Expression of green fluorescent protein using baculovirus vectors.
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Biomedical subjects
Publications and source records attributed to N Wilkinson.
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Thirty-four premenopausal women were randomized to receive 3.75 mg of leuprorelin acetate depot or placebo for 8 weeks before hysterectomy. Postoperatively, the myometrium was examined by two independent pathologists and the pathologic features were graded. Computer analysis was used to assess myometrial cellularity and arterial wall structure (on hematoxylin and eosin-stained sections) and vascularity (on sections immunostained for Factor VIII-related antigen). The cellularity of the gonadotrophin-releasing hormone agonist-treated myometrium was higher than the controls with less stromal edema. Focal myometrial hyalinization was present in a minority of cases, all in the gonadotrophin-releasing hormone agonist-treated cases. The arteries in the gonadotrophin-releasing hormone agonist-treated uteri underwent atrophy of the tunica media and had significantly more perivascular fibrosis. The number of vessels per 100 myocytes also was decreased. Hypoestrinism secondary to leuprorelin treatment leads to myocyte atrophy, decreased stromal edema, atrophy of the arcuate arteries, and decreased myometrial vascularity.
Endometriosis can represent with a variety of symptoms including pelvic pain, dyspareunia and pain with defaecation, up to several years after hysterectomy and bilateral salpingo-oophorectomy. This may occur when all endometriotic tissue is not excised at the time of the initial procedure. Although excision of endometriosis at this time would be preferable, we have found laparoscopic excision of residual endometriosis to be effective in relieving endometriosis associated pain.
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The gene encoding the major occlusion body protein, spheroidin, of Amsacta moorei entomopoxvirus (AmEPV) was introduced into a baculovirus vector under control of the polyhedrin gene promoter. A recombinant virus produced large, ovoid occlusion body-like structures in both Spodoptera frugiperda and Trichoplusia ni cells. These structures resembled the spheroids found in AmEPV-infected Lymantria dispar cells, except they were devoid of virus particles and were not surrounded by a membrane- or envelope-like structure. These results were confirmed by immunofluoresence microscopy and Western blotting using a specific antipeptide antibody to spheroidin, and suggest that the supramolecular assembly of spheroids is not dependent on other EPV-encoded gene products. Transmission electron microscopy and subcellular fractionation experiments revealed that the spheroid-like structures were assembled in both the nucleus and cytoplasm of the recombinant virus-infected cells. This contrasts with the solely cytoplasmic localization found in AmEPV-infected cells.
A cross-sectional study of 360 patients presenting with sexually transmitted diseases (STDs) to a primary care clinic in KwaZulu/Natal, South Africa was done. Prevalence of HIV infection was 42.5%. HIV-infected patients were of similar age to uninfected patients (mean age 25.1 vs 26.1 years), but were less likely to be married (9.2% vs 18.8%; P=0.02). HIV prevalence was highest among young women (47.9% among women aged 15-34 years compared with 33.1% among men of the same age; P=0.03). History of a previous STD in the preceding 3 months was high (40.1% in HIV-infected patients). Similar proportions of the HIV-infected and HIV-uninfected had sought care for the previous illness at private practitioners (16.9%), and primary care clinics (50.0%), and traditional healers (14.6%) or had treated themselves (18.5%). Patients with an STD are at very high risk of HIV infection in this setting. Repeat STDs are frequent and opportunities exist to improve treatment seeking behaviour, to reduce the risk of recurrent STDs, and hence to reduce the incidence of HIV infection.
