Detection of malignancy-associated metabolites in the sera of cancer patients by electron capture gas chromatography

A reliable test that detects malignancy and indicates response to therapy is needed. Frequency-pulsed electron-capture gas-liquid chromatography (FPEC-GLC), a selective analytical technique that is sensitive to 15 fmol quantities of metabolites, was used to analyse derivatised acidic chloroform extracts of sera from patients with biopsy-proven cancer, non-malignant infectious and non-infectious disease, and healthy controls. Two peaks designated P1 and P10, not found in serum from healthy controls (n = 7) or patients with non-malignant disease (n = 85), were detected in biopsy-proven samples (n = 52) from cancer patients. P1 and P10 were later shown by chemical and mass spectral studies to be carboxylic acids. When one or both of these peaks were detected in the sera of non-treated patients they were always associated with malignancy. In patients responding to therapy, a reduction or disappearance of these peaks was observed. Further, it was noted that P10 persisted or increased in sera of patients with progressive cancer not responding to therapy. We conclude that this test has potential in diagnosis and for following the response of the disease to therapy.

Identification and sequence of an accessory factor required for activation of the human interferon gamma receptor

Human chromosomes 6 and 21 are both necessary to confer sensitivity to human interferon gamma (Hu-IFN-gamma), as measured by induction of class I human leukocyte antigen (HLA) and protection against encephalomyocarditis virus (EMCV) infection. Whereas human chromosome 6 encodes the Hu-IFN-gamma receptor, human chromosome 21 encodes accessory factors for generating biological activity through the Hu-IFN-gamma receptor. Probes from a genomic clone were used to identity cDNA clones expressing a species-specific accessory factor. These cDNA clones are able to substitute for human chromosome 21 to reconstitute the Hu-IFN-gamma receptor-mediated induction of class I HLA antigens. However, the factor encoded by the cDNA does not confer full antiviral protection against EMCV, confirming that an additional factor encoded on human chromosome 21 is required for reconstitution of antiviral activity against EMCV. We conclude that this accessory factor belongs to a family of such accessory factors responsible for different actions of IFN-gamma.

Sublocalization of the human interferon-gamma receptor accessory factor gene and characterization of accessory factor activity by yeast artificial chromosomal fragmentation

A chromosomal fragmentation procedure was employed to produce a deletion set of yeast artificial chromosomes (YACs) from a parental YAC, GART D142H8, known to map to human chromosome 21q and to encode the human interferon-gamma receptor (Hu-IFN-gamma R) accessory factor gene as well as the phosphoribosylglycinamide formyltransferase (GART) gene. When expressed in Chinese hamster ovary cells, these deleted YACs retain accessory factor activity, as judged by major histocompatibility complex class I antigen inducibility, until the deletions from the acentric end exceed 390 kilobases (kb). Therefore, the accessory factor (AF-1) gene can be localized to a 150-kb region at the left (centric) end of the parental 540-kb GART YAC. Cells containing functional YACs are also able to induce the ISGF3 gamma and gamma-activated factor (GAF) transcription factors, but were not protected against encephalomyocarditis virus (EMCV) upon treatment with Hu-IFN-gamma. Therefore, the Hu-IFN-gamma R and the AF-1 are sufficient for some, but not all, of the actions of Hu-IFN-gamma. We postulate that an additional accessory factor (AF-2) required for antiviral activity against EMCV is encoded on chromosome 21q.

