Conjugation fidelity and bistability in a high-efficiency mutually pumped phase conjugator with ring channels

We describe a high-efficiency mutually pumped phase conjugator with ring channels in a bird-wing incident geometry in copper-doped potassium sodium strontium barium niobate. A transmissivity as great as 35% is measured. Optical switching is obtained. The dependence of phase-conjugation fidelity on the geometric parameters and the input-beam ratio is discussed. Some suggestions are proposed to improve the fidelity further. The response times as a function of the input-beam ratio with the input beam kept constant are measured, and the least-squares minimum is used to simulate the fitting curve equations and to explain the formation of optical switching and the reduction or improvement of image fidelity.

Resistance to fever induction and impaired acute-phase response in interleukin-1 beta-deficient mice

We used gene targeting in embryonic stem cells to introduce an IL-1 beta null allele in mice. The IL-1 beta-deficient mice develop normally and are apparently healthy and fertile. The IL-1 beta null mice responded normally in models of contact and delayed-type hypersensitivity or following bacterial endotoxin LPS-induced inflammation. The IL-1 beta-deficient mice showed equivalent resistance to Listeria monocytogenes compared with wild-type controls. In contrast, when challenged with turpentine, which causes localized inflammation and tissue injury, the IL-1 beta mutant mice exhibited an impaired acute-phase inflammatory response and were completely resistant to fever development and anorexia. These results highlight a central role for IL-1 beta as a pyrogen and a mediator of the acute-phase response in a subset of inflammatory disease models, and support the notion that blocking the action of a single key cytokine can alter the course of specific immune and inflammatory responses.

beta-Amyloid precursor protein-deficient mice show reactive gliosis and decreased locomotor activity

In several pedigrees of early onset familial Alzheimer's disease (FAD), point mutations in the beta-amyloid precursor protein (APP) gene are genetically linked to the disease. This finding implicates APP in the pathogenesis of Alzheimer's disease in these individuals. To understand the in vivo function of APP and its processing, we have generated an APP-null mutation in mice. Homozygous APP-deficient mice were viable and fertile. However, the mutant animals weighed 15%-20% less than age-matched wild-type controls. Neurological evaluation showed that the APP-deficient mice exhibited a decreased locomotor activity and forelimb grip strength, indicating a compromised neuronal or muscular function. In addition, four out of six homozygous mice showed reactive gliosis at 14 weeks of age, suggesting an impaired neuronal function as a result of the APP-null mutation.

[Antikeratin antibodies: another specific antibodies in rheumatoid arthritis patients]

Sera from 107 patients with rheumatoid arthritis (RA), 120 patients with other rheumatic diseases and 60 blood donors were tested with indrect immunofluorescence on the middle third of Wistar rat oesophagus as a substrate for the presence of antikeratin antibodies (AKA). By labelling the stratum corneum and stratum spinosum with IgG antibodies, three patterns of reaction were distinguished. Among them, only one pattern which showed an intense linear laminated fluorescence on stratum corneum and a weak fluorensence on stratum spinosum was valuable for the diagnosis of RA, with a specificity of 99% and a sensitivity of 23%. It was also found that they were not related to the presence of rheumatoid factor or anti-RA 33,000/36,000 antibodies. Thus, AKA might be another marker antibody in RA.

Alternative splicing in human retinal mRNA transcripts of an opsin-related protein

An opsin-related gene encodes a putative RPE-retinal G-protein-coupled receptor (RGR) that is most homologous to the visual pigments and invertebrate retinochrome. A splice variant of human RGR mRNA can be demonstrated by the sequence of isolated cDNA clones and by the amplification and analysis of human retinal mRNA. The shortened transcript contains a deletion of 114 nucleotides that correspond exactly to the sequence of exon 6 in the human rgr gene. The predicted RGR variant lacks the putative sixth transmembrane domain and has a calculated molecular weight of 27,726. Variable amounts of a 28-kDa protein were found in the retinas of some individuals by immunoblot assay. Since a similar shortened RGR transcript was not detected in bovine retina or RPE, the RGR variant is not essential for vertebrate vision. Analysis of the structure of the rgr gene and of the sequences of cDNA clones indicates that the truncated mRNA may be produced through alternative splicing of pre-mRNA from which a cassette exon is removed and the predicted RGR variant is radically altered in primary structure.

beta-Galactosidase transgene expression in transplanted rabbit retinal pigment epithelial cells in vivo

BACKGROUND

Intraocular transplantation of genetically modified cells that release a particular substance could have a major impact on the treatment of various ocular diseases. We studied the expression of the reporter gene beta-galactosidase (lacZ) in transplanted retinal pigment epithelial (RPE) cells in vivo.

