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Biomedical subjects

S Green

Publications and source records attributed to S Green.

At least 109 records · Page 6Linked to original sources
PubMed1999

A multiplex RT-PCR for the detection of parainfluenza viruses 1-3 in clinical samples.

Parainfluenza viruses (PIV) are an important cause of respiratory morbidity. Conventional diagnostic methods for detection of PIV are time consuming or lack sensitivity. A multiplex PCR that detects PIV 1-3 was developed using novel primers for PIV viruses 1 and 2 and primers for PIV 3 described previously. Following RNA extraction a single multiplex reverse transcription was undertaken using antisense primers specific for each virus type. This was followed by a 40-cycle multiplex PCR using primers directed towards the haemagglutinin-neuraminidase coding region of each virus type. Products were probed with type-specific fluorescein labelled internal probes and detected by chemiluminescence. Cultured PIV viruses were detectable to a sensitivity of 1 TCID50. The technique was applied to 57 nasal aspirates taken from children presenting with various acute respiratory conditions and analysed previously by culture, immunofluorescence and/or serology. It was possible to detect PIV 1, 2 or 3 in 13/13 samples found previously positive for PIV by tissue culture, 13/15 found previously positive by immunofluorescence and 6/10 that coincided with positive serology. None of the samples found previously positive for other viruses (26) or negative to virus detection (6) were found positive by RT-PCR. It is concluded that this method is as sensitive as combined immunofluorescence and tissue culture for the detection of the PIV viruses 1-3 and should be useful for rapid diagnosis of PIV 1-3 infections.

Animals↗
PubMed1999

Performance assessment of patient dosimetry services and X-ray quality assurance instruments used in diagnostic radiology.

Experiences of the Regional Radiation Physics and Protection Service (RRPPS) in performance assessment of diagnostic X-ray QA instrumentation and on-patient dosemeters are recounted. Issues relating to the provision of realistic and reproducible reference conditions for calibrated X-irradiations are considered and summary statistics from test measurements of dose and kVp meters are provided. For both dose and kVp meters it is indicated that as many as 25% of instruments used in routine use in the U.K. may require some adjustment before they can truly be said to be performing as the manufacturer intended. Results from intercomparison exercises for patient dosimetry services are also discussed. It is apparent that, for those centres participating in the exercise, dose assessments are generally being obtained to within a bias and a relative standard deviation of less then 10%.

Female↗
PubMed1999

Isolation and species typing of Lyme borreliosis spirochaetes from UK patients with erythema migrans.

Skin biopsies taken from UK cases of erythema migrans rash were cultured for Borrelia burgdorferi sensu lato. Reverse line blotting was used to type the infecting genospecies in PCR-positive cultures and biopsies. B. garinii or B. afzelii was identified in 56% (5/9) of biopsies/cultures tested. All patients were tested by conventional serology. PCR confirmed infection in two patients where serological testing failed to detect antibody.

Bacterial Typing Techniques↗
PubMed1999

Conduct disorder in girls: a review of the literature.

The study of Conduct Disorder (CD) has primarily been limited to boys. The lack of research resulted from a premise that CD in girls was rare. However, CD in girls is a relatively common psychiatric diagnosis, and appears to be associated with several serious outcomes, such as Antisocial Personality Disorder and early pregnancy. Understanding gender differences in the course and severity of CD may lead to important information about etiology. Empirical studies on precursors, developmental course, risk factors and treatment for CD in girls are reviewed, while highlighting similarities and differences between girls and boys. Generally, CD symptoms in girls are stable. Precursors to CD in girls probably include Oppositional Defiant Disorder and temperamental factors, but also may include certain negative cognitions. What distinguishes CD in girls is the high risk they have to develop comorbid conditions, especially internalizing disorders. Risk factors for CD in girls partly overlap with those known for boys, but some factors appear to be highly salient for girls. Finally, there may be some significant effects of gender on treatment efficacy. Implications of these findings for future etiologic research are discussed.

Adolescent↗
PubMed1999

Early immune activation in acute dengue illness is related to development of plasma leakage and disease severity.

