Induction of HIV-specific antibody response and protection against vaginal SHIV transmission by intranasal immunization with inactivated SHIV-capturing nanospheres in macaques

We have previously reported that concanavalin A-immobilized polystyrene nanospheres (Con A-NS) could efficiently capture HIV-1 particles and that intranasal immunization with inactivated HIV-1-capturing nanospheres (HIV-NS) induced vaginal anti-HIV-1 IgA antibody response in mice. In this study, to evaluate the protective effect of immunization, each three macaques was intranasally immunized with Con A-NS or inactivated simian/human immunodeficiency virus KU-2-capturing nanospheres (SHIV-NS) and then intravaginally challenged with a pathogenic virus, SHIV KU-2. After a series of six immunizations, vaginal anti-HIV-1 gp120 IgA and IgG antibodies were detected in all SHIV-NS-immunized macaques. After intravaginal challenge, one of the three macaques in each of the Con A-NS- and SHIV-NS-immunized groups was infected. Plasma viral RNA load of infected macaque in SHIV-NS-immunized macaques was substantially less than that in unimmunized control macaque and reached below the detectable level. However, it could not be determined whether intranasal immunization with SHIV-NS is effective in giving complete protection against intravaginal challenge. To explore the effect of the SHIV-NS vaccine, the remaining non-infected macaques were rechallenged intravenously with SHIV KU-2. After intravenous challenge, all macaques became infected. However, SHIV-NS-immunized macaques had lower viral RNA loads and higher CD4(+) T cell counts than unimmunized control macaques. Plasma anti-HIV-1 gp120 IgA and IgG antibodies were induced more rapidly in the SHIV-NS-immunized macaques than in the controls. The rapid antibody responses having neutralizing activity might contribute to the clearance of the challenge virus. Thus, SHIV-NS-immunized macaques exhibited partial protection to vaginal and systemic challenges with SHIV KU-2.     

Detection methods of possible prion contaminants in collagen and gelatin

Summary.  We describe methods for the preparation of collagen and gelatin samples to detect possible prion contaminants using Western blotting of a major component of prions, PrP^Sc. A commercially available collagen solution containing 2% athero-collagen was spiked with rodent adapted scrapie prion and used as the prion-contaminating collagen. The methods developed center on the enzymatic reduction of the collagen solution viscosity with protease treatments and on the concentration of the prion from the protease-digests with polyethylene glycol-#6000 and NaCl. Recovery of the spiked prion as a partially protease-resistant core fragment of PrP^Sc fluctuated from 30% to 46% of the input amount. Received June 19, 1998 Accepted August 5, 1998     

The NK1 receptor and its participation in the synergistic enhancement of corneal epithelial migration by substance P and insulin-like growth factor-1

1. We have previously shown that substance P (SP) and insulin-like growth factor-1 (IGF-1) act synergistically to enhance the migration of rabbit corneal epithelial cells in an organ culture model. The present study was designed to identify the epithelial cell SP receptor that participates in this synergistic effect.
2. Rabbit corneal blocks were incubated for 24 h, then the length of the path of epithelial migration was measured. Reagents tried in the TC-199 culture medium, in the presence or absence of IGF-1, were: SP, agonists of tachykinin receptors NK₁, NK₂ or NK₃ and antagonists of tachykinin receptors NK₁ or NK₂.
3. The binding characteristics of SP receptors were examined in rabbit cultured corneal epithelial cells by binding assays with [¹²⁵I]-SP in the presence or absence of excess unlabelled SP or ligands of NK₁, NK₂ or NK₃ receptors.
4. As was demonstrated previously, SP and IGF-1 stimulated epithelial migration when they were added to the culture medium together, but individually they had no effect. NK₁ agonists had the same synergistic effect with IGF-1 as did SP, but the NK₂ and NK₃ agonists did not. Furthermore, the NK₁ antagonist abolished the synergistic effect of SP and IGF-1, but the NK₂ antagonist had no effect.
5. SP bound specifically to rabbit cultured corneal epithelial cells. The binding affinity was 0.44 nM and there were 2.43×10⁴ binding sites per cell. The NK₁ ligand competed, in a dose-dependent fashion, with the binding of SP to corneal epithelial cells, but neither the NK₂ nor NK₃ ligand affected binding.
6. We conclude that the SP receptor in rabbit corneal epithelial cells is NK₁ and that this receptor participates in the synergistic enhancement of corneal epithelial migration by SP and IGF-1. The precise mechanism(s) of this interaction requires more study. These findings imply that both neural and humoral factors are essential for the maintenance and healing of corneal epithelium.

