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Biomedical subjects

D Byrne

Publications and source records attributed to D Byrne.

At least 73 records · Page 4Linked to original sources
PubMed1992

Hepatic resections for primary and metastatic tumors using the ultrasonic surgical dissector.

We have previously described the development of new hepatic surgical techniques using the ultrasonic surgical dissector. With 10 years' experience, we have found that major liver resections have been simplified and that the technique is repeatable in hands other than our own. Thirty-three patients had 37 tumors, averaging 5.65 cm in size, resected with an average blood loss of only 1,020 mL per case, which included 5 right trisegmentectomies, 12 lobectomies, 15 segmental resections, and 4 subsegmental resections. Twenty-two patients had metastatic colorectal cancer. Blood transfusion requirements averaged only 2.24 units in long-term survivors, which was significantly less than the 3.5 units received by patients who have since died (p = 0.092). There were no operative deaths. The median survival of these 22 patients was 56 months, and the 5-year actuarial survival rate was 35%. All of the early deaths occurred in patients with more than four tumors, and no patient with less than four tumors died before 42 months with recurrent disease. Six patients had bilateral tumors, and the fact that patients survived into the fourth and fifth post-resectional year indicates that resection was worthwhile. All these patients had Dukes' C primary tumors, but we found no statistical difference in survival between patients with Dukes' B and Dukes' C lesions. The results indicate that hepatic resection with the ultrasonic surgical dissector decreases blood loss, requires few transfusions, is safe to perform, and is associated with excellent long-term survival.

Adolescent↗
PubMed1992

Cost-effectiveness of single dose cefotaxime plus metronidazole compared with three doses each of cefuroxime plus metronidazole for the prevention of wound infection after colorectal surgery.

The cost-effectiveness of prophylaxis for colonic surgery with single dose cefotaxime plus metronidazole has been compared with that of three doses each of cefuroxime plus metronidazole, by analysing data from a previously published study supplemented with additional data on the hospital and community costs of wound infection after colonic surgery. The original trial included 942 patients having elective colonic surgery in 14 hospitals. The data on costs of wound infection were collected from a further 124 patients undergoing elective colonic surgery at Ninewells Hospital. All these patients received a three dose regimen of cefuroxime plus metronidazole. The Dundee patients received three injections of 0.75 g cefuroxime at 8-hourly intervals whereas the trial patients received a single dose of 1.5 g followed by two further doses of 0.75 g at 8-hourly intervals. The cefuroxime prophylaxis regimen used in the trial cost 24.16 pounds per patient more than the cefotaxime regimen. The components of the excess cost were drugs (15.18 pounds), equipment (6.14 pounds) and staff time (2.84 pounds). The median cost to the hospital of a wound infection was 978.04 pounds (95% CI 482.04 pounds to 1521.22 pounds). The components of the hospital cost of wound infection were: hotel costs 858 pounds (88%), dressing costs 83.02 pounds (8%) and drug costs (excluding prophylaxis) 37.02 pounds (4%). Only five patients received additional antibiotic treatment in the community, and only one required home visits from the District Nurse. Applying the difference in costs of prophylaxis as 21 pounds (costs of drugs plus equipment) and the cost per wound infection as 1000 pounds to the observed wound infection rate of 7% in the cefuroxime group, the wound infection rate in the cefotaxime group would have to be 2.1% higher for the two regimens to be equally cost-effective. The probability that such a difference in efficacy exists is 0.088. A model was developed to calculate the probability of equal cost-effectiveness over a range of costs of wound infection.

Anti-Infective Agents↗
PubMed1992

The emergence of clinical psychology departments in Australian teaching hospitals.

Over recent years, clinical psychological services have diversified within the health sector, leading to a breakdown in the traditional nexus between clinical psychology and psychiatry, and to the emergence of the interdisciplinary field of behavioral medicine. From their earlier limited role as providers of psychometric assessments in educational and psychiatric hospital settings, clinical psychologists now provide a wide range of therapeutic services and research skills to general hospitals, universities, community health centres, and the private sector. This evolving trend has significant implications for the future structure and direction of clinical practices in clinical psychology, psychiatry and medicine.

Adaptation, Psychological↗
PubMed1992

Effects of long-term bilateral and unilateral fitting of different hearing aid types on the ability to locate sounds.

