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Biomedical subjects

A Farnsworth

Publications and source records attributed to A Farnsworth.

At least 19 recordsLinked to original sources
PubMed2003

Screening and follow up assessment in three cases of auditory neuropathy.

Three children with auditory neuropathy are described. Two were detected via a targeted neonatal hearing screening programme based on auditory brain stem response testing, and one via the routine Health Visitor Distraction Test. Auditory neuropathy is an important but poorly understood disorder which has implications on planning future hearing screening policy and management of hearing impairment.

Evoked Potentials, Auditory, Brain Stem↗
PubMed1998

Field sensitivity of targeted neonatal hearing screening using the Nottingham ABR Screener.

OBJECTIVE: A population of children having bilateral moderate to profound hearing impairment was investigated to find out the number who passed (false negatives) and who failed (true positives) a screening test based on the auditory brain stem response (ABR). DESIGN: This study of the ABR is a parallel report to Lutman, Davis, Fortnum, and Wood (1997), where the transient evoked otoacoustic emission was examined on a similar but not identical population of at-risk neonates. Hearing screening was undertaken in at-risk neonates (targeted screening) at seven hospitals in the UK using the Nottingham ABR Screener. During the period from January 1988 to December 1993, a total of 6983 neonates had been tested. Assessment of audiological records from the participating centers ascertained that 201 children born between January 1988 and December 1993 had hearing threshold levels in both ears of 50 dB or more, averaged over the speech frequencies 0.5, 1, 2, and 4 kHz. Of these, 51 had completed the ABR screening test. Examination of the ABR records, which included both machine and visual scoring, indicated whether they had passed or failed the screening test. RESULTS: Forty-six of the 51 hearing impaired babies failed the neonatal ABR screen either on one or both ears (five false negatives), and 42 failed the test on both ears (nine false negatives). This resulted in field sensitivities of 90% and 82%, respectively. Two cases of suspected progressive hearing loss have been included in the numbers of false negative results. The percentage of babies passing the screen on both ears and subsequently having normal hearing (specificity) is typically 93%. CONCLUSIONS: Neonatal hearing screening in an at-risk population using a highly automated ABR test is a viable and effective tool for identification of hearing impairment. Although the field sensitivity of the test is high, it is unable to identify all babies with a criterion level of hearing loss. There are a number of possible explanations as to the origin of false negative results: configuration of the pure-tone audiogram, a progressive hearing loss, acquired sensorineural or conductive loss, retrocochlear deafness, or an incorrect interpretation of the screening test. Passing a neonatal screening test, therefore, does not exclude the possibility of subsequent hearing impairment and highlights the need for further surveillance.

Auditory Threshold↗
PubMed1998

Anomalous screening outcomes from click-evoked otoacoustic emissions and auditory brainstem response tests.

Transiently evoked otoacoustic emissions (TEOAE) and auditory brainstem response (ABR) tests were used in parallel to screen 862 neonates with risk factors for hearing loss. Seven neonates (0.81%) passed on TEOAE screen yet failed on ABR in one ear (six neonates) or both ears (one neonate). This combination of results has been termed 'anomalous'. Examination of audiometric results obtained on follow-up shows that in one ear of one neonate the result was consistent with the later confirmed audiogram shape. The explanation for the anomalous results in the remaining ears is unclear although neural maturation and the effects of hyperbilirubinaemia are possibilities. There were no instances of progressive or retrocochlear hearing loss identified. None of the seven neonates had better ear hearing loss of > or = 40 dB on long term follow-up.

Acoustic Stimulation↗
PubMed1997

Evaluation of the CytoRich slide preparation process.

