A genome-wide analysis of Arabidopsis Rop-interactive CRIB motif-containing proteins that act as Rop GTPase targets

The plant-specific Rop family GTPases are versatile molecular switches in many processes during plant growth, development, and responses to the environment. To understand how Rop achieves its functional versatility in signaling, we performed a genome-wide identification of putative Rop targets using a combination of the yeast two-hybrid method, bioinformatic tools, and a robust functional assay in pollen. In this study, we have identified 11 Arabidopsis genes encoding novel proteins, termed RICs (for Rop-interactive CRIB motif-containing proteins), that contain a CRIB (for Cdc42/Rac-interactive binding) motif required for their specific interaction with GTP-bound Rop1. RICs are divergent and classified into five groups that share little sequence homology outside of the conserved Rop-interactive domain. Overexpression in tobacco pollen tubes of the nine Ric genes that are expressed in Arabidopsis pollen causes distinct phenotypes, implying distinct functions for various RICs. RIC3 (group III) and RIC4 (group V) both cause depolarized growth like Rop1 and display Rop1-enhanced localization to the tip of pollen tubes, suggesting that these RICs may be two distinct targets of Rop1. In contrast, RIC10 (group I) promotes pollen tube elongation but does not affect pollen tube growth polarity and shows Rop1-independent localization to the cytoplasm, suggesting that RIC10 may participate in a Rop1-independent pathway probably controlled by a different Rop. Expression of all other RICs causes various degrees of growth inhibition in pollen tubes. Furthermore, these inhibitory RICs also exhibit distinct patterns of localization in pollen tubes. Our results suggest that various RICs have evolved to interact with Rops differentially and to perform distinct functions in pollen tubes. Reverse transcriptase-mediated polymerase chain reaction analysis showed that six of the nine RICs are expressed in various parts of Arabidopsis plants. On the basis of these observations, we propose that RICs function as Rop GTPase targets that control various Rop-dependent signaling pathways in plants.

Isochorismate synthase is required to synthesize salicylic acid for plant defence

Salicylic acid (SA) mediates plant defences against pathogens, accumulating in both infected and distal leaves in response to pathogen attack. Pathogenesis-related gene expression and the synthesis of defensive compounds associated with both local and systemic acquired resistance (LAR and SAR) in plants require SA. In Arabidopsis, exogenous application of SA suffices to establish SAR, resulting in enhanced resistance to a variety of pathogens. However, despite its importance in plant defence against pathogens, SA biosynthesis is not well defined. Previous work has suggested that plants synthesize SA from phenylalanine; however, SA could still be produced when this pathway was inhibited, and the specific activity of radiolabelled SA in feeding experiments was often lower than expected. Some bacteria such as Pseudomonas aeruginosa synthesize SA using isochorismate synthase (ICS) and pyruvate lyase. Here we show, by cloning and characterizing an Arabidopsis defence-related gene (SID2) defined by mutation, that SA is synthesized from chorismate by means of ICS, and that SA made by this pathway is required for LAR and SAR responses.

Identification and characterization of a novel androgen receptor coregulator ARA267-alpha in prostate cancer cells