Aided localization ability of 87 hearing-impaired listeners was tested for horizontal and vertical sound sources, at two signal levels, and for two orientations to the loudspeaker array (facing, sideways). Some listeners wore behind-the-ear (BTE) aids, others in-the-ear (ITE) aids. Some were bilaterally fitted, others unilaterally fitted. Listeners were tested only with types of aids and fittings that they were accustomed to wearing. The results strongly supported bilateral fitting for moderately and severely hearing-impaired listeners. However, for mildly impaired listeners, those fitted unilaterally performed as well, on average, as those fitted bilaterally. This suggests a need to consider individual listening requirements and also to provide such listeners with experience in unilaterally-aided listening before assessing the possible advantages of bilateral fitting. When hearing level was controlled, there was no overall difference in the performance of ITE and BTE aid wearers. This discrepancy with other research may be explained by measures (removal of intensity cues, permitting of head movement) designed to make the test situation more representative of real-life listening.

Adult↗
PubMed1992

Key issues in hearing aid selection and evaluation.

This article examines three key issues in hearing aid selection and evaluation. First, two studies are analyzed to determine the extent to which differences in frequency response characteristics result in differences in judgments of the intelligibility or pleasantness of amplified speech. Small to moderate frequency response differences usually did result in different judgments although occasionally large differences did not. When two dissimilar responses are equally intelligible, it is likely that the best response is something in between them. Second, evidence indicates that it is not always satisfactory to allow frequency response to be determined by prescribing gain at each frequency separately. This suggests, therefore, that separate frequency response prescription rules are needed. Third, signal audibility is discussed in the context of using simplified Articulation Index schemes to predict aided performance. It is demonstrated how wrong conclusions may easily be drawn in the absence of accurate knowledge of the signal levels received when different hearing aid options are used. Data suggest that the Articulation Index may not be applicable to steeply sloping high-frequency hearing losses. This needs further investigation before the Articulation Index can be recommended for hearing aid evaluations.

Correction of Hearing Impairment↗
PubMed1991

Randomized study of early amniocentesis versus chorionic villus sampling: a technical and cytogenetic comparison of 650 patients.

In a prospective randomized trial of 650 patients at 10-13 weeks' gestation, early amniocentesis was compared to chorionic villus sampling (CVS) for successful sampling and cytogenetic results and the speed with which results can he obtained. The indications for fetal karyotyping were advanced maternal age, parental anxiety or a family history of chromosomal abnormality in the absence of a balanced parental translocation. At early amniocentesis, 10 ml of amniotic fluid were successfully obtained in all 324 cases, in 320 (98.8%) at the first attempt and in four cases (1.2%) after two needle insertions. CVS provided sufficient material for cytogenetic analysis in 314 of 326 (96.3%) cases at the first attempt and in nine (2.8%) after two needle insertions; in three cases only maternal tissue was obtained and subsequently early amniocentesis was performed. Cell culture and chromosomal analysis were successful in 318 of 324 (98.1%) cases of early amniocentesis and in 321 of the 323 (99.4%) cases of CVS where villi were obtained. The median interval between sampling and successful result from cell culture was 12 days for early amniocentesis and 11 days for CVS. Mosaicism was detected in five cases of CVS but in none of the early amniocenteses; three of these cases were confirmed as true fetal mosaics. This study illustrates that early amniocentesis is a viable alternative to CVS for first-trimester fetal karyotyping. The results of the continuing prospective 1 trial will establish the safety and cytogenetic accuracy of the two techniques.

Clinical Trial↗
PubMed1991

A comparison of diagnostic related group length of stay outliers: motor vehicle crash versus penetrating injuries.

The incidence and degree to which patients injured by motor vehicle crashes (MVCs) and penetrating wounds remain in the hospital beyond the diagnostic related group (DRG) mean length of stay (LOS) are compared. During a 12-month period, records for consecutive patients admitted to eight hospitals (including three trauma centers) were studied. Patients aged 13 or younger, staying less than 48 hours, or with major burns or only distal fractures were excluded. In that time, 2,914 patients were eligible. Twenty percent of injuries were penetrating; 27% were MVC injuries; and, 53% were blunt injuries from other causes. Patients injured in MVCs and with penetrating injuries were compared with respect to mean LOS, incidence of DRG outliers, number of hospital days beyond the DRG mean LOS, and demographic variables. Patients injured in MVCs had a greater proportion of DRG LOS outliers and higher mean numbers of DRG excess days than did patients with penetrating wounds (p less than 0.01, for both). Injuries were distributed among relatively more DRGs for MVC patients. The DRG scheme may lack sufficient attention to factors more likely to affect MVC patients, such as multiplicity of injuries, incidence of CNS injuries, ICU requirements, and older age. In structuring more appropriate reimbursement for trauma care, special attention must be paid to patients injured in MVCs.

