Infertility prevalence and the methods of estimation from 1990 to 2021: a systematic review and meta-analysis.

STUDY QUESTION: What is the contemporary prevalence of infertility in world populations and how do they differ by methodological and study characteristics? SUMMARY ANSWER: Pooled estimates of lifetime and period prevalence of 12-month infertility were 17.5% and 12.6%, respectively, but this varied by study population and methodological approach. WHAT IS KNOWN ALREADY: Infertility affects millions of individuals worldwide. Accurate measures of its magnitude are needed to effectively address and manage the condition. There are distinct challenges and variation in how infertility is defined and measured, limiting comparability of estimates across studies. Further research is needed to understand whether and how differences in methodological approaches and study characteristics account for heterogeneity in estimates. STUDY DESIGN SIZE DURATION: We conducted a systematic review and meta-analysis. Six electronic databases, websites of relevant organizations, and conference proceedings were systematically searched. Searches were limited to those published between 1 January 1990 and 11 March 2021, with no language restrictions. PARTICIPANTS/MATERIALS SETTING METHODS: Descriptive and random-effects meta-analysis models were used to examine range of estimates and generate estimates of pooled lifetime and period prevalence of 12-month infertility, respectively, among representative populations. Meta-regression using restricted maximum likelihood was applied to account for definitional and study characteristics and to obtain adjusted estimates. Risk of bias was assessed with a validated tool. MAIN RESULTS AND THE ROLE OF CHANCE: The search yielded 12 241 unique records of which 133 studies met the criteria for the systematic review. There were 65 and 69 studies that provided data for lifetime and period prevalence of 12-month infertility, respectively. Five methodological approaches were identified: prospective time-to-pregnancy (TTP) design, current duration design, retrospective TTP design, self-reported infertility measure and constructed infertility measure. Ranges for lifetime (3.3-39.7%) and period estimates (1.6-34.0%) were similar and wide even after accounting for methodological and study characteristics. Pooled estimates of lifetime and period prevalence were 17.5% (95% CI: 15.0, 20.3, n = 37 studies, I 2 = 99.5%) and 12.6% (95% CI: 10.7, 14.6, n = 43 studies, I 2 = 99.8%), respectively, with some variation in magnitude by region and methodological approach, but with most CIs overlapping. LIMITATIONS REASONS FOR CAUTION: Pooled estimates generated from meta-analysis were derived from 12-month infertility prevalence estimates that were heterogeneous across different domains, even after adjusting for definitional and study characteristics. The number of studies was small for certain strata from which pooled estimates were derived (e.g. there were only two studies for lifetime prevalence in Africa). WIDER IMPLICATIONS OF THE FINDINGS: While findings show a high prevalence of infertility globally and regionally, it also reveals variation in measures to ascertain and compare infertility prevalence. More systematic and comprehensive collection of data using a consistent definition is needed to improve infertility prevalence estimates at global, regional and country-levels. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the World Health Organization. The authors have no conflicts of interest. REGISTRATION NUMBER: PROSPERO CRD42020211704.

Immunomodulatory role of probiotics in poultry and potential in ovo application.

Recently, there has been an increasing debate regarding the use of sub-therapeutic antibiotics in animal feed. This stems from worries that this practice may result in microbial resistance to human antibiotics employed in treating infections, thus causing a human health concern. Due to this tension, the poultry industry is under mounting pressure to reduce the use of these agents as feed additives and alternative control methods have taken the forefront in the research community. Investigators are searching for the latest alternative that will protect flocks from disease, while not hindering performance or negatively impacting profit margins. Probiotic supplementation is one option currently being explored as a means of improving performance and reducing the amount and severity of enteric diseases in poultry, and subsequent contamination of poultry products for human consumption. Probiotics are live, nonpathogenic microorganisms known to have a positive effect on the host by beneficially modifying gut microbiota and modulating the immune system. This review will discuss the role of probiotics in poultry, including their effects on performance, immune response and host defence against disease. Also addressed will be the recent applications of supplementing probiotics in ovo as an innovative means to administer such additives to promote early colonisation of beneficial bacteria.

