Randomized,double-blind comparison of different inspired oxygen fractions during general anaesthesia for Caesarean section

Background. The optimal inspired oxygen fraction FI_O2 for fetaloxygenation during general anaesthesia for Caesarean sectionis not known. Methods. We randomized patients having elective Caesarean sectionto receive one of the following: FI_O2 0.3, FI_N2O 0.7 and end-tidalsevoflurane 0.6% (Group 30, n=20); FI_O2 0.5, FI_N2O 0.5 and end-tidalsevoflurane 1.0% (Group 50, n=20), or FI_O2 1.0 and end-tidalsevoflurane 2.0% (Group 100, n=20) until delivery. Neonataloutcome was compared biochemically and clinically. Results. At delivery, for umbilical venous blood, mean PO₂ wasgreater in Group 100 (7.6 (SD 3.7) kPa) compared with both Group30 (4.0 (1.1) kPa, P<0.0001) and Group 50 (4.7 (0.9) kPa,P=0.002) and oxygen content was greater in Group 100 (17.2 (1.6)ml dl^–1) compared with both Group 30 (12.8 (3.6) ml dl^–1,P=0.0001) and Group 50 (13.8 (2.6) ml dl^–1, P=0.0001).For umbilical arterial blood, PO₂ was greater in Group 100 (3.2(0.4) kPa) compared with Group 30 (2.4 (0.7) kPa, P=0.003),and in Group 50 (2.9 (0.8) kPa) compared with Group 30 (2.4(0.7) kPa, P=0.04); oxygen content was greater in Group 100(10.8 (3.5) ml dl^–1) than in Group 30 (7.0 (3.0) ml dl^–1,P<0.01). Apgar scores, neonatal neurologic and adaptive capacityscores, and maternal arterial plasma concentrations of epinephrineand norepinephrine before induction and at delivery were similaramong groups. No patient reported intraoperative awareness. Conclusions. Use of FI_O2 1.0 during general anaesthesia forelective Caesarean section increased fetal oxygenation. Br J Anaesth 2002; 89: 556–61     

Uptake of 111In-Z2D3 on SPECT imaging in a swine model of coronary stent restenosis correlated with cell proliferation.

Small targets such as cell proliferation in the coronary arteries may potentially be detected with single-photon imaging using high-radiotracer-specific activity. We hypothesized that an antibody linked to polymers to increase specific radioactivity can be visualized on SPECT images and that counts in the target will correlate with the strength of the biologic signal. METHODS: Twenty-four stents were placed using the balloon overexpansion technique in the coronary arteries of 14 juvenile domestic swine. One week later, the animals received 74 MBq of (111)In-diethylenetriaminepentaacetic acid-polylysine Z2D3-F(ab')(2), and SPECT imaging was performed at 24 h. The coronary vessels were removed, and the stented vessels were processed with plastic embedding and sectioning. Medial and neointimal areas, percentage of vessel stenosis, and cell proliferation indices were quantified using a 5-bromo-2-deoxyuridine (BrdU) labeling index. Reconstructed SPECT images were interpreted for tracer uptake in coronary vessels. RESULTS: Sixteen of the vessels were positive on SPECT imaging and 10 were negative. The percentage injected dose was 0.85 +/- 0.28 x 10(-3) in scan-positive vessels and 0.34 +/- 0.11 x 10(-3) in scan-negative vessels (P < 0.001). The medial-plus-neointimal proliferative index was 42 +/- 11 in scan-positive vessels and 11 +/- 11 in scan-negative vessels (P < 0.0001). The percentage stenoses were 21% +/- 22% versus 19% +/- 15% (not statistically significant). When individual values for the stented-to-control vessel counts were plotted against BrdU labeling index, a significant relationship was found (r(2) = 0.441; P = 0.0014). CONCLUSION: These data indicate that small targets relevant to human coronary vascular disease may be detected using polymer-modified radiolabeled antibodies.     

Effects of epidermal growth factor, fibroblast growth factor, and transforming growth factor-beta on corneal cell chemotaxis.

The effects of recombinant basic fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor-beta (TGF-beta) on migration of human and bovine corneal cells were determined using checkerboard analysis in Boyden chambers. EGF, FGF, and TGF-beta each stimulated high levels of chemotactic migration. Each growth factor, however, induced a different dose-response pattern. Migration stimulated by FGF reached a plateau at a concentration between 100 and 200 ng/ml for endothelial, epithelial, and stromal fibroblasts. By contrast, chemotactic responses to EGF peaked between 10 and 50 ng/ml, then decreased at higher concentrations. TGF-beta also stimulated a peak in migration in all three corneal cells, but the peak of migration occurred at an approximately 1000-fold lower concentration (1 pg/ml) than for EGF. Checkerboard analysis demonstrated that FGF and EGF, but not TGF-beta, stimulated chemokinesis of bovine, stromal, and endothelial cells. These results demonstrate that FGF, EGF, and TGF-beta induce migration in pure populations of bovine and human corneal cells and support the concept that these growth factors may play key roles in corneal wound healing by regulating migration of corneal cells.     

