Solution structure of a fragment of the dimerization domain of E2F-1 determined by circular dichroism, 1H nuclear magnetic resonance and distance geometry

The structure of a synthesized peptide with the sequence GVVDLNWAAEVLKVQKRRIYDITNVLEGIQ which corresponds to residues 149-178 of transcription factor E2F-1 was determined by 1H nuclear magnetic resonance in 40% d3-TFE/water. NOE cross peaks and alphaH chemical shifts indicate that the peptide consists of a helix from Ala-8 to Leu-26 in this solution. Circular dichroism measurements confirm the presence of nearly 45% helix in TFE/water solution but show no evidence of helicity in water solution of this peptide. Fifty structures were constructed with 329 upper distance limits by DIANA. The 20 best conformers show a RMSD of 0.78 A for backbone atoms and 1.78 A for heavy atoms from residue Ala-8 to Leu-26. This result, together with our previous work on the solution structure of a fragment of DP-1, supports the proposal that E2F-1 and DP-1 may dimerize with a coiled-coil type interaction.

Superoxide generation from endothelial nitric-oxide synthase. A Ca2+/calmodulin-dependent and tetrahydrobiopterin regulatory process

It has been previously shown that besides synthesizing nitric oxide (NO), neuronal and inducible NO synthase (NOS) generates superoxide (O-2) under conditions of L-arginine depletion. However, there is controversy regarding whether endothelial NOS (eNOS) can also produce O-2. Moreover, the mechanism and control of this process are not fully understood. Therefore, we performed electron paramagnetic resonance spin-trapping experiments to directly measure and characterize the O-2 generation from purified eNOS. With the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), prominent signals of O-2 adduct, DMPO-OOH, were detected from eNOS in the absence of added tetrahydrobiopterin (BH4), and these were quenched by superoxide dismutase. This O-2 formation required Ca2+/calmodulin and was blocked by the specific NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME) but not its non-inhibitory enantiomer D-NAME. A parallel process of Ca2+/calmodulin-dependent NADPH oxidation was observed which was also inhibited by L-NAME but not D-NAME. Pretreatment of the enzyme with the heme blockers cyanide or imidazole also prevented O-2 generation. BH4 exerted dose-dependent inhibition of the O-2 signals generated by eNOS. Conversely, in the absence of BH4 L-arginine did not decrease this O-2 generation. Thus, eNOS can also catalyze O-2 formation, and this appears to occur primarily at the heme center of its oxygenase domain. O-2 synthesis from eNOS requires Ca2+/calmodulin and is primarily regulated by BH4 rather than L-arginine.

[Deiodinase]

The members of deiodinase family including type I, type II and type III deiodinase are seleno-proteins. They play an important role in the regulation of thyroid hormone metabolism. They are different in substrate specificity and sensitivity to inhibitor and kinetics mechanism. Their cDNAs exhibit limited regions of homology, but they have common conserved sequence, TGA codon of selenocysteine and some structures and sequences which are essential for selenocysteine insertion.

Hydrogen peroxide decreases pHi in human aortic endothelial cells by inhibiting Na+/H+ exchange

Postischemic endothelial dysfunction may occur as a result of the effects of endogenous oxidants like hydrogen peroxide. Since endothelium-dependent vasodilator function may be affected by pHi, the effect of hydrogen peroxide on endothelial pHi was examined. Hydrogen peroxide (100 micromol/L for 10 minutes) decreased pHi from 7.24+/-0.01 to 7.02+/-0.02 and inhibited recovery from an ammonium chloride-induced intracellular acid load in carboxy SNARF 1 (c-SNARF 1)-loaded human aortic endothelial cells in bicarbonate-free solution. Prior inhibition of Na+/H+ exchange with 5-(N-ethyl-N-isopropyl)amiloride (10 micromol/L), by removal of extracellular Na+, or by glycolytic inhibition with iodoacetic acid blocked the subsequent effect of hydrogen peroxide on pHi. A 2-minute exposure to 100 micromol/L H2O2 decreased intracellular ATP levels by approximately 40%; this was prevented by 3-aminobenzamide and nicotinamide (1 mmol/L each), inhibitors of the DNA repair enzyme poly(ADP-ribose) polymerase. Both 3-aminobenzamide and nicotinamide significantly inhibited the hydrogen peroxide-induced intracellular acidification and the effect of hydrogen peroxide on recovery from an intracellular acid load. Hydrogen peroxide decreases pHi in human endothelial cells by inhibiting Na+/H+ exchange. This appears to be mediated by activation of the DNA repair enzyme poly(ADP-ribose) polymerase and subsequent depletion of intracellular ATP. Since a decrease in pHi in this range may alter the activity of NO synthase or affect the synthesis of vasodilator prostaglandins, the effect of hydrogen peroxide on the endothelial Na+/H+ exchanger may be important in the pathogenesis of postischemic endothelial dysfunction.

Th2-induced eotaxin expression and eosinophilia coexist with Th1 responses at the effector stage of lung inflammation

The T cell-mediated lung inflammation that is associated with allergic asthma is characterized mainly by massive eosinophil infiltration, which induces airway injury and the subsequent late-phase reactivity. Because Th2 cells are often isolated from asthmatic subjects, these cells are postulated to play a role in asthma pathogenesis. We report that adoptively transferred, influenza hemagglutinin-specific Th1 and Th2 cells induced different patterns of chemokines leading to different types of cellular infiltration. Th2 cells were sufficient to induce dramatic Ag-dependent lung eosinophilia and eotaxin expression; by contrast, Th1 transfer primarily induced neutrophil recruitment with little eotaxin production. To determine whether Th1 cells show inhibitory effects on Th2 cell-mediated responses, Th1 and Th2 cells were cotransferred. Hemagglutinin-specific Th1 cells did not inhibit Ag-induced lung eosinophilia, nor did they inhibit eotaxin expression. Furthermore, influenza virus infection of the lung in mice receiving hemagglutinin-specific Th2 cells also induced eotaxin expression and eosinophilia that could not be inhibited by the cotransfer of Th1 cells. Our results show that Th2-mediated allergic lung inflammation coexists with the Th1-mediated responses that are stimulated by diverse forms of Ags.

