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Biomedical subjects

S M Buckley

Publications and source records attributed to S M Buckley.

At least 19 recordsLinked to original sources
PubMed2002

Optimization of gene transfer into primitive human hematopoietic cells of granulocyte-colony stimulating factor-mobilized peripheral blood using low-dose cytokines and comparison of a gibbon ape leukemia virus versus an RD114-pseudotyped retroviral vector.

Primitive human hematopoietic cells in granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood (MPB) are more difficult to transduce compared to cells from umbilical cord blood. Based on the hypothesis that MPB cells may require different stimulation for efficient retroviral infection, we compared several culture conditions known to induce cycling of primitive hematopoietic cells. MPB-derived CD34(+) cells were stimulated in the presence or absence of the murine fetal liver cell line AFT024 in trans-wells with G-CSF, stem cell factor (SCF), and thrombopoietin (TPO) (G/S/T; 100 ng/ml) or Flt3-L, SCF, interleukin (IL)-7, and TPO (F/S/7/T; 10-20 ng/ml), and transduced using a GaLV-pseudotyped retroviral vector expressing the enhanced green fluorescence protein (eGFP). Compared to cultures without stroma, the presence of AFT024 increased the number of transduced colony-forming cells (CFC) by 3.5-fold (with G/S/T), long-term culture-initiating cells (LTC-IC) by 4.6-fold (with F/S/7/T), and nonobese diabetic/severe immunodeficiency disease (NOD/SCID)-repopulating cells (SRC) by 6.8-fold (with F/S/7/T). Similar numbers of long-term culture-initiating cells (LTC-IC) and SRC could be transduced using AFT024-conditioned medium (AFT-CM) or a defined medium that had been supplemented with factors identified in AFT-CM. Finally, using our best condition based on transduction with the gibbon ape leukemia virus (GaLV)-pseudotyped vector, we demonstrate a 33-fold higher level of gene transfer (p < 0.001) in SRC using an RD114-pseudotyped vector. In summary, using an optimized protocol with low doses of cytokines, and transduction with an RD114 compared to a GaLV-pseudotyped retroviral vector, the overall number of transduced cells in NOD/SCID mice could be improved 144-fold, with a gene-transfer efficiency in SRC of 16.3% (13.3-19.9; n = 6).

Animals↗
PubMed1997

Detection of ventilatory threshold using near infrared spectroscopy in men and women.

The onset of anaerobic (lactate) metabolism during incremental exercise, which may be a result of an imbalance between tissue oxygen supply and demand, has been associated with the gas exchange ventilatory threshold (VT). This study was designed to examine whether near infrared spectroscopy (NIRS) could be used to detect the VT in healthy subjects. Twenty-one men and 19 women completed incremental cycle ergometry during which NIRS measurements were obtained from the right vastus lateralis and gas exchange measurements were monitored simultaneously using a metabolic cart. The VT was identified from the metabolic data by the V-slope method and from NIRS data as the intensity at which tissue absorbency crossed the resting baseline value observed immediately prior to the initiation of exercise. Pearson correlations for the relative oxygen uptake and power output observed for the two methods of detecting VT were 0.90 and 0.88, respectively, in men and 0.89 and 0.86, respectively, in women (P < 0.01). No significant differences were observed between the two methods of detecting VT for any of the physiological responses (P > 0.05). No significant (P > 0.05) gender differences were observed in muscle oxygenation values at the VT, 32% in men and 38% in women. These results validate the use of NIRS as an alternate noninvasive method for detecting VT during cycle exercise in healthy subjects.

Absorption↗
PubMed1993

Falls from moving motor vehicles in New Zealand.

