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Biomedical subjects

J Ball

Publications and source records attributed to J Ball.

At least 55 records · Page 3Linked to original sources
PubMed1995

Evaluation of 99Tcm-tetrofosmin as a myocardial perfusion agent in routine clinical use.

Recent trials with selected patients have indicated that 99Tcm-tetrofosmin is a suitable agent for myocardial perfusion imaging. We performed 99Tcm-tetrofosmin perfusion imaging in an unselected group of 297 patients routinely referred to our department. Single photon emission tomographic (SPET) imaging was performed 45-60 min post-injection using a 2-day stress and rest protocol. Altogether, 192 patients were stressed on a treadmill and 105 using intravenous dobutamine. Comparison with angiography was possible in 86 patients, 65 of whom had atheromatous coronary artery disease and 21 of whom had normal coronary arteries (6 of whom fulfilled the criteria for syndrome X). The sensitivity for the detection of coronary artery disease was 94% (93% for exercise stress and 95% for dobutamine). The overall specificity was 85% (87% for exercise stress and 80% for dobutamine in the 15 normal patients and the segments supplied by disease-free coronary vessels in patients with disease elsewhere). We conclude that 99Tcm-tetrofosmin is a highly sensitive and specific agent for the detection of coronary artery disease, using both exercise and dobutamine stress, with few limitations.

Adult↗
PubMed1995

Early complications of permanent pacemaker implantation: no difference between dual and single chamber systems.

OBJECTIVE: To evaluate the incidence of intraoperative and early postoperative complications (up to two months after implant) of endocardial permanent pacemaker insertion in all patients under-going a first implant at a referral centre. METHODS: Prospective evaluation of all endocardial pacemaker implantation procedures performed from April 1992 to January 1994 carried out by completion of standard audit form at implant. Patients' demographic data, medical history, details of pacemaker hardware used, and any complications were noted. Follow up information was also collected prospectively onto standard forms at pacemaker outpatient clinic. SETTING: United Kingdom tertiary referral cardiothoracic centre. PATIENTS: 1088 consecutive patients underwent implantation of their first endocardial permanent pacemaker from April 1992 to January 1994. Implant and follow up data were available for 1059 (97.3%) patients at analysis. The median (range) age was 77 years (16-99); 51.2 % were male. RESULTS: Dual chamber units were implanted in 54.1% of patients, single chamber atrial in 5.2%, and ventricular in 40.7%. A temporary pacing lead was present at implant in 22.9% of patients. Most (93.6%) implants were performed via the subclavian vein. Immediate complications were rare: eight (0.8%) patients developed pneumothorax requiring medical treatment and 11 (1.0%) an insignificant pneumothorax. There was no significant difference in the pneumothorax rate for dual chamber (DDD) compared with single chamber systems. Arterial puncture without sequelae was documented in 2.7% of attempts at subclavian vein cannulation. A total of 35 patients (3.3%) required reoperation; the reoperation rate for dual chamber (3.5%) was similar to that for single chamber (3.1%) systems. Electrode displacement (n = 15, 1.4%) was the most common reason for reoperation. Atrial lead displacement (n = 10, 1.6% of atrial leads) was significantly more common than ventricular lead displacement (n = 5, 0.5% of ventricular leads, P = 0.047). There was no difference in electrode displacement rates for dual (1.6%) compared with single (1.2%) chamber systems. Pacemaker pocket infection led to reoperation in 10 patients (six dual, four single chamber, P = not significant) and was significantly more common in patients who had a temporary pacing lead in place at implant (2.9%) than in those who did not (0.4%, P = 0.0014). Five patients (0.5%) required reoperation for generator erosion (two dual, three single chamber, P = not significant). and a further five for drainage of haematoma or a serous fluid collection (three dual, two single chamber, P = not significant). Complications that did not require reoperation were also rare. Undersensing occurred in 10 patients (0.9%). Atrial undersensing (n = 8) was significantly more common than ventricular undersensing (n = 2, P = 0.017). All patients were successfully treated by reprogramming of sensitivity. Superficial wound infection was treated successfully with antibiotics in nine patients (six dual, three single chamber, P = not significant). Three patients with DDD generators developed sustained atrial fibrillation: two required reprogramming to VVI mode and one required cardioversion. CONCLUSIONS: Permanent pacing in a large tertiary referral centre with experienced operators carries a low risk. Infection rates are low, < 1% overall but significantly higher in patients who undergo temporary pacing before implantation. Lead displacement and undersensing are more likely to occur with atrial than ventricular leads. The overall complication rate for dual chamber pacing, however, is no higher than for single chamber pacing.

