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Biomedical subjects

J Miller

Publications and source records attributed to J Miller.

At least 55 records · Page 3Linked to original sources

Comparison of linear alkylbenzene sulfonates removal in conventional activated sludge systems and membrane bioreactors.

The potential of a membrane bioreactor (MBR) and a conventional activated sludge (CAS) system to remove polar micropollutants was evaluated using linear alkylbenzene sulfonates (LAS) as model components. Removal efficiencies over 97% were achieved in both reactor systems. The appearance of biological breakdown metabolites and the respirometric response of the sludges to LAS addition indicated that LAS removal was due to biodegradation, rather than sorption phenomena. The effect of operational variables, such as hydraulic retention time, LAS composition and hydrophobicity of the membrane used in the MBR, was negligible in the range tested. A stepwise increase in LAS influent concentration resulted in higher residual effluent concentrations but did not change the procentual removal efficiency. Because an increase in LAS and SPC effluent concentration occurred to a larger extent in the CAS than in the MBR under similar operating conditions, MBRs may turn out to be be more robust with respect to biological degradation of micropollutants than CAS.

Alkanesulfonic Acids↗

The effects of age, death period and birth cohort on asthma mortality rates in Australia.

SETTING AND OBJECTIVE: We assessed the relative effects of age, gender, period of death and birth cohort on asthma mortality rates in Australia from 1907 to 2000. DESIGN: Asthma mortality data obtained from the Australian Institute of Health and Welfare were adjusted for changes to the International Classification of Diseases and examined for changes over time and age, period and cohort effects. RESULTS: Age-adjusted period asthma mortality rates indicated epidemics during the mid 1960s and 1980s, predominantly affecting those aged 5-34 years. The main 1960s epidemic coincided with the introduction of high-dose, non-selective beta-sympathomimetic amines. There was a gradual rise in mortality rates in younger age groups, with rates rising from 0.5/100 000 males and 0.9/100 000 females in the 1940s to a peak of 3/100 000 for both sexes in 1966. Fluctuations in mortality rates were influenced by period of death and birth cohort. There was an increased risk of death from asthma with increasing age. CONCLUSION: There was no overall trend in asthma mortality rates in any age group. The 1960s epidemic was probably treatment related. Other increases in mortality occurring despite therapeutic advances may reflect increasing prevalence and highlight the need for ongoing surveillance.

Adolescent↗

Laparoscopic vs open resection for the treatment of diverticular disease.

INTRODUCTION: The aim of this study was to evaluate whether laparoscopic colon resection (LCR) offers any advantages over open colon resection (OCR) in the treatment of diverticular disease. METHODS: Between 1992 and 2002, 95 patients underwent LCR and 80 patients underwent OCR for the treatment of diverticular disease. Demographics, details of operative procedure, outcome, and pathology were compared. RESULTS: Patients in both groups were matched for age, sex, body mass index, history of previous abdominal operations, comorbidities, location of the disease, and presence of complications. LCR resulted in significantly less estimated blood loss and postoperative complications, shorter time to first bowel movement, and shorter length of stay than the OCR. There was no difference in operative time, intraoperative complications, mortality rates between groups. CONCLUSIONS: LCR is a safe and effective approach for the treatment of patients with diverticular disease. It results in less estimated blood loss, shorter time to first bowel movement, less postoperative complications, and shorter length of hospital stay.

Aged↗

The effect of material characteristics of shoe soles on muscle activation and energy aspects during running.

The purposes of this study were (a) to determine group and individual differences in oxygen consumption during heel-toe running and (b) to quantify the differences in EMG activity for selected muscle groups of the lower extremities when running in shoes with different mechanical heel characteristics. Twenty male runners performed heel-toe running using two shoe conditions, one with a mainly elastic and a visco-elastic heel. Oxygen consumption was quantified during steady state runs of 6 min duration, running slightly above the aerobic threshold providing four pairs of oxygen consumption results for comparison. Muscle activity was quantified using bipolar surface EMG measurements from the tibialis anterior, medial gastrocnemius, vastus medialis and the hamstrings muscle groups. EMG data were sampled for 5 s every minute for the 6 min providing 30 trials. EMG data were compared for the different conditions using an ANOVA (alpha=0.05). The findings of this study showed that changes in the heel material characteristics of running shoes were associated with (a) subject specific changes in oxygen consumption and (b) subject and muscle specific changes in the intensities of muscle activation before heel strike in the lower extremities. It is suggested that further study of these phenomena will help understand many aspects of human locomotion, including work, performance, fatigue and possible injuries.

Elasticity↗

Molecular analysis of the cucumber leaf spot virus genome.

