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Biomedical subjects

K Power

Publications and source records attributed to K Power.

16 recordsLinked to original sources

Myeloma responses and tolerance following combined kidney and nonmyeloablative marrow transplantation: in vivo and in vitro analyses.

Six patients with renal failure due to multiple myeloma (MM) received simultaneous kidney and bone marrow transplantation (BMT) from HLA-identical sibling donors following nonmyeloablative conditioning, including cyclophosphamide (CP), peritransplant antithymocyte globulin and thymic irradiation. Cyclosporine (CyA) was given for approximately 2 months posttransplant, followed by donor leukocyte infusions. All six patients accepted their kidney grafts long-term. Three patients lost detectable chimerism but accepted their kidney grafts off immunosuppression for 1.3 to >7 years. One such patient had strong antidonor cytotoxic T lymphocyte (CTL) responses in association with marrow rejection. Two patients achieved full donor chimerism, but resumed immunosuppression to treat graft-versus-host disease. Only one patient experienced rejection following CyA withdrawal. He responded to immunosuppression, which was later successfully withdrawn. The rejection episode was associated with antidonor Th reactivity. Patients showed CTL unresponsiveness to cultured donor renal tubular epithelial cells. Initially recovering T cells were memory cells and were enriched for CD4+CD25+ cells. Three patients are in sustained complete remissions of MM, despite loss of chimerism in two. Combined kidney/BMT with nonmyeloablative conditioning can achieve renal allograft tolerance and excellent myeloma responses, even in the presence of donor marrow rejection and antidonor alloresponses in vitro.

Adult↗

Early intervention for relapse in schizophrenia: results of a 12-month randomized controlled trial of cognitive behavioural therapy.

BACKGROUND: The paper describes a randomized controlled trial of targeting cognitive behavioural therapy (CBT) during prodromal or early signs of relapse in schizophrenia. We hypothesized that CBT would result in reduced admission and relapse, reduced positive and negative symptoms, and improved social functioning. METHOD: A total of 144 participants with schizophrenia or a related disorder were randomized to receive either treatment as usual (TAU) (N = 72) or CBT+TAU (N = 72). Participants were prospectively followed up between entry and 12 months. RESULTS: At 12 months, 11 (15.3%) participants in the CBT group were admitted to hospital compared to 19 (26.4%) of the TAU group (hazard ratio = 0.53, P = 0.10, 95% CI 0.25, 1.10). A total of 13 (18.1%) participants in CBT relapsed compared to 25 (34.7%) in TAU (hazard ratio = 0.47, P < 0O05, 95% CI 0.24, 0.92). In addition, the CBT group showed significantly greater improvement in positive symptoms, negative symptoms, global psychopathology, performance of independent functions and prosocial activities. CONCLUSIONS: The study provides evidence for the feasibility and effectiveness for targeting CBT on the appearance of early signs of relapse in schizophrenia. The results are discussed in context of the study's methodological limitations.

Cognitive Behavioral Therapy↗

Challenges, benefits and pitfalls of the independent laboratory process.

During 1998 Sydney's drinking water supply system experienced three contamination events in quick succession. These events were revealed by routine monitoring, which indicated the presence of large numbers of Cryptosporidium and Giardia in raw and treated water. Questions were raised regarding the validity of the results produced by Sydney Water's laboratory, Australian Water Technology. In response to the incident a NSW Government Inquiry was carried out which made a range of recommendations, one of which was that "A suitably qualified independent laboratory should be established to provide accurate data for regulatory authorities." The NSW Department of Health (DOH) was given the responsibilty for interpretation and implementation of this recommendation. The role of Independent Laboratory was awarded to the Australian Water Quality Centre (AWQC) and monthly program of duplicate sample analysis was established. The implementation of the program and interpretation of the results have provided a challenge for all parties involved. A protocol was developed which defined conditions under which differences in results from the two laboratories were to be investigated. Over the time period of the Independent Laboratory process there has been only one occasion where a difference between results, as defined by the protocol, has been seen. The process has provided additional assurance of quality control procedures for the laboratories. The future role of the process will need to be readdressed in light of the results of the previous 18 months and as changes in the area of testing methodologies occur.