T lymphocyte activation and increased cytokine levels have been described in retrospective studies of children presenting with dengue hemorrhagic fever (DHF). Serial plasma samples obtained in a prospective study of Thai children presenting with <72 h of fever were studied. Plasma levels of 80-kDa soluble tumor necrosis factor receptors (sTNFRs) were higher in children who developed DHF than in those with dengue fever (DF) or other nondengue febrile illnesses (OFIs) and were correlated with the degree of subsequent plasma leakage. Soluble CD8 and soluble interleukin-2 receptor levels were also elevated in children with DHF compared with those with DF. Interferon-gamma and sTNFR 60-kDa levels were higher in children with dengue than in those with OFIs. TNF-alpha was detectable more often in DHF than in DF or OFIs (P<.05). These results support the hypothesis that immune activation contributes to the pathogenesis of DHF. Further studies evaluating the predictive value of sTNFR80 for DHF are warranted.

Acute Disease↗
PubMed1999

Early CD69 expression on peripheral blood lymphocytes from children with dengue hemorrhagic fever.

Recent reports have demonstrated immune activation in dengue hemorrhagic fever (DHF) by cytokine and soluble receptor detection in blood. The goal of this study was to determine which cell types are activated and likely to be responsible for cytokine production. Whole blood specimens from 51 Thai children presenting within 72 h of fever onset and with detectable plasma dengue viral RNA were studied by flow cytometry. Absolute CD4 T cell, CD8 T cell, NK cell, and gammadelta T cell counts were decreased in children with DHF compared with those with dengue fever (DF) early in the course of illness. The percent of cells expressing CD69 was increased on CD8 T cells and NK cells in children who developed DHF more than in those with DF. These data directly demonstrate that cellular immune activation is present early in acute dengue and is related to disease severity.

Antigens, CD↗
PubMed1999

The monitoring of contaminated impervious planar surfaces.

The responses of several types of surface contamination monitor have been investigated for three typical working surfaces contaminated by three radionuclides commonly used in diagnostic or analytical biomedical applications. Of the three radionuclides, 99mTc is an intermediate-energy gamma emitter, 125I decays by electron capture, emitting low-energy x-rays, and 32P is a moderate-energy beta emitter. For each radionuclide monitored values have generally been found to be within 30% of projected response, this being based on calibrations which make use of standard radionuclide sources and conditions. The several types of contaminated non-absorbent surface that have been investigated produce monitored values which for a given type of monitor and radionuclide cannot be differentiated from each other.

Equipment Contamination↗
PubMed1999

Morphology comparison of individually selected hyperactivated and non-hyperactivated human spermatozoa.

The objective of this study was to compare the morphology of human spermatozoa undergoing hyperactivated motility in vitro with those that were non-hyperactivated (non-hyp). Hyperactivation criteria were established by the Hobson Sperm Tracker (HST), sampling at 25 Hz, as curvilinear velocity (VCL) > or = 70 microns/s, amplitude of lateral head displacement (ALH) > or = 7 microns, linearity (LIN) < or = 30% and straight-line velocity (VSL) < or = 30 microns/s. Specially developed software incorporated in the HST produced a white computer-generated overlay for spermatozoa satisfying hyperactivation criteria. These spermatozoa, visually identified on a tracking monitor, were individually removed with micromanipulation equipment using a 12 microns-diameter needle. Fifty-six patient ejaculates were examined comprising a total morphological analysis of 1886 non-hyp spermatozoa and 1051 hyperactivated spermatozoa. Hyperactivated spermatozoa had a significantly higher mean percentage of normal heads and small acrosomes (P < 0.0001 and < 0.0001 respectively) and a significantly lower percentage of large and round heads, midpieces and tail defects (P = 0.002, < 0.0001, 0.02 and < 0.0001 respectively) when compared with non-hyp spermatozoa. These data demonstrate, for the first time, that a homogeneous live population of human hyperactivated spermatozoa, selected in vitro from patients with highly variable degrees of teratozoospermia, is comprised predominantly of cells with normal morphology (P < 0.0001).

Fertilization↗
PubMed1999

The incidence of spontaneous acrosome reaction in homogeneous populations of hyperactivated human spermatozoa.

The incidence of spontaneous acrosome reaction occurring in 1314 individually selected hyperactivated (HA) human spermatozoa was compared to that occurring in 8226 individually selected non-hyperactivated spermatozoa (non-HA) sampled over an incubation time course to allow for capacitation. Two-way analysis of variance showed a significant difference between HA and non-HA spermatozoa for the mean percent acrosome reacted (R), partially acrosome reacted (PR) and combined total (R+PR) (P < 0.001). One-way analysis showed that among the HA spermatozoa there were marked differences among the proportion showing R+PR at the various time points (P = 0.005). Using the same end point, there was no significant evidence of change with time for the non-HA spermatozoa. The overall data indicated that HA human spermatozoa have a greater propensity for spontaneous acrosomal loss than non-HA spermatozoa during incubation in synthetic culture media.

