Transplacental distribution of labetalol stereoisomers at delivery.
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Biomedical subjects
Publications and source records attributed to T M Fiddes.
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AIMS: To investigate the transplacental distribution of salbutamol enantiomers after administration of racemate to women prior to Caesarian section. METHODS: Five women about to undergo elective Caesarian section were administered a single 0.25 mg bolus intravenous dose of (R,S)-salbutamol. The time from drug administration to delivery was different for each woman (27-105 min). Maternal and foetal umbilical cord venous blood samples were collected immediately after delivery and the plasma fraction analysed for salbutamol enantiomer concentrations by enantioselective high pressure liquid chromatography. RESULTS: The concentrations (mean +/- s.d.) of the active (R) enantiomer of salbutamol in cord and maternal plasma were 0.46 +/- 0.35 and 0.89 +/- 0.50 ng ml-1, respectively, and the difference was statistically significant (95% confidence interval (CI) of the difference: 0.12-0.74 ng ml-1). The corresponding concentrations of the (S) enantiomer of 0.92 +/- 0.45 and 1.11 +/- 0.67 ng ml-1, respectively, were not significantly different (95% CI of the difference -0.08-0.48 ng ml-1). The ratio of (R):(S) in cord plasma was significantly less than that in maternal plasma (P=0.016). CONCLUSIONS: Transplacental distribution of salbutamol enantiomers at Caesarian section after prior administration of racemate to mothers leads to concentrations in cord plasma that are significantly less for the active (R) enantiomer and not significantly different for the (S) enantiomer than in maternal plasma presumably due to enantioselective placental-foetal metabolism.
OBJECTIVE: To evaluate the efficacy of injecting 1% lignocaine into the subserosal aspect of the cornual end of the fallopian tubes to control post-operative pain after laparoscopic Filshie clip application. DESIGN: A double blind, randomised controlled trial. SETTING: The day surgery unit of the Dunedin Public Hospital, Otago, New Zealand. PARTICIPANTS: Fifty-nine women attending the public hospital requesting sterilisation. INTERVENTIONS: The experimental group received an infiltration of 1% lignocaine into the subserosal aspect of the cornual end of the fallopian tubes. The control group received an infiltration of normal saline in the same site. MAIN OUTCOME MEASURES: The use of post-operative pethidine and the scores obtained on a modification of the McGill present pain intensity score, a visual analogue scale of present pain, a pain relief score and comparisons of time to first analgesia use. RESULTS: The use of pethidine in the experimental group was significantly reduced [P = 0.001] Pain relief scores indicated significant benefit from the intervention. The time to first analgesic use was significantly greater in the experimental group. CONCLUSION: Lignocaine infiltration at the cornual end of the fallopian tubes during laparoscopic Filshie clip application is highly effective in producing post-operative pain relief.
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We describe a series of 100 cases of prenatal genetic diagnosis using the technique of chorion villus sampling. The advantage of chorion villus sampling in terms of earlier diagnosis, and its disadvantage of a higher incidence of false results, compared with amniocentesis, are noted. The comparative risks for pregnancy loss are discussed.
The in vitro production of immunoglobulins in response to stimulation with pokeweed mitogen (PWM) and fixed/killed Staphylococcus aureus Cowan 1 (SAC) was measured in conjunction with in vivo assays of plasma immunoglobulin levels to examine the quality and quantity of humoral immunity during human pregnancy and at parturition. Following stimulation with PWM, there is a significant enhancement of in vitro immunoglobulin-G (IgG) production during pregnancy. Following stimulation with PWM and SAC, there was a significant reduction in in vitro immunoglobulin-M (IgM) production immediately following parturition. There was a significant decrease in the plasma levels of IgG during pregnancy, although no change in the plasma levels of IgM were observed. The decrease in plasma immunoglobulin levels during pregnancy cannot be explained as the result of hemodilution and transplacental transfer. Altered humoral immunoregulation is the most likely means whereby an increase in immunoglobulin production during human pregnancy could occur. The possible effects of this on the outcome of pregnancy are discussed.
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Trisomy 16 detected at chorion villus sampling (CVS) may reflect the placental but not the fetal karyotype. We describe a case in which the pregnancy continued until intrauterine death at 37 weeks. Cytogenetic study of two placental samples showed 47, + 16 and 46,XX; the fetus was morphologically grossly normal, but fetal tissue culture was unsuccessful. Conservative management may be appropriate when trisomy 16 is detected at CVS and the pregnancy is normal ultrasonographically.
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To evaluate the potential role of immunoregulatory cells modulating the maternal immunologic response during pregnancy, we carried out phenotypic and functional studies in patients with normal obstetrical histories during each trimester and in patients with chronic idiopathic spontaneous abortions. Using monoclonal antibodies (Ortho), total numbers of T cells (T3+) and T4+ cells progressively increased during pregnancy (compared to nonpregnant controls) and then declined in the third trimester. Increased percentages of T8+, T10+, and Ia+ cells were found in the third trimester. The relative decline in numbers of T4+ cells, with increased numbers of T8+ cells, led to a significantly reduced T4/T8 ratio in the third trimester. Histamine receptors on T cells were quantitated by an immunofluorescent technique. Significantly reduced numbers of H1-type receptors were noted during the second trimester of pregnancy and this was associated with a decreased H1/H2 ratio. Functionally, histamine-induced suppression was measured in a lymphocyte proliferation assay. Patients in the first and second trimester of pregnancy had greater histamine-induced suppression of phytohemagglutinin (PHA)-stimulated proliferation at high concentrations of histamine (10(-3) to 10(-7)) but less suppression at the lower concentrations (10(-9) to 10(-11) M), compared to nonpregnant controls. In contrast, patients studied in the third trimester failed to respond to any concentration of histamine. MLC-induced suppressor activity was generated by incubating the maternal cells with either paternal or third-party mononuclear cells for 2 or 6 days and assaying the cell-free supernatant for its suppressive effects on PHA-stimulated proliferation. Maternal responses to paternal cells did not result in significant suppression in 2-day supernatants during any trimester but by 6 days the suppressive activity was equivalent to non-pregnant controls in patients during the first and second trimester. Maternal responses to third party cells was greater during the second trimester than either the first or third trimesters in both 2- and 6-day supernatants. Patients with histories of chronic idiopathic spontaneous abortions, who were not pregnant at the time of study, exhibited normal numbers of T-cell subsets and T4/T8 ratios. Numbers of both H1 and H2 receptor bearing T cells were proportionally reduced, resulting in a normal H1/H2 ratio. Despite having decreased numbers of H1 and H2 receptor bearing cells, histamine-induced suppression of PHA-stimulated proliferation was comparable to nonpregnant controls over the concentration range (10(-3) to 10(-11) M) employed.(ABSTRACT TRUNCATED AT 400 WORDS)
Inhibitor production (P)-typing was used as a strain marker in epidemiological studies of Streptococcus salivarius. 43 per cent of 180 adult subjects had inhibitory Strep. salivarius strains as components of their oral microbiota. Strains of 13 different P-type patterns were detected and strains of different P-types often co-existed in the same subject. Adults from whom inhibitor-producing Strep. salivarius strains had been isolated retained their characteristic bacteriocinogenic strains over a 3-yr period. A specific Strep. salivarius-inhibitor screening method was used to study oral acquisition of Strep. salivarius by 14 newborn babies. Initially the babies were colonized by a wide variety of strains, many of which were not detected in the mothers' mouths. By the fifth day of life, strains with P-types identical with those in the mother had often become established as quantitatively prominent members of the babies' Strep. salivarius population.
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