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Biomedical subjects

M Tasker

Publications and source records attributed to M Tasker.

18 recordsLinked to original sources
PubMed2005

Is it possible to predict or prevent third degree tears?

OBJECTIVES: This paper reviews the causes anal sphincter injury during vaginal delivery. It emphasises that they are not usually the result of poor obstetric care. The role of the colorectal surgeon in their management is discussed. METHODS: Medline was searched using the key words third degree tears, pregnancy, risk factors, prevention and recurrence risk. A hand search of journals and located articles was made. Two hundred and twenty three papers were identified, 84 are referenced. RESULTS: The reported incidence of anal sphincter tears is usually between 0.5% and 2.5% of vaginal deliveries. Maternal factors such as parity and age and obstetric factors such as mode of presentation, the use of forceps and the size of the baby all influence the incidence of sphincter tears. Predicting tears in individual women is inaccurate and midwifery practices can do little to prevent them. Reducing pelvic floor morbidity by increasing the caesarean section rate would require that a large number of caesarean sections be done to prevent a small number of tears. The recognition of perineal trauma is improved by training. Accurate apposition of the sphincters with antibiotic cover and post-operative laxatives are the important technical aspects of the repair. Colorectal follow up helps to identify those women with symptoms and allows advice about the advisability of subsequent vaginal deliveries. A previous third degree tears increases the risk of a subsequent one, although the overall risk remains low. A second vaginal delivery after a third degree tear that has resulted in a functional deficit predisposes to worsening function. When there is no residual anatomical defect and no functional loss, there is no evidence of increased risk of incontinence following another vaginal delivery. CONCLUSION: Vaginal delivery will continue to be the main method of delivery and will continue to generate a low incidence of pelvic floor morbidity. The management of injury to the anal sphincter is facilitated by close co-operation between obstetricians and colorectal surgeons.

Delivery, Obstetric↗
PubMed2004

Anal function following third degree tears.

OBJECTIVE: To assess the anal function of women who have suffered a third degree perineal tear during parturition. PATIENTS: Fifty-three consecutive women who sustained a third degree tear, between January 1998 and March 2000, at the Princess Anne Maternity Unit, Royal Bolton Hospital were assessed. METHODS: Women were assessed at 3 months post partum using the Cleveland Clinic Incontinence Score, digital assessment of anal sphincter and endo-anal ultrasound scan. RESULTS: At 3 months post partum 75% of the participants had no symptoms of anal incontinence, 18% had mild symptoms and 7% had more severe symptoms. Anal endosonography demonstrated normal anal sphincters in 66% of participants, an abnormality in the external sphincter in 29% and a defect in both sphincters in 2%. There was poor correlation between symptoms and scan defects. CONCLUSION: The incidence of anal incontinence following repair of a third degree tear was not high and it is unlikely that we are missing a hidden pool of symptomatic women. No major change in management policy is required. The routine assessment of anal function in women who had sustained a third degree tear was appreciated by the women and enabled us to identify the small portion of women with significant symptoms.

Anal Canal↗
PubMed2001

Cytochrome oxidase subunit VI of Trypanosoma brucei is imported without a cleaved presequence and is developmentally regulated at both RNA and protein levels.

Mitochondrial respiration in the African trypanosome undergoes dramatic developmental stage regulation. This requires co-ordinated control of components encoded by both the nuclear genome and the kinetoplast, the unusual mitochondrial genome of these parasites. As a model for understanding the co-ordination of these genomes, we have examined the regulation and mitochondrial import of a nuclear-encoded component of the cytochrome oxidase complex, cytochrome oxidase subunit VI (COXVI). By generating transgenic trypanosomes expressing intact or mutant forms of this protein, we demonstrate that COXVI is not imported using a conventional cleaved presequence and show that sequences at the N-terminus of the protein are necessary for correct mitochondrial sorting. Analyses of endogenous and transgenic COXVI mRNA and protein expression in parasites undergoing developmental stage differentiation demonstrates a temporal order of control involving regulation in the abundance of, first, mRNA and then protein. This represents the first dissection of the regulation and import of a nuclear-encoded protein into the cytochrome oxidase complex in these organisms, which were among the earliest eukaryotes to possess a mitochondrion.

