The order of calcium and phosphate ion deposition on chemically treated titanium surfaces soaked in aqueous solution

The mechanism of apatite deposition on chemically treated Ti surfaces still is being studied. In this study, simulated body fluid, calcium aqueous solution, phosphate aqueous solution, and accelerated calcification solution are used as media to investigate the order of calcium and phosphate ion deposition on chemically treated Ti surfaces. The results of inductively coupled plasma spectra, scanning electron microscopy, and energy dispersive X-ray analysis show that calcium deposition is the prerequisite for phosphate ion deposition.

Analysis of the rds/peripherin.rom1 complex in transgenic photoreceptors that express a chimeric protein

Mice homozygous for the retinal degeneration slow (rds) mutation completely lack photoreceptor outer segments. The rds gene encodes rds/peripherin (rds), a membrane glycoprotein in the rims of rod and cone outer segment discs. rds is present as a complex with the related protein, rom1. Here, we generated transgenic mice that express a chimeric protein (rom/D2) containing the intradiscal D2 loop of rds in the context of rom1. rom/D2 was N-glycosylated, formed covalent homodimers, and interacted non-covalently with itself, rds, and rom1. The rds.rom/D2 interaction was significantly more stable than the non-covalent interaction between rds and rom1 by detergent/urea titration. Analysis of mice expressing rom/D2 revealed that rds is 2.5-fold more abundant than rom1, interacts non-covalently with itself and rom1 via the D2 loop, and forms a high order complex that may extend the entire circumference of the disc. Expression of rom/D2 fully rescued the ultrastructural phenotype in rds+/- mutant mice, but it had no effect on the phenotype in rds-/- mutants. Together, these observations explain the striking differences in null phenotypes and frequencies of disease-causing mutations between the RDS and ROM1 genes.

Preliminary study on HA coating percutaneously implanted in bone

A comparative investigation on the possibility of hydroxyapatite (HA) coating and pure Ti column to form biological sealing with skin tissue was completed in this study. HA coating and pure Ti column were percutaneously implanted in the tibia of rabbits. Compared with titanium (Ti) implant, HA coating forms epithelial sealing with skin tissue at 6 weeks postoperatively, while the Ti implant may loosen from the implanted site and be lost. The Ti column loosing rate at this time was 50%. However, once the Ti implant becomes fixed with the bone tissue, it can form epithelial sealing with skin tissue just like the HA coating, at 8 weeks postoperatively. At 8 weeks postoperatively, the epithelial sealing is not destroyed in spite of the fact that the HA coating is biodegraded. Our results show that the HA coating can become fixed with the bone faster than the Ti, which is beneficial for epithelial sealing formation. The main role of HA coating for epithelial sealing is beneficial for sealing at the initial period after it is implanted.

High frequency of mutations in MODY and mitochondrial genes in Scandinavian patients with familial early-onset diabetes

AIMS/HYPOTHESIS

To investigate the contribution of mutations in maturity-onset diabetes of the young (MODY) and mitochondrial genes to early-onset diabetes with a strong family history of diabetes in a cohort with a high prevalence of Type I (insulin-dependent) diabetes mellitus.

METHODS

Screening for sequence variants in the hepatocyte nuclear factor (HNF)-4alpha (MODY1), glucokinase (MODY2), HNF-1alpha (MODY3) genes and mitochondrial DNA was carried out in 115 Finnish and Swedish patients with early-onset ( </= 40 years) diabetes using the single strand conformation polymorphism (SSCP) technique and direct sequencing. Allele frequencies were compared with 118 patients with onset of diabetes Type II (non-insulin-dependent) diabetes mellitus after the age of 40 and 92 non-diabetic control subjects without a family history of diabetes.

RESULTS

In total 52 sequence variants were found in the HNF-1alpha, HNF-4alpha and glucokinase genes, 12 of which were considered as MODY mutations. Three families had the A3243G mutation in the mitochondrial tRNA(Leu) gene, which resulted in an overall prevalence of these mutations of 13 %.

CONCLUSION/INTERPRETATION

Among 115 Scandinavian families, mutations in the HNF-1alpha gene represented the most common cause of familial early-onset ( </= 40 years) diabetes: MODY3 (5.2 %) more than MODY2 (3.5 %) more than MIDD (2.6 %) more than MODY1 (1.7 %).