Immunological responses to Clostridium perfringens alpha-toxin in two genetically divergent lines of chickens as influenced by major histocompatibility complex genotype.

Chickens genetically selected for low (LA) or high (HA) antibody response to SRBC displayed a correlated change in MHC, so that LA chickens were 96% B13 and HA chickens were 96% B21. The LA line appears to be less susceptible to invasion by extracellular pathogens, whereas HA chickens are more resistant to infection by intracellular organisms. Resistance to Clostridium perfringens is one instance in which the lines do not follow their established trend of pathogen susceptibility, where during a clinical outbreak of necrotic enteritis, B21B21 genotypes experienced significantly less mortality than B13B13 genotypes. A study was carried out to assess immunological differences between LA and HA lines during exposure to C. perfringens α-toxin. Peripheral blood mononuclear cells were isolated from each genetic line, cultured with or without lipopolysaccharide (4 h), and exposed to varying concentrations of α-toxin (1; 10; 100; and 1,000 U/L) for 2 and 4 h. Evaluation of cellular proliferation, percentage of cytotoxicity, and immunological gene expression was carried out in a series of experiments. Cells isolated from HA chickens had significantly increased proliferation than those from LA chickens at low toxin levels (1 and 10 U/L) and significantly decreased proliferation at high toxin levels (100 and 1,000 U/L). Following exposure to lipopolysaccharide, the percentage of cytotoxicity was higher for LA than HA cells. In both assays, HA cells displayed superior performance following lipopolysaccharide-stimulation. Gene expression analysis of immune transcripts by quantitative real-time PCR revealed significantly upregulated expression of interferon (IFN)-γ, interleukin (IL)-8, IL-13 (2 h), IL-15, and CXCLi1 (4 h) in HA than LA chickens. Cells isolated from the LA line displayed significantly elevated expression of IL-2, IL-10, IL-13 (4 h), IL-16, IL-18, inducible nitric oxide synthase (iNOS), CXCLi1 (2 h), and lipopolysaccharide-induced tumor necrosis factor-α factor (LITAF) compared with the HA line. Clearly, these 2 genetic lines display highly divergent immune responses in regards to C. perfringens toxin exposure.

Immune responses to dietary beta-glucan in broiler chicks during an Eimeria challenge.

Escalating consumer concerns regarding pathogen resistance have placed the poultry industry under mounting pressure to eliminate the use of chemotherapeutic agents as feed additives. One possible alternative receiving increased attention is the use of immunomodulators such as ß-glucan. A study was conducted to investigate the effects of a yeast-derived ß-glucan (Auxoferm YGT) on broiler chick performance, lesion scores, and immune-related gene expression during a mixed Eimeria infection. Day-old chicks were fed diets containing 0, 0.02, or 0.1% YGT. On d 8 posthatch, one-half of the replicate pens were challenged with a mixed inoculum of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Measurements were taken and samples collected on d 4, 10, 14, and 21 posthatch. Dietary supplementation had no effect on performance or mortality. On d 14, 3 birds per pen (n = 24/treatment) were scored for intestinal coccidia lesions. Gross lesion severity was significantly reduced in birds supplemented with 0.1% YGT. On d 10, inducible nitric oxide synthase (iNOS) expression was downregulated in the jejunum of challenged birds fed 0.1% YGT. Expression of iNOS in the ileum was downregulated in the nonchallenged birds, but upregulated in the challenged birds fed 0.1% YGT on d 14. Interleukin (IL)-18 was upregulated in the jejunum of 0.1% YGT-treated birds. Interferon (IFN)-γ expression was decreased in challenged and nonchallenged birds fed 0.1% YGT. The IL-4 expression was downregulated in the nonchallenged birds with 0.1% YGT diet supplementation. The IL-13 and mucin-1 levels were also reduced due to ß-glucan supplementation. Mucin-2 expression was increased in the nonchallenged birds, but decreased in the infected birds fed 0.1% YGT. These results suggest that although Auxoferm YGT at doses of 0.02 and 0.1% does not influence performance, it significantly reduces lesion severity and is capable of altering immune-related gene expression profiles, favoring an enhanced T helper type-1 cell response during coccidiosis.