Animals↗

Effects of hyperbaric (6 ATA) pressure on voluntary and evoked skeletal muscle contractile properties.

The objective of this study was to investigate the effect of 6 atmospheres of pressure (ATA) on plantar flexors' (PF) voluntary force and activation, force-frequency characteristics, and rate of torque development (RTD). Eight subjects performed PF isometric contractions. Muscle activation was monitored by electromyographic (EMG) activity (PF and dorsiflexors) and the interpolated twitch technique (ITT). Maximal evoked contractions of the PF were elicited at 1, 2, 3, 5, 10, 20, and 40 Hz. PF RTD was calculated with maximal voluntary, 1 and 40 Hz contractions. Hyperbaric pressures significantly decreased PF voluntary torque; 6.2%, ITT activation; 2.8% with a trend for a 19.1% decrease in EMG (p = 0.1). There were no significant differences in the dorsiflexors/PF EMG ratio. One Hz torque was potentiated 15.7% with an increased absolute RTD of 12.8%, but no change in relative RTD. The results suggested hyperbaric-induced decreases in PF activation contributed to voluntary torque loss. A lack of torque reduction with higher frequency tetanic stimulation (2-40 Hz) suggested that 6 ATA does not impair myofilament kinetics, whereas twitch potentiation may include changes in excitation-contraction coupling.

Adult↗

Intermuscle differences in activation.

The objective of this study was to investigate differences within individual subjects in the ability to activate the quadriceps, plantar flexors (PF), dorsiflexors (DF), and elbow flexors (EF) during isometric contractions. Twelve male subjects performed submaximal and maximal voluntary isometric contractions, and maximal tetanic contractions were also induced by electrical stimulation. The interpolated twitch technique was used to gauge the extent of muscle inactivation or inability to produce maximum force. Measurements included torque output, absolute and relative rate of force development (RFD), and percentage of muscle inactivation. The quadriceps exceeded all other muscle groups in voluntary and tetanic torque output, voluntary absolute RFD, and absolute and relative tetanic RFD. The quadriceps also exceeded the PF and DF in voluntary relative RFD and had greater muscle inactivation (15.5%) than the EF (5.0%), PF (5.0%), and DF (1.3%). Although the higher RFD may suggest a higher percentage of type II fibers in the quadriceps, their higher threshold of recruitment leads to greater difficulty in fully activating the quadriceps.

Adult↗

Comparison of interpolation and central activation ratios as measures of muscle inactivation.

The objective of this study was to investigate different methods of estimating muscle inactivation, derived from single and multiple voluntary contractions. Ten subjects performed maximal and submaximal leg extensor contractions to determine an interpolation (IT) or central activation ratio (CAR). A superimposed evoked force was compared with the force output of either a voluntary (CAR) or resting evoked contraction (IT ratio), or the ratios were inserted into regression equations (linear, polynomial, exponential). Linear-regression estimates of CAR using doublets and tetanus provided physiologically inaccurate values. Whereas IT ratios using doublets (IT-doublet) and tetanus (IT-tetanus) had a significant difference in only one interaction, IT-tetanus and CAR using a tetanus (CAR-tetanus) estimates provided the most extensive correlation within and between measures. Thus, tetanic stimulation superimposed upon single maximal or multiple contractions seems to provide the most valid measure of muscle inactivation when using the interpolated-twitch technique.

Adult↗

The interaction of perceived maternal and paternal parenting styles and their relation with the psychological distress and offending characteristics of incarcerated young offenders.