Endothelial cells are activated by cytokine treatment to kill an intravascular parasite, Schistosoma mansoni, through the production of nitric oxide

Like many pathogens that undergo an intravascular stage of development, larvae of the helminth parasite Schistosoma mansoni migrate through the blood vessels, where they are in close contact with endothelial cells. In vitro exposure of murine endothelial cells to various cytokines (interferon gamma, tumor necrosis factor alpha, and interleukin 1 alpha or 1 beta) resulted in their activation to kill schistosomula through an arginine-dependent mechanism involving production of nitric oxide (NO). Cytokine-treated endothelial cells showed increased expression of mRNA for the inducible form of the NO synthase, and both NO production and larval killing were suppressed by treatment with competitive inhibitors. The effector function of cytokine-treated endothelial cells was similar to that of activated inflammatory tissue macrophages, although activation appeared to be differentially regulated in these two cell types. Activated endothelial cells killed older (18-day) forms of the parasite, such as those currently thought to be a primary target of immune elimination in the lungs of mice previously vaccinated with radiation-attenuated cercariae, as well as newly transformed larvae. In C57BL/6 mice, which become resistant to S. mansoni infection as a result of vaccination with irradiated cercariae, endothelial cell morphology characteristic of activation was observed in the lung by 1-2 weeks after challenge infection. Similar endothelial cell changes were absent in P-strain mice, which do not become resistant as a result of vaccination. Together, these observations indicate that endothelial cells, not traditionally considered to be part of the immune system, may play an important role in immunity to S. mansoni and, by means of NO-dependent killing, could serve as effectors of resistance to other intravascular pathogens.

Intrasubject reliability and validity of somatosensory source localization using a large array biomagnetometer

Neuromagnetic fields were evoked by tactile stimuli and detected with a multi-channel biomagnetometer through 72 independent repetitive measurements on a single subject. Each measurement consisted of a somatosensory evoked response (N = 256 stimuli) using a single probe placement. These fields were then analyzed for source localization using an equivalent current dipole model and demonstrated highly reliable localizations. The 3 major neuromagnetic somatosensory response components peaking at 35, 65 and 110 msec all localized to the same area of cortex. The relative contributions of intrinsic brain activity, habituation, probe placement, and choice of fiduciary points for headframe determination were quantified. Intrinsic factors were found to constitute the major source of inter-measurement error. Sources localized by magnetic source imaging (MSI) appeared valid relative to neuroanatomical estimation of the central fissure on MRI. Non-invasive presurgical biomagnetic localization of somatosensory cortex produces reliable and valid functional localizations which can be of potential value in risk assessment and may provide a useful guide for invasive functional mapping.

Pediatricians' diagnostic approach to pharyngitis and impact of CLIA 1988 on office diagnostic tests

OBJECTIVE

To determine the factors associated with an optimal diagnostic approach to a child with pharyngitis, characterize office laboratory methods for throat swab culture and group A streptococcal rapid antigen testing, and assess the potential impact of the Clinical Laboratory Improvement Amendments (CLIA) of 1988 on the performance of these tests.

DESIGN AND SETTING

Mailed survey to all board-certified primary care pediatricians from seven western states with telephone follow-up for nonrespondents.

OUTCOME MEASURES

Differences in practice characteristics and use of office laboratory tests for physicians who usually (> 80%) diagnose pharyngitis using a recommended approach vs those who follow this approach less often (< 50%); characteristics of physicians who indicate that they intend to discontinue office throat culture because of CLIA and those who will continue to perform this test also are compared.

RESULTS

Responses from 531 pediatricians were analyzed. Forty-four percent diagnosed pharyngitis appropriately for more than 80% of patients, and 17% did so for fewer than 50%. Optimal diagnosis was significantly more common among physicians who cultured throat swabs in their office (relative risk, 1.40; 95% confidence interval, 1.19 to 1.66) and less common among solo practitioners (relative risk, 0.71; 95% confidence interval, 0.56 to 0.88). Factors that may decrease the sensitivity of office throat culture include short duration of incubation (59%), lack of quality control (51%), and limited education of the persons reading results (6%). With implementation of CLIA, 24% of pediatricians reported that they already have discontinued or will discontinue office throat culture, and 23% have discontinued or will discontinue antigen detection testing for group A streptococci. Those most likely to stop office culture include solo practitioners and practitioners who do not currently perform quality control of culture methods.