The androgen receptor (AR) is a member of the steroid receptor superfamily that binds to the androgen response element to regulate target gene transcription. AR may need to interact with some selected coregulators for maximal or proper androgen function. Here we report the isolation of a new AR coregulator with a calculated molecular mass of 267 kDa named the androgen receptor-associated protein 267-alpha (ARA267-alpha). ARA267-alpha contains 2427 amino acids, including one Su(var)3-9, Enhancer-of-zeste, and Trithorax (SET) domain, two LXXLL motifs, three nuclear translocation signal (NLS) sequences, and four plant homeodomain (PHD) finger domains. Northern blot analyses reveal that ARA267-alpha is expressed predominantly in the lymph node as 13- and 10-kilobase transcripts. HepG2 is the only cell line tested that does not express ARA267-alpha. Yeast two-hybrid and glutathione S-transferase pull-down assays show that both the N and C terminus of ARA267-alpha interact with the AR DNA- and ligand-binding domains. Unlike other coregulators, such as CBP, which enhance the interaction between the N and C terminus of AR, we found that ARA267-alpha had little influence on the interaction between the N and C terminus of AR. Luciferase and chloramphenicol acetyltransferase assays show that ARA267-alpha can enhance AR transactivation in a dihydrotestosterone-dependent manner in PC-3 and H1299 cells. ARA267-alpha can also enhance AR transactivation with other coregulators, such as ARA24 or PCAF, a histone acetylase, in an additive manner. Together, our data demonstrate that ARA267-alpha is a new AR coregulator containing the SET domain with an exceptionally large molecular mass that can enhance AR transactivation in prostate cancer cells.

SEL-10 is an inhibitor of notch signaling that targets notch for ubiquitin-mediated protein degradation

Notch receptors and their ligands play important roles in both normal animal development and pathogenesis. We show here that the F-box/WD40 repeat protein SEL-10 negatively regulates Notch receptor activity by targeting the intracellular domain of Notch receptors for ubiquitin-mediated protein degradation. Blocking of endogenous SEL-10 activity was done by expression of a dominant-negative form containing only the WD40 repeats. In the case of Notch1, this block leads to an increase in Notch signaling stimulated by either an activated form of the Notch1 receptor or Jagged1-induced signaling through Notch1. Expression of dominant-negative SEL-10 leads to stabilization of the intracellular domain of Notch1. The Notch4 intracellular domain bound to SEL-10, but its activity was not increased as a result of dominant-negative SEL-10 expression. SEL-10 bound Notch4 via the WD40 repeats and bound preferentially to a phosphorylated form of Notch4 in cells. We mapped the region of Notch4 essential for SEL-10 binding to the C-terminal region downstream of the ankyrin repeats. When this C-terminal fragment of Notch4 was expressed in cells, it was highly labile but could be stabilized by the expression of dominant-negative SEL-10. Ubiquitination of Notch1 and Notch4 intracellular domains in vitro was dependent on SEL-10. Although SEL-10 interacts with the intracellular domains of both Notch1 and Notch4, these proteins respond differently to interference with SEL-10 function. Thus, SEL-10 functions to promote the ubiquitination of Notch proteins; however, the fates of these proteins may differ.

High-field 127I NMR of solid sheelite structures: periodates revisited

We report new solid-state 127I NMR results for sheelite periodates, MIO4 (M = Na+, K+, Rb+, and NH4+), and for pseudo-scheelite CsIO4 and HIO4. The observed 127I quadrupole coupling constants were between 1.0 and 43.0 MHz in agreement with previous NQR data. In contrast to an early 127I NMR study (S. L. Segel and H. M. Vyas, 1980, J. Chem. Phys. 72, 1406), we found that the 127I chemical shift anisotropy is negligibly small in sheelite periodates. A small but definite 127I chemical shift tensor was observed for pseudo-scheelite CsIO4.

Impairment of non-specific immunity in patients under persistent vegetative state resulting from trauma

OBJECTIVE

To investigate the immune response in patients under persistent vegetative state (PVS) resulting from trauma.

METHODS

Peripheral blood monocytes were obtained from 12 PVS patients (Group PVS)and individuals in normal control group by density gradient centrifugation; the enzyme linked immunosorbent assay kit was then used to measure monocyte HLA-DR antigen expression on the surface of peripheral blood monocytes before and after monocyte activation with either IFN-gamma or LPS.

RESULTS

Compared with normal control group, the peripheral blood monocyte HLA-DR antigen expression in the Group PVC fell significantly in PV S patients (P<0.001); the level of HLA-DR antigen express ion on the monocyte surface rose notably after stimulation with either IFN-gamma or LPS (P<0.01). As for PVS patients, it was still difficult to restore to normal (P<0.05).

