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M Irvine

Publications and source records attributed to M Irvine.

17 recordsLinked to original sources
PubMed2005

Evaluation of PCR testing of ethanol-fixed nasal swab specimens as an augmented surveillance strategy for influenza virus and adenovirus identification.

Viral culture isolation has been widely accepted as the "gold standard" for laboratory confirmation of viral infection; however, it requires ultralow temperature specimen storage. Storage of specimens in ethanol at room temperature could expand our ability to conduct active surveillance and retrospective screenings of viruses with rapid and inexpensive real-time PCR tests, including isolates from remote regions where freezing specimens for culture is not feasible. Molecular methods allow for rapid identification of viral pathogens without the need to maintain viability. We hypothesized that ethanol, while inactivating viruses, can preserve DNA and RNA for PCR-based methods. To evaluate the use of ethanol-stored specimens for augmenting surveillance for detection of influenza viruses A and B and adenoviruses (AdV), paired nasal swab specimens were collected from 384 recruits with febrile respiratory illness at Fort Jackson, S.C., in a 2-year study. One swab was stored at ambient temperature in 100% ethanol for up to 6 months, and the other swab was stored at -70 degrees C in viral medium. For viral detection, frozen specimens were cultured for a variety of respiratory viruses, and ethanol-fixed specimens were tested with TaqMan (TM) probe and LightCycler SYBR green (SG) melting curve assays with at least two different PCR targets for each virus. The sensitivities of the TM and SG assays on specimens stored in ethanol for 1 month were 75% and 58% for influenza A, 89% and 67% for influenza B, and 93 to 98% and 57% for AdV, respectively. Lower specificities of the real-time assays corresponded to the increased detection of PCR-positive but culture-negative specimens. Influenza virus RNA was detected as well or better after 6 months of storage in ethanol.

Adenovirus Infections, Human↗
PubMed1997

Identification of larval-stage-specific antigens of Onchocerca volvulus uniquely recognized by putative immune sera from humans and vaccination sera from animal models.

Immunity to Onchocerca volvulus is indicated by the existence of putative immune individuals (PI), who do not develop patent infections or clinical symptoms after living in endemic areas for extended periods of time. To gain insight into the nature of the humoral response of PI from Liberia and Ecuador, their sera and those of infected individuals were investigated and compared using western blots. The antigen preparations used were extracts of third- and fourth-stage larvae (L3 and L4, respectively), excretory-secretory proteins (ES-L3) and extracts of third-stage larvae (L3-day2) that had been cultured for 2 days, and extracts of nodular and skin microfilariae. Whereas some antigens were commonly recognized by all individuals, many stage-specific antigens (of 68, 60, 55, 46, 43, 42, 20 and 18 kDa in L3; 100, 88, 80, 50, 48, 45, 40 and 20 kDa in L3-day2; 110, 80 and 72 kDa in ES-L3; 48, 18, 16 and 14 kDa in L4; and 115, 60, 47, 43 and 17 kDa in skin and/or nodular microfilariae) were uniquely recognized by sera from PI. Some of the unique antigens were also recognized by sera from mice and a chimpanzee that were resistant to challenge after immunization with irradiated third-stage larvae. The results support the validity of the assumption that a unique status of immunity develops in certain individuals living in areas where onchocerciasis is endemic.

Animals↗
PubMed1995

Onchocerca volvulus: a comparative study of in vitro neutrophil killing of microfilariae and humoral responses in infected and endemic normals.

In vitro neutrophil-mediated microfilarial killing, humoral responses to crude adult worm antigens (OVAg) and to four recombinant Onchocerca antigens (GST-OV7, GST-OV103, GST-OV3.6, and MBP-OV16), as well as Western blot analysis to stage-specific Onchocerca proteins were studied in individuals from Bassa County, Liberia, infected with onchocerciasis and in endemic normals, defined as individuals without microfilaridermia. Both groups exhibited high levels of specific serum-dependent killing of microfilariae but could not be differentiated on the basis of these results. However, infected individuals had a significantly higher frequency of antibody response to OVAg (P = 0.0001) except GST-OV103. Based on the pattern of response to the different antigens, 17 categories of specific recognition were observed. Nine of these categories were common to both the infected individuals and the endemic normals, 2 were unique to the infected individuals, and 6 were unique to the endemic normals. Among the endemic normals, we identified a subcategory of individuals who had nondetectable levels of total IgG to OVAg by ELISA and had significantly lower IgG4 responses to OVAg. These same individuals demonstrated evidence of past infection, based on serum antibodies detectable by Western blot analysis to male and female adult worms and skin microfilariae, and had a positive response to two or less of the recombinant antigens. We believe that this subcategory may represent individuals with a unique status of immunity.

Adolescent↗
PubMed1995

Louise's first words.

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Attitude of Health Personnel↗
PubMed1994

The bcl-2 proto-oncogene is overexpressed in systemic lupus erythematosus.

Systemic Lupus Erythematosus (SLE) is a disease in which lymphoid hyper-reactivity occurs. Whether this is primary or secondary is not always clear. SLE occurs on a well defined genetic background including genes associated with the major histocompatibility complex (MHC) although family studies demonstrate that other genes must be involved as well. Other potential genes include those involved in intrinsic lymphoid hyper-reactivity, for example by preventing programmed cell death. Such examples exist in murine models of SLE, and in this study we provide evidence that one such controlling protein, bcl-2, is expressed in an increased proportion of both B and T cells in SLE patients. The increased expression was not readily related to disease activity measured by the SIS, nor by routine serological markers. This raises the possibility that the increased expression of bcl-2 seen in lymphoid cells from SLE patients may be of intrinsic genetic origin rather than being secondary to the auto-reactive process. Such increased expression could be expected to interfere with programmed cell death, to produce lymphoid hyper-reactivity and to contribute to the induction and maintenance of this prototypic systemic autoimmune disease.