Constitutive and antibody-induced internalization of prostate-specific membrane antigen

Prostate-specific membrane antigen (PSMA) is a cell surface glycoprotein expressed predominantly by prostate cancer cells. We have characterized four monoclonal antibodies that bind to the extracellular domain of PSMA (Liu et al., Cancer Res., 57: 3629-3634, 1997). Here we report that viable LNCaP cells internalize these antibodies. Laser scanning confocal microscopy reveals that the internalized antibodies accumulate in endosomes, and immunoelectron microscopy reveals that endocytosis of the PSMA-antibody complex occurs via clathrin-coated pits. In addition, a quantitative cell surface biotinylation assay demonstrates that PSMA is constitutively endocytosed in LNCaP cells and that anti-PSMA antibodies increase the rate of internalization of PSMA. These studies suggest that PSMA might function as a receptor mediating the internalization of a putative ligand. The availability of prostate-specific internalizing antibodies should aid the development of novel therapeutic methods to target the delivery of toxins, drugs, or short-range isotopes specifically to the interior of prostate cancer cells.

Role for neuronally derived fractalkine in mediating interactions between neurons and CX3CR1-expressing microglia

A recently identified chemokine, fractalkine, is a member of the chemokine gene family, which consists principally of secreted, proinflammatory molecules. Fractalkine is distinguished structurally by the presence of a CX3C motif as well as transmembrane spanning and mucin-like domains and shows atypical constitutive expression in a number of nonhematopoietic tissues, including brain. We undertook an extensive characterization of this chemokine and its receptor CX3CR1 in the brain to gain insights into use of chemokine-dependent systems in the central nervous system. Expression of fractalkine in rat brain was found to be widespread and localized principally to neurons. Recombinant rat CX3CR1, as expressed in Chinese hamster ovary cells, specifically bound fractalkine and signaled in the presence of either membrane-anchored or soluble forms of fractalkine protein. Fractalkine stimulated chemotaxis and elevated intracellular calcium levels of microglia; these responses were blocked by anti-CX3CR1 antibodies. After facial motor nerve axotomy, dramatic changes in the levels of CX3CR1 and fractalkine in the facial nucleus were evident. These included increases in the number and perineuronal location of CX3CR1-expressing microglia, decreased levels of motor neuron-expressed fractalkine mRNA, and an alteration in the forms of fractalkine protein expressed. These data describe mechanisms of cellular communication between neurons and microglia, involving fractalkine and CX3CR1, which occur in both normal and pathological states of the central nervous system.

Interspecies comparative genome hybridization and interspecies representational difference analysis reveal gross DNA differences between humans and great apes

Comparative chromosome G-/R-banding, comparative gene mapping and chromosome painting techniques have demonstrated that only few chromosomal rearrangements occurred during great ape and human evolution. Interspecies comparative genome hybridization (CGH), used here in this study, between human, gorilla and pygmy chimpanzee revealed species-specific regions in all three species. In contrast to the human, a far more complex distribution of species-specific blocks was detected with CGH in gorilla and pygmy chimpanzee. Most of these blocks coincide with already described heterochromatic regions on gorilla and chimpanzee chromosomes. Representational difference analysis (RDA) was used to subtract the complex genome of gorilla against human in order to enrich gorilla-specific DNA sequences. Gorilla-specific clones isolated with this technique revealed a 32-bp repeat unit. These clones were mapped by fluorescence in situ hybridization (FISH) to the telomeric regions of gorilla chromosomes that had been shown by interspecies CGH to contain species-specific sequences.

Inducible nitric-oxide synthase generates superoxide from the reductase domain

In the absence of L-arginine, the heme center of the oxygenase domain of neuronal nitric-oxide synthase reduces molecular oxygen to superoxide (O-2). Our recent work has provided evidence that inducible NOS (iNOS) may also catalyze O-2 formation in macrophages. However, there has been a lack of direct evidence of superoxide generation from the purified iNOS, and it was previously hypothesized that significant O-2 production does not occur. Moreover, the mechanism and enzyme site responsible for O-2 generation is unknown. To determine whether iNOS produces O-2 and to identify the mechanism of this process, we performed electron paramagnetic resonance measurements on purified iNOS using the spin trap 5,5-dimethyl-1-pyrroline N-oxide. In the presence of NADPH, prominent O-2 adduct signals were detected from iNOS. These signals were totally abolished by superoxide dismutase but not affected by catalase. High concentrations of L-arginine decreased this O-2 formation, whereas its enantiomer D-arginine did not. Pre-incubation of iNOS with the flavoprotein inhibitor diphenyleneiodonium totally blocked these O-2 signals. Conversely, pretreatment of the enzyme with the heme blocker cyanide had no effect on O-2 generation. Furthermore, strong O-2 generation was directly detected from the isolated iNOS reductase domain. Together, these data demonstrate that iNOS does generate O-2, and this mainly occurs at the flavin-binding sites of the reductase domain.

Nitric oxide functions as a signal in plant disease resistance

Recognition of an avirulent pathogen triggers the rapid production of the reactive oxygen intermediates superoxide (O2-) and hydrogen peroxide (H2O2). This oxidative burst drives crosslinking of the cell wall, induces several plant genes involved in cellular protection and defence, and is necessary for the initiation of host cell death in the hypersensitive disease-resistance response. However, this burst is not enough to support a strong disease-resistance response. Here we show that nitric oxide, which acts as a signal in the immune, nervous and vascular systems, potentiates the induction of hypersensitive cell death in soybean cells by reactive oxygen intermediates and functions independently of such intermediates to induce genes for the synthesis of protective natural products. Moreover, inhibitors of nitric oxide synthesis compromise the hypersensitive disease-resistance response of Arabidopsis leaves to Pseudomonas syringae, promoting disease and bacterial growth. We conclude that nitric oxide plays a key role in disease resistance in plants.

Nitric oxide functions as a signal in plant disease resistance

Recognition of an avirulent pathogen triggers the rapid production of the reactive oxygen intermediates superoxide (O2-) and hydrogen peroxide (H2O2). This oxidative burst drives crosslinking of the cell wall, induces several plant genes involved in cellular protection and defence, and is necessary for the initiation of host cell death in the hypersensitive disease-resistance response. However, this burst is not enough to support a strong disease-resistance response. Here we show that nitric oxide, which acts as a signal in the immune, nervous and vascular systems, potentiates the induction of hypersensitive cell death in soybean cells by reactive oxygen intermediates and functions independently of such intermediates to induce genes for the synthesis of protective natural products. Moreover, inhibitors of nitric oxide synthesis compromise the hypersensitive disease-resistance response of Arabidopsis leaves to Pseudomonas syringae, promoting disease and bacterial growth. We conclude that nitric oxide plays a key role in disease resistance in plants.