METHODS

RPE cells from pigmented rabbits were transduced with the beta-galactosidase gene in a retroviral vector. Cells were then assayed for gene expression and transplanted subretinally into the eyes of New Zealand White rabbits. RPE cells that were transduced with a similar vector without the beta-galactosidase gene were used as controls. Rabbits were killed on days 1, 7, and 21 and the eyes processed for transmission electron microscopy

RESULTS

Neomycin-resistant rabbit RPE cells that showed beta-galactosidase activity were generated within 2-5 weeks. After transplantation, viable RPE cells that expressed the transgene and that phagocytosed rod outer segments were observed on days 1, 7, and 21

CONCLUSIONS

The results show that generation of genetically modified RPE cells is feasible and that the transplanted cells remain viable and continue to express the transgene in the subretinal space of the host animal for at least 21 days. Transplantation of such genetically modified RPE cells could provide a new tool for studying retinal diseases and, potentially, for correcting metabolic abnormalities in retinal degenerations and dystrophies.

Asymmetric transmission device using Fe-doped KTa(x)Nb(1-x)O(3) crystal

A new type of asymmetric optical transmission device based on contradirectional two-wave mixing between an incident beam and its backward-scattering beams in Fe-doped KTa(x)Nb(1-x)O(3) crystal is demonstrated. The transmittance ratio of the beams propagating in opposite directions can be adjusted by a change in the angle between the incident beam and the c axis; the maximum ratio is nearly 50:1 at only one incident beam. Approximate solutions of two opposite transmittances are derived and discussed. It is possible to use this device as an optical isolator or an optical diode.

[Aorto-profunda femoris bypass grafting in the treatment of aorto-ilio-femoral atherosclerotic occlusive disease]

Fourteen patients with aorto-ilio-femoral or ilio-femoral atherosclerotic occlusive disease were treated with aorto-profunda femoris bypass grafting. Excellent results were confirmed after a mean follow-up period of 15 months. Ankle-brachial index raised from 0.1 +/- 0.12 before operation to 0.64 +/- 0.26 months after operation. The authors considered that the profunda femoral artery plays an important role in aorto-femoral arterial reconstruction. It is a good outflow providing arterial blood to severely ischemic legs with occlusion of aorto-ilio-superficial femoral or ilio-superficial femoral arteries.

Vascular barrier-enhancing effect of an endogenous beta-adrenergic agonist

Exogenous catecholamines have been proved to be active in the reduction of vascular permeability induced by various inflammatory mediators via beta-adrenoceptor activation, but it is not known whether an endogenous beta-adrenergic agonist has any effect. We studied it in skin and lung vessels. The results revealed that an intravenous bolus of isoproterenol (10 micrograms/kg) attenuated platelet-activating factor- and histamine-induced Evans blue dye extravasation in rat dorsal skin, while intraperitoneal administration of beta-adrenoceptor blocker propranolol (0.1 mg/kg) significantly increased the dye extravasation. Blockade of beta-adrenoceptor by propranolol for 12 h noticeably increased wet/dry lung weight ratio, lung water content, bronchoalveolar lavage (BAL) protein concentration, leukocyte count, and lipoperoxide degradation product malondialdehyde (MDA) content. In isolated perfused lung in vitro, propranolol (2.5 micrograms/ml) had no obvious effects on lung weight gain, fluid filtration coefficient, and pulmonary vascular pressure during the 20-min perfusion compared with control. The results suggested that endogenous beta-adrenergic agonist is an important factor in the maintenance of vascular integrity and the quiescent state of leukocytes, indicating the antiinflammatory role of catecholamines in physiological states and critical illnesses.

[Minocycline potentiates the antimetastatic effect of boanmycin]

Boanmycin (bleomycin A6, BAM) was found to markedly inhibit the spontaneous pulmonary metastasis of Lewis carcinoma in mice. Compared at equitoxic doses (1/9 LD50), BAM was more effective than mitomycin. Minocycline (MNO) at 5 mg.kg-1 showed no inhibition on the growth of sc transplanted Lewis primary tumor; however, it markedly potentiated the antimetastatic effect of BAM. Treated with BAM (5 mg.kg-1) alone, the number of total metastatic foci and that of large foci (> 2 mm in diameter) in the lung were suppressed by 67% and 85%, respectively. When BAM was used in combination with MNO, the number of those foci was further reduced by 88% and 100%, respectively. By NAG enzyme assay, MNO was not cytotoxic and showed no synergism with BAM against PG cells, a cell line derived from a highly metastatic human giant cell carcinoma of the lung. Determined by ELISA with a monoclonal antibody, the expression of type IV collagenase in PG cells was remarkably inhibited by MNO. The intracellular free Ca2+ level in PG cells was reduced from 76.7 nmol.L-1 to 42.2 nmol.L-1 by MNO treatment. The study suggests that the combination of boanmycin and minocycline may be useful for control of tumor metastasis and the inhibition of type IV collagenase expression may be involved in the mechanism of minocycline potentiation.