Injuries due to falls from moving motor vehicles have received relatively little attention from the research community. Injury events of this type in New Zealand were examined using national injury mortality and hospitalisation data from the New Zealand National Health Statistics Centre (NHSC). Also used were data obtained from the New Zealand Post Motor Registration Centre and from coroner's investigation reports held by the Department of Justice. Fifty-six fatal falls from moving motor vehicles occurred during the period 1977-1986 (0.18 per 100,000 population per year). The average age of fatalities was 23. The total potential years of life lost due to these fatalities was 2,696, or an average of 48 years per person. Thirty-nine persons (70%) fell while riding on the exterior of a vehicle. None of the 56 fatalities was using a belt restraint when he/she fell. Four hundred and twenty-three admissions to hospital occurred during 1986 and 1987 (6.5 per 100,000 persons per year). The average age of those hospitalised was 18. Incidence rates were highest in the 0-4, 15-19, and 20-24 year age groups. In the case of both deaths and hospitalisations, the incidence rate for males was approximately double the rate for females. In addition, the rate of falls (per unit registered motor vehicle) from trucks was significantly higher than the rate of falls from cars. Means of preventing falls from motor vehicles are discussed.

Accidental Falls↗
PubMed1993

Injuries due to falls from horses.

This study describes the epidemiology of injuries due to falls from horses in New Zealand. There were 54 fatalities from 1977 to 1986 (0.17 per 100,000 persons per year). There were 773 hospitalisations in 1987 (23.7 per 100,000 persons per year). Head injuries were predominant among both fatal and nonfatal injuries. The incidence of nonfatal head injury in the 10 to 19 age group was significantly higher than the incidence in all older groups (P = 0.003). Young people, particularly females, were the segment of the population most affected by the problem of falls from horses. Reference to data on horse-riding participation rates, however, did not indicate that young people were overrepresented in the series studied. Reference to the same data showed that the rate of hospitalisation due to falls from horses is comparable to the rate for injuries from playing rugby. The magnitude and severity of the problem indicates that there is a need need for helmet use, safe-riding practices, and further research.

Accidental Falls↗
PubMed1988

Genetic relatedness of the Kemerovo serogroup viruses: I. RNA-RNA blot hybridization and gene reassortment in vitro of the Kemerovo serocomplex.

The dsRNA profiles of the Czechoslovakian and Siberian serotypes of the Kemerovo serocomplex viruses examined were similar in agarose, while their dsRNA profiles were distinct in polyacrylamide gel. Blot hybridization studies of the Kemerovo serocomplex viruses demonstrated that the genes were highly conserved among the members within each type, but not between types. Gene reassortment in vitro was demonstrated among selected pairs of the Kemerovo serocomplex viruses by intra- and inter-typic crosses. The majority of the reassortant progeny from inter-typic crosses were single gene replacements, whereas the majority of the reassortant progeny from intra-typic crosses were multiple gene replacements suggesting that certain gene combinations were restrictive under conditions of the experiment.

Genes, Viral↗
PubMed1984

Arthropod studies with rabies-related Mokola virus.

A cell culture-adapted variant of the rabies-related Mokola virus was demonstrated to replicate in inoculated Aedes aegypti mosquitoes. Replication was slow compared to many arboviruses in their vectors. Maximum titers were not obtained until after approximately 6 weeks of extrinsic incubation. Mokola virus underwent nine mosquito-mosquito passages at approximately monthly intervals and was thus maintained in insects for 340 days before terminating the study. Virus antigen was detected by immunofluorescence in a variety of mosquito tissues and organs, including salivary glands, but primarily in nervous tissue. Irrefutable virus transmission by bite could not be demonstrated because of equivocal results. Transovarial passage of virus was observed in the mosquito. Viremia in baby mice was demonstrable. Ornithodoros moubata nymphal ticks were exposed to viremic mice but failed to become infected.

Aedes↗
PubMed1975

Isolation of chikungunya virus contaminating an Aedes albopictus cell line.

