Search PubMed⌕ Search

Biomedical subjects

K Miller

Publications and source records attributed to K Miller.

At least 163 records · Page 9Linked to original sources

Blinded, multicenter quality control study for the quantification of human immunodeficiency virus type 1 RNA in plasma by the Belgian AIDS reference laboratories.

OBJECTIVE: In order to evaluate the interlaboratory variation of HIV-1 RNA measurements in plasma, the Belgian AIDS reference laboratories organized a blinded multicenter quality control study. METHODS: Atest panel of coded spiked HIV-1 plasma samples reflecting the dynamic range of the assay was composed and distributed. The HIV-1 RNA concentration of these samples was determined by the eight Belgian AIDS reference laboratories by means of the Amplicor HIV-1 Monitor version 1.5 assay. RESULTS: Analysis of the results demonstrated that there was little interlaboratory variation for the high concentration range (4.0-5.7 log10 copies/mL), never exceeding 0.2 log10 copies/mL. However the standard deviation for the low concentration range (2.6-3.9 log10 copies/mL) reached up to 0.22 log10 copies/mL. CONCLUSIONS: Since interlaboratory variability never reached 0.5 log10 copies/mL and each of the laboratories was able to detect four-fold differences in plasma HIV-1 RNA levels, the Amplicor assay can be used in multicenter studies without a centralized analysis of samples. Furthermore, this well-characterized proficiency panel of spiked plasma samples could be used as a standard in the study of interassay comparisons.

Belgium↗

Cardiovascular fitness in premenarcheal girls and young women.

Maximal oxygen uptake (VO2max) in females, expressed as ml x kg(-1) x min(-1), declines steadily during the first three decades of life. The contribution of diminished cardiovascular function to this apparent fall in aerobic fitness is unknown. Cardiac responses to maximal cycle exercise were compared in 24 premenarcheal females (mean age 11.7 years) and 17 young adult women (mean age 27.4 years) using Doppler echocardiography. Mean VO2max was 40 ml x kg(-1) x min(-1) and 34.7 ml x kg(-1) x min(-1) in the girls and women, respectively (p < 0.05). When VO2max was expressed relative to allometrically-derived mass(0.52), however, no significant difference was observed in aerobic fitness between the two groups. Similar allometric analyses revealed no significant differences in average maximal cardiac output (10.50 vs 10.07 L x min(-1) BSA(-1.11) for girls and women, respectively) nor maximal stroke volume (53 vs 56 ml BSA(-1.13) respectively). These findings suggest that 1) allometric scaling is important in eliminating the effects of body size on VO2max, 2) body dimension differences can account for variations in VO2 in young females, and 3) cardiac functional reserve is similar in premenarcheal girls and young adult women.

Adolescent↗

Evaluation of urinary bladder cancer antigen as a marker for diagnosis of transitional cell carcinoma of the urinary bladder.

The purpose of the present study was to assess a new quantitative urinary tumor marker for transitional cell carcinoma of the urinary bladder (TCC), measuring fragments of cytokeratin 8 and 18 in the urine (UBC). Urine samples of 355 individuals (77 healthy volunteers, 111 patients with benign urologic disorders, 167 patients with histologically proven bladder cancer) were examined for the presence of UBC antigen. Samples of all patients were obtained prior to therapy. Compared to healthy volunteers or patients with benign urologic disease, patients with TCC had significantly higher median urinary levels of UBC antigen (0 vs. 4.18 vs. 7.46 microg/g creatinine; p<0.001, and p<0.01, respectively). UBC antigen levels were positively correlated with tumor grade and stage. Patients with invasive TCC had significantly higher levels of UBC antigen than patients with superficial TCC (p<0.001). Elevated levels of UBC antigen were also found in patients with benign urologic disorders (median: 4.18 microg/g creatinine vs. 7.46 microg/g creatinine in cancer patients). Using a cutoff of 14.06 microg/g creatinine (corresponding to 95% specificity in the group of healthy individuals), sensitivity of UBC antigen ranged between 21.6% (pTa) and 75% (pT4). Overall specificity was 76.6%. Based on our data we conclude that the UBC antigen test in its current format is not clinically useful for detection of bladder cancer.

Antigens, Neoplasm↗

Routine hospital alcohol detoxification practice compared to symptom triggered management with an Objective Withdrawal Scale (CIWA-Ar).