[The spectral study of the surface modified medical rubber]

In this article ,the drug-resistance of two kinds of medical rubber whose surfaces have been modified were investigated by ATR-FTIR and XPS. The experimental results show that the compositions of the two samples'surface and body are different. The surface is fluorinated rubber although the body is butyl rubber. The ratio of fluorine to carbon atom in sample Ii -1 is higher than that in sample I -1. The principal join between F and C is the form--CF2--in sample II -1,but in sample I -1 it is the form--CF2-- and--CHF--. The change for F/C of the different depth in sample II- 1 was relatively less than that in sample I -1 when they were etched by argon ion bundle in the same conditions.

Insights into the function of Rim protein in photoreceptors and etiology of Stargardt's disease from the phenotype in abcr knockout mice

Rim protein (RmP) is an ABC transporter of unknown function in rod outer segment discs. The human gene for RmP (ABCR) is affected in several recessive retinal degenerations. Here, we characterize the ocular phenotype in abcr knockout mice. Mice lacking RmP show delayed dark adaptation, increased all-trans-retinaldehyde (all-trans-RAL) following light exposure, elevated phosphatidylethanolamine (PE) in outer segments, accumulation of the protonated Schiff base complex of all-trans-RAL and PE (N-retinylidene-PE), and striking deposition of a major lipofuscin fluorophore (A2-E) in retinal pigment epithelium (RPE). These data suggest that RmP functions as an outwardly directed flippase for N-retinylidene-PE. Delayed dark adaptation is likely due to accumulation in discs of the noncovalent complex between opsin and all-trans-RAL. Finally, ABCR-mediated retinal degeneration may result from "poisoning" of the RPE due to A2-E accumulation, with secondary photoreceptor degeneration due to loss of the RPE support role.

[Effect of xuefu zhuyu decoction on function of platelet and endothelial cell]

OBJECTIVE

To explore the effect of Xuefu Zhuyu Decoction (XFZYD) on function of platelet and endothelial cell.

METHODS

Through incubation of XFZYD, in different concentration, with platelet and human umbilical vein endothelial cell, the platelet membrane glycoprotein II b/III a complex and thrombomoduline (TM) of human umbilical vein endothelial cell were determined by radioimmunoassay.

RESULTS

XFZYD in 40 mg/ml or 80 mg/ml could obviously inhibit the adenosine diphosphate induced glycoprotein II b/III a molecular expression, as compared with the control group, the difference was significant (P < 0.05, P < 0.01), but it did not influence the TM level significantly.

CONCLUSION

XFZYD could inhibit the adenosine diphosphate induced activation of platelet through blocking the exposure of glycoprotein II b/III a complex.

Studies of the neutralizing activity and avidity of anti-human immunodeficiency virus type 1 Env antibody elicited by DNA priming and protein boosting

DNA vaccination is an effective means of eliciting strong antibody responses to a number of viral antigens. However, DNA immunization alone has not generated persistent, high-titer antibody and neutralizing antibody responses to human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env). We have previously reported that DNA-primed anti-Env antibody responses can be augmented by boosting with Env-expressing recombinant vaccinia viruses. We report here that recombinant Env protein provides a more effective boost of DNA-initiated antibody responses. In rabbits primed with Env-expressing plasmids, protein boosting increased titer, persistence, neutralizing activity, and avidity of anti-Env responses. While titers increased rapidly after boosting, avidity and neutralizing activity matured more slowly over a 6-month period following protein boosting. DNA priming and protein immunization with HIV-1 HXB-2 Env elicited neutralizing antibody for T cell line-adapted, but not primary isolate, viruses. The most effective neutralizing antibody responses were observed after priming with plasmids which expressed noninfectious virus-like particles. In contrast to immunizations with HIV-1 Env, DNA immunizations with the influenza virus hemagglutinin glycoprotein did not require a protein boost to achieve high-titer antibody with good avidity and persistence.