A shortened form of the Parental Bonding Instrument (PBI) (Pederson, 1994) was used to examine the relationship between parenting styles and the psychological distress and offending patterns of a group of young male offenders held in custody in Scotland. High levels of psychological distress were linked with low parental care, but there was no association between psychological distress and parental control. Parental care was not a distinguishing factor in offending patterns, although high paternal control was linked with a younger age of first arrest. When interactions of paternal and maternal parenting styles were examined, young offenders who perceived poor parenting (i.e. neglectful parenting or affectionless control) from both parents had the highest levels of psychological distress overall.

Adolescent↗

Case-control study of GP attendance rates by suicide cases with or without a psychiatric history.

BACKGROUND: Targets for reduction in suicide deaths have been set against a background of an increasing number of people committing suicide. It is often assumed that a reduction can be effected by increasing the detection in primary care of patients at risk. This presupposes that there are indicators that enable suicide risk to be detected reliably. AIM: To compare the characteristics of those who commit suicide with an age- and sex-matched control group in terms of level of general practitioner attendance, diagnosis and pharmacological treatment of mental illness, and to compare those suicides with and without a psychiatric history in terms of general practitioner attendance and history of pharmacological treatment. METHOD: From a total of 48 deaths attributed to suicide and undetermined causes in the Forth Valley in 1993, general practice case notes were located for 41. Live controls were matched to index cases by age, sex and practice. Information on consultations, referrals to secondary care, medication and diagnoses in the previous 10 years was extracted from general practice and, for suicides, psychiatric case notes. RESULTS: Over the 10-year period, suicide patients attended their general practitioner at a higher level than control subjects. However, the number of suicide patients who attended their general practitioner in the month before their death did not differ in comparison with control subjects over a similar period. Suicide cases, in comparison with control subjects, were more likely to have received a psychiatric diagnosis from their general practitioner, been prescribed psychotropic medication and received referral to specialist mental health services. Those suicide patients with a psychiatric history had a significantly higher number of general practitioner consultations than those without a psychiatric history in four out of the five years preceding death. Those suicide patients without a psychiatric history did not differ significantly from control subjects on any of the variables assessed. CONCLUSION: For those people committing suicide who do not have a psychiatric history and whose consultation patterns do not differ from the norm, it is difficult to suggest how general practitioners might improve their detection of relevant suicidal risk factors. For those patients with a psychiatric history who commit suicide, until we have more detailed information regarding the specific content of general practitioner's consultations before death and how these differed from other consultations of the deceased, then it is premature to assume that general practitioners are failing to identify indicators of impending suicide.

Adult↗

Human hydatidosis in New South Wales and the Australian Capital Territory, 1987-1992.

OBJECTIVE: To determine the prevalence of human hydatidosis in New South Wales and the Australian Capital Territory. METHODS: Data on human hydatid infection occurring between 1987 and 1992 were collected retrospectively from 25 hospitals and 13 health services in New South Wales and four hospitals in the Australian Capital Territory. Mean annual prevalences of human hydatidosis were determined for shires in eastern New South Wales and data on infection in immigrants and Australian-born patients were compared. RESULTS: 321 patients were diagnosed with hydatid disease, 1987-1992; 195 were new cases and 117 readmissions (nine cases were not identified as new or recurrent). Most patients lived in the eastern half of New South Wales (which includes the Australian Capital Territory), half in rural areas and half in the major coastal cities. Most Australian-born rural patients lived in 39 shires in the north-eastern and south-eastern Tablelands. Sixty per cent of the patients in major cities were born overseas. CONCLUSIONS: Hydatid infection occurs more commonly in south-eastern Australia than the official figures suggest. In rural areas of the north-eastern and south-eastern Tablelands hydatid infection is of public health importance. The national notification system must be improved and control campaigns alerting the public to the dangers of hydatid infection promoted.

Adolescent↗

Transcortical and cervical magnetic stimulation with recording of the diaphragm.