Charts of patients hospitalized for uncomplicated alcohol withdrawal were examined and detoxification practices compared. Patients detoxified using a Clinical Institute Withdrawal Assessment for Alcohol-revised (CIWA-Ar) based PRN protocol on the addiction unit received significantly fewer chlordiazepoxide milligram equivalents over shorter duration than patients managed by other detoxification methods on other hospital units. Significantly fewer patients received benzodiazepines in the CIWA-Ar protocol managed group, but inter-group differences (p < 0.01) remained when only medicated patients were compared. Differences between the protocol and non-protocol groups did not reach statistical significance when PRN only strategies were examined, suggesting that the use of a symptom-triggered strategy may account for the noted effects.

Adult↗

Immunological properties of mononuclear cells from blood stem cell harvests following mobilization with erythropoietin + G-CSF in cancer patients.

BACKGROUND: Although the recombinant granulocyte colony-stimulating factor (G-CSF) is a good CD34 cell mobilizer, the effects of G-CSF mobilization on the immune effector function of the individual is not always optimal. We studied the functional and phenotypic properties of peripheral blood stem cells (PBSC) collected from 15 cancer patients mobilized with G-CSF plus recombinant erythropoietin (EPO). METHODS: The patients received EPO (300 U/kg) and (G-CSF 1 microg/kg) per day as mobilizing cytokines and an autologous graft product was collected with at least daily apheresis procedures until a target number of CD34 cells and mononuclear cells were obtained. Mononuclear cells from the first four PBSC collections were tested for their natural killer (NK), activated NK and lymphokine activated killer (LAK) cytotoxicity in vitro against K562 and Raji tumor target cells. RESULTS: There was a significant increase in NK, activated NK and LAK cytotoxicity in EPO + G-CSF mobilized cells when compared to mononuclear cells from premobilization blood baseline values. Although there was no increase in CD3+ T cells, there was a significant increase in myeloid cells (CD14+), B-cells (CD20+) and NK cells (CD56+) following mobilization. There was no difference in T cell response to the mitogens PHA and Con-A, but there was an increase in B-cell response to PWM following mobilization. Thus, the combination of EPO + G-CSF not only mobilized hematopoietic precursor cells but also increased the number of immune effector cells in the PBSC collections.

Adult↗

Profiling the trauma related symptoms of Bosnian refugees who have not sought mental health services.

The objective of this study was to profile trauma related psychiatric symptoms in a group of refugees not seeking mental health services and to consider the services implications. The study involved research assessments of two groups of Bosnian refugees: those who have not presented for mental health services and those who have. A total of 28 of 41 nonpresenters (70%) met symptom criteria for posttraumatic stress disorder (PTSD) diagnosis. All service presenters (N = 29) met symptom criteria for PTSD diagnosis. The group that did not present for services reported substantial but lower trauma exposure, PTSD symptom severity, and depression symptom severity. They had significant differences on all subscales of the MOS SF-36, indicating better health status. We concluded that those who do not seek services have substantial symptom levels, but their self-concept appears to be less oriented toward illness and help seeking. Innovative access, engagement, and preventive interventions are needed to address those who have symptoms but do not readily seek help for trauma mental health services.

Adult↗

Cardiac responses to exercise in competitive child cyclists.

PURPOSE: Cardiovascular responses to exercise in highly trained child endurance athletes have not been well-defined. This study compared hemodynamic responses with progressive cycle exercise in seven competitive child cyclists (mean age 11.9 yr) compared with 39 age-matched untrained boys. METHODS: Doppler echocardiography and gas exchange variables were utilized to assess cardiovascular changes during submaximal and maximal exercise. RESULTS: Mean VO2max was 60.0 (+/-6.0) and 47.0 (+/-5.8) mL x kg(-1) x min(-1) in the cyclists and nonathletes, respectively. At rest and maximal exercise, the cyclists demonstrated greater stroke index than the untrained subjects (resting mean 59 (+/-6) vs 44 (+/-9) mL x m(-2); maximal mean 76 (+/-6) vs 60 (+/-11) mL x m(-2)), but the ratio of maximal:rest stroke index was similar in both groups (1.31 for cyclists, 1.41 for nonathletes). Both groups showed a plateau in stroke volume beyond low-intensity work levels. No significant difference was observed in maximal arteriovenous oxygen difference. CONCLUSIONS: These findings indicate that 1) maximal stroke volume is the critical determinant of the high VO2max in child cyclists and 2) factors that influence resting stroke volume are important in defining VO2max differences between child endurance athletes and untrained boys.

Bicycling↗

Validity of accelerometry for the assessment of moderate intensity physical activity in the field.