Adolescent↗
PubMed1994

Identification and characterization of an Onchocerca volvulus cDNA clone encoding a highly immunogenic calponin-like protein.

The identification and characterization of a recombinant cDNA clone, designated OV9M, expressing an antigen present in Onchocerca volvulus infective larvae and adult stages is described. Clone OV9M was identified by screening a lambda gt11 cDNA expression library derived from adult O. volvulus mRNA using pooled rabbit antisera raised against the third (L3) and fourth (L4) stage larvae of the parasite. The cDNA clone encodes an open reading frame of 238 amino acids corresponding to a 27-kDa polypeptide. This polypeptide contains a series of five highly conserved repeats of 25 amino acids that are similar to repeats found in calponin, a protein previously only identified in vertebrate smooth muscle. Extension of the 5' end of the cDNA clone revealed two additional repeats extending the sequence to 378 amino acids, encoding a 41.8-kDa protein. Affinity purified antibodies, which bound specifically to the glutathione S-transferase-OV9M fusion polypeptide, recognize a series of antigens in extracts of O.volvulus microfilariae, L3, L4 and adult stages. The apparent molecular weight of the native OV9M protein in the adult is 45 kDa. Similar proteins are present in extracts of other nematodes including Caenorhabditis elegans, and antibodies from other filarial infections are cross reactive with glutathione S-transferase-OV9M fusion polypeptide. Immunoelectron microscopy revealed that the antigen encoded by this clone is present in the longitudinal muscles of the various larval stages and adult worms. Antibodies to the OV9M protein are present in 40-60% of both patently infected and non-patent individuals residing in onchocerciasis endemic areas.

Amino Acid Sequence↗
PubMed1994

Onchocerca volvulus: in vitro cytotoxic effects of human neutrophils and serum on third-stage larvae.

The cytotoxic effects of neutrophils co-cultured with infective third-stage larvae (L3) and autologous serum from three groups of individuals: infected (INF), non-patent endemic normals (EN) and non-endemic controls (NEC), were compared using a MTT (3-(4,5 dimethylthiazol-2yl)-2,5 diphenyl tetrazolium bromide) reduction assay as a biochemical parameter of larval viability. The MTT assay permitted the detection of L3 which had suffered varying levels of necrosis. The observations from this study indicate that infected individuals and endemic normals are capable of mounting a specific immune response against the infective L3. This is based on our findings of i) significantly greater numbers of L3 showed necrosis in neutrophil cultures of the INF and EN compared to those from the NEC, ii) a superior ability of cultures from these individuals to inhibit the molting of L3 to fourth-stage larvae, iii) IgG antibodies reactive with the surface of L3, detected by immunofluorescence in the serum of the INF and the EN and iv) recognition of specific antigens in extracts of L3 detected by Western blot analysis. The specific immune response directed against L3 is probably a significant immunological defense mechanism used to limit infection in endemic areas.

Adolescent↗
PubMed1970

Observations on coronary collateral communications and the control of flow in the coronary circulation of the dog.

1. Pressure was measured in the small arterial anastomosing branches of the coronary vascular network. The mean value was 30 mm Hg not significantly different from the mean value of 33 mm Hg for peripheral coronary pressure measured distal to a ligature on the anterior descending branch of the left coronary artery. Evidence was adduced to show that either the anterior descending or the circumflex artery had the capacity to maintain network pressure at levels adequate for tissue perfusion.2. The network has both capacity and compliance. Filling of the network compliance during systole probably accounts for the systolic phase of coronary flow. Flow through the microcirculation is probably entirely diastolic, the combined compliance of the aorta and large vessels together with the network provides the necessary reservoir, the potential energy indicated by diastolic pressure provides the perfusion pressure head.3. Resistance of vessels between the aorta and network cannula (pre-net) was approximately double that of the microcirculation (post-net). The smaller pre-network vessels are of the order 70 mum in diameter. Both pre- and post-network vessels are vaso-active and respond similarly to adrenaline and haemorrhage.

Animals↗
PubMed1966

Observations on temperature distribution in the cardiovascular system, thorax and abdomen of monkeys in relation to environment.

1. Thermo-electric observations of temperature distribution in the ;core' area of monkeys and baboons are reported.2. Temperature gradients were shown to exist in the inferior vena cava, temperatures rising by a mean value of 0.2 degrees C at the entry of the renal veins and again by a further 0.2 degrees C at the level of the hepatic veins.3. Temperatures in the right atrium were on average 0.1 degrees C lower than in the inferior vena cava due to the return of relatively cooler blood from the superior vena cava.4. Net heat exchanges in the thorax were small. Right atrial and aortic blood temperatures were not significantly different and it was concluded that heat losses in the thorax were balanced by heat production in lungs and heart.5. The mean liver temperature was 0.1 degrees C higher than that of the aortic blood irrespective of the environment.6. The mean temperature recorded from the lumen of the jejunum was 0.2 degrees C warmer than the aorta in the ;warm' environment and 0.4 degrees C hotter than the aorta in the ;cool' environment. In both environments intrajejunal temperature was higher than the liver but the differential was increased by exposure to a ;cool' environment.7. Evidence is adduced to suggest that the gastro-intestinal tract in the body at rest is a major heat producer contributing about double the amount of heat generated by the liver.8. It is suggested that blood flow redistribution in the splanchnic area on exposure of the body to cold is the main cause of the change in aortic-jejunal and jejunal-liver differentials. Metabolic factors have, however, not been excluded.

Animals↗