Biomedical subjects

Brian Hollis

Publications and source records attributed to Brian Hollis.

7 recordsLinked to original sources

PubMed2006

Thymosin beta4 inhibits benzalkonium chloride-mediated apoptosis in corneal and conjunctival epithelial cells in vitro.

Thymosin beta-4 (Tbeta(4)) is known to promote ocular wound healing, to decrease ocular inflammation, and to have anti-apoptotic effects on corneal epithelium. In this study, the effect of Tbeta(4) on the survival of human ocular surface epithelial cells exposed to benzalkonium chloride (BAK) was measured. Human conjunctival epithelial cells (HC0597) or human corneal epithelial cells (HCET) were treated with 0%, 0.001%, 0.01%, or 0.1% BAK for 15 min. After 3 or 24h of recovery in culture medium containing 1 microg/ml Tbeta(4), a dosage that has been demonstrated effective in several published studies, DNA synthesis was measured using a colorimetric BrdU incorporation assay. Both conjunctival and corneal epithelial DNA synthesis was inhibited by BAK in a dose-dependent manner. Tbeta(4) did not protect the epithelial cells from BAK-induced inhibition of proliferation. To assess the ability of Tbeta(4) to prevent apoptosis, epithelial cells were treated with 0.01% BAK+Tbeta(4) and cell death was measured using a colorimetric assay. BAK-induced apoptosis increased throughout the duration of the assay, which was carried out to 5 days in culture. Treatment of HC0597 cells with Tbeta(4) significantly inhibited the apoptosis shown to be initiated by BAK. Treatment of non-transformed human corneal epithelial cells (HCEC) with Tbeta(4) also significantly inhibited the apoptosis shown to be initiated by BAK at later times in culture. Ocular solutions containing BAK as a preservative are typically used for extended periods of time. This study suggests that Tbeta(4) may be able to overcome the apoptotic side effect of BAK, and may be a useful additive to solutions containing this preservative.

Apoptosis↗

PubMed2005

Feasibility study of a Latest Date of Delivery (LDD) system of managing pregnancy.

BACKGROUND: This study aimed to establish the acceptability of a Latest Date of Delivery (LDD) system of managing pregnancy. An LDD is the date at 42 weeks on which labour will be induced if a woman has not delivered by then. This study examined whether women under conventional expected date of delivery (EDD) management would find an LDD system acceptable in principle, and whether they would prefer it to the EDD system. An additional objective was to examine changes in state anxiety in late pregnancy, post-term, and after delivery. METHODS: This was a preliminary survey of women's attitudes towards an LDD system. Sixty-two women under normal pregnancy management completed questionnaires about the acceptability of an LDD system at 36 weeks gestation. In addition, questionnaires measuring state anxiety were completed at 36, 38, 40, and 41 weeks. RESULTS: The majority of women evaluated an LDD system positively, with 64% of women saying they would agree to an LDD and only 11.3% saying they would not. Forty percent of women said they would prefer an LDD to an EDD system and 36% said they were not sure. Women who had not delivered by 41 weeks had significantly more anxiety than those who had delivered. CONCLUSIONS: The LDD system appears to be acceptable to women and, for 40% of women, preferable to the EDD. Anxiety appears to increase as women go post-term, but problems of attrition mean the results regarding anxiety should be treated cautiously. Potential difficulties with implementing an LDD system are discussed.

Adult↗

PubMed2004

Maternal ethnic origin and fetal nasal bones at 11-14 weeks of gestation.

OBJECTIVES: Failure to visualise the fetal nasal bones at 11-14 weeks of gestation is associated with a significant increase in the risk for trisomy 21. However, it is not known whether the ethnic origin of the mother has any effect on the fetal profile and the prevalence of this marker. DESIGN: Prospective study. SETTING: London Teaching Hospital. POPULATION: Four thousand and four hundred and ninety-two consecutive fetuses undergoing routine first trimester ultrasound scanning at 11-14 weeks of gestation in a multiethnic population. METHODS: Examination of the nasal bones was attempted in the fetuses. MAIN OUTCOME MEASURE: Rate of visualisation of the fetal nasal bones. RESULTS: Five hundred fetuses were excluded from the analysis because of chromosomal abnormalities or a technically unsatisfactory examination. In the remaining 3992 fetuses, the maternal ethnic origin was African in 13.0%, Asian in 15.3% and Caucasian in 66.0%. Compared with Caucasians, the failure to visualise the fetal nasal bones was significantly higher in women of African (P= 0.0001) but not Asian origin (P= 0.24). A multivariable logistic regression model showed that having a mother of African origin is still significantly associated with an increased likelihood of absent fetal nasal bones compared with Caucasians (odds ratio 2.33), even after correcting for maternal age, parity and crown-rump length. CONCLUSION: There is a significant difference in the rate of visualisation of the fetal nasal bones in the first trimester in mothers of different ethnic origin. This suggest that corrections for maternal ethnicity will be required to ensure equity of fetal nasal bone screening in multiracial populations. Whether corrections are required for the father's ethnic origin remains to be determined.

Adult↗

PubMed2003

Nurse-led dyspepsia clinic using the urea breath test for Helicobacter pylori.