PURPOSE: This study was undertaken to examine the validity of accelerometry in assessing moderate intensity physical activity in the field and to evaluate the metabolic cost of various recreational and household activities. METHODS: Twenty-five subjects completed four bouts of overground walking at a range of self-selected speeds, played two holes of golf, and performed indoor (window washing, dusting, vacuuming) and outdoor (lawn mowing, planting shrubs) household tasks. Energy expenditure was measured using a portable metabolic system, and motion was recorded using a Yamax Digiwalker pedometer (walking only), a Computer Science and Application, Inc. (CSA) accelerometer, and a Tritrac accelerometer. Correlations between accelerometer counts and energy cost were examined. In addition, individual equations to predict METs from counts were developed from the walking data and applied to the other activities to compare the relationships between counts and energy cost. RESULTS: Observed MET levels differed from values reported in the Compendium of Physical Activities, although all activities fell in the moderate intensity range. Relationships between counts and METs were stronger for walking (CSA, r = 0.77; Tritrac, r = 0.89) than for all activities combined (CSA, r = 0.59; Tritrac, r = 0.62). Metabolic costs of golf and the household activities were underestimated by 30-60% based on the equations derived from level walking. CONCLUSION: The count versus METs relationship for accelerometry was found to be dependent on the type of activity performed, which may be due to the inability of accelerometers to detect increased energy cost from upper body movement, load carriage, or changes in surface or terrain. This may introduce error in attempts to use accelerometry to assess point estimates of physical activity energy expenditure in free-living situations.

Activities of Daily Living↗

Out-of-hospital intravenous cannulation: the perspective of patients treated by London Ambulance Service paramedics.

OBJECTIVES: Previous research has highlighted concern about infection rates in field-placed intravenous (IV) cannulae. In a study of IV placement by London Ambulance Service (LAS) paramedics, 17% of placements were judged to be inappropriate. Large variations in rates of IV placement between LAS paramedics were found. The authors' hypothesis was that placement of an IV carries disadvantages-pain, discomfort, distress, and infection-which may be unacceptable to patients. METHODS: This was a survey of all patients having an IV placed by LAS paramedics and transported to one of three London emergency departments (EDs) over a three-week period in December 1996. Patients were excluded if they had a self-inflicted injury/illness, were less than 14 years old, had no known address, or were visitors to the UK, or if their family doctor suggested it was not appropriate to contact the patient. Pain, discomfort, and distress; infection; satisfaction; understanding of the reason for cannulation; and out-of-hospital cannula use were all ascertained and analyzed with chi-square analysis. RESULTS: Thirty-nine percent of the respondents experienced some discomfort, 39% some pain, and 17% some distress. No patient reported an infection. Distress was more likely to be reported if there was no understanding of why the IV cannula was placed (chi2 [1] 6.1; p < 0.05). Further unstructured information revealed satisfaction with the IV cannulation and with general care. CONCLUSIONS: Despite the disadvantages of IV placement being reported by some respondents, overall levels of satisfaction were high, suggesting that these disadvantages were not unacceptable to patients. However, in the context of the 24,000 patients cannulated each year by LAS paramedics, "costs" to the patient are considerable.

Adolescent↗

Immunohistochemical detection of steroid receptors in breast cancer: a working protocol. UK Receptor Group, UK NEQAS, The Scottish Breast Cancer Pathology Group, and The Receptor and Biomarker Study Group of the EORTC.

The biochemical assay for the oestrogen receptor has shown the clinical value of knowing the concentration of the receptor within tissue. The immunohistochemical assay is rapidly taking over from the biochemical assay. Therefore, it is vital to have an equivalent scoring system that will have the same predictive value. This paper reports both a practical protocol and a scoring system that should achieve this aim. This approach should be applicable to many more biomarkers detected by immunohistochemistry.

Biomarkers, Tumor↗

Qualitative determination of urinary human complement factor H-related protein (hcfHrp) in patients with bladder cancer, healthy controls, and patients with benign urologic disease.

OBJECTIVES: To assess the diagnostic quality of human complement factor H-related protein (hcfHrp, BTA STAT(TM)) as a qualitative urinary marker for bladder cancer. METHODS: Urine samples of 354 individuals (76 healthy volunteers, 111 patients with benign urologic disorders, 167 patients with histologically proven bladder cancer) were examined prior to therapy for the presence of hcfHrp. RESULTS: Overall test sensitivity was 62.9%. Sensitivity of low-grade/low-stage tumors was <50% and was thus comparable to published sensitivities of urinary cytology. In high-stage, high-grade tumors sensitivity was 100 and 77.3%, respectively. Superficial tumors with high risk of progression (pT1G3) were detected significantly better (88.9% sensitivity) than low-risk superficial tumors (pTa G1-3/pT1G1-2; 48.2%; p < 0.001). The overall specificity (healthy individuals and patients with benign urologic disease) was 93.0%. CONCLUSION: Since test sensitivity is comparable to urinary cytology and specificity is excellent, hcfHrp should be further evaluated in prospective studies focussing on the follow-up of patients with bladder cancer.