Adolescent↗
PubMed1995

Shapeless figures.

Explore the source record for details and available documents.

Community Health Nursing↗
PubMed1994

The international mobility of nurses: a United Kingdom perspective.

This paper examines available information on the flows of qualified nurses to and from the United Kingdom, and reports on the results of a questionnaire survey of U.K.-based nurses who had worked abroad. The data examined reveals an upward trend in both "inflow" and "outflow" of nurses in the period 1984-91, with indications of a net outflow. The survey results indicated that Australia was the most common destination; most nurses working abroad had moved to the English-speaking countries of North America and Australasia. Barriers and incentives to international mobility of nurses are discussed, and likely future trends in mobility are examined.

Adult↗
PubMed1994

The role of ultrasound in the management of zone 1 flexor tendon injuries.

We have reviewed 22 flexor tendon repairs in zone 1 undertaken in Hobart, Tasmania, during the period 1986 to 1991. The repairs were assessed using both ultrasound and Strickland's clinical criteria. The results are presented, and the two methods of assessment compared. A new method of grading results is proposed based on the ultrasound findings. We have demonstrated that ultrasound has an important role to play in assessing tendon repairs, both in the on-going management and as an objective method of measuring the results of repair.

Finger Injuries↗
PubMed1994

Benzodiazepine-induced outcome revaluation and the motivational control of instrumental action in rats.

It has been argued that the control of instrumental action by motivational states is indirect, being mediated by the effects these states have on the incentive value of the instrumental outcome (A. Dickinson & B. W. Balleine, 1994). In this study, the benzodiazepine agonist midazolam was found to control instrumental action in a similar manner. Midazolam (1 mg/kg) increased rewarded instrumental performance in rats trained undeprived but only elevated performance in extinction when rats were reexposed to the instrumental outcome under midazolam before the test. This effect of reexposure under midazolam did not transfer to a test conducted under food deprivation, suggesting that it was not produced by drug-induced hunger. Finally, in animals trained hungry, midazolam was found to block outcome devaluation induced by a reduction in food deprivation, indicating that midazolam and food deprivation affect outcome value via a common substrate.

Animals↗
PubMed1994

46,XY pure gonadal dysgenesis (Swyer-James syndrome)--Y or Y not?: a review.

The designation "pure gonadal dysgenesis" is applied to a particular variety of defective organo-genesis, in which phenotypically female patients with a 46,XY karyotype have complete lack of functioning gonadal tissue. The latter are represented anatomically by the presence of bilateral, elongated, nonfunctioning, rudimentary "streak" gonads composed of fibrous tissue, although normal female internal genitalia are present. The purpose of this review is to present the existing literature accumulated from 1955 to 1992 pertaining to 46,XY pure gonadal dysgenesis (Swyer-James syndrome), add the findings of a personally observed patient, and highlight the complexities in attempting to determine the etiology of this rare condition.

Adult↗
PubMed1994

Detection of immunoglobulin M (IgM), IgA, and IgG Norwalk virus-specific antibodies by indirect enzyme-linked immunosorbent assay with baculovirus-expressed Norwalk virus capsid antigen in adult volunteers challenged with Norwalk virus.