Full-length clones of the genome of the Aureusvirus, Cucumber leaf spot virus (CLSV), have been constructed and infectious T7 polymerase derived synthetic transcripts have been produced. Mutational analysis of the genome indicates a role for p84 in viral RNA replication, the CP in systemic movement, p27 in viral cell-to-cell movement and p17 in symptom induction. A CLSV mutant lacking ORFs for the CP, p27 and p17 (CLSV YX) was capable of replication and systemic movement in transgenic Nicotiana benthamiana plants expressing the Red clover necrotic mosaic virus (RCNMV) movement protein (MP) suggesting that p25 and p84 are sufficient for viral RNA replication and that the RCNMV MP can permit CLSV cell-to-cell as well as systemic movement. Moreover, CLSV YX induced severe necrosis in both inoculated and uninoculated leaves of transgenic plants suggesting that CLSV p25 and/or p84 are important determinants of the necrotic phenotype. Another mutant similar to CLSV YX but expressing only limited amino-terminal portions of CP, p27 and p17 failed to produce necrosis or to move systemically in RCNMV MP transgenic N. benthamiana plants. These results suggest that these short translated regions or cis-acting sequences present in the CLSV CP, p27 and/or p17 ORFs suppress the necrosis induced by p25/p84 and also suppress systemic movement mediated by the RCNMV MP.

Amino Acid Sequence↗

Intracochlear administration of thiourea protects against cisplatin-induced outer hair cell loss in the guinea pig.

Amelioration of cisplatin-induced side-effects is of great clinical importance. Local administration of a cytoprotective agent to the inner ear offers a possibility to prevent cisplatin-induced ototoxicity without risk of interference with the antitumour effect. The ideal substance for local administration has yet to be identified. Thiourea (TU) has unique properties that make it an interesting candidate. This study was initiated to test the hypothesis that TU given by local administration protects against cisplatin ototoxicity in the guinea pig. After baseline auditory brainstem response (ABR) assessment, the left cochlea was implanted with a microtip catheter connected to an osmotic pump filled with either 27 mg/ml TU in artificial perilymph (AP), or AP administered for the full duration of the study. Three days post-implant, animals with normal ABRs received an intravenous injection of 8 mg/kg body-weight cisplatin. Five days after the cisplatin treatment ABRs were reassessed, animals decapitated and bilateral cytocochleograms prepared. TU-treated ears demonstrated significantly lower outer hair cell (OHC) loss as compared to contralateral untreated ears, and significantly lower OHC loss compared to AP-treated ears. ABR threshold shift did not differ significantly between the two groups. It can be postulated that TU demonstrates partial protection against cisplatin-induced ototoxicity.

Animals↗

Total parenteral nutrition vs oral diet in autologous hematopoietic cell transplant recipients.

Autologous HCT patients often have poor oral intake for 2-4 weeks post transplant. To compare outcomes between patients provided prophylactic total parenteral nutrition (TPN) or an oral diet (OD), 55 well nourished breast cancer/ hematopoietic cell transplantation (HCT) patients were randomized to TPN (n=27), beginning day -1, or OD (n=28). Parameters studied include length of stay (LOS), engraftment, infections, survival, weight, anthropometrics, handgrip strength, and quality of life (QOL) In all, 50% of OD patients were given TPN due to poor oral intake for 10 consecutive days. No significant differences were found between the groups for any of the above parameters except weight and anthropometrics, which were better maintained in the TPN group than the OD group. Trends were seen for increased infections, more stable handgrip strength, and improved QOL in the TPN group vs the OD group. Prophylactic TPN did result in a more intact nutritional status and preservation of lean body mass post transplant but did not impact LOS or survival when compared to OD. For this reason, TPN should be reserved for autologous HCT patients with pretransplant nutritional depletion, complications post transplant, or prolonged poor oral intake. These results should not be extrapolated to allogeneic HCT patients but are likely applicable to other well nourished autologous HCT patients.

Adult↗

A qualitative study, using focused interviews, of the information needs of families whose children's names are on a cerebral palsy register.

BACKGROUND: We were concerned that information held on a register of children with cerebral palsy was not being made available to contributing families, and that the existence and purpose of the register was not sufficiently understood. METHODS: Focused interviews with 13 families selected by purposive sampling. RESULTS: Many parents would like more information about the data on registers which include their child. They would also like to be more involved in the design of the register and its reports, but there are practical difficulties in making time available for such activity. Although parents were surprised that they had not already been given more information about the existence and purpose of the register, none were resentful that their child's name was on the register once they were reassured about confidentiality and database security. Parents also had general concerns unrelated to the register which were about their need to be treated as equals by professionals, to have more information about equipment and to have earlier and clearer diagnoses. CONCLUSIONS: Registers of children with uncommon conditions have well-established roles in epidemiology, planning and research. By fully involving parents in ways suggested by this study, registers can also empower parents. The study should also provide reassurance to those who hold such registers without explicit consent that the requirement to now obtain consent should not create resentment or jeopardize completeness.