Adolescent↗

Flow cytometric immunophenotypic characterization of pediatric and adult minimally differentiated acute myeloid leukemia (AML-M0).

We reviewed the clinicopathologic and immunophenotypic profiles of 7 pediatric and 11 adult minimally differentiated acute myelogenous leukemias (AML-M0). We also compared and evaluated myeloperoxidase in leukemic blasts using standard cytochemical and polyclonal antibody immunohistochemical stains. No distinctive clinical findings were noted in either patient group; however, thrombocytopenia typically was more prominent in adults. Adult AML-M0 also was associated with an immature myeloid profile (CD34+, terminal deoxynucleotidyl transferase positive, CD13+, and CD33+), in contrast with pediatric AML-M0, which usually lacked terminal deoxynucleotidyl transferase or CD34 but expressed bright CD33 with weak or negative CD13. Coexpression of the T-cell-associated antigen CD7 was observed in both groups. Antibody immunohistochemical stains were more sensitive than cytochemical stains for detection of myeloperoxidase activity and a useful adjunct for establishing a diagnosis of myeloid leukemia in paraffin-embedded marrow tissues.

Adolescent↗

[Revascularization of the corpora cavernosa in ischemia-induced erectile dysfunction].

Revascularization of the cavernous bodies (CB) has its place in a highly selected patient population as the only causal therapy for erectile dysfunction (ED) and provides an alternative to the implantation of alloplastic erectile aids. The indication for arterialization of the CB is currently only established when conservative treatment has failed. The most important criteria for the intervention are controversial: an age of under 50, an incidence of not more than two classical risk factors for impotence and the exclusion of diabetes mellitus. The leading revascularization procedure in German-speaking countries comprises arteriovenous shunting of the inferior epigastric artery with the dorsal vein and artery of the penis. A retrospective analysis of results is problematic due to the nonuniform indicational criteria, the multiplicity of applied revascularization procedures and a nonstandardized follow-up. Subjective assessment of improved erectility is the sole target criterion in the majority of studies. Therapeutic results range from 33 to 87% with regard to subjective success rates. Attempts to objectify the treatment results were made in only few of the studies and disclosed bypass patency in 44 to 92% one year after the intervention. The conclusions drawn at the last "Consensus Development Conference on Impotence" (CDCI) of the National Institutes of Health (NIH) in Washington have not lost their topicality in view of the great number of still unanswered questions. There the recommendation was made in 1992 to perform penile arterialization only in controlled prospective clinical trials. The European Urological Association (EUA) is currently organizing a Consensus Conference that will provide the framework for prospective studies that can serve as a basis for clarifying the open questions.

Aged↗

New UWA robot--possible application to robotic surgery.

This research is motivated by the need to design a Nuclear Magnetic Resonance Image guided surgical robot. The achievement of this objective requires the solution of two problems: design and construction of a magnetic resonance compatible mechanical manipulator and development of the appropriate robot control system. It is beneficial to keep robot actuators outside the magnet. Therefore, the parallel architecture should be used for the mechanical manipulator. Newly developed University of Western Australia Robot satisfies this requirement. Moreover, it has substantially larger workspace and torsional stiffness when compared to existing parallel configurations such as the Delta. The plausible method of dealing with the delays in the robot control system caused by the image analysis is the prediction of the deformation based on the mathematical model of the organ mechanical and geometric properties. The hyper-viscoelastic constitutive models offer a good way of representing non-linear stress-strain and stress-strain rate relations of soft tissues such as the brain. The numerical values for material constants for brain tissue are given. Additional advantage of the proposed model is that it can be easily implemented in commercially available finite element codes and immediately applied to large-scale computer simulations.

Animals↗

Objective monitoring of physical activity using motion sensors and heart rate.

Although neither motion sensors nor heart rate are perfect markers of physical activity, they certainly eliminate subjectivity of obtaining physical activity information. The objective method of choice depends on how the measurement will be used. For example, if walking behavior is the desired outcome, then a pedometer may be sufficient. If patterns and intensity of activity over longer periods of times such as a week or longer are needed, then an accelerometer with large memory capacity should be selected. In the future, efforts should be directed towards developing an objective motion sensor as inexpensive as a pedometer but with the data acquisition capabilities of the CSA or Tritrac accelerometer. Providing simultaneous heart rate with motion is also recommended to further verify that elevated heart rate does in fact represent a physical activity response. As the cost of the electronic components continues to decrease, these activity monitor configurations may become possible.

Heart Rate↗