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Biomedical subjects

J R Miller

Publications and source records attributed to J R Miller.

At least 289 records · Page 16Linked to original sources

A rapid test for infectious and inflammatory enteritis.

BACKGROUND: Inflammatory illnesses are an indication for specific diagnostic studies and possible antimicrobial therapy. The presence of fecal leukocytes has been used as a marker of inflammatory diarrhea; however, microscopic examination of the fecal smear is unreliable if the specimen is transported, refrigerated, frozen, or collected by swab. OBJECTIVE: To evaluate a rapid, sensitive, semiquantitative test for detection of fecal leukocytes using antilactoferrin latex bead agglutination (LFLA), a test that remains sensitive even after specimens are refrigerated, frozen, or stored on swabs. METHODS: LFLA titers were determined in stool specimens from previously healthy volunteers before and after experimental infection with different enteric pathogens and from patients with nosocomial diarrhea caused by Clostridium difficile. RESULTS: Healthy controls and subjects with noninflammatory diarrhea caused by Vibrio cholerae consistently demonstrated LFLA titers less than 1:50. In contrast, subjects with inflammatory diarrhea caused by Shigella species and C difficile had markedly elevated titers. Titers for subjects with experimental shigellosis ranged from 1:50 to 1:3200, with seven (78%) of nine at 1:400 or greater. Titers for patients with C difficile enteritis ranged as high as 1:1200, with six (50%) of 12 at 1:400 or greater. Subjects with experimental enteropathogenic Escherichia coli infection also had elevated titers, ranging from 1:100 to 1:1600, with three (43%) of seven at 1:400 or greater. Titers for subjects with experimental enterotoxigenic E coli infection were moderately elevated, with nine (53%) of 17 ranging from 1:50 to 1:200 (only one [6%] of 17 was > or = 1:400), suggesting a mild inflammatory process. CONCLUSIONS: The fecal LFLA assay distinguishes inflammatory from noninflammatory diarrhea, may provide new information on mildly inflammatory processes, and may be a useful, rapid test in a diagnostic algorithm for acute, infectious diarrheal illnesses.

Communicable Diseases↗

Faeriefungin: a new broad-spectrum antibiotic from Streptomyces griseus var. autotrophicus.

Faeriefungin, a polyol polyene macrolide lactone antibiotic, was isolated from the mycelium of Streptomyces griseus var. autotrophicus, MSU-32058/ATCC 53668, collected from the soil sample of a fairy ring in an old lawn in Lansing, Michigan. Faeriefungin has some properties similar to the previously reported polyene macrolides, mycoticin and flavofungin, but possesses different physiochemical and biological properties. Aspergillus, Fusarium, Microsporum, Trichophyton, and Alternaria spp. were completely inhibited by faeriefungin at 3.2 micrograms/ml, Candida spp. at 5.5 micrograms/ml, and Pythium, Phialophora, Leptosphaeria spp., and some selected Gram-negative penicillin-resistant strains of Neisseria gonorrhoeae at 16.0 micrograms/ml. At a concentration of 100 ppm, it caused 100% mortality of mosquito larvae (Aedes aegypti, Rockefeller strain) and free-living nematodes (Panagrellus redivivus). Unlike the related polyene macrolides, faeriefungin is crystalline and stable with broad-spectrum antimicrobial and insecticidal activity. Preliminary cytotoxicity studies with human erythrocytes and rat liver epithelial cells indicated that faeriefungin and amphotericin B have comparable toxicity. Solution nmr study has indicated that faeriefungin is a mixture of two compounds, faerifungins A [1] and B [2], and that they differ in the attachment of a H or an Me at C-33.

Acetylation↗

Homoeobox gene expression in mouse embryos varies with position by the primitive streak stage.

Pattern formation in animal development requires that genes be expressed differentially according to position in the sheets of cells that make up the early embryo. The homoeobox-containing genes of Drosophila are control genes active both in the establishment of a segmentation pattern and in the specification of segment identity. In situ hybridization experiments confirm that these genes are expressed in a segmentally-restricted manner and that their expression presages morphological differentiation of segmental structures. Homoeobox genes have recently been isolated from the mouse and have been shown to be expressed during mouse development. Using in situ hybridization, we show here that expression of the mouse homoeobox gene Mo-10 (ref. 7) is spatially restricted in the developing embryo and that localization of expression is already evident within the germ layers before their morphological differentiation. These findings support the suggestion that the homoeobox genes of mammals, like those of Drosophila, may be important in pattern formation.

Animals↗

First arch malformation: a new craniofacial mutant in the mouse.