CONCLUSIONS

The level of HLA-DR antigen expression on the sur face of peripheral blood monocytes in PVS patients decreases obviously. Therefore, the function of non-specific immunity in PVS patients is suppressed.

Suppression of T cells results in long-term survival of mouse heart xenografts in C6-deficient rats

The present study aimed to investigate the role of cellular immune response in the absence of membrane attack complex (MAC) formation in the concordant mouse-to-rat heart xenografting. Hearts from BALB/c mice were transplanted into the neck vessels of C6-competent (C6(+)) and C6-deficient (C6(-)) PVG rats. Liposome-encapsulated dichloro-methylene diphosphonate (Lip-Cl2MDP) was administered at a dose of 10 ml/kg 2 days before transplantation and every 5 days thereafter. Cyclosporine (CsA) was administered intramuscularly (i.m.) at a dose of 15 mg/kg per day. The heart xenografts were harvested for immuno-histological analysis at the time of rejection and the functioning grafts were removed at 70 days after transplantation. In untreated C6(+) rats, xeno-grafts survived for 2.3 +/- 0.5 days. Treatment with CsA or Lip-Cl(2)MDP in C6(+) rats did not significantly affect graft survival (2.5 +/- 0.6 and 2.3 +/- 0.4 days, respectively). In untreated C6(-) rats, xenografts survived for 5.0 +/- 0.6 days. However, Lip-Cl(2)MDP in C6(-) rats resulted in a prolongation of graft survival to 11 +/- 2.3 days (P < 0.05 vs. untreated C6(-) rats), while treatment with CsA alone in these rats led to more than 70 days' survival in four out of six grafts (61 +/- 16 days). In untreated C6(+) rats, immunohistology showed a severe myocardial necrosis and thrombosis with a scarce cellular infiltrate in the rejected xenografts. By contrast, in untreated C6(-) rats, xenografts were heavily infiltrated by macrophages and T cells. The number of macrophages, but not T cells, was markedly reduced in Lip-Cl(2)MDP-treated rats. In CsA-treated C6(-) rats, the grafts harvested at 70 days after transplantation had a normal morphology, with a minimal cellular infiltrate. Our data indicate that MAC-mediated injury plays an essential role in concordant xenograft rejection. Once this mechanism has been prevented, suppression of T cells allows for long-term xenograft survival.

[The influence of two different casting temperatures on properties of the incorporated keeper]

OBJECTIVE

To probe the clinical possibility of making incorporated keeper cap by high temperature casting.

METHODS

The incorporated keepers were equally divided into two groups, and cast by applying medium and high temperatures respectively. The two groups were compared with the following items: the morphological changes and thickness of keeper's oxide film, the combining quality between keeper and alloy, and the magnetic retention force.

RESULTS

The two different casting temperatures had the similar influence on the keeper's properties, such as the keeper's metallographical view, magnetic force (medium temperature casting group: 433.6 g; high temperature casting group: 433.8 g), and combining quality with alloy, except for the morphology and thickness of the keeper's oxide film. The oxide films of the high temperature casting group (surface: 7.59 microns combining surface of keeper and alloy: 6.17 microns) were thicker than those of the medium temperature casting group (surface: 4.65 microns; combining surface of keeper and alloy: 3.95 microns).

CONCLUSIONS

The incorporated keeper could be made by using high temperature casting method instead of medium temperature one in clinic.