OBJECTIVE: To determine the feasibility, accuracy and cost-effectiveness of a rapid, on-site, HIV testing strategy in a rural hospital, and to assess its impact on test turnaround time and the proportion of patients post-test counselled. DESIGN: Prospective comparison of two testing strategies [double rapid test on-site versus central enzyme-linked immunosorbent assay (ELISA)-based testing], and an economic evaluation. SETTING: Hlabisa Hospital, a rural South African district hospital. PATIENTS: A total of 454 consecutive adult inpatients requiring and consenting to HIV testing as part of their clinical management. MAIN OUTCOME MEASURES: Concordance between rapid tests, and between the rapid and ELISA strategies, test turnaround time, proportion of patients post-test counselled, and cost-effectiveness. RESULTS: HIV seroprevalence was 49.6%. Both rapid tests were concordant in all patients [one-sided 95% confidence interval (CI) of probability, 99.3-100]. The rapid strategy was 100% sensitive (95% CI, 97.9-100) and 99.6% specific (95% CI, 97.2-100) compared with the ELISA strategy. The mean interval between ordering a test and post-test counselling fell from 21 days prior to the introduction of the rapid test strategy to 4.6 days after its introduction (P < 0.00001). The proportion of patients post-test counselled increased to 96% from 17% after the introduction of the rapid test strategy (P < 0.00001). By using a double rapid test strategy the cost per patient post-test counselled was almost halved to US$ 11. Accuracy of the rapid strategy was not substantially increased by performing two tests. CONCLUSION: In high prevalence, resource-poor settings, rapid, on-site HIV testing is feasible, accurate and highly cost-effective, substantially increasing the number of patients post-test counselled. A single rapid test may be sufficient.
A rapid procedure for the production and identification of recombinant baculoviruses is described that uses the autofluorescent properties of the Aquorea victoria green fluorescent protein (GFP). Expression of the GFP cDNA (without signal peptide sequence) in Spodoptera frugiperda cells resulted in the synthesis of a 30-kDa protein, which was confirmed as GFP by Western blotting and by the emission of green fluorescence when illuminated with longwave UV light (495 or 365 nm). To use GFP as a marker for the selection of recombinant baculoviruses, we prepared a virus, BacGFP1, in which the GFP cDNA was inserted in lieu of lacZ in BacPAK6. Before the use of BacPAK6 or BacGFP1 in a cotransfection to prepare recombinant baculoviruses, the virus DNA was linearized with Bsu361 to improve the recovery of non-parental virus plaques. The use of BacGFP1 DNA resulted in the recovery of 79%-91% plaques with the non-parental phenotype. Plaques were rapidly identified by simply exposing them briefly to longwave UV light (365 nm) without the need for exogenous substrates or biological stains.
This ethnographic research among rural South African men and women seeking care for STDs explores constraints to communication among partners and defines predominant patterns of sexual networking. A series of fifteen open-ended interviews explored topics related to sexual networking and partner communication. Patterns of sexual networking showed clear gender variation, with men more likely to discuss multiple partners. Both men and women believed they should tell one partner about their STD, most often a steady partner. Strong distinctions were made between regular and casual partners, with an emphasis on the role of trust in a steady relationship. Men and women expressed anxiety about telling their partners of their illness, but women more often expressed fear whereas men felt embarrassed. Multi-partnered sexuality is common and is widely accepted for men. While the importance of regular partnerships is clear for both men and women, sexual relationships appear to be highly unstable. Communication among partners could be facilitated by stronger health promotion messages, such as the importance of telling a partner about an STD. Prevailing patterns of communication and sexual networking have profound implications for the STD epidemic.
Interleukin 8 (IL-8) is a potent neutrophil chemoattractant and activator. Two IL-8 receptor subtypes, A and B, are expressed in neutrophils. In this work, we analyzed the role of the C terminus domain of the IL-8 receptor on the signal transduction and receptor internalization mechanisms. The IL-8 receptor A was tagged with an epitope corresponding to the monoclonal antibody 1D4 to monitor the localization of the IL-8 receptor. We demonstrated IL-8-dependent receptor internalization by monitoring the density of surface 125I-labeled IL-8 binding sites and by immunofluorescence microscopy. Truncation of the last 27 amino acids of the IL-8 receptor A severely impaired the IL-8-induced internalization of the receptor. Of importance was the observation that binding of IL-8 to receptors A and B triggered a dramatically faster rate of internalization of receptor B than receptor A, suggesting that the heterologous C termini among receptor subtypes modulate the rate of internalization of IL-8 receptors. However, substitution of the C terminus of the receptor subtype A for the C terminus of receptor B reduced the internalization rate of receptor A. Furthermore, we found that the rate of internalization of IL-8 receptor B triggered by IL-8 was faster than the one induced by the IL-8-related peptide, melanoma growth stimulatory activity. Studies with human neutrophils pretreated with 100 nM IL-8 for 5 min revealed a positive and a negative calcium response mediated by receptors A and B, respectively. In contrast, neutrophils pretreated with melanoma growth stimulatory activity showed positive calcium responses to both receptors A and B. These data suggest that the neutrophil responses mediated by IL-8 are modulated by the rate of internalization of receptors.