Attitude to Health↗

A preliminary comparison of flow cytometry and tube agglutination assays in detecting red blood cell-associated C3d.

This study compared flow cytometric analysis with tube agglutination assays for the detection of red blood cell (RBC)-associated complement and immunoglobulins (Igs). RBCs from 20 patients with reactive tube direct antiglobulin tests (DATs) were evaluated by flow cytometry with anti-C3d, anti-IgG, anti-IgM and anti-IgA. Serial samples were also tested from a patient at risk of passenger lymphocyte haemolysis. Results of flow cytometry and tube assays for anti-IgG were as follows: 12 of 20 samples reactive in both; six of 20 nonreactive in both; two of 20 discordant with a reactive tube and a nonreactive flow cytometry assay. Anti-C3d results showed nine of 20 reactive in both and 11 of 20 discordant with a nonreactive tube and a reactive flow cytometry assay. In the IgM flow cytometry assay, three samples were reactive with anti-IgM. Samples from a group A woman who was transplanted with stem cells from a group B donor showed that on days 3 through 6 post-transplant, the flow cytometry assays for anti-IgG and/or anti-C3d were reactive, whilst the tube assays were nonreactive. In conclusion, flow cytometric analysis is more sensitive than the tube assay for the detection of RBC-associated C3d. Further studies are needed to determine the correlation of C3d levels with clinical sequelae.

Adult↗

HIV lipodystrophy: prevalence, severity and correlates of risk in Australia.

OBJECTIVE: To establish the prevalence, severity and factors associated with the HIV lipodystrophy syndrome. METHODS: Cross-sectional study of lipodystrophy conducted in high HIV caseload primary care sites and HIV outpatient clinics. A subset of patients was examined using dual energy X-ray absorptiometry (DEXA) and single cut abdominal computerized tomography (CT) at the L4 vertebral level to quantify regional and total body fat. Factors associated with lipodystrophy, lipoatrophy and lipohypertrophy were assessed using multiple logistic regression based on assignment of cases and non-cases. RESULTS: One thousand, three hundred and forty-eight patients (95% male) were surveyed, 20% had AIDS, the mean CD4 lymphocyte count was 486 cells/microL, and 55% had <500 HIV-1 RNA copies/mL. Most participants (87%) had previously received or were currently receiving combination antiretroviral therapy, 73% with at least one protease inhibitor (PI) and 14% a non-PI-containing regimen. Lipodystrophy prevalence was 53% and of these, 55% reported both peripheral lipoatrophy and central lipohypertrophy, 31% experienced peripheral lipoatrophy only and 14% had central lipohypertrophy only. The prevalence of any body habitus change was 62% in PI-experienced patients, 33% in PI-naive patients and 21% in antiretroviral-naive patients. Lipodystrophy severity was less in antiretroviral-naive patients and most severe in PI-experienced patients. Increasing severity of lipodystrophy was both positively and significantly correlated with elevated liver enzymes, decreased testosterone levels, decreased skin-fold thickness, lower levels of total and peripheral fat (DEXA) and higher levels of visceral fat (CT). Lipodystrophy was also significantly associated with increasing age, symptomatic HIV disease, effective viral suppression, and increasing duration of therapy with both nucleoside reverse transcriptase inhibitors and PIs. CONCLUSIONS: The prevalence and severity of lipodystrophy reflects both length and type of treatment with antiretroviral therapy and is associated with decreased testosterone, increases in liver enzymes and greater suppression of HIV RNA. The reports of lipodystrophy in a small percentage of antiretroviral-naive patients suggests that factors other than antiretroviral therapy may be involved in the aetiology of this syndrome or that some conditions, such as wasting or age-associated obesity, may mimic lipoatrophy and lipohypertrophy, respectively.

Absorptiometry, Photon↗

The functional and psychosocial impact of fecal incontinence on women with urinary incontinence.

OBJECTIVES: The study was undertaken to determine the impact of fecal incontinence (FI) on functional status and quality of life in women with urinary incontinence (UI). STUDY DESIGN: In 24 months 732 women completed a standardized assessment and questionnaire, including the Short Form (SF)-12 and Incontinence Quality of Life (I-QOL) scores. Analysis of variance was used to compare SF-12 scores between groups defined as having UI, FI, or both UI and FI. I-QOL scores in patients with UI or UI and FI were compared by using the Student t test. RESULTS: Of the 732 patients enrolled, 425 patients had either UI (n = 342, 80%), FI (n = 18, 4%), or both (n = 65, 15%). Greater impairment in physical functioning was seen in the group with UI and FI (38.6; P =.027) compared with the group with UI (42.4). Significant decreases in I-QOL scores were seen for the group with UI and FI compared with those with UI (P <.005). CONCLUSION: Fecal incontinence further reduces the functional status and quality of life of women with urinary incontinence.

