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Biomedical subjects

H R Hill

Publications and source records attributed to H R Hill.

At least 19 recordsLinked to original sources
PubMed1998

Comparison of an inhalant allergy immunoassay with allergen specific IgE determinations in human serum.

The diagnosis of inhalant allergy can be elusive, with symptoms resembling viral or bacterial infection, as well as immunologic deficiency. In this study an inhalant allergy immunoassay was investigated as a possible screen to rule in or out respiratory inhalant allergy in patients with allergic-type symptoms. The results of this screen were compared in 192 serum specimens submitted to our laboratory for specific IgE allergy testing and 73 blood bank samples. When the discrepant results of the inhalant allergy immunoassay were resolved by Western blot, a final sensitivity of 94.7% and specificity of 97.5% was calculated. We have found this inhalant allergy immunoassay to be an effective screen for detecting inhalant allergies, and believe it to be a useful tool for the primary care physician or non-allergist trying to differentiate inhalant allergens from chronic sinusitis or other causes of sinopulmonary congestion.

Allergens↗
PubMed1998

The face of Job.

We evaluated facial features in 9 patients from 7 kindreds with Job syndrome. Consistent features included prominent forehead with deep-set eyes, increased width of the nose, a full lower lip, and thickening of the nose and ears. The mean alar width (Z score = +3.9) and outer canthal distance (Z score = +2.2) were significantly increased. A recognizable face of Job syndrome exists.

Adolescent↗
PubMed1998

The effect of lactic acid on mononuclear cell secretion of proinflammatory cytokines in response to group B streptococci.

This study found that lactate alone had a stimulatory effect (207.1 +/- 16.3%; P = .001) on tumor necrosis factor (TNF)-alpha production by human mononuclear cells with the most profound secretion being at pathologic concentrations of 4-8 mM lactate. Furthermore, exposure of these mononuclear cells to group B streptococci (GBS, 10(5) cfu) resulted in TNF-alpha production of up to 621.1 +/- 42% of control; the combination of lactic acid and GBS increased TNF-alpha production up to 1019.3 +/- 16.1% (P = .001). The combination of GBS and lactate also enhanced the secretion of interleukin (IL)-1beta and IL-6. Lactate in pathologic concentrations, therefore, likely enhances the secretion of these inflammatory mediators and contributes to septic shock and meningitis caused by GBS.

Cells, Cultured↗
PubMed1997

Analysis of phage MS2 coat protein mutants expressed from a reconstituted phagemid reveals that proline 78 is essential for viral infectivity.

A full-length cDNA copy of the RNA genome of bacteriophage MS2 was assembled by the in-frame ligation of the central portion of the genome into a plasmid containing the 5' and 3' ends. Upon transformation of the ligation reaction into Escherichia coli, infectious phage particles were released into the medium. The plaquing ability of the phage produced from the cDNA construct was assessed against various bacterial strains confirming that the bacteriophage produced were male-specific. Sensitivity to RNase in agar overlay was used to confirm that the phage contained RNA. In addition, the phage were unable to infect piliated cells overexpressing MS2 coat protein, a resistance conferred by the binding of recombinant coat protein to the infecting strand of RNA at the replicase initiation region, thus preventing translation of the replicase gene. The phage capsids were visualised after negative staining by transmission electron microscopy, and appeared as spherical particles of approximately 25 nm diameter. The capsid proteins were examined by Western blotting, confirming the presence of a single protein of approximately 14 kDa, which bound anti-MS2 coat protein antibodies. The genomic RNA from single plaques was analysed by reverse transcription-PCR and the presence of the MS2 coat protein gene confirmed by DNA sequencing. The production of replicative MS2 phage from cDNA fragments was used to assess the viability of MS2 coat protein mutants, which had previously been shown to assemble into T = 3 capsid-like particles when expressed in vivo from a bacterial vector. The E76D mutation did not appear to affect phage viability, whilst replacement of the completely conserved P78 residue with asparagine abolished the production of infectious particles, suggesting that P78 may be involved in interactions with the phage maturation protein.

Base Sequence↗
PubMed1997

Detection of Epstein-Barr viral DNA in serum using rapid-cycle PCR.

Our study describes the comparison of a rapid nested PCR assay to standard serology techniques for the detection of Epstein-Barr virus (EBV) in serum. The sera of 81 patients with suspected EBV infection were analyzed; 54 were positive for one or more of the standard serology markers, i.e., IgM viral capsid antigen (VCA), IgG-VCA, Epstein-Barr nuclear antigen 1 (EBNA-1), and early antigen (EA), and 27 were negative for all serology markers. The sera from 15 normal healthy blood donors were also included. No EBV DNA was detected in any of the 15 blood donor samples or in any of the 27 samples with negative serology results. Eleven samples (20%) of the 54 with positive EBV serology results were positive for EBV DNA. Of these samples, 9 were EBV IgM-VCA positive and anti-EBNA negative, suggesting acute infection. One of the 11 samples had high titers of IgM-VCA, IgG-VCA, anti-EBNA, and anti-EA. The last of the 11 samples was from a patient with acute infectious mononucleosis without sufficient sample volume for EBV serology testing. Seventeen of the total 96 samples from the study were IgM-VCA positive and anti-EBNA negative and 9 of these 17 samples (53%) tested positive for EBV DNA. These data suggest that the detection of EBV DNA by PCR in serum may be a useful indicator of active infection rather than latent virus.