Transcortical and cervical magnetic stimulation is a potential method of examining the central inspiratory pathway to phrenic motor neurons. The reliability and accuracy of this technique were studied. We performed magnetic stimulations of the cortex and cervical spinal cord with recording from both hemidiaphragms in 35 normal subjects using two different stimulation coils (90-mm circular coil and 70-mm figure-of-eight coil). Needle electrode recordings and ultrasound real-time documentation in 2 subjects excluded volume-conducted contaminations from adjacent chest wall and abdominal muscles. The effect of diaphragmatic facilitation (stimulation at the end of a deep breath) on latency, and amplitude were compared to the effect of hypothenar muscle facilitation. Normal ranges were established for: latency; central motor conduction time; amplitude; amplitude ratio between between peripheral and both cortical and cervical amplitude; and excitability threshold. The latencies were similar for both coils. The amplitudes were significantly higher, and excitability thresholds significantly lower for the 90-mm circular coil, indicating that this coil is preferable for transcortical diaphragmatic stimulations. The effect of facilitation was greater for hypothenar than diaphragmatic recordings. There was excellent right-left agreement for all measurements. Transcortical and cervical magnetic stimulation with recording from the diaphragm can be used routinely to diagnose and monitor patients with impaired central respiratory drive.

Action Potentials↗

Initial experience with single lead VDD system. Case study.

A single pass lead with dual chamber electrode system, designed for atrial and ventricular sensing and ventricular pacing (VDD), was implanted in a 63-year-old man with a history of syncope and second degree atrioventricular (AV) block. Intact VDD pacing function was confirmed at rest and during treadmill exercise. There were no postoperative complications. A single pass lead system that allows VDD mode pacing in patients with symptomatic AV block and competent sinus node function offers several advantages over traditional two lead dual chamber systems. These advantages include enhanced atrial sensing due to a differentially processed signal reliable for P wave detection and effective for rejection of far field ventricular signals, lowered cost and reduced implant time.

Cardiac Pacing, Artificial↗

Börjeson-Forssman-Lehmann syndrome: clinical manifestations and gene localization to Xq26-27.

We have studied 7 males in one family with mild/moderate intellectual handicap, long thick ears, deep-set eyes, small testes, and post pubertal gynecomastia. The affected males and some of the heterozygous females also had tapering fingers and short, widely spaced flexed toes. The pedigree demonstrates X-linked recessive inheritance. The clinical manifestations are similar to those described in the Börjeson-Forssman-Lehmann (BFL) syndrome but differ in the degree of mental handicap and the absence of "dwarfism" and microcepaly. This milder manifestation may represent either phenotypic or genotypic variation. DNA marker studies demonstrated linkage to the DXS86, DXS51, and F9 cluster at Xq26-q27. The maximum lod score was 2.1 with DXS51, at theta = 0.0. Definite recombinants were observed between DXS10 (at Xq26 but proximal to DXS86), DXS105 (at Xq27 but distal to F9), and BFL. Thus, the regional localization for BFL is Xq26-q27 between DXS10 and DXS105.

Abnormalities, Multiple↗

Predicting outcome after appendicectomy.

AIM: To validate an intraoperative appendicitis severity score (IASS) and examine outcome following emergency appendectomy. METHODS: A prospective study was undertaken, enrolling consecutive patients undergoing emergency appendicectomy. Data were obtained independently on preoperative Alvarado scores, IASS (0-3: 0 no inflammation, 1 engorged appendix/no peritonitis, 2 peritoneal reaction/exudate or 3 evidence of perforation/abscess) and postoperative outcome parameters. RESULTS: There were 149 patients identified with a mean age of 20.7 years. There was no association between Alvarado score and length of hospital stay, septic complication, patient sex or duration of symptoms (p>0.05). IASS was found to be an independent risk factor for septic complication, wound infection (p<0.05) and length of hospital stay (p<0.001). There was no correlation between preoperative duration of symptoms or time until surgery and intraoperative score. CONCLUSIONS: This simple scoring system can identify patients more likely to suffer morbidity following emergency appendicectomy. Specifically, this system identifies patients who have a high risk of sepsis and therefore could be of use when comparing healthcare performance.

Adult↗