Acrosome Reaction↗
PubMed1999

'Neo-FAC' (5-fluorouracil, doxorubicin, and cyclophosphamide) for poor-prognosis stage IV breast cancer: a Southwest Oncology Group Phase II Study.

The authors report a phase II pilot investigation in the Southwest Oncology Group examining a combination of 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC) incorporating modulated 5-FU in patients with poor-prognosis stage IV breast cancer. Patients with poor-prognosis stage IV breast cancer were treated with this "neo-FAC" as front-line therapy. The regimen consisted of 5-fluorouracil by continuous ambulatory infusion pump at 200 mg/m2/day for 42 days, repeated at 56-day intervals; doxorubicin at 20 mg/m2/week intravenously to a maximum cumulative total dose (including adjuvant therapy, if any) of 500 mg/m2; cyclophosphamide 60 mg/m2/day taken orally; methotrexate 15 mg/m2/week intravenously beginning 1 week after termination of doxorubicin; and oral prednisone decreasing from 60 mg/day on a tapering schedule for a total of 7 weeks of treatment. Treatment was continued until progression, unacceptable toxicity, or patient refusal. Twenty-four patients were accrued to this study. Of these, two were ineligible, and the remaining 22 were evaluable for response. Ten patients experienced grade 3 toxicity, and six had grade 4. There were no treatment-associated deaths. Best responses were a complete response in one patient (5%) and partial responses in 6, for an overall response rate of 32% (7/22 evaluable patients). Overall survival in five pilot studies in the Southwest Oncology Group in this poor-prognosis population are relatively superimposable. The present regimen, with its relatively poor outcome and the expense and inconvenience of administering chemotherapy by ambulatory infusion pump, will not be pursued further.

Adult↗
PubMed1999

Patients' attitudes to medical students in the accident and emergency department.

The objective of this study was to assess patients' attitudes towards medical students in the accident and emergency department. Patients attending a university department of accident and emergency were given a questionnaire asking about their attitudes to medical students. Ninety-three per cent of the patients would not object to being seen and examined by a medical student in the accident and emergency department. No patients reported feeling pressurized to accept this proposal. It is concluded that most patients attending the emergency department had favourable attitudes towards medical students.

Adult↗
PubMed1999

Design for an accelerator-based orthogonal epithermal neutron beam for boron neutron capture therapy.

This paper is concerned with the proposed Birmingham accelerator-based epithermal neutron beam for boron neutron capture therapy (BNCT). In particular, the option of producing a therapy beam at an orthogonal direction to the incoming protons is considered. Monte Carlo radiation transport simulations, both with and without a head phantom, have shown that an orthogonal beam geometry is not only acceptable but is indeed beneficial, in terms of a lower mean neutron energy and an enhanced therapeutic ratio for the same useful neutron fluence in the therapy beam. Typical treatment times for various beam options have been calculated, and range from 20 to 48 min with a 5 mA beam of 2.8 MeV protons, if the maximum photon-equivalent dose delivered to healthy tissue is to be 12.6 Gy Eq. The effects of proton beam diameter upon the therapy beam parameters have also been considered.

Boron Neutron Capture Therapy↗
PubMed1999

Toward a final design for the Birmingham boron neutron capture therapy neutron beam.

This paper is concerned with the proposed Birmingham accelerator-based epithermal neutron beam for boron neutron capture therapy (BNCT). Details of the final moderator design, such as beam delimiter, shield, and beam exit surface shape are considered. Monte Carlo radiation transport simulations with a head and body phantom have shown that a simple flat moderator beam exit surface is preferable to the previously envisioned spherical design. Dose rates to individual body organs during treatment have been calculated using a standard MIRD phantom. We have shown that a simple polyethylene shield, doped with natural lithium, is sufficient to provide adequate protection to the rest of the body during head irradiations. The effect upon the head phantom dose distributions of the use of such a shield to delimit the therapy beam has been evaluated.

Boron Neutron Capture Therapy↗
PubMed1999

Follow up of workers previously exposed to silver solder containing cadmium.