Association of apolipoprotein E polymorphism and concentration with serum lipids and apolipoprotein level in the Chinese from Shanghai

The influence of apolipoprotein E polymorphism and apoE level on serum lipids and apolipoproteins was investigated in 71 healthy people and 43 patients with coronary artery disease from Shanghai. The frequency of apoE alleles was 0.06 for epsilon2, 0.86 for epsilon3, and 0.07 for epsilon4 in the healthy group, and 0.14 for epsilon2, 0.77 for epsilon3, and 0.09 for epsilon4 in the coronary artery disease group. There was no significant difference in the frequency of apoE alleles between these two groups. Serum levels of triglyceride and apo AI did not differ according to apoE genotypes, whereas serum level of apoB was significantly different according to apoE genotypes (p<0.05) both in healthy and coronary artery disease groups. However, in the healthy group, apo epsilon2 allele carriers had significantly higher level of apoE than apo epsilon3 and epsilon4 allele carriers (p<0.001) and apo epsilon4 allele carriers had significantly higher level of total cholesterol than apo epsilon3 and epsilon2 allele carriers. These were not observed in the coronary artery disease group. ApoE concentration was positively correlated with cholesterol, apoAI, and apoB levels in the control subjects and no significant correlation was observed with triglyceride level. In contrast, apoE level was positively related only to triglyceride level in the coronary artery disease group. In the control group, apoE genotypes and apoE level explained together 19.3% and 26.6% of the variability of apoB and cholesterol level, respectively, apoE polymorphism explained 23% of the variability of apoE level and apoE level explained 13.2% of the variability of apoAI level. In the coronary artery disease group, only apoE level explained 41.7% of triglyceride variability. Finally we compared our results with those previously obtained in a French healthy population, the Stanislas cohort. Results suggested that there were some difference between the Chinese control and the French subjects.

Human recombinant NACP/alpha-synuclein is aggregated and fibrillated in vitro: relevance for Lewy body disease

The precursor of non-amyloid beta protein component of Alzheimer's disease amyloid (NACP/alpha-synuclein) is aggregated and fibrillated under certain conditions, i.e., increasing time lag, high temperature and low pH. These in vitro aggregates form Thioflavine-S-positive filamentous structures, reminiscent of amyloid-like fibrils. Since some Lewy bodies in Parkinson's disease display Thioflavine-S reactivity, our results may suggest that amyloidogenic properties of NACP/alpha-synuclein may play a crucial role in pathogenesis of disorders with Lewy bodies such as Parkinson's disease.

Differences in a dinucleotide repeat polymorphism in the tau gene between Caucasian and Japanese populations: implication for progressive supranuclear palsy

Previous studies of a tau polymorphism in Caucasian subjects with progressive supranuclear palsy (PSP) showed an over-representation of one genotype, A0/A0, versus normal control subjects. This result suggested that tau may be playing a genetic role in the progression of PSP. This study examines whether the over-representation of A0/A0 is Caucasian-specific or universal to PSP. Unfortunately, we found this dinucleotide repeat was relatively non-polymorphic in Japanese subjects. As a result, the genotypes were virtually the same, A0/A0, between Japanese PSP and control subjects. However, this outcome, albeit negative, does suggest two possible roles of the tau gene in PSP pathogenesis: (1) the role of this dinucleotide repeat in PSP may be different between Caucasian and Japanese populations or (2) this repeat may not be causal for PSP but represents a marker for other molecular genetic risk factors within or close to the tau gene on chromosome 17.

In vivo inhibition of CC and CX3C chemokine-induced leukocyte infiltration and attenuation of glomerulonephritis in Wistar-Kyoto (WKY) rats by vMIP-II

Chemokines play a central role in immune and inflammatory responses. It has been observed recently that certain viruses have evolved molecular piracy and mimicry mechanisms by encoding and synthesizing proteins that interfere with the normal host defense response. One such viral protein, vMIP-II, encoded by human herpesvirus 8, has been identified with in vitro antagonistic activities against CC and CXC chemokine receptors. We report here that vMIP-II has additional antagonistic activity against CX3CR1, the receptor for fractalkine. To investigate the potential therapeutic effect of this broad-spectrum chemokine antagonist, we studied the antiinflammatory activity of vMIP-II in a rat model of experimental glomerulonephritis induced by an antiglomerular basement membrane antibody. vMIP-II potently inhibited monocyte chemoattractant protein 1-, macrophage inflammatory protein 1beta-, RANTES (regulated on activation, normal T cell expressed and secreted)-, and fractalkine-induced chemotaxis of activated leukocytes isolated from nephritic glomeruli, significantly reduced leukocyte infiltration to the glomeruli, and markedly attenuated proteinuria. These results suggest that molecules encoded by some viruses may serve as useful templates for the development of antiinflammatory compounds.

Expression pattern of synucleins (non-Abeta component of Alzheimer's disease amyloid precursor protein/alpha-synuclein) during murine brain development

The non-Abeta component of Alzheimer's disease amyloid precursor protein (NACP) is predominantly a neuron-specific presynaptic protein that may play a central role in neurodegeneration because NACP fragments are found in Alzheimer's disease amyloid and a mutation in the NACP gene is associated with familial Parkinson's disease. In addition, NACP may play an important role during synaptogenesis and CNS development. To understand better the patterns of NACP expression during development, we analyzed the levels of this protein as well as the levels of another synaptic protein (synaptophysin) by ribonuclease protection assay, western blotting, and immunocytochemistry in fetal, juvenile, and adult mouse brain. From embryonic day 12 to 15, there was a slight increase, which was then followed by a more dramatic increase at later time points. Immunocytochemical staining for NACP increases throughout these stages as well. Although NACP appeared early in CNS development, synaptophysin levels started to rise at a later stage. These findings support the contention that NACP might be important for CNS development. Furthermore, the cytosolic component of NACP precedes the particulate component in development, indicating that a redistribution of the protein to the membrane fraction may be important for events later in neuronal development and in synaptogenesis.

[A study of photographic standardization in rhinoplasty]

OBJECTIVE

A method of photographic standardization for rhinoplasty is presented.

METHOD

To delineate the nose objectively before and after rhinoplasty, we designed a method to standardize picturing by using the points and lines in the face and camera in nasal photography.

RESULT

With the help of anatomic points in the face and lines in the camera, we can maintain the camera at a constant position to the face. In this way, the nasal picture is more comparable and instructive.

CONCLUSION

This method has been proved to be helpful in rhinoplasty.

