Biomedical subjects
Publications and source records attributed to Gregory K Davis.
Although in Drosophila pair-rule genes play crucial roles in the genetic hierarchy that subdivides the embryo into segments, the extent to which pair-rule patterning is utilized by different arthropods and other segmented phyla is unknown. Recent data of Dearden et al.1 and Henry et al.,2 however, hint that a pair-rule mechanism might play a role in the segmentation process of basal arthropods and vertebrates.
OBJECTIVES: To determine whether routine urinalysis in the antenatal period facilitates diagnosis of pre-eclampsia. Can routine urinalysis during pregnancy be discontinued in women with normal results of dipstick urinalysis and microscopy at the first antenatal visit? DESIGN: Prospective observational study. SETTING: A metropolitan public hospital and a private hospital in Sydney (NSW). PARTICIPANTS: One thousand women were enrolled at their first antenatal visit (March to November 1999), and 913 completed the study. OUTCOME MEASURES: The primary outcome was a diagnosis of de novo hypertension (gestational hypertension, pre-eclampsia, or pre-eclampsia superimposed on chronic hypertension). RESULTS: Thirty-five women had dipstick proteinuria at their first antenatal visit. In 25 (71%) of these women, further dipstick proteinuria was detected during pregnancy, and two (6%) were diagnosed with pre-eclampsia. Of the 867 without dipstick proteinuria at the first visit, 338 (39%) had dipstick proteinuria (> 1+) at some time during pregnancy. There were no statistically significant differences in the proportion of women with and without dipstick proteinuria at their first visit who developed hypertension during pregnancy. Only six women developed proteinuria before the onset of hypertension. Women who had an abnormal result of a midstream urine test at their first visit, compared with women with a normal result, were more likely to have a urinary tract infection diagnosed during pregnancy; however, the numbers were small. CONCLUSION: In the absence of hypertension, routine urinalysis during pregnancy is a poor predictor of pre-eclampsia. Therefore, after an initial screening urinalysis, routine urinalysis could be eliminated from antenatal care without adverse outcomes for women.
OBJECTIVE: to compare the experiences of women who received a new model of continuity of midwifery care with those who received standard hospital care during pregnancy, labour, birth and the postnatal period. DESIGN: a randomised controlled trial was conducted. One thousand and eighty-nine women were randomly allocated to either the new model of care, the St George Outreach Maternity Project (STOMP), or standard care. Women completed a postal questionnaire eight to ten weeks after the birth. PARTICIPANTS: women in the trial were of mixed obstetric risk status and more than half the sample were born in a non-English speaking country. FINDINGS: questionnaires were returned from 69% of consenting women. STOMP women were significantly more likely to have talked with their midwives and doctors about their personal preferences for childbirth and more likely to report that they knew enough about aspects of labour and birth, particularly induction of labour, pain relief and caesarean section. Almost 80% of women in the STOMP group experienced continuity of care, that is, one of their team midwives was present, during labour and birth. STOMP women reported a significantly higher 'sense of control during labour and birth'. Sixty-three per cent of STOMP women reported that they 'knew' the midwife who cared for them during labour compared with 21% of control women. In a secondary analysis, women who had a midwife during labour who they felt that they knew, had a significantly higher sense of 'control' and a more positive birth experience compared with women who reported an unknown midwife. Postnatal care elicited the greatest number of negative comments from women in both the STOMP and the control group. CONCLUSION: The reorganisation of maternity services to enable women to receive continuity of care has benefits for women. The benefits of a known labour midwife needs further research.