Histological and mechanical comparison of hydroxyapatite-coated cobalt-chrome and titanium implants in the rabbit femur

The purpose of this study was to compare hydroxyapatite (HA)-coated titanium (Ti) and HA-coated cobalt-chrome (CoCr) implants in the distal femur of the rabbit by evaluating bone apposition and interfacial shear strength. Bilateral cylindrical implants with a plasma sprayed 50-microns thick HA coating were press-fit into the metaphyseal cancellous bone of the lateral femoral condyles in a transverse fashion, and the animals were sacrificed at 2, 4, and 8 weeks postimplantation. Mechanical strength of the interface between HA and bone was measured using the pushout method. For histologic analysis, the fractional linear extent of bone apposition was quantitated. No differences were found in the interfacial shear strength between the Ti and CoCr at any time period. The amount of bone apposition increased significantly at each time interval for both substrate metals, but there were no significant differences between the two substrates at any of the time periods studied. The HA-coated CoCr implants performed in a similar manner to the HA-coated Ti implants, both mechanically and histologically, suggesting that HA-coated CoCr implants deserve further study as a viable alternative to Ti for the biological fixation of total joint components in orthopaedic surgery.

A human opsin-related gene that encodes a retinaldehyde-binding protein

The ligand-binding property of a cytoplasmic membrane-bound protein from bovine retinal pigment epithelium (RPE) has been demonstrated. The putative RPE-retinal G protein coupled receptor (RGR) covalently binds both all-trans- and 11-cis-retinal after reduction by sodium borohydride. The 32-kDa receptor binds all-trans-retinal preferentially, rather than the 11-cis isomer. The amino acid sequence of the opsin-related protein in humans is 86% identical to that of bovine RGR, and a lysine residue, analogous to the retinaldehyde attachment site of rhodopsin, is conserved in the seventh transmembrane domain of RGR in both species. The human gene that encodes the novel retinaldehyde receptor spans 14.8 kb and is split into seven exons. The structure of the gene is distinct from that of the visual pigment genes. These findings support the notion that the rgr gene represents the earliest independent branch of the vertebrate opsin gene family. A second form of human RGR in retina is predicted by alternative splicing of its precursor mRNA. This RGR variant results from the alternative use of an internal acceptor splice site in the second intron of the human gene, and it contains an insertion of four amino acids in the connecting loop between the second and thrid transmembrane domains. Since RGR binds all-trans-retinal preferentially, one of its functions may be to catalyze isomerization of the chromophore by a retinochrome-like mechanism.

Suppression by isoproterenol of endothelial cell morphology and barrier function changes induced by platelet-activating factor

Using a model to study vascular permeability on hydrostatically perfused bovine pulmonary artery endothelial cell (EC) monolayers and software to analyze cell morphological parameters automatically in a computer image workstation, we studied the effects of isoproterenol (IPN) on platelet-activating factor (PAF)-induced changes in EC monolayer permeability and cell morphological parameters. Albumin has fortifying effects on endothelial barrier function. As albumin concentration in the perfusate increased (0, 1, 5, 10, 20 mg/ml), EC monolayer hydraulic conductivity (Lp) decreased gradually while Lp of the filter membranes did not change. After treatment of the EC monolayer with PAF 10(-8) mol/liter for 30 min, transmonolayer fluid flow, protein clearance rate, and Lp value increased noticeably. At the same time, cell area decreased and intercellular distance and percentage of intercellular space area in total cell monolayer increased. Pretreatment with 10(-4) mol/liter IPN blocked PAF-induced EC permeability and morphological changes, suggesting that EC contraction and intercellular gap formation are important mechanisms for PAF-induced high vascular permeability. IPN inhibits the effects of PAF via stabilization of EC morphology, protection of intercellular junction, and blockade of intercellular gap formation.