Adult↗

Characterization of secreted and intracellular forms of a truncated hepatitis C virus E2 protein expressed by a recombinant herpes simplex virus.

A replication-defective herpes simplex virus type 1 (HSV-1) recombinant lacking the glycoprotein H (gH)-encoding gene and expressing a truncated form of the hepatitis C (HCV) E2 glycoprotein (E2-661) was constructed and characterized. We show here that cells infected with the HSV/HCV recombinant virus efficiently express the HCV E2-661 protein. Most importantly, cellular and secreted E2-661 protein were both readily detected by the E2-conformational mAb H53 and despite the high expression levels, only limited amounts of misfolded aggregates were detected in either the cellular or secreted fractions. Furthermore, cell-associated and secreted E2-661 protein bound to the major extracellular loop (MEL) of CD81 in a concentration-dependent manner and both were highly reactive with sera from HCV-infected patients. Finally, BALB/c mice immunized intraperitoneally with the recombinant HSV/HCV virus induced high levels of anti-E2 antibodies. Analysis of the induced immunoglobulin G (IgG) isotypes showed high levels of IgG2a while the levels of the IgG1 isotype were significantly lower, suggesting a Th1-type of response. We conclude that the HSV-1 recombinant virus represents a promising tool for production of non-aggregated, immunologically active forms of the E2-661 protein and might have potential applications in vaccine development.

Adolescent↗

Benchmark studies of the effectiveness of structural and internal materials as radiation shielding for the international space station.

Accelerator-based measurements and model calculations have been used to study the heavy-ion radiation transport properties of materials in use on the International Space Station (ISS). Samples of the ISS aluminum outer hull were augmented with various configurations of internal wall material and polyethylene. The materials were bombarded with high-energy iron ions characteristic of a significant part of the galactic cosmic-ray (GCR) heavy-ion spectrum. Transmitted primary ions and charged fragments produced in nuclear collisions in the materials were measured near the beam axis, and a model was used to extrapolate from the data to lower beam energies and to a lighter ion. For the materials and ions studied, at incident particle energies from 1037 MeV/nucleon down to at least 600 MeV/nucleon, nuclear fragmentation reduces the average dose and dose equivalent per incident ion. At energies below 400 MeV/nucleon, the calculation predicts that as material is added, increased ionization energy loss produces increases in some dosimetric quantities. These limited results suggest that the addition of modest amounts of polyethylene or similar material to the interior of the ISS will reduce the dose to ISS crews from space radiation; however, the radiation transport properties of ISS materials should be evaluated with a realistic space radiation field.

Aluminum↗

Mechanical and electrophysiological effects of isoprostanes on bronchial arterial smooth muscle.

We investigated the mechanical and electrophysiological responses of human and porcine bronchial arterial smooth muscle to isoprostanes (metabolites of membrane lipid peroxidation). These evoked a constrictor response which was sensitive to blockade of thromboxane receptors, as well as to a non-specific tyrosine kinase inhibitor and an inhibitor of Rho-kinase. The patch clamp technique was used to characterize the K+ and Ca2+ currents in these tissues, and to show that isoprostanes caused a brief enhancement of K+ currents followed by prolonged and marked suppression of the same.

Animals↗

Importance of PCR in the diagnosis and understanding of rotavirus illness in the community.

Rotavirus infections pose a significant economic burden due to hospitalisation and missed workdays. Recent studies have shown that RT-PCR may detect more symptomatic cases of rotavirus infection than antigen detection methods. We compared RT-PCR, enzyme immunoassay (EIA) and an immunochromatography method (ICG) applied to 107 stool samples. The RT-PCR detected 58 positive samples whereas the EIA and ICG detected 28 and 29 positive samples respectively. The RT-PCR assay detected all 17 samples found positive by both the EIA and ICG. Without sensitive diagnosis, infection control policies will be disadvantaged and the true economic burden of rotavirus underestimated.

Communicable Disease Control↗

Daclizumab as induction therapy in kidney and simultaneous pancreas-kidney transplantation.

Acute rejection still remains a major problem in organ transplantation and is a significant risk factor for chronic rejection, and chronic rejection is one of the most important causes of late graft loss. Current new immunosuppressive drugs such as tacrolimus, rapamycin and mycophenolate mofetil have been developed to reduce acute rejection and to improve renal allograft survival. More recently, antihuman antibodies, either monoclonal or polyclonal, have been developed to use for induction therapy at the time of transplantation or to treat rejection. Daclizumab, a new engineered human immunoglobulin monoclonal antibody to the interleukin-2 receptor a-subunit was approved to prevent acute rejection after solid organ transplantation. Data from clinical trials show daclizumab to be well tolerated in solid organ transplantation. It does not increase the incidence of infection, including cytomegalovirus infection.

Adrenal Cortex Hormones↗