Abalone, Haliotis discus hannai Ino, can synthesize myo-inositol de novo to meet physiological needs

The experiments were conducted to investigate the effects of dietary myo-inositol on the survival, growth, proximate composition and de novo synthesis of myo-inositol in abalone, Haliotis discus hannai Ino. The possible inositol-synthesizing capacity of intestinal microflora was also examined. Seven semipurified diets were formulated to provide graded levels of myo-inositol (28.7-1020.1 mg/kg diet). A control diet, the basal diet supplemented with 4 g/kg tetracycline hydrochloride, was employed to suppress synthesis of myo-inositol by intestinal bacteria. Abalone juveniles of similar size (weight, 144.6 +/- 0.8 mg; shell length, 10.92 +/- 0.10 mm) were distributed in a flow-through system using a completely randomized design with eight treatments and three replicates per treatment. They were fed the appropriate diets once daily for 16 wk. Survival, growth, crude protein, lipid, moisture of whole soft body and visceral inositol content were independent of myo-inositol supplementation (P > 0.05). The addition of the antibiotic also did not affect the survival, growth and whole soft body composition. It indicated that intestinal microflora contributed little to the myo-inositol nutrition in abalone. The present study, for the first time, demonstrated de novo synthesis of myo-inositol in mollusks because the visceral tissue of abalone showed high levels of myo-inositol synthetase activities (combined activities of myo-inositol-1-phosphate synthetase and inositol-1-phosphatase), ranging from 74.0 to 98.2 micromol/(h x g protein). The enzyme activity significantly and negatively correlated with dietary myo-inositol level (r = -0.81). Hence, dietary myo-inositol is not essential for abalone because tissue synthesis of the vitamin appears to be sufficient to support normal growth and health of this mollusk.

Prenatal nicotine affects catecholamine gene expression in newborn rat carotid body and petrosal ganglion

Nicotine exposure modifies the expression of catecholamine and opioid neurotransmitter systems involved in attenuation of hypoxic chemosensitivity. We used in situ hybridization histochemistry to determine the effect of prenatal and early postnatal nicotine exposure on tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), preproenkephalin (PPE), and D2-dopamine receptor mRNA levels in the rat carotid body and petrosal ganglion during postnatal development. In the carotid body, nicotine increased TH mRNA expression in animals at 0 and 3 postnatal days (both, P < 0.05 vs. control) without affecting TH mRNA levels at 6 and 15 days. At 15 postnatal days, DbetaH mRNA levels were increased in the carotid body of nicotine-exposed animals. Dopamine D2-receptor mRNA levels in the carotid body increased with postnatal age but were unaffected by nicotine exposure. PPE was not expressed in the carotid body at any of the ages studied in control or treated animals. In the petrosal ganglion, nicotine increased the number of ganglion cells expressing TH mRNA in animals at 3 days (P < 0.01 vs. control). DbetaH mRNA expression was not induced nor was PPE mRNA expression increased in the petrosal ganglion in treated animals. Prenatal nicotine exposure upregulates mRNAs involved in the synthesis of two inhibitory neuromodulators, dopamine and norepinephrine, in peripheral arterial chemoreceptors, which may contribute to abnormalities in cardiorespiratory control observed in nicotine exposed animals.

Activation of caspase-3 activity and apoptosis in MDA-MB-468 cells by N(omega)-hydroxy-L-arginine, an inhibitor of arginase, is not solely dependent on reduction in intracellular polyamines

We have shown previously that (NOHA) an intermediate in the nitric oxide (NO) synthetic pathway and an inhibitor of arginase significantly reduced intracellular polyamines, activated caspase-3 and induced apoptosis in the human breast cancer cell line MDA-MB-468. These actions of NOHA were abolished in the presence of exogenous L-ornithine suggesting that a reduction in the intracellular polyamine content might be responsible for the activation of caspase-3 and apoptotic actions of NOHA. In order to further explore this possibility, we used SAM-486A and alpha-difluoromethylornithine (DFMO), which are inhibitors of S-adenosylmethionine decarboxylase (SAMDC), and ornithine decarboxylase (ODC), respectively, either alone or in combination to reduce the intracellular polyamine levels. We then assessed whether a reduction in polyamine levels by these two compounds to a similar degree to that produced by NOHA activated caspase-3 which occurs prior to the onset of apoptosis. We observed that both SAM-486A and DFMO, either alone or in combination, inhibited cell proliferation, induced p21 and arrested cells in the G(0)-G(1) phase of the cell cycle but failed to activate caspase-3 as assessed by enzymatic assay of caspase-3, western blot analysis of the proteolytic cleavage of caspase-3 protein as well as TUNEL assay. Furthermore, pre-incubation of the cells with SAM-486A and DFMO for 4 days, either alone or in combination significantly inhibited the activation of caspase-3 and apoptosis by NOHA when compared with that observed with cells treated with NOHA alone. Our results, therefore, indicate that the activation of caspase-3 and apoptosis observed with NOHA cannot be solely explained by a reduction in intracellular polyamine levels and that other mechanisms need to be also considered.