Performance and immune responses to dietary beta-glucan in broiler chicks.

During the first week posthatch, the avian immune system is immature and inefficient at protecting chicks from invading pathogens. Among immunomodulators, beta-glucans are known as biological response modifiers due to their ability to activate the immune system. Current research suggests that beta-glucans may enhance avian immunity; however, very little is known about their influence on regulation of immune function. A study was performed to evaluate the effects of dietary beta-glucan on growth performance, immune organ weights, peripheral blood cell profiles, and immune-related gene expression in the intestine. One-day-old chicks were fed a diet containing 0, 0.02, or 0.1% yeast beta-glucan (n = 30/treatment). On d 7 and 14 posthatch, body and relative immune organ weights were measured and small intestinal sections were collected to evaluate gene expression by quantitative real-time PCR. Peripheral blood samples were also collected to determine heterophil:lymphocyte ratios. Supplementation of beta-glucan did not significantly affect BW gains, and no significant differences were observed among groups for relative immune organ weights or heterophil:lymphocyte ratios. Compared with controls, expression of interleukin (IL)-8 was downregulated in the beta-glucan-treated groups on d 7 and 14. On d 14, beta-glucan inclusion resulted in increased inducible nitric oxide synthase expression. Expression of IL-18 was upregulated on d 7 but reduced on d 14 due to beta-glucan supplementation. On d 7, interferon-gamma and IL-4 expression decreased in the beta-glucan-treated groups. However, on d 14, IL-4 expression was upregulated in the supplemented groups. Intestinal expression of IL-13 was also downregulated in the beta-glucan-treated birds on d 7. These results suggest that dietary inclusion of beta-glucans altered the cytokine-chemokine balance; however, it did not elicit a robust immune response in the absence of a challenge, resulting in no deleterious effects on performance.

Reactions of Perennial Grain Accessions to Four Major Cereal Pathogens of the Great Plains.

Methods of disease management used in annual grain crops, especially cultural practices designed to disrupt the disease cycle of a particular pathogen, will not necessarily be applicable to perennial grain crops. Resistance to multiple pathogens, therefore, will clearly be important in disease management. The objective of this research was to evaluate disease resistance in 10 perennial grain accessions (one to two accessions of each: perennial wheat (Thinopyrum sp. × Triticum aestivum), intermediate wheatgrass (Thinopyrum intermedium), perennial rye (Secale montanum), hexaploid triticale (Triticum turgidum × S. montanum), octoploid triticale (Triticum aestivum × S. montanum), tetraploid perennial rye (Secale cereale × S. montanum), and tall wheat-grass (Thinopyrum ponticum)) to tan spot (caused by Pyrenophora tritici-repentis), take-all (caused by Gaeumannomyces graminis var. tritici), wheat streak mosaic, and barley yellow dwarf, four important diseases of the Great Plains. Several of the grasses were resistant to tan spot, barley yellow dwarf, and wheat streak mosaic. Indeed, the wild grasses and perennial donors T. intermedium (including BFPMC1), T. ponticum, and S. montanum, in addition to Permontra, a tetraploid perennial rye, were highly resistant to all three diseases. Additionally, the remaining grasses tested were also more resistant to tan spot than the susceptible wheat control. However, none of the 10 grass accessions appeared highly resistant to take-all, and substantial losses in biomass were observed, although such effects may be moderated under field conditions due to the potential for take-all decline in perennial plantings.

Cultivar mixtures for the simultaneous management of multiple diseases: tan spot and leaf rust of wheat.