OBJECTIVE: To compare the quality and sensitivity of CytoRich slides with conventional cytologic smears and to evaluate the benefits of using this technology as an add-on procedure. STUDY DESIGN: The study design consisted of non-randomized, paired cervical samples. The subjects were 2,125 Sydney women who were routine patients of 13 gynecologists and 8 general practitioners and had cytologic smears taken between January and June 1995. All smears were taken using the Cervex brush. After preparing the conventional cytologic smear slide, the head of the sampler was detached and placed in a vial of fluid fixative. Paired slides were then prepared in the laboratory from the cells in the fluid fixative, using the CytoRich processing machine. The CytoRich and conventional cytologic smear slides were compared for quality, ease of screening, presence of endocervical cells, recognition of infections, and detection of squamous and glandular abnormalities. RESULTS: CytoRich slides were of much better quality, were easier to screen, had substantially fewer unsatisfactory results (0.3% vs. 2.6%) but lacked endocervical cells more often (16.1% vs. 10.6%). As regards abnormalities, the CytoRich slides showed fewer abnormalities, particularly in the low grade category. However, as a result of screening the paired CytoRich slide, some additional abnormalities were detected and a number of abnormalities reported on the conventional slide were reclassified (some to higher grades but more to negative). CONCLUSION: As an add-on technology, the CytoRich process has much to offer, in particular in the virtual elimination of unsatisfactory smears and in helping to resolve the difficult dichotomy between normal and low grade categories. Examining additional cellular material on a CytoRich slide enhances the sensitivity and accuracy of the combined results.

Cytodiagnosis↗
PubMed1996

Evaluation of the PAPNET system in a general pathology service.

OBJECTIVE: To compare the results of an automated rescreening device (PAPNET) with manual screening of Papanicolaou (Pap) smears. DESIGN: All normal or technically unsatisfactory smears and a random sample of abnormal smears on manual screening were submitted for PAPNET rescreening. SETTING: Large general pathology laboratory in Sydney between January and September 1995. RESULTS: Of 54,658 PAP smears classified on manual screening as normal 266 were reclassified as abnormal after PAPNET screening (32 atypical squamous cells of uncertain significance, 217 low-grade squamous intraepithelial lesions and 17 high-grade intraepithelial lesions). Of the random sample of 1022 smears classified on manual screening as abnormal, all high-grade intraepithelial lesions (122 smears) and squamous cell carcinomas (2 smears) were also detected by PAPNET, and 112 were reclassified as normal by PAPNET (14 atypical squamous cells of uncertain significance and 98 low-grade squamous intraepithelial lesions). Histological follow-up confirmed 15 of the 17 smears classified as high-grade intraepithelial lesions on PAPNET screening and detected a further seven that had been classified by PAPNET as either atypical squamous cells of uncertain significance or low-grade squamous intraepithelial lesions. CONCLUSIONS: When used as a quality-control measure in a general pathology laboratory, the PAPNET automated screening system detects higher numbers of abnormal PAP smears than manual screening.

Australia↗
PubMed1995

An Australian trial of ThinPrep: a new cytopreparatory technique.

To evaluate the sensitivity and suitability of ThinPrep, a new slide preparation technique, 2026 paired cervical cytology slides were examined. After conventional Papanicolaou smears were prepared, the sampling instruments were rinsed in a fluid fixative. ThinPrep slides were then prepared in the laboratory from the surplus cells in the fixative. Compared with the Pap smears, ThinPrep slides were easier and quicker to screen, were inconclusive less often, and had similar rates for detecting abnormalities and infection. There were more unsatisfactory ThinPrep slides and more ThinPrep slides lacked endocervical cells. Both of these shortcomings were found to be linked to the choice of sampling implements. This study, in which a variety of sampling instruments was used, fails to confirm some of the previous claims made for the new technique.

Australia↗
PubMed1994

The value of Medicare statistics in monitoring Pap smear screening. Screening versus non-screening smears: the role of the laboratory.