Development of porcine embryos and offspring after intracytoplasmic sperm injection with liposome transfected or non-transfected sperm into in vitro matured oocytes

The objective of this study was to evaluate in vitro and in vivo development of porcine in vitro matured (IVM) porcine oocytes fertilised by intracytoplasmic sperm injection (ICSI) and the possibility of producing transgenic embryos and offspring with this procedure. Activated ICSI oocytes had a higher pronuclear formation than non-activated ICSI oocytes (mean 64.8+/-17.3% vs 28.5+/-3.4%, p<0.05). When the zygotes with two pronuclei were cultured to day 2, there was no difference (p<0.05) in the cleavage rate (mean 60.0+/-7.0% vs 63.3+/-12.7%) between the two groups. The blastocyst rate in the activation group was significantly higher than that in the non-activation group (mean 30.0+/-11.6% vs 4.6+/-4.2%, p<0.05). After injection of the sperm transfected with DNA/liposome complex, destabilised enhanced green fluorescent protein (d2EGFP) expression was not observed on day 2 in either cleaved or uncleaved embryos. But from day 3, some of the embryos at the 2-cell to 4-cell stage started to express d2EGFP. On day 7, about 30% of cleaved embryos, which were in the range of 2-cell to blastocyst stage, expressed d2EGFP. However, for the IVF oocytes inseminated with sperm transfected with DNA/liposome complex, and for oocytes injected with sperm transfected with DNA/liposome complex, and for oocytes injected with DNA/liposome complex following insemination with sperm not treated with DNA/liposome complex, none of the embryos expressed d2EGFP. Sixteen day 4 ICSI embryos derived from sperm not treated with DNA/liposome complex were transferred into a day 3 recipient. One recipient delivered a female piglet with normal birthweight. After transfer of the ICSI embryos derived from sperm transfected with DNA/liposome complex, none of the four recipients maintained pregnancy.

[Textual research on genealogy and related problems of Xu Lingtai]

This paper deals with Xu Lingtai's genealogy from his grand-grand father down to six generations with the short biographical acounts of each generation. From these, one can learn the origin, development of the literary and medical aspects of Xu's family. It also discusses the name, nickname, other names, dates of birth and death, tombs of Xu Lingtain by studies on relics and literatures, intending to solve the puzzles and errors of the above problems.

[Living-related small bowel transplantation: report of 2 cases]

OBJECTIVE

To investigate the result in treating short bowel syndrome with living-related small bowel transplantation.

METHODS

Two patients with short bowel syndrome underwent living-related small bowel transplantation. One patient was an 18-year-old boy and the donor was his father. A segment of 150 cm distal small bowel was resected as the graft from the donor. Another patient was a 15-year-old boy and the donor was his mother. The graft was 160 cm long, with arteries and veins anastomosed to the recipient's infrarenal aorta and cava respectively. Intestinal continuity was restored with an end-to-end anastomosis between the recipient's jejunum and the donor's ileum, and the distal end was made as fistulization. Treatment of immunosuppression, antibiotics, anti-thrombosis and nutritional support were given posttransplantation.