Pre- and postexposure sera collected from 17 adult volunteers challenged with Norwalk virus as described previously (D. Y. Graham, X. Jiang, T. Tanaka, A. Opekun, P. Madore, and M. K. Estes, J. Infect. Dis. 170:34-43, 1994) were examined for Norwalk virus-specific immunoglobulin M (IgM), IgA, and IgG by indirect enzyme-linked immunosorbent assays with recombinant Norwalk virus antigen bound to the solid phase. Sixteen of the 17 volunteers had evidence of past infection, all presenting with preexisting IgG antibody of high avidity; only one volunteer had no evidence of previous infection. Virus infection was detected in 14 of the 16 volunteers with evidence of past infection, and 9 of the infected volunteers had symptomatic illness. A significant rise in both virus-specific IgA and IgG titers was detected after challenge in all of the volunteers who became ill. Five of the asymptomatic volunteers who were infected had rising titers of virus-specific IgG, but only two of the five had a concomitant rise in their virus-specific IgA antibody titers. Antibody rises were detectable in eight of nine ill volunteers 8 to 11 days after challenge but in the asymptomatic volunteers only after more than 15 days had elapsed. Virus-specific IgM was detected after challenge in all 14 infected volunteers. Between symptomatic and asymptomatic volunteers there were no significant differences in titers of virus-specific IgG and IgA in serum before challenge; however, there were significantly higher titers in symptomatic volunteers between 8 and > 90 days after challenge for virus-specific IgG and 8 and 24 days after challenge for virus-specific IgA.

Adult↗
PubMed1993

Multiple myeloma: the biology of malignant plasma cells.

Multiple myeloma remains a difficult disorder to treat and cures are virtually unknown. Most modalities of treatment have been tried on an empirical basis, and a greater understanding of the nature of myeloma progenitors may lead to more specific therapies. In the past few years interest in the biology of myeloma plasma cells has increased and the current state of knowledge is summarised in this review. Myeloma clonogenic, or colony, assays have been attempted by many groups. Despite this, no direct equivalent is available of the CFU-GM assay for granulocyte-macrophage progenitors in normal marrow. No published methods have been exported widely to other laboratories. Recently, myeloma plasma cells were found to express a wide range of adhesion molecules permitting cell to cell and cell to stroma interactions. This finding may explain the difficulty of myeloma colony assays, since adhesive clumping must be prevented. The observation that interleukin (IL)-6 can stimulate myeloma plasma cells led to further work with other cytokines such as IL-3 and GM-CSF. The precise role of IL-6 in the usual case of bone marrow myeloma remains unclear however.

Aged↗
PubMed1993

Familial Alzheimer's disease. A pedigree with a mis-sense mutation in the amyloid precursor protein gene (amyloid precursor protein 717 valine-->glycine).

Ten affected individuals are described from a kindred with autosomal dominant familial Alzheimer's disease in which a mutation in the amyloid precursor protein gene results in a valine to glycine substitution at amyloid precursor protein 717 which co-segregates with the disease. The mean age at onset of symptoms was 52 years with a range from 40 years to 67 years. The median duration of the disease was 11 years, with a range of 7-16 years. All individuals fulfilled the National Institute for Neurological and Communicative Disorders and Stroke criteria for probable Alzheimer's disease. A homogeneous clinical and neuropsychological pattern was evident within the family. Myoclonic jerks, seizures, depression and a lack of insight were common features. Positron emission tomography demonstrated biparietal bitemporal hypometabolism in the one affected individual who was studied. The diagnosis was confirmed histopathologically in one individual.

Adult↗
PubMed1993

Discrimination of moving events which accelerate or decelerate over the listening interval.

Grantham [Grantham, J. Acoust. Soc. Am. 79, 1939-1949 (1986)] has proposed that subjects are able to resolve the velocity of a moving sound source simply by determining the distance traveled and the time required to complete the movement. In the current experiment, subjects were able to discriminate between accelerated and decelerated movements which were identical on both parameters; that is, the accelerated and decelerated movements began and ended at the same locus and required the same amount of time to be completed. The minimum duration required to discriminate between these two movement patterns was 310 and 90 ms, respectively, for displacements of 9 degrees and 18 degrees. These results suggest that, under some conditions, the perception of velocity in the auditory modality may be based upon something more than a simple comparison of the total distance traveled and the time required to complete the movement.

Acoustic Stimulation↗
PubMed1993

Alcohol education courses for offenders: ten years after.

Data from a survey of U.K. agencies are presented. Trends in service provision for drinking offenders are reported, in the context of two previous surveys. National development of service provision is examined, since the original survey, reported in 1982. Findings from the survey have suggested that the field has become stagnant, due to a failure to merge research and practice. Alcohol educators who continue to ignore lessons from such surveys may face extinction from the field.

Adolescent↗