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Biomedical subjects

A Herbert

Publications and source records attributed to A Herbert.

At least 73 records · Page 4Linked to original sources
PubMed1996

Rapid in situ harvesting and cytogenetic analysis of perinatal tissue samples.

Thirty perinatal solid tissue samples were used in a pilot study to test the efficacy of collagenase disaggregation onto coverslips, open system culture under low O2 conditions, pre-harvest incubation in bromodeoxyuridine (BrdU) and colcemid, and in situ automated harvesting. Following the success of the pilot study, the new method was applied to a further 126 consecutive diagnostic samples making a total of 156. The method reduced average tissue culture times from 17 to 8.7 days (range 2-17), improved success rates from 76 to 88 per cent, and simultaneously increased the resolution of cytogenetic analysis.

Amnion↗
PubMed1996

Primary cervical lymphoma: the role of cervical cytology.

Two cases of primary malignant lymphoma of the uterine cervix are reported. Both were confirmed by histology as high grade B cell lymphomas. In one case, the diagnosis was made on a second colposcopic biopsy after an initial cervical smear and colposcopic biopsy were negative. In the second case, dyskaryotic cells of uncertain type were identified in a cervical smear taken at colposcopy performed as part of follow up for previous cervical intraepithelial neoplasia (CIN)I. The cytologic features and differential diagnosis of this rare cervical neoplasm are discussed, with emphasis on the role of the Papanicolaou smear in the initial diagnosis of this tumour.

Adult↗
PubMed1996

Comparison of cervical cytology reporting rates: a useful adjunct to external quality assurance.

Reporting rates for abnormal and inadequate cervical smears have been compared during a 5-year period in nine laboratories and related to targets and achievable ranges recently recommended by the National Health Service Cervical Screening Programme (NHSCSP). There was improved consistency in rates for all grades of abnormality as well as inadequate smears. The average rate for moderate and severe dyskaryosis combined increased to 1.6%, which is the target recommended by the NHSCSP, and the standard deviation fell from 0.52 to 0.27. Although average rates for mild dyskaryosis and borderline nuclear change combined and inadequate smears both remained within the achievable range recommended by the NHSCSP, four laboratories were above the upper limit for each of those categories in the final year. During the 5 years of the study there was a fall in the number of 'inflammatory' smears coded as negative with a recommendation for early repeat. Only one laboratory still uses that category. The challenge for the future lies in controlling high rates for minor abnormalities and inadequate smears while maintaining acceptable rates for moderate and severe dyskaryosis. Comparison of reporting rates is regarded by the participating laboratories as a useful adjunct to external quality assurance.

Cell Nucleus↗
PubMed1996

Invasive cervical cancer in Southampton and South West Hampshire: effect of introducing a comprehensive screening programme.

A study of invasive cervical cancer in Southampton and South West Hampshire is reported, covering three consecutive three year periods during which the screening coverage increased from an estimated 60% to a recorded 87% of eligible women aged 20-64. From the first to the third periods of the study in that age group registrations of fully invasive squamous cell carcinoma (stage lb and above) fell from 64 to 30 (53%), which was largely counteracted by an increase in microinvasive squamous cell carcinoma (linear trend: P<0.0001). In the same age group registrations of adenocarcinoma rose slightly, which resulted from an increase in the number diagnosed at a depth of invasion of less than 3 mm. There were no significant changes in the numbers of stage III and IV cancers or among cancers in women aged 65 and over. A strong inverse association was found between stage of both histological types of cancer and their likelihood of being screen detected rather than symptomatic: 91% of screen detected cancers were diagnosed at stage I compared with 38% of symptomatic cancers. There was a slight downward trend in the incidence of cancer per 100,000 total female population across the three periods of the study with a significant trend towards low stage disease, which is likely to reduce mortality in years to come. The trend towards screen detected cancers and cancers of less than 3 mm depth of invasion is presented as a positive outcome to be expected in early rounds of increasing the screening coverage.

Adenocarcinoma↗
PubMed1996

Relation between the incidence of invasive cervical cancer and the screening interval: is a five year interval too long?