AIM: To audit the results of a nurse-led dyspepsia clinic. METHODS: Referrals to the Gastroenterology Department at Auckland Hospital for gastroscopy were assessed in a dyspepsia clinic. Initial evaluation included consultation and a urea breath test (UBT). Patients given eradication treatment prior to initial clinic assessment were excluded. Patients with a positive UBT were given eradication treatment and were reviewed two months later for symptom assessment and follow-up UBT. Patients with a negative UBT were usually referred back to the GP. RESULTS: There were 173 patients; mean age 38 years; 73 had a positive UBT (42%). A positive UBT was significantly associated with place of birth (NZ 16%; other place of birth 60%; p = 0.001). If the dominant symptom was epigastric pain 54% had a positive UBT; if it was reflux or bloating 29% were positive, p = 0.005. Forty nine UBT-positive patients had follow-up data and of these 43 had successful eradication (88%). Of patients with successful eradication, 40% had an excellent response, 38% improved, and 22% were not improved. After a mean follow up of 3.3 years 42/173 (24%) patients had a gastroscopy. Of these, 30 were initially UBT negative and 12 were UBT positive (9 had been successfully eradicated). The endoscopic findings were normal in 27, reflux oesophagitis in 13, pyloric stenosis in one, and gastric ulcer (HP+ve) in one. Helicobacter pylori status by biopsy was consistent with the UBT result. One hundred and thirteen patients also had H. pylori serology (Cobas Core, Roche) performed. There were three false negatives (negative predictive value of 94% [51/54]) and seven false positives (positive predictive value of 88% [52/59]). CONCLUSIONS: The urea breath test was found to be useful as part of the initial assessment of selected patients who would otherwise have been referred for endoscopy. It is likely that the need for gastroscopy was reduced, but longer follow up will be required to determine whether or not this effect is simply due to delayed referral. This approach is likely to have value only in patients who have a relatively high chance of being H. pylori positive.

Adult↗

PubMed2003

Placental edge to internal os distance in the late third trimester and mode of delivery in placenta praevia.

OBJECTIVES: To correlate transvaginal ultrasound findings with mode of delivery in cases of placenta praevia. DESIGN: Cohort study. SETTING: A London Teaching Hospital. METHODS: Retrospective review of all cases of placenta praevia diagnosed by transvaginal ultrasound between February 1997 and March 2002. MAIN OUTCOME MEASURES: Likelihood of vaginal delivery and major obstetric haemorrhage. RESULTS: A total of 121 pregnancies were studied with a mean scan-to-delivery interval of 10.5 days. In the 64 women who laboured, the likelihood of vaginal delivery rose significantly as the placental edge to internal os distance increased. Caesarean section rate was 90% when the placental edge-internal os distance was 0.1 to 2.0 cm, falling to 37% when this measurement was over 2.0 cm (P < 0.00045). CONCLUSION: Trial of vaginal delivery is appropriate in cases with a placental to internal os distance >2 cm. The term "praevia" should be restricted to cases where the placental edge is < or =2 cm from the internal os, as the likelihood of operative delivery and significant postpartum haemorrhage is high. Cases where the placenta is more than 2 cm from the internal os have a greater than 60% chance of vaginal delivery and should be defined as "low lying" in order to reduce the clinician's bias towards operative delivery.

Adult↗

PubMed2002

Prolonged pregnancy.

Prolonged pregnancy is defined as any pregnancy that lasts 294 days or more. It is now well recognized that prolonged pregnancy is associated with an increased risk of perinatal mortality and morbidity. It is these complications of pregnancy that have led obstetricians to adopt a policy of induction of labour before the onset of the post-term period. The induction of labour between 41 and 42 weeks is, however, a very crude strategy for reducing term and post-term stillbirth rates. Although the risk of fetal death is increased after 42 weeks, many more fetuses die in utero between 37 and 42 weeks than die in the post-term period. It appears that smaller term fetuses run a greater risk than their larger counterparts, and that current methods of antepartum assessment of the term fetus are still inadequate. It behoves us as obstetricians to improve our capabilities in identifying the compromised fetus at term. This review puts into perspective the most recent publications and highlights areas requiring further study.

Female↗

PubMed2002

Screening for aneuploidy in the first trimester by assessment of blood flow in the ductus venosus.

OBJECTIVE: To assess the role of ductus venosus Doppler assessment in screening for fetal aneuploidy in pregnancies at 11-14 weeks of gestation. DESIGN: Prospective observational study. SETTING: A tertiary referral fetal medicine unit. POPULATION: Two hundred fifty-six consecutive pregnancies between 11 and 14 weeks of gestation referred to our unit. METHODS: Nuchal translucency was measured and colour Doppler imaging was used to assess normal (forward) or abnormal (absence/reversed) ductus venosus flow during atrial contraction. MAIN OUTCOME MEASURES: Fetal karyotype, structural abnormalities and pregnancy outcomes. RESULTS: The nuchal translucency measurement was > or = 95th centile in 90 (35.2%) pregnancies, and 123 (48.0%) had a nuchal translucency-related risk of > or = 1:300. There were 46 chromosomally abnormal pregnancies and six euploid pregnancies with adverse outcome. The prevalence of abnormal ductus venosus Doppler waveforms in normal pregnancies was 4.49% (95% CI 1.76-8.76%). The sensitivities of abnormal nuchal translucency measurement alone, ductus venosus velocimetry alone or nuchal translucency and ductus venosus combined for Down's Syndrome were 80.4%, 58.7% and 93.5%, respectively. The likelihood ratios for aneuploidy with abnormal nuchal translucency measurement alone, ductus venosus velocimetry alone or nuchal translucency and ductus venosus combined were 3.33, 9.83 and 3.48, respectively. CONCLUSION: There is clear association between abnormal flow in the ductus venosus and fetal aneuploidy. The use of ductus venosus velocimetry in combination with nuchal translucency is better than either test alone, since it increases the sensitivity in the detection of Down's Syndrome to 94% and decreases the likelihood ratio of a negative test to 0.08.

Adult↗