Levels of epidermal growth factor binding in third-trimester and term human placentas: elevated binding in term placentas of male fetuses

Specific binding of iodine 125-labeled epidermal growth factor was measured in membrane homogenates of third-trimester and term human placentas of male and female fetuses. All placentas (n = 35) generated curvilinear Scatchard plots, and all placentas had similar equilibrium dissociation constants for both high-affinity (210 pmol/L) and low-affinity (830 pmol/L) binding sites. Mean maximum number of available binding sites of term placentas from male fetuses (330 +/- 110 fmol/mg protein; n = 11) was significantly higher (p less than 0.001) than that of female fetuses (170 +/- 80 fmol/mg protein, n = 13). Occupation of epidermal growth factor receptors by endogenous epidermal growth factor could not account for the difference in levels of epidermal growth factor binding. Kendall's rank order correlation test demonstrated a significant positive correlation of the gestational age in weeks with the maximum number of epidermal growth factor receptors in placentas from male fetuses (p less than 0.002; T = 0.527; n = 17) and female fetuses (p less than 0.01; T = 0.404; n = 18). These results indicate that there is a sexual dimorphism in the level of epidermal growth factor receptors in placentas of male and female fetuses during the third trimester and that the level of epidermal growth factor receptors increases during the third trimester for placentas of both male and female fetuses.     

Measurement of antibody to Mycoplasma hominis by an enzyme-linked immunoassay and detection of class-specific antibody responses in women with postpartum fever

The standard conditions for detection of human IgG, IgM, and IgA antibodies to Mycoplasma hominis by an enzyme-linked immunosorbent assay (ELISA) were established with the use of a cell lysate antigen and alkaline phosphatase conjugates. Antigen was used at a concentration of 10 micrograms of protein per milliliter, sera were diluted 1:200, and conjugates were diluted 1:500. Agreement between cultured isolation of M. hominis from the lower genital tract and presence of antibody in 207 women was 71%, 82%, and 86% for IgG, IgM, and IgA, respectively. When the ELISA was compared with the mycoplasmacidal assay, an overall agreement of 81% occurred, with the majority of the discrepancies occurring in the ELISA-positive and mycoplasmacidal-negative category. A linear relationship between end point titer and the A400 value (ELISA or absorbance value at 400 nm) at a standard serum dilution was demonstrated for the IgG, IgM, and IgA classes. Although the ELISA was relatively independent of antigen heterogeneity, no single strain detected more than 87% of positive sera, thus suggesting that optimum detection of antibody to M. hominis by the ELISA will require use of antigen pools derived from multiple strains of M. hominis.     

Macular edema in association with severe carotid artery obstruction

In seven eyes of six patients (four men and two women, 55 to 72 years old), with macular edema associated with severe carotid artery stenosis, the ipsilateral carotid obstruction was 90% or more. Concomitant fundus signs, such as midperipheral retinal hemorrhages, retinal arterial narrowing, and neovascularization of the optic disk, were observed. All eyes demonstrated leakage of fluorescein dye from the retinal vessels and optic disk.     

Retinal neovascularization after branch retinal arterial obstruction

We examined two eyes from two noninsulin-dependent diabetic patients that developed vitreous hemorrhage secondary to retinal neovascularization after branch retinal arterial obstruction. Although there was no ophthalmoscopic evidence of diabetic retinopathy, diabetes mellitus may have predisposed the retinas to a neovascular response, which was precipitated by the arterial obstruction.     

Expression of HLA class I and II antigens on cells of the human trabecular meshwork

Human corneoscleral tissue containing trabecular meshwork and cultured human trabecular cells were examined for HLA-ABC (class I) and HLA-DR (class II) antigens of the major histocompatibility complex using an indirect immunofluorescence assay. Class I antigens were detected in the trabecular meshwork on frozen sections and on cultured trabecular cells. Class II antigens were constitutively expressed on some, but not all, cells within the trabecular meshwork. Many more cells could be induced to express class II antigens by pre-incubation in human gamma interferon. Cultured trabecular cells did not express class II antigens constitutively, but expression could be induced by gamma interferon. This study suggests that, in addition to Langerhans' cells at the limbus, other cell types within the anterior segment express major histocompatibility complex-encoded class II antigens either constitutively or inducibly. These cells may be important for the initiation and regulation of ocular immunity.     