OBJECTIVE: To examine the incidence of invasive cervical cancer per 100,000 women years at risk and relative risk according to screening history among eligible women aged 25-69 in Southampton and South West Hampshire during the three years after completion of the first round of comprehensive screening. RESULTS: There was a significantly higher incidence of invasive cervical cancer in women who had not been screened during the preceding 0.5-5.5 years than in those who had been screened (relative risk (RR) 2.6; 95% confidence interval (CI) 1.6 to 4.3). Among the latter group of women (with interval cancers) there was a significantly higher incidence in those with a long interval of 3.5-5.5 years since their most recent smear than in those with a short interval of 0.5-3.5 years (RR 2.2; 95% CI 1.3 to 3.8). Among women with non-interval cancers, there was a significantly higher incidence among those who had no cytology record than among those who had been screened but were overdue for a smear (RR 3.0; 95% CI 1.2 to 7.3). When screen detected cancers were excluded from the figures the relative risks for all the comparative groups described above were greater, though the 95% confidence limits were wider because the numbers were smaller. The most pronounced difference in incidence was between symptomatic cancers in women with a short screening interval (5.8 per 100,000 women years at risk) and in women with no cytology record (71.3 per 100,000 years at risk). Most cancers were interval cancers (76%) because of the high screening coverage: 89.2% of eligible women aged 25-69 had been screened during the preceding 0.5-5.5 years. The overall incidence per 100000 women years at risk approached that of interval cancers, and was nearer to that observed in the short than the long interval because 74.7% of women had been screened within 3.5 years. CONCLUSION: The results confirm the effectiveness of screening but suggest that a five year screening interval may be too long, at least during the early rounds of screening.

Adult↗
PubMed1996

[Postoperative evaluation of different surgical procedures in genuine stress urinary incontinence: a retrospective study].

An evaluation of the surgical treatment for stress and mixed urinary incontinence and pelvic relaxation. One-year follow-up, was done. A retrospective study with 144 files from the surgeries performed between February 1993 and June 1994, at the Clínica de Urología Ginecológica del Instituto Nacional de Perinatología. We excluded 37 files because of incomplete information. The age, parity, hormonal stage, preoperative diagnosis by urodynamic studies, surgical treatments and one-year follow-up were analyzed. The mean age was 45.5 years. Pereyra procedure was performed in 53, Burch procedure in 47, anterior colporrhaphy in 5, and sling procedure in 2 patients. The incidence of complications was similar between the different groups. Resumption of spontaneous postsurgical voiding was delayed in the Pereyra group. The Burch urethropexy and Pereyra procedures were equally effective, with no statistical differences observed. Burch vaginal suspension was not more effective for the correction of urinary stress incontinence than Pereyra procedure.

Adult↗
PubMed1995

Chicken double-stranded RNA adenosine deaminase has apparent specificity for Z-DNA.

A M(r) 140,000 protein has been purified from chicken lungs to apparent homogeneity. The protein binds with high affinity to a non-BNA conformation, which is most likely to the Z-DNA. The protein also has a binding site for double-stranded RNA (dsRNA). Peptide sequences from this protein show similarity to dsRNA adenosine deaminase, an enzyme that deaminates adenosine in dsRNA to form inosine. Assays for this enzyme confirm that dsRNA adenosine deaminase activity and Z-DNA binding are properties of the same molecule. The coupling of these two activities in a single molecule may indicate a distinctive mechanism of gene regulation that is, in part, dependent on DNA topology. As such, DNA topology, through its effects on the efficiency and extent of RNA editing may be important in the generation of new phenotypes during evolution.

Adenosine Deaminase↗
PubMed1995

Achievable standards, benchmarks for reporting and criteria for evaluating cervical cytopathology.

The cervical smear test, like all screening tests, is not 100% effective in detecting abnormality. In order to prevent 80-90% of invasive cancers, cervical screening requires cervical smears to be taken competently at regular intervals and correctly interpreted. With laboratories following the guidelines in this report, the NHSCSP should be able to meet the Health of the Nation target to reduce the incidence of invasive cervical cancer to less than 12 cases per 100 000 women in the UK by the year 2000.

Biomarkers, Tumor↗
PubMed1995

Double-stranded RNA adenosine deaminase binds Z-DNA in vitro.

