During period B, subjects fasted for 23 h and were then given a dinner. These meals were designed to contain negligible antioxidants. Blood samples were collected for analyzing total antioxidant capacity (TAC) and individual antioxidants. The results showed that serum TAC significantly increased by up to 23% after the consumption of the lunch and dinner during period A. Serum TAC did not increase until after the consumption of the dinner during period B. Among the antioxidants (vitamin C, alpha-tocopherol, bilirubin, and uric acid) examined, serum uric acid was the only one that showed a significant postprandial increase, which was also parallel to the postprandial response in serum TAC. These results indicate that food intake, even if low in antioxidants, can increase the serum total antioxidant activity.