RESULTS

Complications such as anaemia and acute rejection occurred in the first recipient and were handled properly and brought under control after operation. The patient has been surviving 26 months since the transplantation. The graft's function is well. The patient can eat food and resume his daily work. In the second recipient, acute rejection occurred on day 26 after operation and was controlled by implosion therapy. Serious rejection occurred on day 80 again and did not respond to implosion therapy with methylprednisolone. After use of OKT3 and ATG the rejection was minimized. Because of uncontrolled infection, the patient died on 5th month after operation.

CONCLUSION

Living-related small bowel transplantation is an ideal treatment for short bowel syndrome.

[Expression of vascular endothelial growth factor and nm23 as prognostic factors in nasopharyngeal carcinoma]

OBJECTIVE

To evaluate the prognostic significance of vascular endothelial growth factor (VEGF) and nm23 expression for patients with nasopharyngeal carcinoma(NPC).

METHODS

From Jan. 1991 to Dec. 1995, 75 NPC patients treated in Department of Radiotherapy & Chemotherapy, Zhongnan Hospital of Wuhan University, with follow-up of more than 4 yrs, were selected to enter this study. Specimens of 75 NPC were studied by immunohistochemical staining for VEGF and nm23. The immunohistochemical data were correlated with development of locoregional failure, distant metastasis and survival.

RESULTS

Positive expression of VEGF and negative expression of nm23 were found in 54.7% and 56% of NPC specimens. Positive expression of VEGF and negative expression of nm23 correlated with the development of distant metastasis (P = 0.0181; P = 0.0091) and shorter survival (P = 0.0136; P = 0.0207). No association was observed with locoregional failure. No association was observed between the expression of VEGF and the expression of nm23.Cox proportional hazard model was used to compare the various factors and found the VEGF and nm23 expression were significant prognostic factors for patients with NPC.

CONCLUSION

The results of the study show that the VEGF and nm23 expression are significant prognostic factors for patients with NPC and indicate that expression of VEGF and nm23 may be useful in identifying patients who may benefit from systemic chemotherapy or other novel treatment strategies.

The tumor cells in nodular lymphocyte-predominant Hodgkin disease are clonally related to the large cell lymphoma occurring in the same individual. Direct demonstration by single cell analysis

Large cell lymphoma (LCL) sometimes occurs concurrently or subsequently in patients with nodular lymphocyte-predominant Hodgkin disease (NLPHD). Although there is evidence of a clonal relationship between LCL and NLPHD, there has been no direct demonstration that the lymphocytic and histiocytic (L&H) cells in NLPHD are related to the tumor cells in LCL. We identified 2 cases of NLPHD with an associated LCL. Single L&H cells, the Reed-Sternberg cell variants in NLPHD, were isolated from immunostained tissue sections by micromanipulation, and the immunoglobulin heavy chain gene (IgH) complementarity determining region (CDR) III of the cells was amplified by the polymerase chain reaction (PCR). The products were compared with those obtained from microdissected LCL cells using polyacrylamide gel electrophoresis and nucleotide sequencing. The IgH CDRIII sequences from the L&H cells were related to each other, but also showed nucleotide substitutions, consistent with a germinal center origin. The sequences from the L&H cells also were related to those from the corresponding LCL cells. We have provided direct evidence through sequence analysis of the IgH CDRIII that the L&H cells are clonally related to the corresponding LCL arising in 2 cases of NLPHD.

Structural evaluation of phospholipid bicelles for solution-state studies of membrane-associated biomolecules