Accidents, Traffic↗
PubMed1991

Human and non-financial costs of hospital-acquired infection.

Measurement of morbidity from hospital-acquired infection should include the suffering of patients who are denied treatment, 'the opportunity cost of infection'. We believe that this perspective will also reveal other inefficiencies which may be easier to correct than hospital-acquired infection. Infection control should be seen as a component of quality control and not as an end in itself.

Cost-Benefit Analysis↗
PubMed1991

Why cell culture is successful after early amniocentesis.

The current interest in early amniocentesis as a possible alternative to chorion villus sampling has driven many centres to attempt cell culture from first trimester amniotic fluid. This study examines the cellular content of 125 amniotic fluid specimens collected between 8 and 18 weeks of gestation and shows that there is a higher proportion of viable cells at the time of early amniocentesis than at traditional amniocentesis. Although there is a small increase in viable cell number from 8 to 18 weeks of gestation, this is not as dramatic as the exponential rise in total cell number seen over the same period. The similar concentration of viable cells in early pregnancy to that in the second trimester is sufficient to explain the unexpected culture success after early amniocentesis.

Amniocentesis↗
PubMed1991

Auditory localization under conditions of unilateral fitting of different hearing aid systems.

The spatial localization function of hearing-impaired listeners, usually fitted bilaterally with BTE, ITE or ITC devices, was tested under conditions of unilateral fitting of each of their own hearing aids, and unilateral fitting of stock versions of each of the other types. For the BTE wearers average localization accuracy and individual variability were not greatly changed when wearing only their left ear device, compared with bilateral aided performance. In ITE wearers, unilateral fitting in either ear led to somewhat poorer performance than bilateral. In the ITC wearers unilateral fitting produced inconsistent outcomes. Both BTE and ITE wearers fared poorly when fitted unilaterally with stock forms of devices 'foreign' to them, whereas ITC wearers did not show such a contrasting outcome. A group of non-impaired listeners showed severe disruption of localization under unilateral BTE and ITC hearing aid conditions, and to a lesser extent with ITEs. Results for the hearing-impaired listeners are interpreted in terms of adaptation to different usage patterns, with BTE wearers suggested as having adapted to their own systems unilaterally as well as bilaterally.

Auditory Threshold↗
PubMed1990

Hearing aid gain and frequency response requirements for the severely/profoundly hearing impaired.

The optimal frequency response slope, from the low frequencies (250 or 500 Hz) to 2000 Hz, was estimated for each of 46 severely or profoundly hearing-impaired adults. The estimates were derived from paired comparison judgments of speech filtered to simulate different frequency response conditions, from home trials and ratings of different tone settings of high-powered, behind-the-ear hearing aids, and for 28 subjects, from speech recognition testing. The estimated optimal response, expressed as the slope from 250 to 2000 Hz and as the slope from 500 to 2000 Hz, was compared with the response prescribed by the National Acoustic Laboratories (NAL) procedure and its relationship to audiometric variables was analyzed. Insertion gain was measured for the preferred volume setting with the best frequency response. Preferred gain was typically about 10 dB higher than the NAL prescribed gain. Considering these results in relation to other data, it appears that the "half-gain" rule ceases to apply when HTL exceeds about 70 dB. The estimated optimal frequency response agreed with the NAL response for some subjects but relatively more low frequencies were required for between a third and half of the subjects, depending upon how frequency response is expressed. Generally, more low frequencies were required if HTL at 2000 Hz exceeded 95 dB, whereas the NAL response was usually appropriate for other cases.

Adult↗
PubMed1990

Fluconazole levels in plasma and vaginal secretions of patients after a 150-milligram single oral dose and rate of eradication of infection in vaginal candidiasis.

Mean peak concentrations of fluconazole in plasma and vaginal secretions of females after a 150-mg single oral dose were shown to be 2.82 micrograms/ml and 2.43 micrograms/g, respectively. Our results indicate that clinically efficacious concentrations of fluconazole in vaginal secretions are easily achieved after this single oral dose.

Adult↗
PubMed1990

A comparison of different binaural hearing aid systems for sound localization in the horizontal and vertical planes.

Three groups of hearing-impaired listeners who had been fitted binaurally with behind-the-ear (BTE), in-the-ear (ITE), or in-the-ear-canal (ITC) hearing aids were tested on spatial localization function for sources in the frontal horizontal and vertical planes. No significant differences in unaided performance were observed between the groups, nor between that and aided performance in the BTE and ITE wearers. ITC wearers, by contrast, showed a deterioration in aided over unaided performance. From observations of performance when each group wore temporary fittings of the other two types of system, and from the performance of a non-impaired control group, it appears that the performance decrement for the ITC wearers was due to their own particular systems although specific reasons for this decrement could not be identified. In all conditions, aided and unaided, vertical plane localization was markedly disrupted in all the hearing impaired groups. It was also disrupted, to a lesser but still substantial extent, in aided conditions for the non-impaired listeners.