The effect of benoxinate on the tear stability of Hong Kong-Chinese

We conducted a series of experiments to examine the effect of local anaesthetic instillation on tear stability measurements. All experiments were conducted with the examiner masked with respect to treatments. We measured tear break-up time (TDUT) and non-invasive tear break-up time (NITBUT) 30 s after instillation of benoxinate (0.4%) in a single masked experiment and found that NITBUT was significantly increased while TBUT was unaffected. In separate experiments tear stability was assessed 5 min after instillation of benoxinate and there was no significant effect on either TBUT or NITBUT measurements. In a control experiment to examine the effect of instilling a drop of liquid into the eye, neither TBUT nor NITBUT were affected 30 s after the instillation of saline. No corneal staining was observed in any of the subjects after instillation of benoxinate. The results suggest that benoxinate does not affect the stability of the precorneal tear film, and that tear stability can be assessed after the instillation of unpreserved benoxinate.     

Alpha 2-adrenoceptor subtypes and imidazoline-like binding sites in the rat brain.

1. The binding of [3H]-yohimbine and [3H]-idazoxan to rat cortex and hippocampus is rapid, reversible and of high affinity. Saturation data indicate that a single population of binding sites exist for [3H]-yohimbine in the cortex (Bmax 121 +/- 10 fmol mg-1, protein; Kd 5.2 +/- 0.9 nM) and hippocampus (Bmax 72 +/- 6 fmol mg-1 protein; Kd 5.8 +/- 0.7 nM). [3H]-idazoxan labels one site in the cortex (Bmax 87 +/- 8 fmol mg-1 protein; Kd 4.1 +/- 0.9 nM) and hippocampus (Bmax 30 +/- 6 fmol mg-1 protein; Kd 3.5 +/- 0.5 nM), when 3 microM phentolamine is used to define non-specific binding. A second distinct [3H]-idazoxan binding site (Bmax 110 +/- 21 fmol mg-1 protein; Kd 3.6 +/- 0.07 nM) is identified in rat cortex if 0.3 microM cirazoline is used to define non-specific binding and 3 microM yohimbine is included to prevent binding to alpha 2-adrenoceptors. 2. Displacement studies indicate that the alpha 1-adrenoceptor antagonist prazosin and the 5-HT1 ligands 8-OH-DPAT, RU 24969 and methysergide differentiate [3H]-yohimbine binding into two components; a high and low affinity site. In contrast the displacement of [3H]-idazoxan by each ligand was monophasic. 3. The affinities of 8-OH-DPAT, RU 24969 and methysergide determined against [3H]-idazoxan binding to the cortex and hippocampus correlate significantly with the binding site displaying low affinity for prazosin and previously designated alpha 2A. In contrast, a poor correlation exists for the high affinity site for prazosin designated alpha 2B.(ABSTRACT TRUNCATED AT 250 WORDS)     

Size-fractionated heparins have differential effects on human neutrophil function in vitro

BACKGROUND AND PURPOSE: Heparin is known to possess a range of activities, other than effects on blood coagulation, many of which are anti-inflammatory. Effects with potential anti-inflammatory applications include the inhibition of elastase release from neutrophils, as well as the adhesion of these cells to vascular endothelium. In the present study we aimed to investigate whether fractionation of heparin may yield molecules with enhanced or specific effects on human neutrophil function. EXPERIMENTAL APPROACH: Fractions of defined molecular size were obtained from heparin by different methods and assessed for their effects on elastase release induced by formyl Met-Leu-Phe (fMLP), from neutrophils, in some cases following the priming of these cells with tumour necrosis factor-alpha (TNF-alpha). Effects of the fractions on neutrophil adhesion to interleukin-1beta (IL-beta)-stimulated human umbilical vein endothelial cells (HUVECs) were also examined. KEY RESULTS: Elastase release was inhibited by very low molecular weight fractions of heparin, with an apparent minimum chain length of 10 saccharides required for full effect. In contrast, neutrophil-endothelial adhesion was unaffected by these fractionated heparins, suggesting that certain non-anticoagulant actions of heparin may be lost by such an approach. CONCLUSIONS AND IMPLICATIONS: These data suggest that an optimum chain length of heparin possibly exists for certain non-anticoagulant actions of heparin, which may prove to be useful in the design of novel drugs with specific anti-inflammatory actions.