Preoptic projections to Barrington's nucleus and the pericoerulear region: architecture and terminal organization

The medial preoptic area (MPO), a sexually dimorphic region, plays a pivotal role in neuroendocrine function and reproductive behavior. We recently reported that MPO projects heavily to the midbrain periaqueductal gray (PAG). We also noted that MPO projects to the dorsolateral pontine tegmentum. Here we identified the cells of origin of the MPO-->tegmental projection and delineated the terminal organization of MPO projections to Barrington's nucleus, locus coeruleus (LC), and the rostromedial pericoerulear region (pLCrm). Correlative cyto- and chemoarchitectonic studies were done to define better the nuclear groups of the dorsolateral pontine tegmentum. Retrograde tracing revealed that MPO neurons projecting to the dorsolateral pontine tegmentum are preferentially distributed in distinct subregions of MPO, including the sexually dimorphic medial preoptic nucleus (MPN). Anterograde tracing with wheat germ agglutinin-horseradish peroxidase or Phaseolus vulgaris leucoagglutinin demonstrated considerable target specificity in projections from MPO to the dorsolateral pontine tegmentum. Barrington's nucleus receives a dense focal input along its entire rostrocaudal axis. In addition, pLCrm is heavily targeted by MPO inputs; pLCrm contains a concentrated plexus of extranuclear dendrites of LC neurons. The lateral dorsal tegmental (LDT) nucleus and LC proper receive only sparse input from MPO. MPO projections to Barrington's nucleus could regulate micturition reflexes during reproductive behavior. The MPO-->pLCrm projection could influence noradrenergic LC neurons in relation to reproductive and/or gonadal steroid function. Given the strong established connections from olfactory structures to MPO, it is possible that the MPO-->LC pathway provides an anatomical substrate for olfactory modulation of arousal.

Antitumor activity of immunoconjugates composed of boanmycin and monoclonal antibody

Boanmycin (bleomycin A6, BM), an antitumor antibiotic, was conjugated to monoclonal antibodies including R19, H111 and CCT2. The immunoconjugates exhibited selective cytotoxicity to related target cells including cecum cancer Hce-8693 cells, liver cancer BEL-7402 cells and leukemia CEM cells. They were highly effective against related human tumor xenografts in nude mice, and the inhibition rates by the conjugates were much higher than those by free BM. The inhibition rate by R19-BM conjugate against human cecum cancer xenografts reached 90%. BY immunoelectron microscopy, CCT2-BM conjugate showed specific binding and internalization in leukemia CEM cells. The results indicate that boanmycin-monoclonal antibody immunoconjugates are highly active both in vitro and in vivo.

Cytoplasmic retinal localization of an evolutionary homolog of the visual pigments

A rhodopsin-related protein is preferentially expressed at high levels in retinal pigment epithelium (RPE) and in Müller cells. The putative RPE-retinal G protein-coupled receptor (RGR) was localized in light-adapted bovine retina by means of electron microscopic immunocytochemistry. In the RPE, the protein was localized to a widespread intracellular compartment. Except for the region adjacent to the basal surface, the RPE cytoplasm was labeled throughout the cell including the apical surface. In Müller cells also RGR was found in the intracellular compartment, especially in the cytoplasm in the region of the Müller cell endfeet and proximal cell processes. Subcellular fractionation studies of bovine RPE and neural retina indicated that RGR is a membrane-bound protein. The intracellular localization of RGR is a unique variation in the subcellular distribution of seven-transmembrane-domain receptors and suggests an unconventional role for RGR in the signal transduction process.

[Evaluation of anti-rheumatoid arthritis 36 kD and anti-33 kD antibodies in the diagnosis of rheumatoid arthritis]

By using soluble nuclear extracts from Ehrlich mice ascite cells, immunoblot analysis showed reactivity of rheumatoid arthritis (RA) serum with a 36 kD band. It was found that 28 of 88 patients with RA had anti-RA 36 kD antibody (31.8%), but there was no reactivity in the serum samples from 100 patients with other connective tissue diseases and 40 normal controls. However, the nuclear antigen mentioned above could react with either anti-RA 33 kD antibody or anti-RNP antibody in the 33 kD band. Thus, anti-RA 33 kD antibody was not a specific antibody for RA. Anti-RA 36 kD antibody appeared to be a marker antibody in RA. If anti-RA 36 kD and anti-33 kD antibodies appeared in a serum sample simultaneously, it might be more valuable for the diagnosis of RA.