Antimyosin-labeled monocrystalline iron oxide allows detection of myocardial infarct: MR antibody imaging.

The synthesis and in vivo antigen targeting of a novel iron oxide compound were studied. A monocrystalline iron oxide nanoparticle (MION) was synthesized that contains a small (mean diameter, 2.9 nm +/- 0.9) single crystal core, passes through capillary membranes, and exhibits superparamagnetism. The MION was attached to antimyosin Fab (R11D10) and used for immunospecific magnetic resonance (MR) imaging of cardiac infarcts One hour after intravenous administration of MION-R11D10 in rats (100 mumol/kg), a marked decrease in the signal intensity of infarcted myocardium was observed. Immunohistochemical correlation confirmed the specific binding of the immunoconjugate to infarcted, but not to normal, myocardium. No decrease in cardiac signal intensity was observed when unconjugated MION was administered intravenously. The results indicate the feasibility of immunospecific MR imaging in living organisms.     

C-peptide, IGF-I, sex-steroid hormones and adiposity: a cross-sectional study in healthy women within the European Prospective Investigation into Cancer and Nutrition (EPIC)

Objectives: The risk of some cancers is positively associated with body weight, which may influence circulating levels of sex-steroid hormones, insulin and IGF-I. Interrelationships between these hormones and the associations with adiposity were evaluated in healthy women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC).Methods: A cross-sectional analysis was performed on anthropometric and hormonal data from 743 pre- and 1217 postmenopausal women. Body mass index (BMI) and waist circumference were used as indicators of adiposity. C-peptide, Insulin Growth Factor (IGF)-I, Insulin Growth Factor binding protein (IGFBP)-3, androgens, estrogens and sex hormone binding globulin (SHBG) were measured by immunoassays; free sex steroid concentrations were calculated.Results: BMI and waist circumference were positively correlated with estrogens in postmenopausal women and with C-peptide, free testosterone and inversely with SHBG in all women. C-peptide and IGF-I were inversely correlated with SHBG, and positively with free sex steroids in postmenopausal women. IGF-I was positively associated with postmenopausal estrogens and androgen concentrations in all women.Conclusions: Sex-steroid concentrations appear to be regulated along several axes. Adiposity correlated directly with estrogens in postmenopausal women and with insulin, resulting in lower SHBG and increased levels of free sex steroids. Independent of adiposity and insulin, IGF-I was associated with decreased SHBG levels, and increased concentrations of androgens and postmenopausal estrogens.     

Age at menarche in relation to adult height: the EPIC study

In the last two centuries, age at menarche has decreased in several European populations, whereas adult height has increased. It is unclear whether these trends have ceased in recent years or how age at menarche and height are related in individuals. In this study, the authors first investigated trends in age at menarche and adult height among 286,205 women from nine European countries by computing the mean age at menarche and height in 5-year birth cohorts, adjusted for differences in socioeconomic status. Second, the relation between age at menarche and height was estimated by linear regression models, adjusted for age at enrollment between 1992 and 1998 and socioeconomic status. Mean age at menarche decreased by 44 days per 5-year birth cohort (beta = -0.12, standard error = 0.002), varying from 18 days in the United Kingdom to 58 days in Spain and Germany. Women grew 0.29 cm taller per 5-year birth cohort (standard error = 0.007), varying from 0.42 cm in Italy to 0.98 cm in Denmark. Furthermore, women grew approximately 0.31 cm taller when menarche occurred 1 year later (range by country: 0.13-0.50 cm). Based on time trends, more recent birth cohorts have their menarche earlier and grow taller. However, women with earlier menarche reach a shorter adult height compared with women who have menarche at a later age.     