In November 1991 separate Medicare item numbers were introduced to distinguish screening from non-screening cervical smears for the purposes of monitoring the screening programme. Referring doctors are now expected to indicate the appropriate item number on the request form accompanying the Pap smear. To test compliance with this requirement, we examined 1000 consecutive request forms for cervical smears received in August 1993. We found that 22.7% had no item number indicated and that for a further 10.4% the item number given appeared to be incorrect. As the account issued by the laboratory must show an item number the ultimate responsibility for the choice of the item number rests with the laboratory. Using the guidelines supplied by Medicare, we formulated detailed criteria to classify smears as screening or non-screening, based on the patient's past smear history and/or clinical information provided by the referring doctor. Applying these criteria to cervical smears received in this laboratory in 1993 resulted in 70% being classified as screening and 30% as non-screening smears. Analysis of the cytological predictions for these smears showed substantially higher rates for all grades of abnormalities in the non-screening smears, thus lending support to the validity of our classification system. We conclude that classifying smears into screening and non-screening categories provides valuable information for statistical and quality assurance purposes but can only be useful for monitoring purposes if the criteria for assigning smears are applied consistently by all doctors and laboratories.

Australia↗
PubMed1994

Rollerball endometrial ablation: a histological study in danazol pretreated patients.

Endomyometrial biopsies were taken from danazol pretreated patients about to undergo rollerball endometrial ablation for menorrhagia. The biopsies were taken with a loop electrode at hysteroscopy before and after 1, 2, 3 passes of a rollerball electrode over the endometrium using powers of electrocoagulation diathermy varying from 30 to 100 watts. The biopsies were then assessed histologically. Nineteen biopsies from the perceived endocervical canal, 25 posttreatment curettings and 3 hysterectomy specimens were also assessed. Biopsies taken after danazol pretreatment but before diathermy showed a thinned inactive endometrium. A histological classification of the effect of electrocoagulation diathermy on the endometrium was developed describing increasing endometrial damage. The degree of endometrial damage was directly related to the number of rolls of the ball over the endometrium and to the power of electrocoagulation diathermy. Endometrium was found in 84% of biopsies from the perceived endocervical canal and endometrium was found in curettings from 3 of 11 patients who were amenorrhoeic following ablation.

Adult↗
PubMed1993

The efficacy of the pipelle endometrial biopsy in detecting endometrial carcinoma.

The purpose of this study was to determine the efficacy rate of the Pipelle endometrial biopsy sampler (Pipelle de Cornier) (1) in detecting endometrial carcinoma, and to analyze the tumour variables that may influence the success rate. Thirty seven women with known endometrial carcinoma were tested preoperatively; there were 25 correct diagnoses (67%), the remaining 12 cases (33%) failed to demonstrate the correct diagnosis: 4 showed 'atypical epithelium', 2 showed 'atypical hyperplasia', 3 showed 'nonspecific epithelium' and the remaining 3 showed 'necrotic hyalinized material'. All cases were analyzed with respect to several tumour parameters, including the degree of differentiation, tumour volume, depth of invasion, and the extent to which the tumour filled the endometrial cavity. Poor results were obtained in well differentiated, low volume, and minimally invasive tumours, i.e. most early tumours, precluding its use as a screening tool. A positive biopsy can save patients the time, cost, and inconvenience of a dilatation and curettage. However, in the light of these findings, a nonspecific finding should be interpreted with caution.

Biopsy↗
PubMed1993

The feasibility of evoked otoacoustic emissions as an in-patient hearing check after meningitis.

The desirability of finding children with hearing impairment after bacterial meningitis as soon as possible prompted us to examine the feasibility of using evoked otoacoustic emissions (EOAE) as an in-patient check of hearing status in children recovering from bacterial meningitis. Sixty-six episodes of bacterial meningitis were studied. Traces could be recorded for only 54.7% of ears. All children subsequently found to have sensorineural hearing impairment who were tested with EOAE, failed the screening test. The low coverage of the screening test and the predicted low specificity due to the high incidence of conductive hearing impairments, lead us to conclude that, with the technology currently available, the measurement of EOAE after bacterial meningitis is not a practical method for a pre-discharge check of hearing. Every effort must still be made to ensure all children are referred for an appropriate auditory assessment.

Adolescent↗
PubMed1993

[Three cases of aortic root replacement by cryopreserved homograft with effective usage of its anterior mitral leaflet].