ABSTRACT Because of differences in life histories between Puccinia triticina, a highly specialized, polycyclic, windborne pathogen with a shallow dispersal gradient, and Pyrenophora tritici-repentis, a residue-borne pathogen with a steep dispersal gradient, wheat mixtures are expected to be more effective at controlling leaf rust than tan spot. The objectives of this research were to determine the effect of two-cultivar mixtures with varying proportions and different pathogen resistance profiles on the severity of tan spot and leaf rust, to evaluate yield of the mixtures in the presence or absence of disease, and to directly compare the relative effectiveness of cultivar mixing for tan spot versus leaf rust. In a field experiment at two sites in Kansas over two growing seasons, winter wheat cvs. Jagger and 2145, which have differential resistance reactions to leaf rust and tan spot, each were planted in proportions of 0.25, 0.50, 0.75, and 1.00. Plots were inoculated with each pathogen alone, both pathogens, treated with a fungicide, or exposed to ambient conditions. For both diseases for all siteyears, severity decreased substantially on the susceptible cultivar as the proportion of that cultivar decreased in mixture. Mixtures were significantly more effective at reducing leaf rust than tan spot in three of four site-years. Mixtures generally yielded the same as the weighted mean of components in monoculture although, in two of three site-years, at least one fungicide-treated and one diseased mixture each yielded higher than expected values. Although this particular mixture produced only modest yield benefits, the potential for simultaneous reductions in tan spot and leaf rust was demonstrated.

Perennial Wheat Germ Plasm Lines Resistant to Eyespot, Cephalosporium Stripe, and Wheat Streak Mosaic.

A perennial wheat cropping system on the Palouse Prairie of eastern Washington may provide an alternative to the Federal Conservation Reserve Program and reduce soil erosion while providing a harvestable crop for growers. Twenty-four perennial wheat germ plasm lines resulting from crosses between wheat and wheatgrass were evaluated under controlled environment conditions for resistance to Wheat streak mosaic virus (WSMV), Cephalosporium gramineum, and Tapesia yallundae (anamorph Pseudocercosporella herpotrichoides var. herpotrichoides). Perennial wheat lines SS452, SS103, SS237, MT-2, and PI 550713 were resistant to all three pathogens. Eight lines (33%) were resistant to WSMV at 21°C and 25°C; AT3425 was resistant to WSMV at 21°C but not at 25°C. Thirteen lines (54%) were highly to moderately resistant to C. gramineum. Thirteen lines (54%) were resistant to T. yallundae in each experiment, but the reactions of four lines differed between experiments. The wheatgrasses Thinopyrum intermedium (PI 264770) and Thinopyrum ponticum (PI 206624) are reported as new sources of resistance to T. yallundae. Perennial wheat must have resistance to these diseases in order to be feasible as a crop in the Pacific Northwest.

Is it possible to decrease antibiotic prescribing in primary care? An analysis of outcomes in the management of patients with sore throats.

OBJECTIVES: The aim of this study was to assess whether it was possible to change clinical practice through the introduction of an evidence-based protocol for the management of sore throats. The impact of the changed clinical practice on patients was also assessed. METHOD: An observational study was carried out comparing management of patients with sore throats in a semi-rural general practice (14 000 patients), before and after the introduction of an evidence-based protocol, using a multidisciplinary approach. All patients over the age of 2 years presenting with sore throats as their chief presenting complaint were included in the study which ran for two 6-month periods: February-July 1997 (n = 435) and February-July 1998 (n = 350). Antibiotic prescribing rates, consultation and reconsultation rates, duration of sore throat, analgesia requirements and satisfaction were assessed. RESULTS: Antibiotic prescribing was significantly reduced in period 2 (56% compared with 19%). Consultation rates decreased by 19% in period 2. Median number of days to recovery of sore throats was the same in both groups. Reconsultation rates and dissatisfaction rates were the same in both groups. CONCLUSION: Using a multidisciplinary approach, it is possible to reduce antibiotic prescribing for sore throats significantly without adversely affecting outcome.

The role of FGF and VEGF in angioblast induction and migration during vascular development.