The purpose of this study was to quantify vascular density in the stroma of normal, hyperplastic, and neoplastic endometria and to explore its relationship to other prognostic features of endometrioid adenocarcinoma. Curettage specimens of proliferative and mid-secretory endometrium; simple, complex, and atypical endometrial hyperplasia; and grade I endometrioid adenocarcinoma were stained with Factor VIII-related antigen. The number of vessels per mm2 of stroma was calculated for each case. The stroma of mid-secretory and hyperplastic endometrium was more vascular than that of proliferative endometrium. The stroma of adenocarcinoma, though reduced in proportion to the epithelium, was significantly more vascular than that of normal or hyperplastic endometrium. Stromal vascular density was not related to the depth of invasion, the presence of lymphovascular space permeation, or the state of the adjacent endometrium, whether atrophic or hyperplastic.
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Qualitative digital X-ray mapping techniques were employed to determine the distributions of essential and non-essential elements in three invertebrate "models": (1) Pb, Zn, Cd, Cu, Fe in thin cryosections of the hepatopancreas of the terrestrial isopod, Oniscus asellus; (2) Pb, Zn, Cd, Ca in thin cryosections of the chloragogenous tissue of the earthworm, Lumbricus rubellus; and (3) As in air-dried smears and thin cryosections of chloragogen in L. rubellus. Four general conclusions were drawn from the results of these studies: (a) non-essential elements can accumulate, distribute and be compartmentalized because they, or the organo-complexes that they form, act as "mimics" of essential elements with which they share to a greater or lesser extent certain chemical affinities; (b) thermodynamic considerations notwithstanding, the influence of biological factors on the sequestration and fates of certain elements (e.g., arsenic) is profound through modifications of redox states and organo-compound formation; (c) X-ray mapping, combined with anhydrous preparative procedures, yields unbiased information concerning the relative spatial distributions of several elements in structurally heterogeneous sampling "fields", although the morphological characterization of (occasionally unsuspected) subcellular compartments may be constrained by the intrinsic quality of the preparation; and (d) X-ray microanalysis yields codistribution data, when integrated with biochemical information from other sources, which give strong pointers to the identity of binding ligands and of the valence state of sequestered cations.
Interleukin-8 (IL-8) is a potent inflammatory mediator that belongs to the family of C-X-C chemokines. IL-8 promotes the activation and the extravasation of circulating neutrophils to the site of inflammation. Two IL-8 receptor isotypes (type A and B) are identified in human and rabbit neutrophils. IL-8 receptors belongs to the superfamily of G-protein-coupled receptors. Both receptor subtypes A and B bind with high affinity to human IL-8, but they exhibit distinct binding affinity to two functional and structurally related IL-8 peptides, melanoma growth-stimulating activity peptide (MGSA) and neutrophil-activating peptide-2 (NAP-2). Human IL-8 receptor A binds with low affinity to MGSA or NAP-2. In contrast, human IL-8 receptor B binds MGSA with high affinity, and NAP-2 with lesser affinity. Using receptor subtype chimeras, we determined that the N-terminal domain of the receptor confers ligand binding specificity (LaRosa, G. J., Thomas, K. M., Kaufmann, M. E., Mark, R., White, M., Taylor, L., Gray, G., Witt, D., and Navarro, J. (1992) J. Biol. Chem. 267, 25402-25406). In this work, we characterized by molecular cloning and expression a mouse receptor structurally homologous to the IL-8 receptor. We isolated a clone by screening a mouse genomic library with a rabbit IL-8 receptor A cDNA fragment as a probe. The mouse clone exhibited an open reading frame encoding