A Z-DNA binding protein of 140,000 M(r) has been purified from chicken lungs by sedimentation through 40%(w/w) sucrose and Z-DNA affinity chromatography. Specificity of the protein for Z-DNA was confirmed by competition with polyd(CG) that had been stabilized in the Z-DNA conformer by chemical bromination and also with a supercoiled plasmid that contains a Z-DNA-forming insert. In addition to a Z-DNA binding site, the protein also has a separate binding site for double-stranded RNA. Peptide sequence of the protein shows that it has high similarity to the RNA editing enzyme double-stranded RNA adenosine deaminase (dsRAD), which deaminates adenosine in dsRNA to form inosine. The Z-DNA binding protein has this enzymatic activity, confirming its identity to dsRAD. Recombinant human dsRAD also binds to Z-DNA. Z-DNA is stabilized in a sequence-dependent manner by negative supercoiling, which occurs in actively transcribed genes upstream to RNA polymerase. It is proposed that Z-DNA links editing to transcription by localizing dsRAD to a particular region of a gene and thus determines the efficiency with which an RNA is edited. The presence of Z-DNA forming elements in many genes raises the possibility that RNA editing by dsRAD is far more prevalent than is currently thought.

Adenosine Deaminase↗
PubMed1994

Follow up of women with a history of mildly abnormal cervical smears which have returned to normal without treatment.

The progress of 124 women with at least two negative cervical smears following a history of mildly abnormal smears for which no treatment had been given was compared with 106 women with negative smears and a clinical history of genital warts or herpes virus infection and 460 age-matched controls. After 4 years, excluding those for whom there was no follow up, 5.8% of those with a history of abnormal smears, none of those with a clinical history of genital warts or herpes virus and 1.1% of controls had developed histological evidence of at least cervical intraepithelial neoplasia grade III (CINIII) when referred for investigation of subsequent abnormal smears; one woman, from the control group, had developed invasive cervical cancer. Women with two negative smears after a history of abnormal smears who subsequently developed CINIII were more likely to have had a previous smear reported as moderate or mild-moderate dyskaryosis (2/6) compared with those whose follow up was negative (2/89). The results suggest that two negative cervical smears may not necessarily indicate that a lesion has regressed, but that a clinical history of genital warts or herpes virus infection should not be an indication for increased surveillance.

Adult↗
PubMed1993

Determination of Ki67 growth fraction and oestrogen receptors in screen-detected breast cancer using cytological preparations.

Oestrogen receptor (ER) status of 77 cases of screen-detected breast cancer has been determined using cytological preparations. In 48% ER status was positive, which was the same proportion as that formed in a control group of age-matched patients with symptomatic breast carcinoma. Since the screen-detected group contained more low grade tumours, the percentage of ER-positive cases would be expected to be higher. The reasons for the discrepancy are discussed. Ki67 score has been determined for 41 cases of screen-detected cancer. Ki67 score showed a positive correlation with histological tumour grade and a negative correlation with ER status. However, there was no correlation with tumour size or lymph node status. The Ki67 scores in the screen-detected cancers were essentially similar to those found in an age-matched symptomatic group, but the very low scores were only found in the screened group.

Biopsy, Needle↗
PubMed1993

Management of screen-detected breast cancer: audit of the first 100 cases in the Southampton and Salisbury breast screening programme.

With the natural history and optimal treatment of a high proportion of screen-detected breast cancers yet to be determined, treatment poses the management team with a number of therapeutic dilemmas. This study surveys the management policy and treatment of a consecutive series of 100 screen-detected cancers treated in a single breast unit. The problems encountered are discussed. There were 87 women with stage Tis or T1 tumours, including 26 women with in situ cancers, four with invasive cancers less than 5 mm in size, and seven with tubular cancers. Sixty-six women were managed with breast-conserving surgery and 36 women underwent localisation biopsy as the sole surgical treatment of the breast. With selection bias for high-grade and lateral tumours, only 2/13 cancers up to 10 mm in size were lymph node positive on axillary clearance. All lymph node positive women received adjuvant therapy. No adjuvant therapy was given in 43 cases, including those with in situ cancer. Thirty-six had extensive intraductal component (EIC). Patient and surgeon choice tends to be a major factor both in type of surgery and adjuvant therapy for screen-detected breast cancer. The optimal treatment for tumours detected by breast cancer screening is debatable and randomised trials on their management need to be expedited.

Breast Neoplasms↗