Biomedical subjects

L Fenwick

Publications and source records attributed to L Fenwick.

6 recordsLinked to original sources

PubMed2006

Assessment of fetal atrioventricular time intervals by tissue Doppler and pulse Doppler echocardiography: normal values and correlation with fetal electrocardiography.

OBJECTIVE: To establish gestational age-specific reference values of normal fetal atrioventricular (AV) time interval by spectral tissue Doppler imaging (TDI) and pulse-wave Doppler (PD) methods, and to assess their correlation with signal-averaged fetal PR intervals (ECG). DESIGN: Cohort study. SETTING: Tertiary centre for fetal cardiology. PATIENTS AND MEASURES: 131 pregnant women between 14 and 42 weeks' gestation underwent 196 fetal echocardiograms and 158 fetal ECG studies. TDI-derived AV intervals were measured as the intervals from atrial contraction (Aa) to isovolumic contraction (IV) and from Aa to ventricular systole (Sa) at the right ventricular free wall. PD-derived AV intervals were measured from simultaneous left ventricular inflow/outflow (in/out) and superior vena cava/aorta (V/AO) recordings. RESULTS: Measurements were possible by ECG in 61%, by TDI in 100%, by in/out in 100% and by V/AO in 97% of examinations. Aa-IV correlated significantly better with PR intervals (y = 0.67x + 38.29, R(2) = 0.15, p < 0.0001, mean bias 8.0 ms) than did in/out (R(2) = 0.10, p = 0.002, bias 18.7 ms) and V/AO (R(2) = 0.06, p = 0.02, bias 12.4 ms). Gestational age and AV intervals were positively correlated with all imaging modalities (R(2) = 0.19-0.31, p < 0.0001). CONCLUSION: This study showed the feasibility of fetal AV interval measurements by TDI, and established gestational age-specific reference data. TDI-derived Aa-IV intervals track ECG PR intervals more closely than PD-derived AV intervals and thus should be used as the ultrasound method of choice in assessing fetal AV conduction.

Atrial Function↗

PubMed1991

Management information and self-governing NHS hospital trusts.

The proposal for self-governing hospital trusts within the NHS, announced in the White Paper Working for Patients on 31 January 1989 and enacted through passage of the National Health Service and Community Care Act 1990 last July, introduces free market incentives to NHS hospitals. Hospitals applying for self-governing status must first demonstrate that they have an information system appropriate to support decision making in the new context. An overall information systems flow and an approach to information systems development are recommended based upon the Freeman Hospital model. The Freeman Hospital is a national pilot site selected by the NHS Management Executive for development of information systems for NHS hospitals.

Budgets↗

PubMed1987

Maternal positioning to prevent or alleviate dystocia in labor.

Women have always used different positions to make labor more comfortable and, when allowed, spontaneously change position numerous times during labor and birth. The positions they choose, while dictated by comfort, frequently prove to be beneficial in promoting labor progress. For 50 years, the value of mobility and position change received little attention, but recent research and advances in the design of birthing equipment indicate that maternal positioning provides a valuable, noninvasive, and acceptable intervention. This paper reviewed six mechanisms by which dystocia may be prevented or corrected through the use of maternal positioning.

Animals↗

PubMed1986

Maternal position during parturition in normal labor.

While controversy exists as to the relationship between maternal position in labor and such measures as the labor duration, subjective discomfort, and fetal outcome, little appears to be known about the positions women assume in labor when they are permitted to do so without coercion or instruction. To learn more about maternal position in labor, we observed 80 consecutive patients with uncomplicated normal spontaneous vaginal delivery over the course of labor to ascertain the positions volitionally chosen by each. Data were collected on position preferences and phase of labor. All labors were analyzed; a codified lexicon was established to describe the position pattern in each phase and the principal positions the patient assumed over the course of labor. The frequencies and distributions were determined for nulliparas and multiparas separately and rates of position change were assessed. It was found that gravidas chose a number of different principal positions in the early phases of labor, but that they became more narrowly selective in the deceleration phase and second stage; at the same time, they tended to change position more often in late labor.

Adolescent↗

PubMed1985

Toxicity testing for human in vitro fertilization programs.

Using a mouse embryo culture system, several procedures and materials associated with human in vitro fertilization protocols were tested for potential toxicity. Also, quality-control assays were performed for media prepared by nine different human in vitro fertilization programs. Detrimental effects upon embryo development were observed when culture media were exposed to the following substances: surgical instruments sterilized with Cidex or Cidex-7 or sterilized with ethylene oxide after packaging in Nest Protector Packs, various brands of surgical gloves, and various synthetic materials being evaluated as possible needle or catheter "liners." Results from comparative testing of media and serum supplements prepared by different in vitro programs indicated a wide range in culture medium quality, as assayed by the ability of the reagents to support mouse embryo development. The importance of an animal model system available to all human in vitro programs for routine quality-control analysis and testing of novel uses of materials and innovative methods is discussed.

Animals↗

PubMed1977

Production of prostaglandins by the pseudopregnant rat uterus, in vitro, and the effect of tamoxifen with the identification of 6-keto-prostaglandin F1alpha as a major product.

1 Prostaglandin production by rat uterus homogenates has been studied, in vitro, on days 2 to 13 of pseudopregnancy. 2 The highest production of prostaglandins occurred on day 5. 3 The amounts of prostaglandins F and D formed were higher than the amounts of prostaglandin E on every day studied. 4 The ratios of prostglandins F and D to prostaglandin E produced steadily decreased up to day 6. It then increased with the highest values occurring between days 10 and 13, 5 Progesterone levels in peripheral plasma increased rapidly from days 2 to 5, remained high up to day 9, then steadily decreased between days 10 and 13. 6 The anti-oestrogenic drug, tamoxifen administered on day 2, significantly inhibited the increase of prostaglandin production which occurred on day 5. Prostaglandin E production was inhibited more than the production of prostaglandins F and D. 7 Analysis of the uterine extracts by gas chromatography and mass spectrometry showed prostaglandin F2alpha, F1alpha (in trace amounts), E2 and D2 to be present. 8 The major product detected was 6-keto-prostaglandin F1alpha. Its identification forms an addendum to the paper. 9 Also present as a major product was 6(9)-oxy-11,15-dihydroxyprosta-7,13-dienoic acid.

Animals↗