Biological evaluation of biphasic calcium phosphate ceramic vertebral laminae

An artificial vertebral lamina with a dense inside surface and porous outside part, fabricated with a biphasic calcium phosphate (70% hydroxyapatite/30% tricalcium phosphate) (HA-TCP) ceramic (abbr. CVL), was evaluated by animal experiments. The animal experiments showed that at half a month postoperation, no bone formation occurred on the macropore surfaces of the implants, however, fibrous connective tissues and blood vessels had grown into the macropores, contributing to the early fixation of the CVLs. The degradation of TCP phase was detected through X-ray diffraction (XRD); in the meanwhile, needle-like and plate-like crystals were found in the materials through scanning electron microscopy (SEM), and infrared spectroscopy (IR) observations showed that the carbonate apatites similar to bone apatites began to occur in the materials. At one month postoperation, the degradation of the TCP phase became moderate, new bone began to grow into the porous structures of the implants, and further degradation of the implants provided rich Ca and P ions for new bone formation. The newly formed bone in the macropores of the implants increased with implantation time. At one year postoperation, the implant was completely fused with natural bone on the interfaces between them, new bone had grown into most of the porous structures of the implants, and a natural bone tissue layer formed on the inside surface of the artificial vertebral lamina. The new bone tissue layer played a more effective role in protecting the spinal cord and improving the spinal stability in the later implantation time.

The human photoreceptor rim protein gene (ABCR): genomic structure and primer set information for mutation analysis

Rim protein (RmP) is an integral membrane glycoprotein localized to the rims of photoreceptor outer-segment discs. It belongs to the ABC transporter superfamily, but its function in the retina has not been determined. The gene for human RmP (ABCR) is affected in several recessively inherited human retinal degenerations, including Stargardt's macular dystrophy, retinitis pigmentosa, and cone-rod dystrophy. The complete structure of ABCR has not been determined. Here, we report the cloning of the human ABCR gene and present its complete intron-exon structure. The gene contains 50 exons that range in size from 33 to 406 bp. Almost all of the splice junctions follow the AG/GT rule. We have identified the site of transcription initiation by 5' RACE. The first several hundred bases upstream of the transcription unit are relatively conserved between mouse and human and contain several predicted cis-regulatory elements including a TATA-like box at -27 bp, and two Ret-4-like elements that reportedly confer photoreceptor-specific gene expression. We also present a complete set of tested oligonucleotide primers for the amplification and analysis of exons 1-50 by the polymerase chain reaction. These data should help with the identification of new disease-causing mutations in ABCR.

Identification of two rds/peripherin homologs in the chick retina

PURPOSE

To identify possible homologs of mammalian rds/peripherin in chick photoreceptors.

METHODS

An embryonic day-15 chick retinal library was screened by polymerase chain reaction with degenerate oligonucleotide primers derived from conserved segments of the mammalian retinal degeneration slow (rds) mRNA. The resultant amplification products were used to isolate cDNAs, containing complete coding regions. These clones were studied by nucleotide sequence, Northern blot, and in situ hybridization analyses.

RESULTS

Two new homologs of rds/peripherin were discovered: crds1 and crds2. The predicted crds1 protein is 78%, and the predicted crds2 protein is 54%, identical to mammalian rds/peripherin. The crds1 mRNA is an abundant 4.4-kb species present in photoreceptors. The crds2 mRNA is of similar size but is much rarer. No homologs of rom1 were identified in our screen. Developmentally, the crds1 mRNAs were first detectable at embryonic day 18.

CONCLUSIONS

Crds1 likely represents the chick ortholog of mammalian rds/peripherin, whereas crds2 is a more distant homolog. Both share an elongated C-terminal domain, an unusual feature compared with other members of the rds family.

Immunogenicity of DNA vaccines expressing human immunodeficiency virus type 1 envelope glycoprotein with and without deletions in the V1/2 and V3 regions

DNA vaccines that express the human immunodeficiency virus type 1 HXB-2 envelope glycoprotein (Env) with or without deletions of the major variable regions V1/V2 and V3 were tested for the ability to raise enzyme-linked immunosorbent assay (ELISA) and neutralizing antibody in New Zealand White (NZW) rabbits. Three forms of the Envs were examined: gp120, the surface (SU) receptor-binding domain; gp140, the entire extracellular domain of Env; and gp160, the complete form of Env. For the forms of Env containing the variable regions, the gp120-expressing DNA plasmid was more immunogenic than the gp140- or gp160-expressing DNA plasmids. Removing the V1/2 and V3 variable regions increased the immunogenicity of the gp140- and gp160-expressing DNAs. Deletion of the variable regions also resulted in antibody responses against determinants that were not presented by the forms of Env containing the variable regions. Despite the improved immunogenicity, removing the V1/V2 and V3 domains did not improve the ability of Env to raise neutralizing antibodies. These results suggest that increasing the exposure of internal structures of Env that include the CD4-binding site does not necessarily result in the generation of better neutralizing antibody.