Role of Pr160gag-pol in mediating the selective incorporation of tRNA(Lys) into human immunodeficiency virus type 1 particles

COS-7 cells transfected with human immunodeficiency virus type 1 (HIV-1) proviral DNA produce virus in which three tRNA species are most abundant in the viral tRNA population. These tRNAs have been identified through RNA sequencing techniques as tRNA(3Lys) the primer tRNA in HIV-1, and members of the tRNA(1,2Lys) isoacceptor family. These RNAs represent 60% of the low-molecular-weight RNA isolated from virus particles, while they represent only 6% of the low-molecular-weight RNA isolated from the COS cell cytoplasm. Thus, tRNA(Lys) is selectively incorporated into HIV-1 particles. We have measured the ratio of tRNA(3Lys) molecules to copies of genomic RNA in viral RNA samples and have calculated that HIV-1 contains approximately eight molecules of tRNA(3Lys) per two copies of genomic RNA. We have also obtained evidence that the Pr160gag-pol precursor is involved in primer tRNA(3Lys) incorporation into virus. First, selective tRNA(Lys) incorporation and wild-type amounts of tRNA(3Lys) were maintained in a protease-negative virus unable to process Pr55gag and Pr160gag-pol precursors, indicating that precursor processing was not required for primer tRNA incorporation. Second, viral particles containing only unprocessed Pr55gag protein did not selectively incorporate tRNA(Lys), while virions containing both unprocessed Pr55gag and Pr160gag-pol proteins demonstrated select tRNA(3Lys) packaging. Third, studies with a proviral mutant containing a deletion of most of the reverse transcriptase sequences and approximately one-third of the integrase sequence in the Pr160gag-pol precursor resulted in the loss of selective tRNA incorporation and an eightfold decrease in the amount of tRNA(3Lys) per two copies of genomic RNA. We have also confirmed herein finding of a previous study which indicated that the primer binding site is not required for the selective incorporation of tRNA(Lys).

Reverse transcriptase is an important factor for the primer tRNA selection in HIV-1

During assembly, HIV-1 selectively packages tRNA(Lys3), the primer tRNA for reverse transcriptase (RT). Because of tRNA(Lys3)'s ability to interact with RT, RT may be the viral protein which binds to primer tRNA and carries it into the virus. We have tested this hypothesis by measuring the amount of tRNA(Lys3) incorporated into wild type and RT(-) virus, and have also measured the tRNA tightly associated with the RNA genome, a characteristic of primer tRNA. We find that in RT(-) HIV-1, primer tRNA(Lys3) is reduced approximately 10 fold compared to wild type virus (which contains 8 molecules tRNA(Lys3)/virus), and the tRNA found tightly associated with the RNA genome is also greatly reduced in these mutant virus.

An indirect comparison of third-body wear in retrieved hydroxyapatite-coated, porous, and cemented femoral components

The osteoconductive properties of hydroxyapatite (HA)-coated titanium implants are well documented, but eventual coating degradation may result in HA particles adjacent to the substrate, and if the particles were to migrate into the joint space then accelerated polyethylene wear might be expected. As an indirect indication of third-body wear, the authors used laser interference microscopy to measure and compare surface roughness on modular heads from 15 clinically retrieved HA-coated femoral components, with heads from 15 retrieved uncemented (porous) and 15 cemented implants. The results showed increased median surface roughness over initial manufacturer specifications in all groups, but the cobalt-chrome heads from the HA-coated group showed significantly less surface roughness and less deep scratches than the heads from either the porous or uncemented group. Three-body wear appears to be a common problem, but evidence available suggests that it is no more of a problem with HA-coated devices than porous or cemented.

An opsin homologue in the retina and pigment epithelium

PURPOSE

The aim of this project was to investigate the retinal pigment epithelium (RPE) at the molecular level by identification of novel RPE-specific cDNAs that may encode proteins of signal transduction pathways or other proteins that are expressed preferentially in the RPE.

METHODS

A bovine RPE cDNA library was constructed in bacteriophage lambda g10 using RPE-enriched poly(A)+ RNA. The library was screened by differential hybridization to bovine RPE and kidney cDNA probes.

RESULTS

A member of the hepatahelical receptor family was identified in bovine RPE by molecular cloning. Its deduced amino acid sequence predicts a protein that has 291 amino acid residues and resembles most closely the family of visual pigments. A lysine residue, analogous to the retinaldehyde attachment site in rhodopsin, is conserved in the seventh hydrophobic segment of the novel sequence. Messenger RNA encoding the putative G protein-coupled receptor was detected by in situ hybridization in the RPE, inner nuclear layer, and specific cells of the ganglion cell layer. Immunohistochemical staining of bovine retina showed that the receptor protein is localized in Müller cells, as well as in the RPE.

CONCLUSIONS

A novel heptahelical receptor defines a distant evolutionary branch of the visual pigment tree. The selective localization of this putative receptor, its abundance in RPE and retina, and its homology to the visual pigments suggest that the function of this receptor is important in a visual process involving the RPE and Müller cells.