     

Antitumor effects of oral administration of an interferon-inducing pyrimidinone,Bropirimine, on murine renal-cell carcinoma

Bropirimine [2-amino-5-bromo-6-phenyl-4-(3H)-pyrimidinone] is a low-molecular-weight compound that acts as an inducer of interferon in several animal species. Experiments were designed to explore the possibility of using this drug for the treatment of renal-cell carcinoma (RCC). Euthymic BALB/c mice were inoculated with murine RCC (Renca) cells and given graded doses of Bropirimine p.o. for 5 consecutive days beginning on day 1 following tumor inoculation. These mice were killed and tumors were excised on day 21. Bropirimine significantly (P<0.01) inhibited the tumor growth at a daily dose of 1,000 or 2,000 mg/kg. No adverse effect or toxicity was noted at 1,000 mg/kg, and at 2,000 mg/kg there was only a marginal body-weight reduction without any other appreciable side effect. In addition to the inhibition of tumor growth, there was a small yet significant (P<0.05) increase in the duration of survival (in days) in the Bropirimine-treated animals. When the treatment was delayed to begin on day 6 following tumor inoculation, Bropirimine did not suppress tumor growth in euthymic mice, pointing to the importance of the timing of the treatment. In athymic nude BALB/c mice lacking T-cells or T-cell function, Bropirimine also inhibited tumor growth (P<0.01). The antitumor effect of this drug was abolished by pretreatment with anti-asialo GM1 serum, which eliminated natural killer (NK) activity in euthymic mice. In vivo treatment with Bropirimine augmented the cytotoxicity of lymphocytes isolated from the spleens or lungs of the tumor-bearing mice, which were active against Renca and YAC-1 cells in vitro. This activity was NK-cell-dependent as judged on the basis of the results of the in vitro complement-dependent cytotoxicity assay. Since Bropirimine induced interferon (IFN)-/ production, significantly (P<0.05) elevating its serum concentration, and since this drug mimics the effects of IFN-/, it seemed likely that the Bropirimine-induced NK cell augmentation we found was mediated by IFN-/. These results suggest that Bropirimine, a booster of NK activity, may have potential as an adjunct to other therapeutic modalities in the treatment of human RCC.     

Clinical, immunological and MRI features of myelitis with atopic dermatitis (atopic myelitis)

In order to clarify the characteristic features of myelitis with atopic dermatitis (AD), we compared the clinical, immunological and MRI findings between 14 myelitic patients with AD and 12 myelitic patients without AD. The myelitic patients with AD showed the following distinct features, compared with those without AD. (1) A preferential involvement of the cervical cord, as shown by neurologic as well as MRI examinations (14/14 vs. 5/12; P=0.0012), (2) paresthesia/dysesthesia as the predominant symptoms and a rare occurrence of definite muscle weakness (0/14 vs. 5/12; P=0.0120) and dysuria (1/14 vs. 8/12; P=0.0029), (3) a lower Expanded Disability Status Scale score (mean, 1.5 vs. 3.5; P=0.0018), (4) normal cerebrospinal fluid (CSF) findings including those for the IgG index and oligoclonal IgG bands and (5) a persistence of neurologic symptoms and MRI lesions during the follow-up periods (mean, 17 months). In addition, both the serum total IgE level and the frequency of specific IgE to Dermatophagoides farinae were significantly higher in the myelitic patients with AD (median IgE=1266 U/ml, specific IgE 14/14) than in those without AD (145 U/ml, P=0.0034 and 8/12, P=0.0331, respectively) and in 40 healthy controls (86 U/ml, P<0.0001 and 12/40, P<0.0001, respectively). Since myelitis with AD has distinct features and atopy to mite antigens appears to be the underlying cause of this condition, it may therefore be a distinct subtype of myelitis.     