Homograft aortic root replacement was done to three patients and the anterior mitral leaflet of the homograft was used with success in all cases. Case 1. A 37-year-old man had late-onset active prosthetic valve endocarditis with a fistula from the aortic annulus to the left atrium. The fistula was closed by using a homograft anterior mitral leaflet and the aortic root was replaced by a homograft with reimplantation of the coronary arteries. He is very well without evidence of recurrent endocarditis 29 months after the operation. Case 2. A 37-year-old man had early-onset active prosthetic valve endocarditis and developed the same fistula as case 1. He was treated successfully as in case 1. He is very well 4 months after the operation. Case 3. A 50-year-old woman, who had undergone aortic commissurotomy due to aortic valvular stenosis fifteen years before, deteriorated again. She had subvalvular membranous stenosis and a small aortic annulus. Konno-Soma procedure was applied to enlarge the annulus and the aortic root was replaced by a homograft. The interventricular septal incision was closed successfully with use of the anterior mitral leaflet of the homograft. Homograft aortic root replacement was an attractive procedure for prosthetic valve endocarditis or a small aortic annulus, and the homograft anterior mitral leaflet was useful for closing the fistula due to the infection and for closing the interventricular septal incision of Konno-Soma procedure.

Adult↗
PubMed1993

[Surgical treatment with aortic valve homograft harvested from heart transplant recipients or donors].

From March 1988 to November 1991, 24 patients underwent aortic valve replacement or aortic root replacement with an aortic homograft harvested from a heart transplant recipient or donor that was not suitable for heart transplantation. Those patients were followed from 2 to 34 months (mean 12.6 months). The mean age was 44 years (range 19 to 77 years). The main lesion was aortic stenosis in 8 patients, aortic regurgitation in eight, mixed lesion in eight, annulo-aortic ectasia in two, active prosthetic valve endocarditis in two, and recurrent LVOTO in one. Cardiac status before operation was NYHA class II in one patient, III in nineteen, IV in four. Aortic valve replacement was performed in 17 patients, and aortic root replacement in seven. There was no early or late death. No structural deterioration was found. Surgical technical error resulted in moderate aortic regurgitation in one patient and mild paravalvular leak in another patient immediately after operation. All patients except one were not given anticoagulants postoperatively, but the entire group was free from thromboembolism. All patients returned to NYHA class I. Most homografts in this series were cryopreserved without antibiotic sterilization immediately after harvest, but homograft valve endocarditis did not occur. The results in this series suggested that homografts from heart transplant recipients or donors were encouraging, but more long-term follow-up was required to be determined whether homografts from heart transplant recipients without antibiotic sterilization were superior to homografts prepared in ordinary manner.

Adolescent↗
PubMed1992

Cervical carcinoma after negative Pap smears: evidence against rapid-onset cancers.

Recently, suggestions have been made that a 'rapid-onset' type of cervical cancer is emerging. Evidence for this entity is based on the diagnosis of invasive cervical carcinoma within 2 or 3 years of a 'normal' Pap smear. Analysis of 237 patients presenting to our unit between November 1986 and July 1990 with the histologic diagnosis of invasive carcinoma of the cervix revealed 51 patients (21.5%) who reported having had a 'normal' Pap smear within 2 years of diagnosis. Strenuous efforts were made to verify and retrieve these smears in an attempt to isolate a group of 'rapid-onset' cancers. Despite the patients' claim to the contrary, there was no record of a smear being performed in 15 patients (29%). The slides of six patients could not be located either due to lack of laboratory co-operation or because the slides had been destroyed: four of these patients had very early adenocarcinomas. The slides of 30 patients were retrieved and reviewed: 16 slides reported as negative contained cells consistent with either invasive carcinoma or carcinoma in-situ; four cases had virtually no cellular material on the slide; four cases contained atypical cells but requests for further material were not followed-up. Six patients had previously been treated for pre-invasive lesions over a range of 3-18 years. We found no case of invasive carcinoma in a patient with a confirmed adequate negative smear within 2 years of diagnosis. At most, six patients (2.52%) could have had 'rapid-onset' cancers but this could not be confirmed as these slides could not be reviewed. In summary, this study suggests that in our patient population, 'rapid-onset' cervical carcinoma is rare.

Journal Article↗