Antibodies, Viral↗
PubMed1997

Regulation of decidual cell chemokine production by group B streptococci and purified bacterial cell wall components.

OBJECTIVE: Our purpose was to determine whether cultured human decidual cells produce chemokines in response to different strains of group B streptococci and purified bacterial cell wall components. STUDY DESIGN: Human decidual cells were cultured from term placentas by standard techniques. Different strains of group B streptococci were isolated from neonates with early-onset group B streptococci sepsis. Confluent cell monolayers were incubated with these different strains of group B streptococci and various concentrations of purified bacterial cell wall components (including lipoteichoic acid, sialic acid, lipopolysaccharide, and lipid A) for 16 hours at 37 degrees C. Culture supernatants were collected and assayed for macrophage inflammatory protein-1 alpha and interleukin-8. Statistical analysis was by analysis of variance. RESULTS: We found that cultured human decidual cells produced significant amounts of the two chemokines macrophage inflammatory protein-1 alpha and interleukin-8 in a strain-specific fashion to the various different strains of group B streptococci tested, from 215% to 421% over baseline production (p < 0.05 by analysis of variance). Also, we found that incubation of decidual cells with various concentrations of lipoteichoic acid, sialic acid, lipopolysaccharide, and lipid A resulted in significant concentration-dependent increases in decidual cell macrophage inflammatory protein-1 alpha and interleukin-8 production (p < 0.05.) CONCLUSIONS: Decidual cells produced significant amounts of the chemokines macrophage inflammatory protein-1 alpha and interleukin-8 in response to intact group B streptococci in a strain-specific fashion and in response to various concentrations of different bacterial cell wall components. Because chemokines are important mediators signaling migration of different immune effector cells into areas of inflammation, we suggest that decidual cell chemokine production in response to bacteria and bacterial cell wall components may be a key early event in the pathogenesis of infection-associated preterm labor.

Analysis of Variance↗
PubMed1997

A role for C5 and C5a-ase in the acute neutrophil response to group B streptococcal infections.

Congenic C5-deficient and C5-sufficient mice were infected with group B streptococci (GBS) to determine if the polymorphonuclear leukocyte (PMNL) chemoattractant C5a contributes to PMNL recruitment in GBS infection and if GBS C5a-ase reduces C5a-induced PMNL recruitment in vivo. PMNL accumulation was greater in the peritoneum and air spaces of C5-sufficient mice than in C5-deficient mice. Administration of human C5 to C5-deficient mice caused a significant increase in PMNL recruitment following infection with C5a-ase-negative GBS. GBS C5a-ase did not reduce PMNL accumulation in C5-sufficient mice but reduced PMNL recruitment in C5-deficient mice reconstituted with human C5. These data indicate that C5a is important for rapid PMNL recruitment to sites of GBS infection and that GBS C5a-ase inactivates human, but not murine, C5a in vivo. Reduction of the acute inflammatory response by C5a-ase likely contributes to GBS virulence in human neonates.

Adhesins, Bacterial↗
PubMed1997

Immunologic response to Bartonella henselae as determined by enzyme immunoassay and Western blot analysis.

Bartonella henselae is now regarded as the etiologic agent of cat-scratch disease and a cause of bacillary angiomatosis. We examined the human immune response to Bartonella henselae infection using a newly developed enzyme immunoassay (EIA) and a Western blot procedure using outer-membrane proteins. The EIA showed 98.6% and 91.4% agreement with an indirect fluorescence method (IFA) for detection of IgM and IgG antibodies, respectively. By using Western blot analysis, reactivity to an 8-kd band showed significant correlation with positive results by the IgM IFA and EIA. In contrast, reactivity to 209-, 208.5-, 208-, 116-, and 80-kd bands was identified only in positive IgG IFA serum samples. The EIA and Western blot should be useful tests in determining the antibody response to B. henselae infection and may also be important in determining the critical epitopes in the host-parasite interaction of this organism.

Adolescent↗
PubMed1997

Immunologic and clinical correlations in rheumatic fever and rheumatic heart disease.

The intimate relationship of Streptococcus pyogenes and rheumatic fever is well-established, but the precise pathogenesis of rheumatic fever and rheumatic heart disease continues to elude intense investigative efforts by students of the disease worldwide. Technologic advances in molecular biology, not thought possible two decades ago, have given additional insight into the immunologic aspects of the disease. On the clinical side echocardiography has proved to be a marvelous, non-invasive technique to evaluate cardiac anatomy and function. We are now able to gain a closer correlation of the clinical presentation and the autoimmune response. The increased understanding acquired both from the "bench" and the "bedside" are making this perplexing disease somewhat less mysterious. We seem tantalizingly close to grasping a complete understanding of the pathogenesis of rheumatic fever and rheumatic heart disease.

Antibodies↗
PubMed1997

Immunoglobulin A antibodies to Helicobacter pylori.