[Effects of PGMS on the functions of human platelets and endothelial cells]

OBJECTIVE

To study the effects of Propylene glycol mannte sulfate (PGMS), a heparin-like substance on the functions of platelets and endothelial cells.

METHODS

Using 125I labeled monoclonal antibody to measure the expression of GMP-140 on the surface of human platelets; and using naphthol blue black stain method to study the growth of human umbilical vein endothelial cells (HUVEC) and human umbilical vein smooth muscle cells (HUVSMG).

RESULTS

PGMS significantly inhibited thrombin stimulated expression of GMP-140 on the surface of human platelets. IC50 was 127 micrograms/ml. Indomethacin also inhibited GMP-140 expression, but its effect was weaker than that of PGMS with the IC50 of 502 micrograms/ml. PGMS did not affect the growth of HUVSMC. On the contrary, it significantly promoted the growth of HUVEC at very low concentration (1.6 micrograms/ml).

CONCLUSIONS

PGMS showes anticoagulative effects on both platelets and endothelial cells and it might well be developed as a new antithrombotic and anticoagulateve agent.

Characterization of hydroxyapatite film with mixed interface by Ar+ ion beam enhanced deposition

Ar+ ion beam enhanced deposition (IBED) was used to produce a hydroxyapatite (HA) film on polished titanium substrates. In this study, the HA ceramic target was sputtered by an argon-ion beam with an energy of 1.5 KeV, and the sputtered film was intermittently bombarded by energetic argon-ions at 60 KeV. An effective Ca-Ti mixed layer produced by the energetic argon-ion bombardment was confirmed by using Auger electron spectroscopy. The characteristics of the deposited films were evaluated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. XRD analysis revealed that the as-deposited film was amorphous, and a hydroxyapatite-type structure was obtained from the post-heat treatment of the deposited films. SEM observations showed that no distinct difference in surface morphology was found between the as-deposited and heat-treated samples for Ar+ IBED films, suggesting a strongly bonded HA film on the titanium substrate. In comparison with the HA target, some chemistry alterations were brought about in the deposited films, such as the incorporation of CO3, the loss of the OH groups and some distortion of the phosphate lattice.

[Analysis of the pyridinoline and deoxypyridinoline in urine by reversed-phase high performance liquid chromatography (RP-HPLC)]

A method for the simultaneous and rapid determination of pyridinoline and deoxypyridinoline in urine using RP-HPLC has been established. After hydrolysis for 18 hours at 107 degrees C in 6 mol/L HCl, the urine sample was prefractionated by partition chromatography using a column packed with cellulose CF1. The appropriate fractions were freeze-dried. The samples were analyzed by HPLC with a 5 microm Spherisorb C18 column, a mobile phase of MeOH/H2O containing 0.1% heptafluorobutyric acid at a rate of 1.2 mL/min and fluorescence detector monitoring at lambda(ex) 290 nm and lambda(em) 400 nm. The limit of a detection for PYD was 10 nmol/L and DPD 7 nmol/L. The recovery of PYD was 91.5% and that of DPD was 106.1%. Within day CV for the two compounds were 1.39% and 0.16% respectively and day-to-day CV 3.71% and 1.32% respectively.