The first arch malformation arising in a BALB/c strain of mice, has been shown to be inherited as a single autosomal recessive gene and is given the provisional gene symbol far. Affected newborns have extensive bony defects of the face and skull, including a cleft secondary palate, and die within 24 hours of birth. Most of the abnormalities occur in bones derived from the first branchial arch and most of the bony derivatives of the first arch are abnormal in the mutant.

Animals↗

Use of a lactoferrin assay in the differential diagnosis of female genital tract infections and implications for the pathophysiology of bacterial vaginosis.

BACKGROUND AND OBJECTIVES: Lactoferrin has served as a marker for leukocytes (polymorphonuclear neutrophils [PMN]) in clinical specimens. GOAL: To investigate the potential of a lactoferrin latex agglutination test in the differential diagnosis of female genital infection. STUDY DESIGN: Lactoferrin was quantified in the vaginal discharge of women with genital infections. Polymorphonuclear neutrophils were added to vaginal discharge and observed over 8 hours. RESULTS: Vaginal lactoferrin titers were significantly elevated in women with trichomoniasis, candidiasis, and bacterial vaginosis (BV). Using a lactoferrin titer of > or = 1:40, the assay has a sensitivity of 79.3% and a specificity of 83.3% for the presence of trichomoniasis or bacterial vaginosis. Vaginal discharge from women with BV significantly destroyed added PMN. CONCLUSIONS: Vaginal lactoferrin determinations may provide a useful screen for inflammatory genital infections and identify individuals who require additional diagnostic evaluation. The observed absence of PMN in bacterial vaginosis may result from the destruction of PMN in vaginal discharge rather than the absence of a primary inflammatory response.

Agglutination Tests↗

Vegetation stress detection through chlorophyll a + b estimation and fluorescence effects on hyperspectral imagery.

Physical principles applied to remote sensing data are key to successfully quantifying vegetation physiological condition from the study of the light interaction with the canopy under observation. We used the fluorescence-reflectance-transmittance (FRT) and PROSPECT leaf models to simulate reflectance as a function of leaf biochemical and fluorescence variables. A series of laboratory measurements of spectral reflectance at leaf and canopy levels and a modeling study were conducted, demonstrating that effects of chlorophyll fluorescence (CF) can be detected by remote sensing. The coupled FRT and PROSPECT model enabled CF and chlorophyll a + b (Ca + b) content to be estimated by inversion. Laboratory measurements of leaf reflectance (r) and transmittance (t) from leaves with constant Ca + b allowed the study of CF effects on specific fluorescence-sensitive indices calculated in the Photosystem I (PS-I) and Photosystem II (PS-II) optical region, such as the curvature index [CUR; (R675.R690)/R2(683)]. Dark-adapted and steady-state fluorescence measurements, such as the ratio of variable to maximal fluorescence (Fv/Fm), steady state maximal fluorescence (F'm), steady state fluorescence (Ft), and the effective quantum yield (delta F/F'm) are accurately estimated by inverting the FRT-PROSPECT model. A double peak in the derivative reflectance (DR) was related to increased CF and Ca + b concentration. These results were consistent with imagery collected with a compact airborne spectrographic imager (CASI) sensor from sites of sugar maple (Acer saccharum Marshall) of high and low stress conditions, showing a double peak on canopy derivative reflectance in the red-edge spectral region. We developed a derivative chlorophyll index (DCI; calculated as D705/D722), a function of the combined effects of CF and Ca + b content, and used it to detect vegetation stress.

Acer↗

West Nile virus infection in mosquitoes, birds, horses, and humans, Staten Island, New York, 2000.

West Nile (WN) virus transmission in the United States during 2000 was most intense on Staten Island, New York, where 10 neurologic illnesses among humans and 2 among horses occurred. WN virus was isolated from Aedes vexans, Culex pipiens, Cx. salinarius, Ochlerotatus triseriatus, and Psorophora ferox, and WN viral RNA was detected in Anopheles punctipennis. An elevated weekly minimum infection rate (MIR) for Cx. pipiens and increased dead bird density were present for 2 weeks before the first human illness occurred. Increasing mosquito MIRs and dead bird densities in an area may be indicators of an increasing risk for human infections. A transmission model is proposed involving Cx. pipiens and Cx. restuans as the primary enzootic and epizootic vectors among birds, Cx. salinarius as the primary bridge vector for humans, and Aedes/Ochlerotatus spp. as bridge vectors for equine infection.

Animals↗

West Nile virus in overwintering Culex mosquitoes, New York City, 2000.

After the 1999 West Nile (WN) encephalitis outbreak in New York, 2,300 overwintering adult mosquitoes were tested for WN virus by cell culture and reverse transcriptase-polymerase chain reaction. WN viral RNA and live virus were found in pools of Culex mosquitoes. Persistence in overwintering Cx. pipiens may be important in the maintenance of WN virus in the northeastern United States.

Aedes↗