An association between respiratory function and hip bone mineral density in older men: a cross-sectional study

The association between respiratory function and bone mineral density (BMD) among women living in the community has been reported previously. We examined the association between forced expiratory volume in 1 s (FEV₁) and BMD measured at hip using dual-energy X-ray absorptiometry in a group of 947 men (aged 65 to 76 years) recruited from general practice age-sex registers in Cambridge between 1991 and 1995. A positive and significant correlation was seen between FEV₁ and BMD measured at total hip, femoral neck, and trochanter. A unit change (1 l) in FEV₁ was associated with a change of BMD by 0.019, 0.017, and 0.026 g/cm² in the total hip, femoral neck, and tochanteric region, respectively. These associations were independent of possible confounding factors such as age, height, weight, smoking habit, major disease prevalence, and medications, which might affect bone metabolism. In categorical analyses, the highest BMD was seen in the highest FEV₁ quartile, while the lowest BMD was seen in the lowest FEV₁ quartile. This pattern was seen in all three skeletal sites and was independent of covariates listed above. Compared with the bottom FEV₁ quartile, mean hip BMDs in the top quartile were 2–3.5% higher. The exact mechanism of this association is not clear to us. One plausible explanation is that respiratory function and bone health both reflect common but as yet unknown determinants.     

Prophylactic phenylephrine infusion for preventing hypotension during spinal anesthesia for cesarean delivery

In a randomized, double-blinded, controlled trial, we investigated the prophylactic infusion of IV phenylephrine for the prevention of hypotension during spinal anesthesia for cesarean delivery. Immediately after intrathecal injection, phenylephrine was infused at 100 microg/min (n = 26) for 3 min. From that point until delivery, phenylephrine was infused at 100 microg/min whenever systolic arterial blood pressure (SAP), measured each minute, was less than baseline. A control group (n = 24) received IV bolus phenylephrine 100 microg after each measurement of SAP <80% of baseline. Phenylephrine infusion decreased the incidence (6 [23%] of 26 versus 21 [88%] of 24; P < 0.0001), frequency, and magnitude (median minimum SAP, 106 mm Hg; interquartile range, 95-111 mm Hg; versus median, 80 mm Hg; range, 73-93 mm Hg; P < 0.0001) of hypotension compared with control. Heart rate was significantly slower over time in the infusion group compared with the control group (P < 0.0001). Despite a large total dose of phenylephrine administered to the infusion group compared with the control group (median, 1260 microg; interquartile range, 1010-1640 microg; versus median, 450 microg; interquartile range, 300-750 microg; P < 0.0001), umbilical cord blood gases and Apgar scores were similar. One patient in each group had umbilical arterial pH <7.2. Prophylactic phenylephrine infusion is a simple, safe, and effective method of maintaining arterial blood pressure during spinal anesthesia for cesarean delivery. IMPLICATIONS: In patients receiving spinal anesthesia for elective cesarean delivery, a prophylactic infusion of phenylephrine 100 microg/min decreased the incidence, frequency, and magnitude of hypotension with equivalent neonatal outcome compared with a control group receiving IV bolus phenylephrine.     

Childhood smoking is an independent risk factor for obstructive airways disease in women

OBJECTIVE: To assess whether starting to smoke in childhood increases the risk of obstructive airways disease (OAD) in adult life. METHODS: A retrospective cohort analysis was undertaken of 12 504 current and ex-smokers in the EPIC-Norfolk cohort. The main exposure was starting to smoke during childhood (age <16 years). Three definitions of OAD were used: doctor diagnosed asthma, doctor diagnosed bronchitis/emphysema, and "any OAD" (doctor diagnosed asthma or bronchitis/emphysema, or taking medication used in the treatment of OAD). RESULTS: Childhood smokers had significantly more pack years of exposure and poorer lung function than subjects who started to smoke in adulthood (>/=16 years). Compared with starting in adulthood, starting to smoke in childhood was associated with a greater risk of bronchitis/emphysema in female smokers (OR 1.79, 95% CI 1.25 to 2.56) and ex-smokers of both sexes (OR 1.29, 95% CI 1.07 to 1.55 in men and OR 1.40, 95% CI 1.05 to 1.85 in women), and of "any OAD" in female smokers (OR 1.72, 95% CI 1.24 to 2.38) and male and female ex-smokers (OR 1.20, 95% CI 1.03 to 1.40 in men and 1.34, 95% CI 1.07 to 1.57 in women). After adjustment for pack years, childhood smoking was associated with poorer lung function (FEV(1) 92.3% predicted in adult smokers and 89.5% in childhood smokers, p = 0.03) and a greater risk of bronchitis/emphysema (adjusted OR 1.55, 95% CI 1.08 to 2.24) and for "any OAD" (OR 1.54, 95% CI 1.10 to 2.13) in female smokers but not in male and female ex-smokers. CONCLUSION: Starting to smoke in childhood is associated with an increased risk of airways disease because of the extra pack years smoked. In women, childhood smoking is itself an independent risk factor for the development of airways disease.