Formation and characteristics of the apatite layer on plasma-sprayed hydroxyapatite coatings in simulated body fluid

Plasma-sprayed hydroxyapatite (HA) coatings were incubated in simulated body fluids (SBFs) for different periods of time to investigate the nucleation and growth of apatite on their surface. The layer that formed was recognized as having similarities to bone apatite because it is poorly crystallized, non-stoichiometric or calcium deficient, and contains carbonate and magnesium. Scanning electron microscopy (SEM) and infrared spectroscopy (IR) were employed to investigate the morphological changes of the coating surface and the structure of the grown layer respectively. In the first few hours, calcium and phosphate ions dissolved from the coatings so as to increase their local supersaturation to a higher degree, thereafter followed by the nucleation and growth of apatite. The nucleation occurred firstly on the recessed regions, inside pores and cracks where the higher supersaturation was readily maintained. Only after 24 h incubation was a complete layer formed on the surface of the coating. There is no obvious interface between the grown layer and the underlying coating. Heat treatment in the air made the apatite transform into biphasic calcium phosphate of HA and tricalcium phosphate, with a blue colour because of trace manganese ions. The heat-treated HA coating showed no dissolution by SEM observation. This resulted in no precipitation on the surface. When SBF was used with two-fold higher ion concentrations, the apatite layer formed slowly in 72 h without dissolution of the coating surface. This may mean that the microenvironment with a sufficiently high degree of supersaturation of calcium and phosphate ions is crucial for apatite to nucleate and grow in SBF, while the HA crystalline structure is not critical in the nucleation process, as expected.

Learning-based ventricle detection from cardiac MR and CT images

The objective of this work is to investigate the issue of automatically detecting regions of interest (ROI's) in medical images. It is assumed that the regions to be detected can be roughly segmented by a threshold based on a likelihood measure of the ROI. First, an analysis of the global histogram is used to compute a preliminary threshold that is likely near the optimal one. The histogram analysis is motivated by the analytical result of a bell image intensity model proposed in this work. Then, the preliminary threshold is used to segment the input image, resulting in an attention map, which contains an attention region that approximates the ROI as well as many spurious ones. Due to the nonoptimality of the preliminary threshold, it can happen that the attention region contains a part of, or more regions than, the ROI. Learning takes place in two stages: 1) learning for automatic selection of the preliminary threshold value and 2) learning for automatically selecting the ROI from the attention map while dynamically tuning the threshold according to the learned-likelihood function. Experiments have been conducted to approximately locate the endocardium boundaries of the left and right ventricles from gradient-echo magnetic resonance (MR) images. Cardiac computed tomography (CT) images have also been used for testing. The boundary of the segmented region provided by this algorithm is not very accurate and is meant to be used for further fine tuning based on other application-specific measures.

Hepatocyte growth factor, keratinocyte growth factor, and other growth factor-receptor systems in the lens

PURPOSE

To examine the expression and function of hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), epidermal growth factor (EGF) and other growth factor-cytokine-receptor systems in lens epithelial cells.

METHODS

Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis were used to examine the expression of messenger RNAs in primary cultured rabbit and human lens cells and in ex vivo rabbit lens tissue. Protein expression and the effect of HGF and KGF on crystallin expression in lens epithelial cells were evaluated by immunoprecipitation and Western blot analysis. The effect of exogenous HGF, KGF, and EGF and of the coculture of lens epithelial cells with corneal endothelial cells on the proliferation of rabbit lens cells in a Transwell system was determined by cell counting.

RESULTS

Messenger RNAs and proteins of HGF and KGF were expressed in primary rabbit lens epithelial cells and in ex vivo rabbit lens epithelial tissue. Human lens cells also expressed the mRNAs. Other growth factors and receptor messenger RNAs were also expressed. Hepatocyte and keratinocyte growth factors, and coculture with corneal endothelial cells stimulated proliferation of rabbit lens epithelial cells. In first-passage rabbit lens cells, HGF, KGF, and EGF increased the expression of alpha and beta crystallins.

CONCLUSIONS

Hepatocyte and keratinocyte growth factor-receptor systems are expressed in lens cells. HGF and KGF are not expressed in epithelial cells in such tissues as skin, cornea, and lacrimal gland in which fibroblastic and epithelial cells interact in the formation of an organ. Expression of these growth factors in the lens may have evolved because the lens cells are relatively isolated within the anterior chamber of the eye. Our results suggest, however, that growth factors released by the corneal endothelium also could modulate lens functions (aquecrine interactions).