CONCLUSIONS

Office culture for group A streptococci is strongly associated with an optimal diagnostic approach. Implementation of CLIA regulations may substantially decrease the number of physicians who perform this test. The balance between potential improvements in the quality of office culture with CLIA implementation and the decreased availability of this test needs to be assessed.

A nosocomial pseudo-outbreak of Mycobacterium xenopi due to a contaminated potable water supply: lessons in prevention

OBJECTIVES

To determine risk factors for Mycobacterium xenopi isolation in patients following a pseudo-outbreak of infection with the organism.

DESIGN

Retrospective cohort analysis of mycobacteriology laboratory specimen records and frequency-matched case-control study of hospital patients.

SETTING

General community hospital.

PATIENTS

For the case-control study, 13 case patients and 39 randomly selected controls with mycobacterial cultures negative for M xenopi, frequency matched by specimen source, whose specimens were submitted from June 1990 through June 1991.

RESULTS

Between June 1990 and June 1991, M xenopi was isolated from 13 clinical specimens processed at a midwestern hospital, including sputum (n = 6), bronchial washings (2), urine (4), and stool (1). None of the patients with M xenopi-positive specimens had apparent mycobacterial disease, although five received antituberculosis drug therapy for a range of one to six months. Specimens collected in a nonsterile manner were more likely to grow the organism than those collected aseptically (3.1% versus 0, relative risk = infinity, P = 0.003). M xenopi isolation was attributed to exposure of clinical specimens to tap water, including rinsing of bronchoscopes with tap water after disinfection, irrigation with tap water during colonoscopy, gargling with tap water before sputum collection, and collecting urine in recently rinsed bedpans. M xenopi was isolated from tap water in 20 of 24 patient rooms tested, the endoscopy suite, and the central hot water mixing tank, but not from water in the microbiology laboratory. The pseudo-outbreak occurred following a decrease in the hot water temperature from 130 degrees F to 120 degrees F in 1989.

CONCLUSIONS

Maintenance of a higher water temperature and improved specimen collection protocols and instrument disinfection procedures probably would have prevented this pseudo-outbreak.

Anti-rhinoviral activity of recombinant and hybrid species of interferon alpha

To define further differences in antiviral activity as well as to identify candidate interferons for study in the prevention of rhinovirus colds, the antiviral activities of nine species of recombinant interferon alpha (IFN-alpha A, IFN-alpha B, IFN-alpha C, IFN-alpha D, IFN-alpha J, [Ser-116]IFN-alpha J1, IFN-alpha K, IFN-alpha J/C(Fnu4HI), and IFN-alpha A/D(BglII)) were evaluated against rhinovirus types 39 (RV 39) and 1A (RV 1A). WI-38 cells were exposed to various concentrations of each interferon and were then infected with RV 39, RV 1A, or VSV. Efficacy was determined by protection from cytopathic effect using a tetrazolium dye assay. The 50% inhibitory concentrations ranged from 4 +/- 3 pg/ml for IFN-alpha C to > 3000 pg/ml for IFN-alpha D against RV 39, and from 6 +/- 4 pg/ml for IFN-alpha J/C(Fnu4HI) to > 3000 pg/ml for IFN-alpha D against RV 1A. IFN-alpha J/C(Fnu4HI), [Ser-116]IFN-alpha J1, and IFN-alpha C were the most active of the interferons, and were all more active than IFN-alpha A, against RV 39, RV 1A, and VSV. These interferons warrant further study against rhinoviruses and other viruses.