[Influence of HPD on immunological functions in patients with nasopharyngeal carcinoma treated by radiotherapy]

Seventy-eight patients with nasopharyngeal carcinoma were equally divided into two groups: 39 patients were treated by HPD plus radiation and 39 patients by radiation alone. Immunological functions were evaluated in each patient before and after radiation. The results showed that (1) in patients treated by RPD and radiation, no statistical difference was observed on immunological functions before and after treatment; (2) in patients treatd by radiation alone, the immunological functions, including OKT3, OKT4, OKT4/OKT8 ratio and lymphocyte transformation, were significantly decreased after treatment. These findings indicate that the immunological functions in patients with nasopharyngeal carcinoma could be protected by HPD during radiotherapy.

Anti-AIDS agents. 31. Synthesis and anti-HIV activity of 4-substituted 3',4'-di-O-(-)-camphanoyl-(+)-cis-khellactone (DCK) thiolactone analogs

Four DCK-thiolactone analogs (3-6) were synthesized asymmetrically and evaluated for anti-HIV activity against HIV-1 replication in H9 lymphocyte cells. Based on the functionality on the thiolactonecoumarin nucleus, activity was in the order: methyl > H > propyl > benzyl. 4-Methyl-3',4'-di-O-(-)-camphanoyl-(+)-cis-khelthiolactone (4) exhibited extremely potent anti-HIV activity with EC50 and therapeutic index values of 0.00718 microM and > 21,300, respectively.

Chemokine receptor expression in cultured glia and rat experimental allergic encephalomyelitis

Chemokines are a group of pro-inflammatory peptides that mediate leukocyte migration and activation. Several members of the chemokine family have been shown to be synthesized by cells of the central nervous system (CNS). To begin to address the role of chemokine receptors in CNS physiology, we identified, by molecular cloning techniques, the rat orthologs of the chemokine receptors, CCR2, CCR3, CCR5, and CXCR4. CCR2 and CCR5 expression was detected in rat spleen, lung, kidney, thymus and macrophages; CCR5 mRNA was also detected in rat brain. Primary cultures of rat microglia expressed CCR5 mRNA that was regulated by IFN-gamma, while both cultured astrocytes and microglia were found to contain mRNA for CXCR4 and CX3CR1. Induction of experimental allergic encephalomyelitis (EAE) in the rat was accompanied by increased levels of CCR2, CCR5, CXCR4, and CX3CR1 mRNAs in the lumbar spinal cords of animals displaying clinical signs of the disease. These data identify the rat orthologs of chemokine receptors and demonstrate that brain, spinal cord, and cultured glial cells express chemokine receptors that can be regulated both in vitro and in vivo.

Calcineurin preferentially synergizes with PKC-theta to activate JNK and IL-2 promoter in T lymphocytes

Costimulation of the T cell receptor (TCR) and CD28 is required for optimal interleukin-2 (IL-2) induction. These signals, which can be replaced by the pharmacological agents phorbol ester (PMA) and Ca2+ ionophore, synergistically activate the mitogen-activated protein kinase (MAPK) JNK. Cyclosporin A, an inhibitor of the Ca2+-dependent phosphatase calcineurin which blocks IL-2 induction, abrogates Ca2+-triggered synergistic JNK activation. As protein kinase C (PKC) downregulation inhibits PMA+ionophore-induced JNK activation, we examined whether a particular PKC isoform is preferentially involved in this response. We found that PKC-theta but neither PKC-alpha nor PKC-epsilon participates in JNK activation, whereas all three PKCs lead to ERK MAPK activation. PKC-theta specifically cooperates with calcineurin, and together their signals converge on (or upstream of) Rac leading to potent JNK activation. Similarly, calcineurin and PKC-theta specifically synergize to induce transcription of reporters driven by the c-jun and IL-2 promoters. PKC-theta and calcineurin are also partially responsible for the synergistic activation of JNK following TCR and CD28 ligation. Preferential cooperation between PKC-theta and calcineurin is observed in Jurkat T cells but not in HeLa cells. These results indicate that PKC isozymes have distinct biological functions and suggest that synergistic JNK activation is an important function for PKC-theta in T-cell activation.

Relaxation anisotropy in cartilage by NMR microscopy (muMRI) at 14-microm resolution

To study the structural anisotropy and the magic-angle effect in articular cartilage, T1 and T2 images were constructed at a series of orientations of cartilage specimens in the magnetic field by using NMR microscopy (muMRI). An isotropic T1 and a strong anisotropic T2 were observed across the cartilage tissue thickness. Three distinct regions in the microscopic MR images corresponded approximately to the superficial, transitional, and radial histological zones in the cartilage. The percentage decrease of T2 follows the pattern of the curve of (3cos2theta - 1)2 at the radial zone, where the collagen fibrils are perpendicular to the articular surface. In contrast, little orientational dependence of T2 was observed at the transitional zone, where the collagen fibrils are more randomly oriented. The result suggests that the interactions between water molecules and proteoglycans have a directional nature, which is somehow influenced by collagen fibril orientation. Hence, T2 anisotropy could serve as a sensitive and noninvasive marker for molecular-level orientations in articular cartilage.

Association of CYP2D microsatellite polymorphism with Lewy body variant of Alzheimer's disease

OBJECTIVE

To examine the genetic association of CYP2D6 locus with Lewy body variant (LBV) and Parkinson's disease (PD).

METHODS

Allelic association was studied in patients with pure AD, LBV, and PD by using the CYP2D microsatellite, the (dG-dT)n dinucleotide repeat (n=16 to 27) located between CYP2D8P and CYP2D7 genes, and the CYP2D6 B and D mutations.

RESULTS

We found overrepresentation of the alleles longer than 21 repeat (the long-type alleles) in LBV (allele frequency, 0.313) (odds ratio=1.99, p=0.019 by chi2 test) and in PD (0.298) (odds ratio=1.86, p=0.037), but not in pure AD (0.196), compared with the age-matched control (0.186). Strong association was noted of the long-type alleles with the CYP2D6 B mutation (odds ratio=88.50, p < 0.001 by Fisher's exact test), but not with the D mutation or the deletion of CYP2D6 gene.

CONCLUSIONS

The CYP2D locus is closely associated with LBV and PD. The CYP2D6 B mutation may be involved in pathogenesis of LBV and PD in a dominant-negative manner, or in the linkage disequilibrium of the CYP2D microsatellite to another pathogenic gene locus.

Secondary structure of an antibacterial peptide Abp3 studied by two-dimensional proton-NMR

An antibacterial peptide Abp3, an analogue of cecropin B, was investigated by two-dimensional proton-NMR at pH 5.0 in aqueous solution with 15% (v/v) hexafluoroisopropanol. The peptide, which consists of 35 amino acids, was synthesized chemically. Most resonances of the main-chain and side-chain protons were assigned. Several medium range NOE connectivities were observed, showing two separate alpha-helices with one amphiphilic in N-terminal domain (residues 5-21) and the other hydrophobic in C-terminal domain (residues 25-35) and a hinge region between them. The J coupling constants and the chemical shifts in these sections also supported the conclusion.