The embryonic vasculature forms by the processes of vasculogenesis and angiogenesis. Angioblasts (endothelial cell precursors) appear to be induced by fibroblast growth factor 2 (FGF-2). The angioblasts contributing to the dorsal aortae arise by an epithelial to mesenchymal transformation of cells originating from the splanchnic mesoderm. QH-l and vascular endothelial growth factor receptor 2 (VEGFR-2) both appear to label these cells as they adopt a mesenchymal morphology. Since VEGFR-2 is the earliest known VEGF receptor this suggests that VEGF is not involved in angioblast induction. VEGF does appear to be critical, however, for growth and morphogenesis of angioblasts into the initial vascular pattern. Controlled delivery of FGF-2 from beads and aggregates of cells transfected with quail VEGF have been used in our laboratory to study the role of these growth factors in angioblast induction and migration. We have induced cells from the epithelial quail somite to differentiate into angioblasts with FGF-2 both in the embryo and in culture. This is a useful model system to study the origins of endothelial cells that are normally more diffusely induced during gastrulation by an obscure process probably involving signals from the embryonic endoderm. The origins of arterial versus venous endothelial cells is also poorly understood but recent findings on the distribution of ephrins and Eph receptors suggest that molecular differences exist prior to the onset of circulation. Finally, studies on the role of growth factors in such diverse phenomena as stem cell biology, angiogenesis, and molecular medicine in addition to vascular development suggest multiple roles for FGF-2 and VEGF in vascular development.

Angioblast differentiation is influenced by the local environment: FGF-2 induces angioblasts and patterns vessel formation in the quail embryo.

The embryonic vasculature forms by the segregation, migration, and assembly of angioblasts from mesoderm, a process termed vasculogenesis. The initial role of fibroblast growth factor 2 (FGF-2) in vascular development appears to be in the induction of endothelial precursors, angioblasts. Quail somites transplanted into chick embryos will give rise to angioblasts of quail origin. The number of angioblasts present within the chimera is dependent on the host environment. Angioblast induction can be demonstrated in vitro by the addition of FGF-2 to cultures of dissociated somitic mesoderm, as assessed by QH-1 epitope expression. Manipulation of FGF-2 concentration in the quail/chick chimeras by FGF-2 peptide or neutralizing antibody injections increases or decreases angioblast induction in the predicted manner. To better control growth factor release in vivo we have implanted beads that release FGF-2 into the embryonic environment. FGF-2 beads implanted into the somite induce angioblast differentiation in the epithelial somite; whereas, beads lateral to the somitic mesoderm induce the formation of ectopic vessels. These studies suggest that FGF-2 is important for both the induction of angioblasts and the assembly of angioblasts into the initial vasculature pattern.

Different ontogeny of rate of force generation and shortening velocity in guinea pig trachealis.

Juveniles of many species, including humans, display greater airway responsiveness than do adults. This may involve changes in airway smooth muscle function. In the present work we studied force production and shortening velocity in trachealis from 1-wk-old (1 wk), 3-wk-old (3 wk), and 3-mo-old (adult) guinea pigs. Strips were electrically stimulated (60 Hz, 18 V) at their optimal length (l(o)) to obtain maximum active stress (P(o)) and rate of stress generation. Then, force-velocity curves were elicited at 2.5 s from the onset of the stimulus. By applying a recently developed modification of Hill's equation for airway smooth muscle, the maximum shortening velocity at zero load (V(o)) and the value alpha. gamma/beta, an index of internal resistance to shortening (Rsi), were calculated (alpha, beta, and gamma are the constants of the equation). P(o) increased little with maturation, whereas the rate of stress generation increased significantly (0.40 +/- 0.03, 0.45 +/- 0.03, 0. 51 +/- 0.03 P(o)/s for 1 wk, 3 wk, and adult animals). V(o) slightly increased early with maturation to decrease significantly later (1. 79 +/- 0.67, 2.45 +/- 0.92, and 0.55 +/- 0.09 l(o)/s for 1 wk, 3 wk, and adult animals), whereas the Rsi showed an opposite trend (14.98 +/- 5.19, 8.99 +/- 3.01, and 32.07 +/- 5.54 mN. mm(-2). l(o)(-1). s for 1 wk, 3 wk, and adult animals). This early increase of force generation in combination with late increase of Rsi may explain the changes of V(o) with age. An elevated V(o) may contribute to the incidence of airway hyperresponsiveness in healthy juveniles.