Amino Acid Sequence↗
PubMed2000

A novel selection regime for differentiation defects demonstrates an essential role for the stumpy form in the life cycle of the African trypanosome.

A novel selection scheme has been developed to isolate bloodstream forms of Trypanosoma brucei, which are defective in their ability to differentiate to the procyclic stage. Detailed characterization of one selected cell line (defective in differentiation clone 1 [DiD-1]) has demonstrated that these cells are indistinguishable from the wild-type population in terms of their morphology, cell cycle progression, and biochemical characteristics but are defective in their ability to initiate differentiation to the procyclic form. Although a small proportion of DiD-1 cells remain able to transform, deletion of the genes for glycophosphatidyl inositol-phospholipase C demonstrated that this enzyme was not responsible for this inefficient differentiation. However, the attenuated growth of the Delta-glycophosphatidyl inositol-phospholipase C DiD-1 cells in mice permitted the expression of stumpy characteristics in this previously monomorphic cell line, and concomitantly their ability to differentiate efficiently was restored. Our results indicate that monomorphic cells retain expression of a characteristic of the stumpy form essential for differentiation, and that this is reduced in the defective cells. This approach provides a new route to dissection of the cytological and molecular basis of life cycle progression in the African trypanosome.

Aconitic Acid↗
PubMed1996

Obstetric factitious disorder: is it more common than we think?

This case discusses the diagnosis of obstetric factitious disorder in a 27-year-old woman with bleeding per vagina. The case illustrates the need for a high index of suspicion in patients with unexplained physical symptoms during pregnancy, and highlights issues related to subsequent child care.

Adult↗
PubMed1990

Tubal pregnancy.

Explore the source record for details and available documents.

Female↗
PubMed1985

The outlook for women with borderline epithelial tumours of the ovary.

Seventy-two women with borderline epithelial tumours of the ovary have been followed up for between 3 and 9 years. Patients with disease confined to one or both ovaries had a good prognosis, irrespective of histological type. When extra-ovarian spread was present at the time of diagnosis, neither the histological type nor the amount of residual tumour predicted the long-term outcome in individual patients.

Adult↗
PubMed1985

The use of ROC curves in histopathologic decision making.

The applicability of receiver operator characteristic (ROC) curves to histopathology is presented in three examples, along with a basic discussion of some properties of ROC curves. One major application is in the attempt to define stages in diseases that show a continuous spectrum of histologic patterns, in which the uncertainty of boundary points and the overlap of features makes such definition difficult. Construction and analysis of ROC curves may help to identify the features with the greatest utility, as, for example, in the grading of mucinous carcinomas of the ovary. ROC curves can also be used to assess diagnostic differences between histopathologists, whether they are using different criteria or the same criteria but with different weightings, as, for example, in cervical premalignancy or borderline ovarian tumors.

Adenocarcinoma, Mucinous↗
PubMed1984

Impact of improved perinatal care on the causes of death.

A total of 440 perinatal deaths occurring in a maternity hospital over a 6 year period have been analysed clinically and pathologically. The decline in mortality could be attributed to a reduction in asphyxial deaths, lethal malformations, and macerated stillbirths. The establishment of a neonatal intensive care unit seemed to have been more successful in combating birth asphyxia than respiratory distress syndrome. Although the greatest reduction in perinatal mortality was in babies with birthweights between 1 and 1.5 kg, there was no decline in the deaths from hyaline membrane disease or intraventricular haemorrhage, or both. The most striking change was the drop in asphyxia as a cause of perinatal death which was independent of birth trauma. Earlier diagnosis of fetal distress with obstetric intervention and the establishment of the intensive care unit were seen as the main factors in this change, and their mutual dependence and evolution are emphasised.

Asphyxia Neonatorum↗