Activation of the cytochrome c gene by electrical stimulation in neonatal rat cardiac myocytes. Role of NRF-1 and c-Jun

Activation of cytochrome c (cyt c) transcription in electrically stimulated neonatal rat cardiac myocytes is preceded by transient expression of the activating protein-1 family of transcription factors, c-Fos, c-Jun, and JunB, as well as nuclear respiratory factor-1 (NRF-1). Mutations in either the NRF-1 or in the two cyclic AMP response elements on the cyt c promoter significantly reduce cyt c promoter activation produced either by electrical stimulation (Xia, Y., Buja, L. M., Scarpulla, R. C., and McMillin, J. B. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 11399-11404) or by transfection of c-jun into nonpaced cardiac myocytes. Electrical stimulation of cardiac myocytes activates the c-Jun N-terminal kinase (McDonough, P. M., Hanford, D. S., Sprenkle, A. B., Mellon, N. R., and Glembotski, C. C. (1997) J. Biol. Chem. 272, 24046-24053) so that the fold-activation of the cyt c promoter is increased by pacing when either c-jun or c-fos/c-jun were cotransfected. Physical association of NRF-1 protein with the NRF-1 enhancer element and of c-Jun with the cyclic AMP response element binding sites on the cyt c promoter was demonstrated by gel shift competition assays and by antibody super shifts. This is the first demonstration that induction of NRF-1 and c-Jun by pacing of cardiac myocytes directly mediates cyt c gene expression and mitochondrial proliferation in response to hypertrophic stimuli in the heart.

[Effect of dietary selenium on the activities of glutathione peroxidase and deiodinase in rat liver]

In order to investigate the effect of dietary selenium on the activities of glutathione peroxidase and deiodinase and the least selenium requirement for their optimal activities, fifty four male weanling Wistar rats of 50-60g body weight were randomly divided into 9 groups and were fed with semisynthetic diets of different selenium level for 20 weeks. The selenium in the diets were 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.1, 0.2 and 5 mg/kg diet respectively. The body weight of ratsin the ninth group was different significantly from the seventh and eighth group, but those in the other eight groups were not significantly different. The activities of liver glutathione peroxidase in 0.1, 0.2 and 5 mg/kg groups were the highest among the nine groups. So at least 0.1 mg/kg diet is required for its normal activity. The activities of the liver type I deiodinase of nine groups were high from 0.05 to 0.2 mg/kg diet groups and at least Se 0.05 mg/kg diet is required for its normal activity.

[A research on chemical dynamic changes and drug efficacy of SMS compound prescription: chemical researches on shenmaisan prescription (I)]

To clarify the material base of the distinct curative effect of Shengmaisan (SMS) compound prescription, a study was made on the dynamics of chemical constituents in the decoction prepared according to the compound prescription. From the decoction a new compound was isolated and identified by UV, IR, MS and NMR as 5-hydroxymethy-2-furaldehyde (5-HMF). The study suggests that the distinct curative effect of SMS compound prescription hinges on a material base which is different chemically from that in the other three single drugs used separately, thus presenting scientific criteria for rational compatibility and quality check in making preparations on compound prescriptions.

Antitumor agents. 181. Synthesis and biological evaluation of 6,7,2',3',4'-substituted-1,2,3,4-tetrahydro-2-phenyl-4-quinolones as a new class of antimitotic antitumor agents

A novel series of 6,7,2',3',4'-substituted-1,2,3,4-tetrahydro-2-phenyl- 4-quinolones were synthesized and evaluated for interactions with tubulin and for cytotoxic activity against a panel of human tumor cell lines, including ileocecal carcinoma (HCT-8), breast cancer (MCF-7), lung carcinoma (A-549), epidermoid carcinoma of the nasopharynx (KB), renal cancer (CAKI-1), and melanoma cancer (SKMEL-2). Most compounds (18, 20, 22-27) showed potent cytotoxic and antitubulin effects. The most active compounds (23, 26, 27) demonstrated strong cytotoxic effects with ED50 values in the nanomolar or subnanomolar range in almost all tumor cell lines. Three active racemates (20, 22, 25) were separated into the enantiomers, and generally, the optically pure (-)-isomers (20a, 22a, 25a) exhibited greater biological activity than the racemates or (+)-isomers. Cytotoxicity and antitubulin activity were closely correlated, with the most active compounds (23, 26, 27) having effects comparable to those of colchicine, podophyllotoxin, and combretastatin A-4.

The liver isoform of carnitine palmitoyltransferase I is activated in neonatal rat cardiac myocytes by hypoxia

Fatty acids are the preferred substrate of ischemic, reperfused myocardium and may account for the decreased cardiac efficiency during aerobic recovery. Neonatal cardiac myocytes in culture respond to hypoxia/serum- and glucose-free medium by a slow decline in ATP which reverses upon oxygenation. This model was employed to examine whether carnitine palmitoyltransferase I (CPT-I) modulates high rates of beta-oxidation following oxygen deprivation. After 5 h of hypoxia, ATP levels decline to 30% control values and CPT-I activity is significantly stimulated in hypoxic myocytes with no alteration in cellular carnitine content or in the release of the mitochondrial matrix marker, citrate synthase. This stimulation was attributed to an increase in the affinity of hypoxic CPT-I for carnitine, suggesting that the liver CPT-I isoform is more dominant following hypoxia. However, there was no alteration in hypoxic CPT-I inhibition by malonyl-CoA. DNP-etomoxiryl-CoA, a specific inhibitor of the liver CPT-I isoform, uncovered identical Michaelis kinetics of the muscle isoform in control and hypoxic myocytes with activation of the liver isoform. Northern blotting did not reveal any change in the relative abundance of mRNA for the liver vs. the muscle CPT-I isoforms. The tyrosine phosphatase inhibitor, pervanadate, reversed the hypoxia-induced activation of CPT-I and returned the affinity of cardiac CPT-I for carnitine to control. Reoxygenation was also associated with a return of CPT-I activity to control levels. The data demonstrate that CPT-I is activated upon ATP depletion. Lower enzyme activities are present in control and reoxygenated cells where ATP is abundant or when phosphatases are inhibited. This is the first suggestion that phosphorylation may modulate the activity of the liver CPT-I isoform in heart.