Adult↗
PubMed1989

Cystic disease of the biliary tract.

Cystic disease of the biliary tract is rare in Western countries with an incidence of 1/2,000,000 live births. Five anatomical types are recognized. The majority (80%) become symptomatic before the age of 30 years. The cysts rarely have an intact epithelial lining and this often exhibits metaplasia. The risk of cancer developing in a choledochal cyst has been variously estimated at 2.5-28%. Malignancy is often associated with an abnormal pancreaticobiliary junction. Surgical treatment is indicated for types I-IV and is by excision rather than drainage. The treatment of Type V is difficult and should be conservative in the first instance. However, patients with severe symptomatic diffuse hepatic disease and progressive deterioration of liver function are best managed by hepatic transplantation.

Adult↗
PubMed1988

Sexual attitudes as correlates of sexual details in human figure drawing.

The hypothesis that sexual attitudes, as measured by the Sexual Opinion Survey, are related to the explicitness with which nude figures are drawn was examined. The presence or absence of various sexual and nonsexual anatomical features, as well as length and width measurements, were assessed in the drawing of nudes by 17 male and 23 female undergraduates. Individuals with relatively positive sexual attitudes (erotophiles), as compared with individuals with relatively negative attitudes (erotophobes), were more likely to include such details as a glans, a urinary meatus, and chest hair on male figures and pubic hair and nipples on female figures. Positive sexual attitudes were also associated with drawing figures with longer and wider penises, breasts, testicles, and mons. Relationships between sexual attitudes and the drawing of nonsexual body parts were generally not significant. The results are discussed in terms of the pervasive generality of sexual attitudes in influencing quite varied sex-related behaviors.

Adult↗
PubMed1988

Perceiving mitosis in eukaryotic cells.

A sensitive method has been developed for visualizing eukaryotic cells in mitosis (M) phase. It employs Zenker's fixative, which makes the plasma membrane but not the nuclear envelope permeable to immunoglobulins. Zenker's-fixed cells are exposed to an antibody which recognizes a major constituent of chromatin. In this case the antibody is a monoclonal (MC 21) which recognizes histone H2b. Because cells in M phase do not have an intact nuclear envelope, the antibody has access to and interacts with their chromatin. The presence of a nuclear envelope in Zenker's-fixed interphase cells precludes access of the antibody to the nuclear chromatin. Consequently, this indirect immunofluorescence procedure selectively labels M-phase cells. At high enough magnification some details of the chromatin figures are revealed. MC 21 recognizes the chromatin of cells of many different species. With appropriate fixation it can be used effectively on cells in culture. With some procedural modifications it can also be used with more complex tissue systems. Detailed mitotic patterns for chick embryos up to Day 3 of development have been obtained by this method.

Animals↗
PubMed1988

Parietal cell carcinoma of the stomach: association with long-term survival after curative resection.

Following the recent identification of gastric parietal cell carcinoma (Capella et al., 1984), a histological and clinical review of 125 consecutive cases of gastric cancers treated surgically during a 9-year period was undertaken. The pathology was reviewed blind and in addition to H & E sections, staining with Luxol Fast Blue, phosphotungstic acid haematoxylin and E-M studies were performed to identify parietal cell differentiation. The surgical procedures performed were curative R2 gastrectomy (n = 56), palliative resection (n = 30), gastro-enterostomy (n = 25) and intubation (n = 14). The 30-day operative mortality was 12/125 (10%) overall and 4/56 (7%) in the curative resection group. Two parietal cell cancers were identified and a further 4 tumours showed areas of parietal cell differentiation. All occurred in male patients (mean age 55 years, range 43-62). Sixteen patients out of the 56 patients (29%) who underwent curative R2 resection have survived long-term (mean 5.5 years, range 2.5-11): 4/5 mucosal/submucosal cancers (T1N0), 5/29 intestinal cancers (T2N0-2) 2/16 diffuse cancers (T2N1) and 5/6 with parietal cell cancer/differentiation (T2-3N0-2). There were no survivors beyond 14 months in the patients who were treated by palliative resection, bypass or intubation irrespective of histology. This study suggests that gastric parietal cell carcinoma carries a good prognosis after curative resection despite the advanced stage at presentation.

Adult↗