Use of nasopharyngeal isolates of Streptococcus pneumoniae and Haemophilus influenzae from children in Pakistan for surveillance for antimicrobial resistance

Antimicrobial resistance of Streptococcus pneumoniae and Haemophilus influenzae presents a challenge to clinical case management, particularly in programs for acute respiratory tract infection (ARI), including pneumonia, in developing countries. To determine whether nasopharyngeal isolates of S. pneumoniae and H. influenzae from a clinically defined group of children could be used to predict the prevalence of antimicrobial resistance of strains that cause disease, 601 urban children with ARI, 133 healthy urban children and 285 rural children were evaluated in Pakistan. Of the urban children with ARI, 216 (35.9%) were bacteremic, predominantly with S. pneumoniae (108 children) and H. influenzae (100 children). Overall 631 (61.9%) children carried S. pneumoniae and 381 (37.4%) carried H. influenzae. The proportions of nasopharyngeal isolates of both organisms from urban children with ARI resistant to penicillin or ampicillin, trimethoprim/sulfamethoxazole, chloramphenicol and erythromycin were similar to the proportions of resistant blood isolates. Nasopharyngeal isolates from rural children had lower rates of resistance to some antimicrobial agents. These findings suggest that nasopharyngeal isolates of S. pneumoniae and H. influenzae from children with ARI can be used to conduct surveillance for antimicrobial resistance in a defined geographic area. Such surveillance would aid programs in developing countries in making a rational choice of antimicrobial agents for use in clinical management of bacterial diseases, including pneumonia.

Cell adhesion markers are expressed by a stable human endothelial cell line transformed by the SV40 large T antigen under vimentin promoter control

Markers of endothelium have been studied in a new endothelial cell line derived from human umbilical cord vein cells by microinjection of a recombinant gene that includes a deletion mutant of the human vimentin gene regulatory region controlling the large T and small t antigen coding region of the SV40 virus. In culture, this immortalized venous endothelial cell line (IVEC) demonstrated morphological characteristics of endothelium; uptake of acetylated low density lipoprotein and presence of the Factor VIII-related antigen. Treatment of IVEC cells with Interleukin-1 beta (IL-1 beta) at 10 U.ml-1 activates the expression of cell adhesion molecules such as endothelial leucocyte adhesion molecule (ELAM-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1), as observed in primary culture. Prostacyclin secretion was induced in the IVEC cells by 100 nM PMA treatment and thrombin at 0.5 U/ml. Angiotensin converting enzyme (ACE) activity detected in IVEC cells was present but lower than ACE activity in primary endothelial cells and was completely blocked by enalaprilat (1 microM), a specific ACE inhibitor. The presence of ACE mRNA was also demonstrated in IVEC cells by RT-PCR amplification. Our data demonstrate that endothelial cells immortalized by use of this recombinant gene retain the morphological organization and numerous differentiated properties of endothelium.

Identification of a yeast artificial chromosome clone encoding an accessory factor for the human interferon gamma receptor: evidence for multiple accessory factors

Human chromosomes 6 and 21 are both necessary to confer sensitivity to human interferon gamma (Hu-IFN-gamma), as measured by the induction of human HLA class I antigen. Human chromosome 6 encodes the receptor for Hu-IFN-gamma, and human chromosome 21 encodes accessory factors for generating biological activity through the Hu-IFN-gamma receptor. A small region of human chromosome 21 that is responsible for encoding such factors was localized with hamster-human somatic cell hybrids carrying an irradiation-reduced fragment of human chromosome 21. The cell line with the minimum chromosome 21-specific DNA is Chinese hamster ovary 3x1S. To localize the genes further, 10 different yeast artificial chromosome clones from six different loci in the vicinity of the 3x1S region were fused to a human-hamster hybrid cell line (designated 16-9) that contains human chromosome 6q (supplying the Hu-IFN-gamma receptor) and the human HLA-B7 gene. These transformed 16-9 cells were assayed for induction of class I HLA antigens upon treatment with Hu-IFN-gamma. Here we report that a 540-kb yeast artificial chromosome encodes the necessary species-specific factor(s) and can substitute for human chromosome 21 to reconstitute the Hu-IFN-gamma-receptor-mediated induction of class I HLA antigens. However, the factor encoded on the yeast artificial chromosome does not confer antiviral protection against encephalomyocarditis virus, demonstrating that an additional factor encoded on human chromosome 21 is required for the antiviral activity.