OBJECTIVE: The purpose of this study was to determine whether platelet activation occurs only in preeclampsia or also in normal pregnancy. STUDY DESIGN: Thirty women with preeclampsia, 30 women with gestational hypertension, 20 women with essential hypertension, 30 pregnant women with normotension, and 30 nonpregnant women were recruited at St George Hospital, Sydney, Australia. Platelet activation was determined by flow cytometry on whole blood samples. RESULTS: Platelet activation was similar in all groups, except the group with preeclampsia. Compared with normal pregnant women, women with preeclampsia had significantly greater CD62 expression (1.35% vs 0.61%; P =.002), CD63 expression (1.73% vs 0.95%; P <.0001) and annexin V binding (1.03% vs 0.66%;P =.03) and significantly fewer circulating platelet microparticles (33 vs 49 x10(9)/L; P =.001). This was unrelated to other parameters that included platelet counts. Women with gestational hypertension in whom preeclampsia developed did not have enhanced platelet activation profiles. CONCLUSION: Platelet activation is increased in preeclampsia but not in other hypertensive disorders or in normal pregnancy. This may be part of the pathophysiologic factors of preeclampsia complications but is not predictable by the platelet count and is not apparent in all women with preeclampsia.
OBJECTIVE: The purpose of this study was to determine whether the slower- and longer-acting nifedipine tablets were as effective and safe as the rapid onset and short-acting nifedipine capsules for the treatment of acute severe hypertension in pregnancy. STUDY DESIGN: Sixty-four women in the second half of pregnancy who were not in labor randomly received 10 mg nifedipine tablets (n = 55 studies) or 10 mg nifedipine capsules (n = 74 studies) if blood pressure was > or =170/110 mm Hg. Blood pressure, heart rate, and cardiotocography were monitored over the subsequent 90 minutes. Successful treatment was a target blood pressure of 110 to 169/80 to 109 mm Hg after 90 minutes; unsuccessful treatment included fetal distress at any stage, the requirement for additional treatment (intravenous hydralazine), or the development of hypotension by 90 minutes after treatment. RESULTS: Nifedipine capsules lowered blood pressure further (28/19 vs 21/13 mm Hg; P =.03) than nifedipine tablets, but more than three quarters of each group had a successful treatment. Twice as many women (28%) who received nifedipine tablets required a second dose to achieve successful treatment (P =.05), but fewer women had hypotensive episodes (P =.001). Fetal distress was uncommon in both groups (3%-4%), and both groups were delivered an average of 4 days after the study. CONCLUSION: Nifedipine tablets, although of slower onset, are as effective as nifedipine capsules for the rapid treatment of severe hypertension in pregnancy.
OBJECTIVES: (i) To document variation in management of hypertension in pregnancy; (ii) to determine whether this variation falls within current management guidelines; and (iii) to make recommendations for developing future guidelines. DESIGN: Questionnaire-based survey. SETTING: Australia and New Zealand. POPULATION: All specialist obstetricians. METHODS: Questionnaires were sent to 1198 obstetricians in Australia and New Zealand. Those returned by respondents currently in obstetric practice were analysed. Information was obtained on their current clinical practices relating to the diagnosis and management of hypertension in pregnancy. RESULTS: Of 1198 obstetricians surveyed, 973 (81%) replied. Of these, 686 (71%) were responsible for obstetric care. Considerable variation in practice was found, particularly in relation to the measurement of blood pressure, the determination of hypertension and significant proteinuria, and the decision to institute antihypertensive drug treatment. The recommendations of the Australasian 1993 Consensus Statement appeared to have had little influence on practice. There has been a striking increase in the use of magnesium sulphate for the prevention of convulsions in preeclampsia. CONCLUSIONS: There is significant variation in management of hypertensive pregnancies that differs from current guidelines. It is not known whether this diversity adversely affects clinical outcomes. Until further outcome evidence is available, consensus statements may be better confined to basic aspects of management for which there is high level evidence.
Over the past dozen years, studies comparing the expression of orthologues of the Drosophila segmentation genes among various insects have served to broaden our view of the ways in which insects make segments. The molecular data suggest that, although the overall genetic mechanisms of segmentation during embryogenesis have been conserved, the details of this process vary both within and between various insect orders. Here we summarize comparative gene expression data relevant to segmentation with an emphasis on understanding the extent of molecular patterning prior to gastrulation. These results are discussed in embryological context with an eye toward understanding the evolution of segmentation within insects.