OBJECTIVES: To study longitudinal biological monitoring data on urinary and blood cadmium collected in a small cohort of nine workers who had been brazing for several years with solders containing cadmium. METHODS: Cadmium was measured by neutron activation analysis in livers and kidneys, and estimates of renal function were carried out in 1983 and 1995. During the intervening period exposure to cadmium was dramatically reduced by local exhaust ventilation control and substitution of the solder containing cadmium. RESULTS: From urinary protein measurements there was evidence within the group of increasing renal tubular damage over the 12 year period, even though exposure to cadmium was dramatically reduced over this period and almost eliminated by 1995. There was no evidence from serum creatinine of decreasing glomerular filtration rate, and the renal tubular handling of calcium, phosphate, or urate had not worsened significantly. Blood and urinary cadmium concentrations reduced significantly over the 12 year period but were still substantial in 1995. Blood cadmium concentrations tended to reflect cadmium body burden in 1995 when exposure had been low for several years, and decreased most significantly during 1983-90. By contrast urinary cadmium concentrations only decreased significantly from about 1990 onwards. Urinary cadmium was not significantly correlated with liver or kidney cadmium concentration in either 1983 or 1995. This may be due to the level of tubular dysfunction in the cohort. Calculated cumulative excretion of cadmium over the 12 year period was substantially greater than the loss of cadmium measured in livers and kidneys and the derived loss in body burden. Reasons for this are discussed. It is possible that in cohorts, where renal damage is apparent, urinary concentrations reflect a substantial component of current exposure rather than stored body losses. CONCLUSIONS: The data reinforce the concept that blood cadmium concentrations may not always reflect recent exposure, but may reflect body burden derived from historical exposure depending on the degree of current exposure; and that the decline in urinary and blood cadmium measurements after removal from, or reduction in, exposure will be slow and depend on the historical body burden.

Adult↗
PubMed1999

P-selectin and ICAM-1 mediate endotoxin-induced neutrophil recruitment and injury to the lung and liver.

The role of leukocyte adhesion molecules in endotoxin-induced organ injury was evaluated by administering intraperitoneal Salmonella enteritidis lipopolysaccharide (LPS) to wild-type (WT) mice, P-selectin-deficient mice, intercellular adhesion molecule (ICAM)-1-deficient mice, and P-selectin-ICAM-1 double-mutant mice. In WT mice, there was a sevenfold increase in the number of neutrophils present in the pulmonary vascular lavage fluid, and there were sevenfold more intracapillary neutrophils by electron-microscopic (EM) morphometry at 4 h after intraperitoneal LPS compared with that in control mice. Extravascular albumin accumulation increased approximately twofold in the lungs and liver of WT mice treated with LPS. In the double-mutant mice, although overall mortality after intraperitoneal LPS was not attenuated, there was a significant delay in mortality in the P-selectin-ICAM-1-deficient mutants compared with that in WT mice after intraperitoneal LPS (P < 0.01). Moreover, compared with LPS-treated WT mice, lung and liver extravascular albumin accumulation was significantly lower in LPS-treated P-selectin-ICAM-1 double-mutant mice. Lung myeloperoxidase activity, normalized per 1,000 circulating neutrophils, increased after endotoxin in WT and P-selectin-deficient mice but not in P-selectin-ICAM-1 double-mutant mice. In addition, lung and liver myeloperoxidase activity per 1,000 circulating neutrophils in endotoxin-treated ICAM-1-deficient mice and P-selectin-ICAM-1 double mutants was significantly lower compared with that in endotoxin-treated WT mice. These data suggest that P-selectin and ICAM-1 significantly contribute to lung and liver injury after systemic endotoxemia.

Animals↗
PubMed1999

Microdialysis and the measurement of muscle interstitial K+ during rest and exercise in humans.

The purpose of this study was to examine whether microdialysis and the internal reference thallium-201 ((201)Tl) could accurately measure muscle interstitial K+ (Ki+) before, during, and after exercise. The relative loss of (201)Tl and simultaneous relative recovery of K+ were measured in vitro for 12 microdialysis probes that were bathed in Ringer acetate medium and perfused at various flows (3-10 microl/min). (201)Tl loss was linearly related to K+ recovery, and their level of agreement was not different from zero. Microdialysis and (201)Tl were then used to measure Ki+ in the gastrocnemius medialis muscle of four humans during rest and static plantar flexion exercise. At rest, Ki+ was 3.9-4.3 mmol/l when the perfusate flow was 2 or 5 microl/min. During exercise, Ki+ increased from 6.9 +/- 0.4 to 7.5 +/- 0.3 mmol/l at low to high intensity and declined to 5.2 +/- 0.3 mmol/l after exercise. These results suggest that large changes in Ki+ in human skeletal muscle can be accurately measured by using microdialysis and (201)Tl.

Adult↗