Determination of the degree of cure of dental resins using Raman and FT-Raman spectroscopy

FT-IR spectroscopy has traditionally been used to determine the degree of conversion of dental resins. FT-Raman scattering provided an alternate method of obtaining degrees of conversion for these systems and was particularly useful for measuring spectra of materials without any sample preparation. Raman and FT-Raman spectroscopy gave identical results, but the latter technique was preferred for the highly fluorescent samples often encountered in commercial composites. Linear calibration curves were obtained for the aromatic mixtures Bis-GMA/TEGDMA and Bisphenol-A/TEGDMA using C = C/phi, and for the wholly aliphatic mixture EGDMA/EGDA using C = C/C = O, over a wide range of mole ratios. If both the mole and intensity ratios [C = C/phi or C = C/C = O] were known for an uncured dental resin, then the degrees of conversion could be obtained for the cured materials using Raman spectroscopy. However, if the mole ratios for the uncured resin were unknown, then the degree of conversion depended on the calibration curve, since the Raman scattering cross section of the vibrational modes depended on the molecules to which they were attached.

Differences of retinal nerve fiber layer thickness between normal and glaucoma-like optic disks (physiological cups) matched by optic disk area

We matched by disk area size 23 eyes of patients with glaucoma-like disks (physiological cups) with normal ocular pressures and no visual field loss with 23 eyes of normal subjects. Using stereophotogrammetry we found a significant decrease in retinal nerve fiber layer thickness in the eyes with glaucoma-like disks compared to the normal eyes (P = 0.0081), especially in the nasal quadrant (18.1%). A similar significant decrease was noted in the neuroretinal rim area and a significant increase in cup volume, area, depth and slope for the total disk and its quadrants. The use of computerized image analysis also showed a significant increase in pallor area for glaucoma-like disks compared to normal disks. Eyes with glaucoma-like disks or physiological cups showed evidence of an optic neuropathy and may be manifesting the same damage to the optic nerve occurring in high pressure open angle glaucoma.

Association of phenotypic and genotypic characteristics of invasive Streptococcus pyogenes isolates with clinical components of streptococcal toxic shock syndrome

Sixty-two invasive Streptococcus pyogenes strains, including 32 strains isolated from patients with streptococcal toxic shock syndrome (STSS), were analyzed for the following phenotypic and genotypic characteristics: M-protein type, serum opacity factor production, protease production, the presence of streptococcal pyrogenic exotoxin (Spe) genes A, B, and C, and in vitro production of SpeA and SpeB. These characteristics were analyzed for possible associations with each other as well as with clinical components of STSS. M-type 1, the most commonly isolated M-type, was significantly associated with protease production. Protease activity was significantly associated with the clinical sign of soft tissue necrosis. M-type 1 and 3 strains from STSS patients were significantly associated with the clinical signs of shock and organ involvement as well as with SpeA production in vitro. Finally, the production of SpeA was significantly associated with the clinical component of shock and organ involvement as well as with rash. These data suggest that STSS does not make up a single syndrome but, rather, that the multiple STSS clinical criteria probably reflect different phenotypic characteristics of individual S. pyogenes isolates.

Three-dimensional evaluation of optic disc pallor in open angle glaucoma

We evaluated the extent of pallor on the walls of the optic cup three-dimensionally using simultaneous stereophotographs of the optic discs of 29 normals, 29 ocular hypertensives and 28 primary open angle glaucomas. Pallor was located at the bottom of the optic cup. Pallor ascends the walls of the cup as its extent increases. Statistically significant differences in the extent of pallor in all four quadrants of the optic cup were observed, with the glaucomas having greater extents of pallor than ocular hypertensives, and the ocular hypertensives greater than the normals. The greatest percentage increase in mean pallor from normals to open angle glaucomas occurred on the nasal and inferior walls. This differential extent of pallor could be useful in characterizing ocular hypertension and chronic open angle glaucoma.