Apolipoprotein AIV codon 360 mutation increases with human aging and is not associated with Alzheimer's disease

In order to evaluate genetic apolipoprotein polymorphisms as risk factors for Alzheimer's disease (AD), we studied apolipoprotein (apo) AIV after apoE, an apolipoprotein also present in the brain. The allelic distribution of apoAIV codon 360 polymorphism was no different in AD group (n = 120) compared with elderly healthy individuals (n = 119). Surprisingly, this polymorphism was over-represented (11.40%, vs. 5.7% P < 0.005) in all these aged subjects (74.29 +/- 8.46 years) and independently of the clinical and mental status compared with the younger population (39.00 +/- 9.69 years) of the same regional recruitment. These results suggest that the apoAIV (360:His) allele could be a marker of aging and longevity.

[Study on a deletion polymorphism of the angiotensin converting enzyme gene in pregnancy induced hypertension]

OBJECTIVE

To study a polymorphism and allele frequency of the angiotensin converting enzyme (ACE) gene in pregnancy induced hypertension (PIH).

METHODS

Polymerase chain reaction (PCR) for detection of ACE gene polymorphism was performed to show the deletion/insertion (D/I) polymorphism in intron 16 of ACE gene. A 490 bp(I) and 190 bp(D) PCR products were identified, corresponding to the PCR amplification of the the allele with or without the insertion.

RESULTS

Derived allele frequencies for insertion and deletion were the different between 35 PIH and 25 control subjects. Compared the frequency of D allele gene (0.76) and the percentage of the ACE DD genotype (65.7%) in the PIH patients with the frequency (0.28) and the percentage (8.0%) in the control population, they were significant higher in individuals with PIH (P < 0.001).

CONCLUSIONS

There was an excess of DD genotype and the frequency of D allele gene in PIH, confirming the genetic variation in the ACE locus could be involved in the risk of PIH and suggesting the ACE gene may contribute to the pathogenesis of PIH.

Role of substrates and products of PI 3-kinase in regulating activation of Rac-related guanosine triphosphatases by Vav

Mitogen stimulation of cytoskeletal changes and c-jun amino-terminal kinases is mediated by Rac small guanine nucleotide-binding proteins. Vav, a guanosine diphosphate (GDP)-guanosine triphosphate (GTP) exchange factor for Rac that stimulates the exchange of bound GDP for GTP, bound to and was directly controlled by substrates and products of phosphoinositide (PI) 3-kinase. The PI 3-kinase substrate phosphatidylinositol-4,5-bisphosphate inhibited activation of Vav by the tyrosine kinase Lck, whereas the product phosphatidylinositol-3,4,5-trisphosphate enhanced phosphorylation and activation of Vav by Lck. Control of Vav in response to mitogens by the products of PI 3-kinase suggests a mechanism for Ras-dependent activation of Rac.

Chlorella virus NY-2A encodes at least 12 DNA endonuclease/methyltransferase genes

The 380-kb chlorella virus NY-2A genome is highly methylated; 45% of the cytosines are 5-methylcytosine (5mC) and 37% of the adenines are N6-methyladenine (6mA). Based on the sensitivity/resistance of NY-2A DNA to 80 methylation-sensitive DNA restriction endonucleases, the virus is predicted to encode at least 10 DNA methyltransferases: 7 6mA-specific methyltransferases, M.CviQI (GTmAC), M.CvQII (RmAR), M.CviQIII (TCGmA), M.CviQIV (GmATC), M.CviQV (TGCmA), M.CviQVI (GmANTC), and M.CviQVII (CmATG): and 3 5mC-specific methyltransferases, M.CviQVIII [RGmC(T/C/G)], M.CviQIX (mCC), and M.CviQX (mCGR). Five of the 6mA methyltransferase genes, M.CviQI, M.CviQIII, M.CviQV, M.CviQVI, and M.CviQVII, were cloned and sequenced. In addition, 2 site-specific endonuclease activities, R.CviQI (G/TAC) and NY2A-nickase (R/AG), were detected in cell-free extracts from NY-2A virus-infected chlorella. Therefore, the NY-2A genome contains at least 12 DNA methyltransferase and endonuclease genes which, altogether, compose about 3-4% of the virus genome.

Hyperbaric oxygen as a signal transducer: upregulation of platelet derived growth factor-beta receptor in the presence of HBO2 and PDGF

The purpose of this study was to test the hypothesis that hyperbaric oxygen (HBO2) may function by modifying the signal transduction pathway of growth factors or their receptors, or both. Studies were conducted with platelet derived growth factor (PDGF) and HBO2 using an established rabbit ear wound model. PDGF, a dimeric compound composed of A chain and B chain components, is found as PDGF-A, AB, and BB. It exerts its effects on cells by binding to one of two membrane-bound receptors, the alpha receptor or the beta receptor. Acutely ischemic wounds in rabbit ears were treated with saline or PDGF-BB and then animals were treated with hyperbaric air or oxygen at 2 atm abs (202.6 kPa). Hyperbaric air was without significant effect compared with control rabbits who breathed air at ambient pressure. Combined treatment with HBO2 plus PDGF-BB was synergistic in upregulating mRNA for PDGF-beta receptor. No treatments, whether alone or in combination, altered mRNA levels for PDGF-alpha receptor or for PGDF-A.

Synthesis and evaluation of polycyclic pyrazolo[3,4-d]pyrimidines as PDE1 and PDE5 cGMP phosphodiesterase inhibitors

Polycyclic pyrazolo[3,4-d]pyrimidines (represented by 3 and 4) were synthesized as analogues of the recently reported polycyclic guanine phosphodiesterase (PDE) inhibitors. From the structure-activity relationship (SAR) development of a series of compounds, it was discovered that C-3 benzyl and N-2 methyl disubstitution on the pyrazole ring gave the best combination of potency and selectivity for PDE1 and PDE5 cGMP PDEs as represented by compound 4c: PDE1, IC50 = 60 nM; PDE3, IC50 = 55,000 nM; PDE5, IC50 = 75 nM. These compounds were also evaluated in vivo and found to be good orally active antihypertensives in laboratory animal models. Finally, comparisons were made of the in vitro and in vivo profiles of the pyrazolo-[3,4-d]pyrimidine compound 4c with those of two representative guanine compounds.