IL-1 upregulates keratinocyte growth factor and hepatocyte growth factor mRNA and protein production by cultured stromal fibroblast cells: interleukin-1 beta expression in the cornea

PURPOSE

To determine whether interleukin 1 beta (IL-1 beta) messenger RNA (mRNA) and protein were expressed in corneal cells and to examine the effects of IL-1 alpha and IL-1 beta on the expression of hepatocyte growth factor (HGF) and keratinocyte growth factor (KGF) mRNAs and proteins in corneal stromal fibroblasts.

METHODS

IL-1 beta mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). IL-1 beta protein was detected by immunohistologic tests. Changes in the expression of HGF and KGF mRNAs and proteins in response to stimulation of cultured corneal stromal fibroblasts with IL-1 alpha and IL-1 beta were monitored by Northern and Western blotting, respectively.

RESULTS

IL-1 beta mRNA is expressed in human primary cultured corneal epithelial, stromal fibroblast, and endothelial cells. IL-1 beta protein was detected in epithelium and endothelium in fresh frozen human and rabbit corneal tissue. Little, if any, IL-1 beta was detected in the unwounded corneal stroma. IL-1 alpha and IL-1 beta at 10 ng/ml upregulated the levels of HGF and KGF mRNAs and proteins in cultured human corneal fibroblasts.

CONCLUSIONS

IL-1 alpha and IL-1 beta may serve as key modulators in an epithelial-stromal regulatory loop in the cornea. These data and previously published observations support the hypothesis that corneal epithelial wounding releases IL-1 alpha and IL-1 beta from epithelial cells; these cytokines in turn upregulate HGF and KGF mRNA and protein levels in keratocytes, and HGF and KGF released by the keratocytes modulate healing of the wounded corneal epithelial cells by regulating proliferation, motility, and differentiation.

Fuchs' corneal endothelial cells transduced with the human papilloma virus E6/E7 oncogenes

We sought to develop corneal endothelial cell cultures with extended lifespan from corneas with Fuchs' dystrophy. Descemet's-endothelial cell explants from histology confirmed recipient corneas of two patients with Fuchs' dystrophy were cultured. After a small number of corneal endothelial cells with irregular, endothelial morphology migrated from the explants onto the culture plate, the cells were transduced with a disabled retrovirus (pLXSN16E6/E7) coding for the human papilloma virus type 16 transforming oncoproteins E6 and E7. Expression of E6/E7 mRNA in the cell cultures with extended lifespan was monitored by RT-PCR. In vitro labeled cellular protein patterns of the Fuchs' E6/E7 cell cultures with extended lifespan were compared with those from normal human corneal endothelial E6/E7 cell cultures with extended lifespan using two-dimensional gel electrophoresis. Two endothelial cell cultures with extended lifespan were derived from Fuchs' corneas. The morphology of the Fuchs' cells expressing E6 and E7 was similar to that of normal corneal endothelial cells expressing E6 and E7. Surprisingly, the rate of proliferation of Fuchs'-derived cells was similar to that of normal endothelial cells transduced with E6/E7. Proliferation of each Fuchs' cell culture with extended lifespan continued for over 30 population doublings. There were limited quantitative differences in the two-dimensional gel electrophoretic protein patterns of the Fuchs'-derived and normal endothelial cell cultures with extended lifespan, respectively. Retroviral integration is dependent on cell proliferation. Thus, cells that migrated from the Fuchs' Descemet's explants were undergoing at least limited in vitro proliferation when the retroviral vector coding for E6/E7 integrated. Fuchs' corneal endothelial cells expressing E6 and E7 had similar proliferation, cellular morphology, and two-dimensional gel protein electrophoretic patterns to normal corneal endothelial cells expressing the same oncoproteins.

Screening of HIV-1 Env glycoproteins for the ability to raise neutralizing antibody using DNA immunization and recombinant vaccinia virus boosting