a 359-amino acid protein. Hydropathy plot analysis of the amino acid sequence reveals seven transmembrane domains characteristic of G-protein-coupled receptors. The N terminus and the second extracellular loop contain one and two putative N-glycosylation sites, respectively. The intracellular C-terminal tail contains Ser and Thr residues as potential phosphorylation sites. Northern blot analysis showed that the mouse receptor gene is expressed in mouse neutrophils. The mouse receptor shows 65, 74, 66, and 70% amino acid identity to the rabbit IL-8 receptor subtypes A and B and human IL-8 receptor subtypes A and B, respectively. However, neither mouse neutrophils nor CHO cells expressing the mouse receptor bind human IL-8 in the nanomolar range. To identify the domain(s) conferring high affinity binding to IL-8, we constructed rabbit/mouse receptor chimeras.(ABSTRACT TRUNCATED AT 400 WORDS)
Interleukin-8 (IL-8) mediates the transendothelial migration and activation of neutrophils to the site of inflammation. Two human IL-8 receptor isotype (A and B) and one rabbit IL-8 receptor isotype (A) cDNAs have been previously cloned and characterized on the basis of their pharmacological profile. Human and rabbit IL-8 receptor subtype A binds IL-8 and structurally related peptide melanoma growth-stimulating activity (MGSA) and neutrophil-activating peptide-2 (NAP-2) according to the following affinity binding profile: IL-8 >>> MGSA > NAP-2, whereas the human IL-8 receptor subtype B profile is IL-8 = MGSA > NAP-2 (LaRosa, G., Thomas, K. M., Kaufmann, M., Mark, R., White, M., Taylor, L., Gray, G., Witt, D., and Navarro, J. (1992) J. Biol. Chem. 267, 25402-25406). In this study, we isolated a cDNA clone (5B1a) from a rabbit neutrophil library encoding a G-protein-coupled receptor of the interleukin-8 receptor family. The 5B1a clone encodes a 358-amino acid protein exhibiting 80% amino acid identity to the human IL-8 receptor B, 74% to the rabbit IL-8 receptor A, and 73% to the human IL-8 receptor A. Tissue distribution by Northern blot analysis reveals that the 5B1a mRNA is expressed preferentially in neutrophils. In contrast to previously described IL-8 receptors, the 5B1a receptor exhibited specific 125I-IL-8 binding with a novel affinity binding profile of IL-8 >> NAP-2 > MGSA. The corresponding apparent Ki values for IL-8, NAP-2, and MGSA were 4, 120, and 320 nM, respectively. IL-8 induced intracellular calcium mobilization and desensitization in Chinese hamster ovary cells stably transfected with 5B1a, indicating that this cDNA encodes a functional IL-8 receptor. Sequence analysis of the 5B1a protein with other IL-8 receptor subtypes within the framework of their pharmacological profile reveals putative structural motifs that may correspond to the ligand binding site of the IL-8 receptor.
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Immunohistochemical staining was carried out on a spectrum of normal, hyperplastic and malignant endometrial curettings, for proliferating cell nuclear antigen--PCNA (using the monoclonal antibody PC10) and for abnormally stabilized p53 (using the polyclonal antibody CM-1). The mean proportion of glandular epithelial cells showing PCNA immunoreactivity was significantly lower in atypical hyperplasia/intra-endometrial adenocarcinoma than in invasive adenocarcinoma, but the degree of overlap between the cases was such that this was not considered to be of diagnostic value. p53 immunoreactivity was detected in 47% of invasive adenocarcinomas and in a much smaller proportion of endometria showing simple hyperplasia and atypical hyperplasia, but staining was only focal in the last two conditions. The majority of p53-positive invasive adenocarcinomas had a large proportion of glandular epithelial cells expressing PCNA, but a significant number of p53-negative cases also had a high PC10 index. This suggests that, in endometrial neoplasia, there is not a simple relationship between abnormally stabilized p53 and PCNA expression.