An Aedes albopictus cell line was found contaminated with structures morphologically compatible with an alphavirus. Rapid isolation of a cytopathic virus was effected by combining sonication, concentration with Aquacide II-r, rate zonal sedimentation and subsequent plating of fractions on Vero cells under agar overlay. The virus caused neithedeath nor disease on inoculation into infant and adult mice. It produced a c.p.e. in Vero and BHK 21 cells, and multiplied in Singh's Aedes aegypti cells. The virus was identified serologically as chikungunya by complement-fixation and plaque reduction netralization test. Virus was not detected in a single attempt by these methods in the American Type Culture Collection A. albopicturs line. The presence of chikungunya virus in A. albopictus cells is not easily recognized and may complicate interpretation of experimental results.

Aedes↗
PubMed1975

Arbovirus infection of vertebrate and insect cell cultures, with special emphasis on Mokola, Obodhiang, and kotonkan viruses of the rabies serogroup.

Multiplication of rabies serogroup viruses, Obodhiang and kotonkan (two presumptive arboviruses), was induced in vertebrate cell cultures with Singh's A. albopictus cell cultures used as "helper cells" in cocultivation experiments. Plaque formation without prior in vitro adaptation was induced in Vero cell cultures with eight rabies serogroup viruses: in all five instances by cocultivation of either infected BHK-21 or A. albopictus cells with Vero cells under agar overlay and in three of eight instances by direct plaque assay of infected mouse brain suspensions. In cross-plaque reduction neutralization tests with cloned viruses that represented human pathogens, rabies, Duvenhage, and Mokola, on the one hand, and the presumptive arboviruses Obodhiang and kotonkan, on the other hand, Mokola virus shared common antigenic components with both the nonarboviruses and the arboviruses. Biologically, Mokola virus was different from the other two human pathogens, rabies and Duvenhage, in that it multiplied in both vertebrate and invertebrate cell cultures. Mokola virus thus appears to be the biologic and serologic bridging agent.

Aedes↗
PubMed1975

Antigenic properties of the arenaviruses.

Arenaviruses are known to show antigenic relationships in the complement-fixation (CF) and fluorescent antibody tests but not in the neutralization test. The humoral response to some of the arenaviruses is characterized by a dissociation between the antibodies determined by the CF test and those determined by the neutralization test and also by its late appearance following natural infection. Investigations are reported showing that, as regards the CF test, Junin, Machupo, Amapari, and Tacaribe viruses are closely related, while LCM and Lassa viruses are distantly related to each other and to the remaining viruses in the group. Studies by agar gel diffusion and precipitation have shown complete specificity except among viruses that are very closely related in the CF test. Observations with sera from persons infected with Lassa fever virus show that CF antibodies rarely appear before the 18th day after onset; they can persist, with diminishing titres, for up to 6 years.

Animals↗
PubMed1975

Small- and large-plaque variants of Chikungunya virus in two vertebrate and seven invertebrate cell lines.

Nine cells lines--BHK-21, Vero, Aedes albopictus, A. aegypti (monolayer and howwow vesicles), A. w-albus, A. vittatus, Anopheles stephensi and Culex quinquefasciatus--were infected with small- and large-plaque (SP, LP) variants of chikungunya virus. Ross strain, and incubated at different temperatures. In the Aedes (29 plus or minus 1 degrees C) and the vertebrate cell lines (36 degrees C), infectivity titers of extracellular virus rapidly reached a peak; cytopathic effect (CPE) occurred only in the latter. In Anopheles cells (29 plus or minus 1 degrees C), infectivity titers increased very slowly to a peak at 10 days post-inoculation (p.i.); in Culex cells (29 plus or minus 1 degrees C or room temperature), persistence of virus only or no multiplication was observed. In infected A. albopictus, A. aegypti and A. w-albus carrier cultures, the SP variant continued to resemble the original stock virus in terms of mouse pathogenicity and plaque morphology in Vero cells, but the LP variant tended to modify toward the SP variant.

Aedes↗
PubMed1974

Mouse interferon in ascitic fluids.

Mouse interferon was obtained in relatively large volumes by the use of ascitic fluid from mice bearing sarcoma 180/TG and subsequently inoculated with Germiston virus.

Animals↗
PubMed1974

Lassa fever.

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Animals↗