[Clinical study on painless labor under drugs combined with acupuncture analgesia]

To study the analgesia efficacy of drugs combined with acupuncture analgesia for painless labor, 462 normal pregnancy women were observed. During the latent phase in labor, several analgesia methods: acupuncture analgesia, analgesics, magnetotherapy and auricular acupressure, TENS combined with dihydroetorphine were used respectively. While the intrauterine pressure and the peripheral content of beta-EP were measured during labor, the experiments of SEPS were also performed on healthy adults to demonstrate the analgesia efficacy of those analgesia methods. The combination of drugs with acupuncture is an excellent method for painless labor without any complications and all the mothers and babies are safety. The effectiveness is 97.5%. The results demonstrate that the mechanism of analgesia efficacy should be regulated the incoordinate uterine action and improve the hypertonic status of uterus, but also can decrease the pain threshold and elevate the tolerance of uterine contractions during labor.

Inhibition of vascular smooth muscle cell proliferation by introduction of retinoblastoma gene via a recombinant adenovirus vector

OBJECTIVE

To investigate the vascular smooth muscle cell (SMC) growth suppression by recombinant adenovirus vector expressing a retinoblastoma (Rb) protein and to explore a gene therapy approach for vascular proliferative disorders including atherosclerosis and artery restenosis.

METHODS

A replication-deficient adenovirus vector encoding a wild-type Rb and AdCMVRb, was constructed and transfected into cultured rabbit aortic SMC. The efficiency of gene transfection and expression was detected by immunochemical staining and polymerase chain reaction. The role of Rb in regulating vascular SMC proliferation was observed by cell-counting, [3H] thymidine incorporation, and flow cytometry.

RESULTS

Wild-type Rb gene transfected effectively into the cultured SMC with AdCMVRb can suppress growth factor-stimulated cell proliferation through regulation of DNA synthesis and cell cycle progression.

CONCLUSION

The results demonstrate the potential of adenovirus-mediated Rb gene therapy for atherosclerosis and artery restenosis after balloon angioplasty.

Direct measurement of nitric oxide generation from nitric oxide synthase

Although nitric oxide synthase (NOS) is widely considered as the major source of NO in biological cells and tissues, direct evidence demonstrating NO formation from the purified enzyme has been lacking. It was recently reported that NOS does not synthesize NO, but rather generates nitroxyl anion (NO-) that is subsequently converted to NO by superoxide dismutase (SOD). To determine if NOS synthesizes NO, electron paramagnetic resonance (EPR) spectroscopy was applied to directly measure NO formation from purified neuronal NOS. In the presence of the NO trap Fe2+-N-methyl-D-glucamine dithiocarbamate, NO gives rise to characteristic EPR signals with g = 2.04 and aN = 12.7 G, whereas NO- is undetectable. In the presence of L-arginine (L-Arg) and cofactors, NOS generated prominent NO signals. This NO generation did not require SOD, and it was blocked by the specific NOS inhibitor N-nitro-L-arginine methyl ester. Isotope-labeling experiments with L-[15N]Arg further demonstrated that NOS-catalyzed NO arose from the guanidino nitrogen of L-Arg. Measurement of the time course of NO formation demonstrated that it paralleled that of L-citrulline. The conditions used in the prior study were shown to result in potent superoxide generation, and this may explain the failure to measure NO formation in the absence of SOD. These experiments provide unequivocal evidence that NOS does directly synthesize NO from L-Arg.

Effect of chronic hypoxia on glucose transporters in heart and skeletal muscle of immature and adult rats

Glucose transporter (GLUT) modulation can be an important mechanism that contributes to adaptation to hypoxic stress, but little is known about GLUT modulation in heart and skeletal muscle with prolonged hypoxia. In this work, the effect of chronic hypoxia on GLUT-4 and GLUT-1 mRNA and protein was studied in these two tissues in the adult and during development. Hypoxia (fractional inspired O2 = 9 +/- 0.5%) was administered to two groups, i.e., an immature group exposed from 3 to 30 days of age and an adult group exposed from 90 to 120 days of age. Rats were then killed and their heart and skeletal muscles were sampled for measurements of GLUT mRNA and protein with Northern and Western blots. In the adult, chronic hypoxia significantly decreased cardiac GLUT mRNA level by > 25% of control (P < 0.05), but had little effect on GLUT protein. A very different hypoxic effect was seen in the immature rat heart with a major increase in protein and no appreciable change in mRNA density. Adult skeletal muscle had no change in GLUT mRNA level but GLUT protein increased (15-20%, P < 0.05) while both GLUT mRNA and protein were significantly increased in the immature skeletal muscles (60-90% over control). We conclude that during chronic O2 deprivation, GLUT-1 and GLUT-4 expressions show a similar pattern but greatly depend on tissue type and age. These differences in GLUT regulation may be due to different strategies for coping with prolonged O2 deprivation in both immature and adult animals.

Developmental and hormonal regulation of the arabidopsis CER2 gene that codes for a nuclear-localized protein required for the normal accumulation of cuticular waxes

The previously cloned CER2 gene is required for the normal accumulation of cuticular waxes and encodes a novel protein. Earlier reports suggested that the CER2 protein is either a membrane-bound component of the fatty acid elongase complex or a regulatory protein. Cell fractionation and immunoblot analyses using polyclonal antibodies raised against a chemically synthesized peptide with a sequence based on the predicted CER2 protein sequence have demonstrated that the 47-kD CER2 protein is soluble and nuclear localized. These results are consistent with CER2 being a regulatory protein. Detailed studies of plants harboring a CER2 promoter/GUS transgene (CER2-GUS), in combination with immunoblot analyses, revealed that CER2 is expressed and the CER2 protein accumulates in a variety of organs and cell types. Expression is highest early in the development of these organs and is epidermis specific in most tissues. In agreement with the activity of the CER2 promoter in hypocotyls, cuticular wax accumulates on this organ in a CER2-dependent fashion. In leaves CER2 expression is confined to the guard cells, trichomes, and petioles. However, application of the cytokinin 6-benzylaminopurine induces ectopic expression of CER2-GUS in all cell types of leaves that emerge following treatment.