Relationship between autofluorescence and advanced glycation end products in diabetic lenses

Autofluorescence and advanced glycation end product (AGE) levels were measured in the lenses of 9 diabetic Chinese hamsters and 6 age-matched controls. Lens autofluorescence also was measured in 37 diabetic patients and 14 age-matched controls. Lens autofluorescence values were measured noninvasively with a lens measurement system using color filters with peak transmission at 365- and 434-nm wavelengths (excitation and emission, respectively) that are characteristic of AGE fluorescence. The peak lens autofluorescence level was used as the lens autofluorescence value, and the mean lens autofluorescence values from both eyes of each subject were used for statistical analysis. The AGE levels in one lens from each hamster were measured by noncompetitive enzyme-linked immunosorbent assay with a polyclonal anti-AGE antibody. We found a 2.2 times increase of the mean lens autofluorescence value of diabetic hamsters in comparison with that of controls (P<0.01). We also found a 1.5 times increase of the mean AGE level from the lenses of diabetic hamsters in comparison with that of controls (P<0.01). Moreover, a statistically significant positive correlation between the AGE level and autofluorescence value in the same lenses was observed in all hamsters (rho=0.58, P<0.05). In human subjects, we found a 1.4 times increase of the mean lens autofluorescence value of diabetic patients in comparison with that of age-matched controls (P<0.01). Our results suggest that non invasive measurement of lens autofluorescence may be a guide to AGE levels in lenses.     

Monophosphoryl lipid A provides biphasic cardioprotection against ischaemia-reperfusion injury in rat hearts

1 We utilized a rat model of myocardial infarction to investigate whether cardioprotection by monophosphoryl lipid A (MLA) is provided in the early and late phases, as well as to determine whether this cardioprotection may be related to the activation of manganese superoxide dismutase (Mn-SOD), an intrinsic radical scavenger. 2 Pretreatment with MLA (0.5 or 1.0 mg kg-1, i.v.) 24 h prior to 20-min left coronary artery (LCA) occlusion and 48-h reperfusion significantly decreased the incidence of ventricular fibrillation (VF) during ischaemia, as well as infarct size. Pretreatment with lower concentrations of MLA, however, was ineffective. 3 When we examined the time course of MLA (0.5 mg kg-1)-induced cardioprotection, both infarct size and the incidence of VF were significantly reduced in rats pretreated with MLA 0.5 h and 24 h before occlusion. We observed no differences, however, 2 and 72 h after MLA treatment. 4 The activity of Mn-SOD paralleled the cardioprotective effects of MLA. Mn-SOD activity in the myocardium was significantly enhanced in rats pretreated with MLA (0.5 mg kg-1) 0.5 and 24 h before. Mn-SOD activity was not altered, however, in rats pretreated 2 or 72 h before. Lower MLA concentrations were not effective even 24 h after the treatment. 5 We conclude that MLA treatment induced a biphasic pattern of cardioprotection. The pattern of Mn-SOD activity suggests that this enzyme may play a major role in the acquisition of cardioprotection against ischaemia-reperfusion injury.     

Age-Specific Native Hawaiian Mortality: A Comparison of Full, Part, and Non-Hawaiians

PURPOSE OF THE PAPER: The purpose of this paper is to test if the previously identified disparity in mortality rates among full Hawaiians, part Hawaiians, and non­Hawaiians in the state of Hawaii has continued into the 1990s. SUMMARY OF METHODS UTILIZED: Based on Hawaii vital records and population data, standardized age­specific mortality rates by cause and 95% confidence intervals were estimated. PRINCIPAL FINDINGS: The most striking finding was the significant differences in mortality rates in four age strata ­­ 45­54, 55­64, 65­74, and 75­84 ­­ with mortality rates highest for full Hawaiians, lowest for non­Hawaiians, and intermediate for part Hawaiians. CONCLUSIONS: Findings suggest that Native Hawaiians continue to be at greater risk of death compared with non­Hawaiians, with full Hawaiians at greatest risk. RELEVANCE TO ASIAN PACIFIC ISLANDER AMERICAN POPULATIONS: Asian and Pacific Islander Americans have been called the model minority. These data provide evidence that Native Hawaiians, especially full Hawaiians, have dramatically higher mortality rates than non­Hawaiians and merit special attention.