Outbreak of pyogenic abscesses after diphtheria and tetanus toxoids and pertussis vaccination

Nine children who received diphtheria and tetanus toxoids and pertussis vaccine from the same vial at a clinic in Colorado developed pyogenic abscesses at the site of injection. Eight abscesses required surgical drainage and five children were hospitalized. Group A Streptococcus (GAS) was cultured from eight wounds and Staphylococcus aureus was also isolated from four. Epidemiologic investigation revealed that within the hour of the first child's vaccination, three children had been diagnosed in the clinic with GAS pharyngitis. GAS recovered from repeat throat swabs from two of these children and the eight case-isolates were all serotype M-12, T-12 and had identical immunoblot patterns on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Laboratory simulation studies demonstrated that GAS can survive for at least 4 days on the external surface of a vaccine vial rubber stopper and contaminate needles inserted through the stopper. Swabbing the stopper with 70% isopropyl alcohol resulted in effective disinfection. To prevent potential contamination meticulous attention to sterile technique is important when withdrawing vaccine from multidose vaccine vials.

Laser scanning tomography and stereophotogrammetry in three-dimensional optic disc analysis

Laser scanning tomography (LST) and computed stereophotogrammetry (CSP) are sophisticated diagnostic tools for the three-dimensional analysis of optic nerve head topography. The two methods are based on different physical principles. To compare the information about the shape of the cup of an optic nerve head obtained by LST and CSP, we evaluated the volume profile (VP; i.e., the cross-sectional area of the cup from top to bottom) in 36 discs of 36 patients (20 control group discs C, 16 glaucoma discs G). The Spearman correlation coefficient between the photogrammetric and the laser scanning VP-slope measurements was rs = 0.931; P < 0.001 (rs = 0.935 G, P < 0.001; rs = 0.910 C, P < 0.001). The results suggest that confocal laser scanning provides readings of the shape of the optic disc cup that are similar to the measurements of computed stereophotogrammetry.

The changing epidemiology of invasive group A streptococcal infections and the emergence of streptococcal toxic shock-like syndrome. A retrospective population-based study

OBJECTIVE

To determine disease incidence and changes in the epidemiology of invasive group A streptococcal infections in a community in Arizona.

DESIGN AND SETTING

We retrospectively surveyed microbiology records from all 10 hospitals in Pima County, Arizona, to identify patients who had Streptococcus pyogenes isolated from blood, sterile body fluid, or tissue biopsy specimens between April 1985 and March 1990. Demographic and clinical information was abstracted from the medical records of these patients.

PATIENTS

A total of 128 patients with a median age of 53.5 years (range, 6 months to 96 years).

OUTCOME MEASURES

Racial/ethnic differences in disease incidence; mortality and changes in the clinical spectrum of disease over the study period.

RESULTS

The annual age-adjusted incidence was 4.3 per 100,000 but was 46.0 per 100,000 among Native Americans. Advanced age, age less than 5 years, hypotension, and multi-organ system involvement were significantly associated with increased mortality. From 1985 to 1990, the proportion of infections with hypotension, rash, desquamation, renal impairment, and gastrointestinal involvement increased significantly (chi 2 for trend P < or = .02 for each feature). A toxic shock-like syndrome occurred in 8% of infections since 1988, compared with none of the infections between 1985 and 1987 (P = .04). Patients with the syndrome were younger than patients with other invasive infections (median age 15 vs 54 years, P = .02), and were less likely to have underlying medical conditions (P = .008).

CONCLUSIONS

Significant changes occurred in the spectrum of invasive group A streptococcal infections in Pima County, Arizona, between 1985 and 1990. Native Americans were at increased risk of acquiring these infections. Patients with the streptococcal toxic shock-like syndrome had epidemiologic features that distinguished them from patients with other invasive infections, including younger age and less underlying illness.