Electrical stimulation of neonatal cardiomyocytes results in the sequential activation of nuclear genes governing mitochondrial proliferation and differentiation

Electrical stimulation of neonatal cardiac myocytes produces hypertrophy and cellular maturation with increased mitochondrial content and activity. To investigate the patterns of gene expression associated with these processes, cardiac myocytes were stimulated for varying times up to 72 hr in serum-free culture. The mRNA contents for genes associated with transcriptional activation [c-fos, c-jun, JunB, nuclear respiratory factor 1 (NRF-1)], mitochondrial proliferation [cytochrome c (Cyt c), cytochrome oxidase], and mitochondrial differentiation [carnitine palmitoyltransferase I (CPT-I) isoforms] were measured. The results establish a temporal pattern of mRNA induction beginning with c-fos (0.25-3 hr) and followed sequentially by c-jun (0.5-3 hr), JunB (0.5-6 hr), NRF-1 (1-12 hr), Cyt c (12-72 hr), and muscle-specific CPT-I (48-72 hr). Induction of the latter was accompanied by a marked decrease in the liver-specific CPT-I mRNA, thus supporting the developmental fidelity of this pattern of gene regulation. Consistent with a transcriptional mechanism, electrical stimulation increased c-fos, beta-myosin heavy chain, and Cyt c promoter activities. These increases coincided with a rise in their respective endogenous gene transcripts. NRF-1, cAMP response element, and Sp-1 site mutations within the Cyt c promoter reduced luciferase expression in both stimulated and nonstimulated myocytes. Mutations in the NRF-1 and CRE sites inhibited the induction by electrical stimulation (5-fold and 2-fold, respectively) whereas mutation of the Sp-1 site maintained or increased the fold induction. This finding is consistent with the appearance of NRF-1 and fos/jun mRNAs prior to that of Cyt c and suggests that induction of these transcription factors is a prerequisite for the transcriptional activation of Cyt c expression. These results support a regulatory role for NRF-1 and possibly AP-1 in the initiation of mitochondrial proliferation.

Sequence analysis of the cloned glossy8 gene of maize suggests that it may code for a beta-ketoacyl reductase required for the biosynthesis of cuticular waxes

The gl8 locus of maize (Zea mays L.) was previously defined by a mutation that reduces the amount and alters the composition of seedling cuticular waxes. Sixty independently derived gl8 mutant alleles were isolated from stocks that carried the Mutator transposon system. A DNA fragment that contains a Mu8 transposon and that co-segregates with one of these alleles, gl8-Mu3142, was identified and cloned. DNA flanking the Mu8 transposon was shown via allelic cross-referencing experiments to represent the gl8 locus. The gl8 probe revealed a 1.4-kb transcript present in wild-type seedling leaves and, in lesser amounts, in other organs and at other developmental stages. The amino acid sequence deduced from an apparently full-length gl8 cDNA exhibits highly significant sequence similarity to a group of enzymes from plants, eubacteria, and mammals that catalyzes the reduction of ketones. This finding suggests that the GL8 protein probably functions as a reductase during fatty acid elongation in the cuticular wax biosynthetic pathway.

Locus of control and problem-solving interaction in families with adolescents

The focus of this study is on further development and refinement of a classification system of family problem-solving interaction in families with adolescents. A rigorous qualitative analysis was conducted on the video-taped problem-solving sessions of 38 families which consisted of a father, mother and their adolescent son or daughter. The analysis concentrated on how families engaged the problem situations, how solutions were generated and evaluated, communication patterns, and how affect was managed. It was discovered through the analysis that family problem-solving interaction could be classified based on a concept the researchers call family locus of control (F-LOC). Four types of F-LOC were described: individualistic, collaborative, authoritarian and external. Internal classification reliability was assessed by three independent raters who were able to accurately classify 95% of the problem-solving sessions by F-LOC. Discussion focuses on comparing the classification system with previously developed classification systems.

A model for p53-induced apoptosis

The inactivation of the p53 gene in a large proportion of human cancers has inspired an intense search for the encoded protein's physiological and biological properties. Expression of p53 induces either a stable growth arrest or programmed cell death (apoptosis). In human colorectal cancers, the growth arrest is dependent on the transcriptional induction of the protein p21WAF1/CIP1 , but the mechanisms underlying the development of p53-dependent apoptosis are largely unknown. As the most well documented biochemical property of p53 is its ability to activate transcription of genes, we examined in detail the transcripts induced by p53 expression before the onset of apoptosis. Of 7,202 transcripts identified, only 14 (0.19%) were found to be markedly increased in p53-expressing cells compared with control cells. Strikingly, many of these genes were predicted to encode proteins that could generate or respond to oxidative stress, including one that is implicated in apoptosis in plant meristems. These observations stimulated additional biochemical and pharmacological experiments suggesting that p53 results in apoptosis through a three-step process: (1) the transcriptional induction of redox-related genes; (2) the formation of reactive oxygen species; and (3) the oxidative degradation of mitochondrial components, culminating in cell death.

Origin of cartilage laminae in MRI

To understand the origin of the laminated appearance of cartilage in MRI (the magic angle effect), microscopic MRI (mu MRI) experiments were performed at 14-microns pixel resolution on normal canine articular cartilage from the shoulder joints. Two-dimensional images of the spin-spin relaxation time (T2) of the cartilage-bone plug at two angles (0 degree and 55 degrees) were calculated quantitatively. A distinct T2 anisotropy was observed as a function of the cartilage tissue depth. The surface and the deep regions exhibit strong orientational dependence of T2, whereas the upper-middle region exhibits little orientational dependence of T2. These three mu MRI regions correspond approximately to the three histologic zones in cartilage tissue. The results from the bulk T2 measurements agreed with these mu MRI results. Our studies show that the laminated appearance of cartilage in MRI is caused by T2 anisotropy of the tissue. We further suggest that the molecular origin of the T2 anisotropy is the nuclear dipolar interaction. The structure of the cartilage tissue indicates that the collagen meshwork defines this T2 anisotropy. The results show that the T2 anisotropy provides an indirect but sensitive indicator for the orientation of macromolecular structures in cartilage. The clinical implications of this anisotropy are discussed.

Monoclonal antibodies to the extracellular domain of prostate-specific membrane antigen also react with tumor vascular endothelium

Prostate-specific membrane antigen (PSMA), initially defined by monoclonal antibody (mAb) 7E11, is a now well-characterized type 2 integral membrane glycoprotein expressed in a highly restricted manner by prostate epithelial cells. 7E11 has been shown to bind an intracellular epitope of PSMA that, in viable cells, is not available for binding. Herein, we report the initial characterization of the first four reported IgG mAbs that bind the external domain of PSMA. Competitive binding studies indicate these antibodies define two distinct, noncompeting epitopes on the extracellular domain of PSMA. In contrast to 7E11, these mAbs bind to viable LNCaP cells in vitro. In addition, they show strong immunohistochemical reactivity to tissue sections of prostate epithelia, including prostate cancer. These mAbs were also strongly reactive with vascular endothelium within a wide variety of carcinomas (including lung, colon, breast, and others) but not with normal vascular endothelium. These antibodies should prove useful for in vivo targeting to prostate cancer, as well as to the vascular compartment of a wide variety of carcinomas.