Several complementary physical techniques have been used to characterize the aggregate structures formed in solutions containing dimyristoylphosphatidylcholine (DMPC)/dihexanoylphosphatidylcholine (DHPC) at ratios of < or =0.5 and to establish their morphology and lipid organization as that of bicelles. (31)P NMR studies showed that the DMPC and DHPC components were highly segregated over a wide range of DMPC/DHPC ratios (q = 0.05-0.5) and temperatures (15 degrees C and 37 degrees C). Only at phospholipid concentrations below 130 mM did the bicelles appear to undergo a change in morphology. These results were corroborated by fluorescence data, which demonstrated the inverse dependence of bicelle size on phospholipid concentration as well as a distinctive change in phospholipid arrangement at low concentrations. In addition, dynamic light scattering and electron microscopy studies supported the hypothesis that the bicellar phospholipid aggregates are disk-shaped. The radius of the planar domain of the disk was found to be directly proportional to the ratio of DMPC/DHPC and inversely proportional to the total phospholipid concentration when the DMPC/DHPC ratio was held constant at 0.5. Taken together, these results suggest that bicelles with low q retain the morphology and bilayer organization typical of their liquid-crystalline counterparts, making them useful membrane mimetics.

[Surgery of substernal goiter]

OBJECTIVE

To study the surgical approaches and operative techniques for substernal goiter.

METHOD

A retrospective study of 27 cases with substernal thyroid nodules was made in our hospital.

RESULT

The operations on 27 patients with substernal nodules have been successfully carried out. Among them, 10 were goiters, 9 adenomas, 4 malignancy and 4 were thyroid cancer metastasizing to paratracheal or substernal nodes. Resection via cervical collar incision was adequate in 23 cases. Three thyroid cancers with paratracheal node metastasis were completely resected by sternotomy and only one thyroid cancer with paratracheal and substernal nodes metastasis was resected by combined thoracotomy and cervical collar incision.

CONCLUSION

Resection via cervical collar incision for all retrosternal thyroid nodules were advised. The preliminary experience with this procedure suggests that it has some advantages in the management of substernal goiter, including: 1. ease of operation compared to both sternotomy and thoracotomy; 2. relatively low morbidity; 3. safe and reliable.

Opposing cardioprotective actions and parallel hypertrophic effects of delta PKC and epsilon PKC

Conflicting roles for protein kinase C (PKC) isozymes in cardiac disease have been reported. Here, deltaPKC-selective activator and inhibitor peptides were designed rationally, based on molecular modeling and structural homology analyses. Together with previously identified activator and inhibitor peptides of epsilonPKC, deltaPKC peptides were used to identify cardiac functions of these isozymes. In isolated cardiomyocytes, perfused hearts, and transgenic mice, deltaPKC and epsilonPKC had opposing actions on protection from ischemia-induced damage. Specifically, activation of epsilonPKC caused cardioprotection whereas activation of deltaPKC increased damage induced by ischemia in vitro and in vivo. In contrast, deltaPKC and epsilonPKC caused identical nonpathological cardiac hypertrophy; activation of either isozyme caused nonpathological hypertrophy of the heart. These results demonstrate that two related PKC isozymes have both parallel and opposing effects in the heart, indicating the danger in the use of therapeutics with nonselective isozyme inhibitors and activators. Moreover, reduction in cardiac damage caused by ischemia by perfusion of selective regulator peptides of PKC through the coronary arteries constitutes a major step toward developing a therapeutic agent for acute cardiac ischemia.

Two-dimensional (17)O multiple quantum magic-angle spinning NMR of organic solids

We report two-dimensional (2D) (17)O multiple-quantum magic-angle spinning (MQMAS) NMR spectra for four (17)O-labeled organic compounds: [(17)O(2)]-D-alanine (1), potassium hydrogen [(17)O(4)]dibenzoate (2), [(17)O(4)]-D,L-glutamic acid.HCl (3) and [2,4-(17)O(2)]uracil (4). The high spectral resolution observed in the 2D (17)O MQMAS NMR spectra allows extraction of precise (17)O NMR parameters for all crystallographically distinct oxygen sites. We demonstrate that rotor synchronization is important in obtaining high-quality (17)O MQMAS spectra for organic compounds. Several issues related to the potential of (17)O MQMAS NMR for large biomolecular systems are also discussed.