HIV-1 envelopes from two series of primary isolates (from Swedish patients 5 and 6), from JR-FL and BaL (prototypic monocyte/macrophage tropic viruses) and from HXB-2 (a prototypic T-cell-line-adapted virus), have been screened for their ability to elicit neutralizing antibody to HIV-1. Rabbits were primed by gene gun inoculation with plasmids expressing secreted monomeric (gp120) and oligomeric (gp140) forms of each Env. After four to six DNA immunizations administered over a 1-year period, rabbits were boosted with 10(8) plaque-forming units of a mixture of seven recombinant vaccinia viruses which express chimeric gp140 Envs (primary clade B sequences in a IIIb-related BH10 backbone). Neutralizing antibodies were assayed against two T-cell-line-adapted viruses (MN and IIIb), two non-syncytium-inducing (NSI) and two syncytium-inducing (SI) primary isolates, and two HIV-1-NL4-3-recombinants with patients 5 or 6 Envs (NL4-3/5A, NL4-3/6C). The DNA priming and recombinant vaccinia virus boosting raised low titers of neutralizing antibody in 10 of 19 rabbits. The highest titers of neutralizing activity (approximately 1:150 for MN) were raised in rabbits DNA primed with Envs from Swedish patients 5. These sera cross neutralized IIIb and MN but did not neutralize the primary isolates or the NL4-3 recombinant with the homologous 5A Env. Sera from rabbits primed with the HXB-2 Env DNA were, for the most part, type-specific for neutralization of IIIb. In one of three assays, sera from rabbits primed with plasmids expressing the JR-FL and BaL had possible low titer neutralizing activity for two NSI, but not two SI, primary isolates. Our results highlight the low immunogenic potential of the HIV-1 Env and demonstrate that different Envs have different potentials to raise low titer neutralizing antibody.

HIV-1 Env glycoproteins from two series of primary isolates: replication phenotype and immunogenicity

Seven envelope regions from two series of patient isolates have been molecularly cloned and analyzed for replication phenotypes and immunogenicity. Growth potential was analyzed for env sequences substituted into an HIV-1-NL4-3 backbone (NL4-3/env recombinants). Immunogenicity studies were conducted on secreted monomeric (gp120) and oligomeric (gp140) forms of the Envs using Env-expressing plasmid DNAs for immunizations. The env regions of the patient isolates conferred a spectrum of replication kinetics and cytotropisms on the NL4-3/env recombinants. Both patient series included non-syncytium-inducing viruses with no ability to grow on T-cell lines, and highly syncytium inducing viruses which grew well on T-cell lines. These differences in growth potential did not correlate with the ability of the DNA-expressed Envs to raise antibody in rabbits. Rather, the relative immunogenicity of the Envs was patient and form specific. The Envs from patient 5 raised higher titers of antibody than the Envs from patient 6. For each primary Env, the gp120 form of the Env raised higher titers of antibody than the gp140 form. Thus, structural features of Env that affect replication do not necessarily affect the ability to raise antibody.

Inactivation of brainstem motor nuclei blocks expression but not acquisition of the rabbit's classically conditioned eyeblink response

Rabbits were eyeblink conditioned while their accessory abducens nucleus (ACC), facial nucleus (FN), and surrounding reticular formation (RF) were temporarily inactivated with microinjections of muscimol to determine whether these structures are critically involved in acquisition of the conditioned eyeblink response (CR). Rabbits performed no CRs or unconditioned responses (URs) during inactivation training. Training was continued without inactivation and rabbits performed the CR at asymptotic levels from the start of training without inactivation. They had fully learned the CR while their ACC, FN, and RF were inactivated, despite performing no CRs or URs at all during inactivation. These results rule out any critical role for neurons within the ACC, FN, or surrounding RF in acquisition of the classically conditioned eyeblink response.

Immune responses to inactivated vaccine in people naturally infected with hantaviruses

An inactivated Hantaan virus vaccine for hemorrhagic fever with renal syndrome (HFRS) was given by injection to 15 people who were naturally infected with either Hantaan or Seoul viruses. Immunofluorescent antibody (IFA), reversed passive hemagglutination inhibition (RPHI), hemagglutination inhibition (HI), and neutralization antibody (NA) assays were used to measure the antibody titers of the vaccinated people before and after three doses of vaccine. The results indicated that IFA and RPHI antibody titers were boosted significantly (P < 0.05) after the vaccination. Either Hantaan or Seoul virus could induce two-way cross-reactive neutralization antibody responses in humans. After HTNV vaccine immunization, the NA titers of people with natural infection increased significantly (P < 0.05) to both Hantaan and Seoul viruses, while the relative dominance between these two type responses was still similar to that of natural infection. It is worthwhile to studying the procedure further to inoculate two different virus vaccines for improving the cross-protective effect.