High-carbohydrate versus high-fat diets: effect on body composition in trained cyclists.

PURPOSE: Recent research suggesting the benefits of high-fat diets for endurance athletes have been viewed with caution because of the potential negative health consequences, including increased adiposity. METHODS: We have examined the effects of a high-fat (HF, 50% of total energy from fat and 37% from carbohydrate) versus a high-carbohydrate (HC, 15% of total energy from fat and 69% from carbohydrate) diet on body fat, lean body mass, and bone mineral density (BMD) in 32 endurance-trained cyclists over a period of 3 months. Body composition was assessed by dual x-ray absorptiometry at baseline and after 3 months. RESULTS: Total and percent body fat, lean tissue mass, and body weight were not significantly different within and between each diet group from baseline to week 12. Total body BMD increased significantly within HF (P = 0.02), but nonsignificantly in HC, over the 12-wk period. CONCLUSIONS: In conclusion, during periods of endurance training when energy requirements are high, increasing the percentage of fat in the diet to approximately 50% of total energy does not increase body weight or adiposity because athletes are able to maintain energy balance.

Effect of cardiopulmonary bypass on pulmonary gas exchange: a prospective randomized study.

BACKGROUND: Conventional coronary artery bypass surgery is associated with postoperative pulmonary dysfunction. Inflammation due to cardiopulmonary bypass has been regarded as one of the main causes. In this study, we investigated the effect of coronary revascularization with or without cardiopulmonary bypass on pulmonary function. METHODS: Fifty-two patients (40 male, mean age 60.1 years) were prospectively randomized to undergo coronary revascularization via median sternotomy, with or without normothermic cardiopulmonary bypass. Alveolar-arterial oxygen gradients were measured before and after induction of anesthesia, postoperatively in the intensive care unit during mechanical ventilation and 6 hours after tracheal extubation. The techniques of anesthesia and mechanical ventilation were standardized throughout. RESULTS: Patient characteristics were similar in the two groups. The alveolar-arterial oxygen gradients increased progressively throughout the perioperative period, with no significant differences in the two groups at any time during the study. CONCLUSIONS: Myocardial revascularization with or without cardiopulmonary bypass caused a similar degree of pulmonary dysfunction, as assessed by alveolar-arterial oxygen gradient. Our study suggests that the deterioration in pulmonary gas exchange associated with cardiac surgery is due to factors other than the use of cardiopulmonary bypass.

Effects of high fat versus high carbohydrate diets on plasma lipids and lipoproteins in endurance athletes.

PURPOSE AND METHODS: Recent research suggesting the performance benefits of high fat diets for endurance athletes have been viewed with caution because of the potential negative health consequences, including increased coronary heart disease risk. This study examined the effects of a high fat (HF: 50% of total energy from fat, 37% carbohydrate) versus a high carbohydrate (HC: 15% of total energy from fat, 69% carbohydrate) diet on plasma lipids and lipoproteins in 32 endurance trained cyclists over a 3-month period. Plasma total, low density lipoprotein (LDL), high density lipoprotein (HDL), HDL2 and HDL3 cholesterol, triglycerides, apolipoprotein A1, and hematocrit (Hct) were measured at baseline and after weeks 4, 8, and 12. RESULTS: Changes in lipids and lipoproteins from baseline to week 12 did not differ between the two groups except for triglycerides, which increased significantly from 1.04 +/- 0.17 mmol.L-1 to 1.28 +/- 0.31 mmol.L-1 in HC (P = 0.012). The only significant changes that occurred within each group from baseline to week 12 was the significant increase in total cholesterol and triglycerides in HC. Body composition changes did not differ between the two groups from baseline to week 12 as measured by dual x-ray absorptiometry. CONCLUSIONS: During periods of endurance training when energy requirements are high, increasing the percentage of fat in the diet to approximately 50% of total energy did not result in adverse changes to the plasma lipoprotein profiles of this group of athletes.