Bioassay of prostate-specific antigen (PSA) using microcantilevers

Diagnosis and monitoring of complex diseases such as cancer require quantitative detection of multiple proteins. Recent work has shown that when specific biomolecular binding occurs on one surface of a microcantilever beam, intermolecular nanomechanics bend the cantilever, which can be optically detected. Although this label-free technique readily lends itself to formation of microcantilever arrays, what has remained unclear is the technologically critical issue of whether it is sufficiently specific and sensitive to detect disease-related proteins at clinically relevant conditions and concentrations. As an example, we report here that microcantilevers of different geometries have been used to detect two forms of prostate-specific antigen (PSA) over a wide range of concentrations from 0.2 ng/ml to 60 microg/ml in a background of human serum albumin (HSA) and human plasminogen (HP) at 1 mg/ml, making this a clinically relevant diagnostic technique for prostate cancer. Because cantilever motion originates from the free-energy change induced by specific biomolecular binding, this technique may offer a common platform for high-throughput label-free analysis of protein-protein binding, DNA hybridization, and DNA-protein interactions, as well as drug discovery.

[A randomized, controlled clinical trial of meropenem and imipenem/cilastatin in the treatment of acute bacterial infections]

OBJECTIVE

Meropenem is a new carbapenem antibiotic developed by Sumitomo Pharmaceuticals and shown to resist degradation by renal dehydropeptidase I (DPH-I), an enzyme which exists chiefly in the kidneys and decomposes carbapenem antibiotics. It has a powerful antibacterial activity with broad antibacterial spectrum. The objective of the study is to evaluate the efficacy and safety of meropenem.

METHODS

A randomized, open-label, controlled study was conducted for treating patients with bacterial infections. A total of 112 hospitalized patients were enrolled in the study. 55 patients received meropenem 500 mg every 12 hours (or 1g every 12 hours if necessary) and 57 patients received imipenem/cilastatin 500 mg/500 mg every 12 hours (or 1g/1g every 12 hours if necessary) intravenously. The duration of treatment was 7-14 days in both groups.

RESULTS

42 of the 55 cases receiving meropenem and 41 of the 57 cases receiving imipenem/cilastatin were assessable for clinical efficacy. The overall efficacy rate was 88.1%(37/42) for the meropenem group and 85.4%(35/41) for the imipenem/cilastatin group, whereas the bacterial eradication rate was 81.1%(30/37) and 84.2%(32/38), respectively. 47(69.1%) of 68 strains isolated from patients produced beta-lactamase. Adverse drug reaction was evaluated in 44 cases of the meropenem group and 41 cases of the imipenem/cilastatin group. The adverse drug reaction rate was 13.6%(6/44) and 12.2%(5/41), respectively. The results showed that there were no statistical differences between these two groups (P > 0.05).

CONCLUSION

Meropenem and imipenem/cilastatin were effective and safe for the treatment of lower respiratory tract infections and urinary tract infections and other infections caused by beta-lactamase-producing strains.

Chronic morphine potentiates the inflammatory response by disrupting interleukin-1beta modulation of the hypothalamic-pituitary-adrenal axis

Interleukin-1-beta (IL-1beta) can promote inflammation by up-regulating vascular adhesion molecules and inhibit inflammation by activating the hypothalamic-pituitary-adrenal (HPA) axis to produce anti-inflammatory glucocorticoids. In this study, chronic morphine was shown to suppress IL-1beta-induction of corticotropin releasing factor (CRF) mRNA and plasma corticosterone levels. Leukocyte-endothelial adhesion (LEA) in rat mesenteric venules increased during IL-1beta- and FMLP-induced inflammation. Chronic morphine potentiated the LEA response to either IL-1beta or FMLP alone, and greatly enhanced LEA in response to combined IL-1beta and FMLP. Thus, it appears that chronic morphine exposure may promote a potentially damaging inflammatory reaction by disrupting the balance between IL-1beta-mediated local inflammation and the anti-inflammatory effects of the HPA axis.