Serological testing for immunoglobulin G (IgG) antibodies to Helicobacter pylori has proven useful in supporting the diagnosis of infection with this organism, but the clinical value of IgA antibodies in H. pylori-related gastritis remains controversial. The purpose of our study was to determine the frequency of IgA-positive IgG-negative patients with symptoms of gastrointestinal (GI) disorders, thus assessing the clinical utility of IgA testing for H. pylori-related gastritis. It was found previously that the frequency of infected individuals in this category (IgA positive and IgG negative) is about 2%, but a large number of IgG-negative patients with GI disorders suggestive of H. pylori infection have not been investigated until now.

Antibodies, Bacterial↗
PubMed1996

Anti-glomerular basement membrane disease: role of enzyme-linked immunosorbent assays in diagnosis.

We compared two enzyme-linked immunosorbent assay (ELISA) tests with indirect immunofluorescence (IFA) for the measurement of anti-glomerular basement membrane (GBM) antibodies to study their sensitivity and specificity. The first ELISA test kit compared well to IFA (96.4% agreement, 93.3% sensitivity, 97.0% specificity). The second ELISA kit was much less sensitive (87.8% agreement, 63.3% sensitivity, 92.2% specificity). ELISA tests for the measurement of anti-GBM antibodies allow for quantitation and may have greater sensitivity than IFA. Sensitivity, however, may depend on the commercial test used.

Adolescent↗
PubMed1996

Screening for antinuclear antibodies by enzyme immunoassay.

Indirect fluorescent antibody (IFA) ia most widely used method in clin clinical laboratories to screen for autoantibodies against a wide variety of nuclear antigens. Recently, a number of antinuclear antibody (ANA) enzyme immunoassay (EIA) screens have become commercially available and claim to be an alternative method to screen for ANAs. Given the subjectivity of technical interpretation of IFA and the high number of ANA negative samples, a suitable EIA method for ANA screening would be beneficial to clinical laboratories with large samples volumes. Five ANA EIA screens were compared (Elias, Helix, Sanofi, TheraTest and Zeus) to IFA using a human epithelial cell line (HEp-2). Sera from 601 patients submitted to our reference laboratory for autoimmune testing, and from 202 normal healthy blood donors, were included in this study. Samples with discordant results between IFA and EIA were further analyzed using single antigen EIAs for SSA, SSB, Sm, RNP, Scl-70, histones, dsDNA, and ssDNA. Analyses were based on clinically significant IFA titers of > or equal to 1:160 as positive and <1:40 as negative. When compared to IFA, agreement, sensitivity and specificity for each ANA EIA screen were as follows: Elias: 87.0%, 69.5% and 97.9%; Helix: 94.6%, 90.2%, and 97.3%; Sanofi: 95.0%, 93.7%, and 95.9%; TheraTest: 95.3%, 97.7%, and 93.5%; Zeus: 87.1%, 96.2%, and 81.4%, respectively. In conclusion, screening for ANAs by EIA using several commercial assays was both sensitive and specific when compared to IFA. Moreover, the EIA is objective and much less labor intensive when screening a large number of clinical specimens. None of the EIAs were 100% sensitive and, thus, may fail to detect a few of the nonspecific ANAs that demonstrate atypical as well as classical IFA patterns. The advantages of employing these nonsubjective assays to screen out the vast majority of ANA negative sera is clear. The authors still recommend confirming titers and patterns of sera with positive EIA screens using classical IFA methods employing HEp-2 cells.

Antibodies, Antinuclear↗
PubMed1996

Polymerase chain reaction detection of Lyme disease: correlation with clinical manifestations and serologic responses.

The authors have developed a simple, nested polymerase chain reaction (PCR) assay for amplification of an outer surface protein A (OspA) gene fragment of Borrelia burgdorferi using rapid temperature cycling and ethidium bromide detection on agarose gels, and applied it to the diagnosis of Lyme disease in humans. With denaturing and annealing temperature spikes instead of holds, cycle times were less than 20 minutes for a 30-cycle amplification. Using this rapid cycle PCR technique, as few as 5 spirochetes per mL of phosphate buffered saline were detected. In addition, B burgdorferi DNA was detected from spirochetes that had been spiked into one of several types of human body fluids including serum, synovial fluid, and cerebrospinal fluid (CSF). A number of clinical samples, which had been tested for Lyme immunoglobulin M (IgM) and immunoglobulin G (IgG) antibody were also examined. In 29 serologic positive samples (14 IgG and IgM positive, 9 IgM alone and 6 IgG alone), B burgdorferi DNA was not detected. In contrast, nine serum samples and one synovial fluid from patients with definite clinical features of Lyme disease were found to be negative by EIA and Western blot analysis for IgG and IgM antibody, but contained B burgdorferi DNA, as detected by PCR. Polymerase chain reaction analysis of serum and synovial fluid may be of significant diagnostic value in Lyme disease, especially in the absence of a serologic response in early, partially treated and seronegative chronic disease. This is the first study to report an association between PCR positivity and the absence of a serologic response to Lyme borreliosis.

Base Sequence↗