Lignocaine to aid the insertion of the laryngeal mask airway with thiopentone. A comparison between topical and intravenous administration.

Conditions for insertion of a laryngeal mask airway in 90 unpremedicated adult were patients were assessed in a randomised, single-blinded trial. Each patient received fentanyl 1 microgram.kg-1 and thiopentone 5 mg.kg-1, and this was preceded either by lignocaine 0.5 mg.kg-1 intravenously (group 1), lignocaine 1.5 mg.kg-1 intravenously (group 2) or 40 mg of topical lignocaine spray to the posterior pharyngeal wall (group 3). Conditions for laryngeal mask airway insertion were recorded. The group receiving topical lignocaine had a lower incidence of laryngospasm (p < 0.05), required fewer attempts for successful insertion of the laryngeal mask (p < 0.05) and coughed or gagged less frequently than either group receiving lignocaine intravenously (p > 0.05). Overall, the conditions for laryngeal mask airway insertion were better in the topical group (p < 0.05). There were no significant differences in haemodynamic response and apnoea between the three groups. Topical lignocaine spray prior to thiopentone provides conditions for insertion of a laryngeal mask that are superior to those provided by lignocaine and thiopentone intravenously.

Topical lignocaine and thiopentone for the insertion of a laryngeal mask airway; a comparison with propofol.

We assessed conditions for insertion of a laryngeal mask airway in 90 unpremedicated adult patients who received either thiopentone 5 mg.kg-1 preceded by 40 mg of topical lignocaine spray to the posterior pharyngeal wall or propofol 2.5 mg.kg-1 alone in a randomised, single-blinded trial. All patients received fentanyl 1 microgram.kg-1. Gagging, coughing and laryngospasm following laryngeal mask insertion were graded and haemodynamic data and apnoea times were recorded. There were no significant differences between the two groups with regard to the incidence of gagging, coughing and laryngospasm, but the apnoea time was significantly less in the thiopentone group (p < 0.005). The decrease in systolic and diastolic blood pressure, following induction and the insertion of a laryngeal mask with propofol was significantly greater than following thiopentone (p < 0.05--systolic, p < 0.01--diastolic). We conclude that thiopentone preceded by topical lignocaine spray provides conditions for insertion of a laryngeal mask equal to those of propofol, with more haemodynamic stability and a shorter period of apnoea.

Response of plasma lathosterol concentration to change in the quality of dietary fat in men and women.

OBJECTIVE: The aim of the study was to determine the effect of replacing saturated fatty acids (SAFA) with polyunsaturated fatty acids (PUFA) in the diet on plasma lathosterol concentration, an index of cholesterol synthesis, in mildly hypercholesterolaemic subjects. DESIGN: The study was a randomised, cross-over trial. SUBJECTS: Seventy-six subjects were recruited and one dropped out. Twenty-nine men and 46 women with baseline plasma cholesterol levels in the range 5.5-7.9 mmol/l were entered into the trial. INTERVENTIONS: Subjects were placed on two isocaloric diets, one rich in SAFA and the other high in PUFA, for 6 weeks each. Plasma lathosterol and lipid and lipoprotein concentrations were measured. RESULTS: When PUFA replaced SAFA in the diet, there was a significant (P = 0.01) fall in plasma lathosterol concentration in all subjects combined [-1.37 (-0.36 to -2.38) mumol/l] which was largely due to a significant (P = 0.03) decrease in men [-2.35 (-0.42 to -4.28) mumol/l] but not in women. The concomitant decreases in plasma cholesterol, low density lipoprotein (LDL) cholesterol and high density lipoprotein (HDL) cholesterol were similar in men and women. Plasma lathosterol concentration and the ratio lathosterol/cholesterol were significantly higher in men at baseline and during diets rich in SAFA but were not significantly different between the sexes during diets rich in PUFA. CONCLUSIONS: These data suggest that replacing SAFA with PUFA in the diet may reduce cholesterol synthesis in mildly hypercholesterolaemic men and markedly reduce the gender-related difference in cholesterol synthesis commonly observed.