Evaluation of organochlorine compounds in peregrine falcon (Falco peregrinus) and their main prey (Columba livia) inhabiting central Spain

The population of peregrine falcon (Falco peregrinus sbs. brookei) inhabiting the Regional Park of southeastern Madrid (RPSM), Spain, has experienced an increase of unsuccessful pairs (from 15% among a total of 20 pairs in 1995 to 55% among a total of 18 pairs in 2001). Traditionally, this area has been known to be contaminated with organochlorine compounds and toxic metals, which are known to be deleterious to the reproductive system of birds. During the breeding seasons of 2000 and 2001, contaminant residues were measured in unhatched eggs of peregrine falcons and liver of their main prey, to determine if they could be affecting the survival of the population. The most abundant contaminants were ortho-polychlorinated biphenyls (ortho-PCBs), ranging from 202.56 to 3,335.16 ng/g (wet wt) in falcon eggs and from 10.25 to 53.51 ng/g (wet wt) in pigeon livers. In all samples, the 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were detected, although these levels never exceeded 20 pg/g (wet wt). The major contributor to total toxic equivalent quantities (TEQs) were non-ortho-PCBs. Organochlorine levels found in this study may contribute to the entire suite of stressors that are negatively affecting the peregrine population.     

An Optimal control approach to marketing-production planning

The problem of finding an optimal advertising and production policy in a firm is analysed using a recently proposed model of a marketing-production system. First, it is shown that the optimal control problem underlying the proposed model is a partially singular control problem. Then, a reverse-time parametric solution procedure is designed to determine the optimal advertising and production policy for the proposed model. Finally, it is shown that the results derived from the new model are applicable to problems of capacity expansion in a firm.     

Ovulation induction in women with polycystic ovary syndrome: randomized trial of clomiphene citrate versus low-dose recombinant FSH as first line therapy

This single centre randomized controlled trial was undertaken to compare the efficacy and safety of clomiphene citrate and low-dose recombinant FSH as first line pharmacological therapy for anovulatory infertility associated with polycystic ovary syndrome (PCOS). Seventy-six infertile patients with PCOS were randomized to receive clomiphene citrate (50-150 mg/day for 5 days) (clomiphene citrate group, n = 38) or recombinant human FSH (FSH group, n = 38) in a chronic, low-dose, step-up protocol (daily starting dose 75 IU) for up to three consecutive cycles. Ovarian response was monitored by transvaginal ultrasonography and human chorionic gonadotrophin (HCG) was given to trigger ovulation in all cycles with appropriate follicular development. The primary outcome measure was cumulative pregnancy after undergoing up to three treatment cycles. Secondary outcomes were cycle cancellation rate, ovulation rate per cycle, cumulative ovulation rate, pregnancy rate per cycle, incidence of OHSS, cumulative live birth rate, and multiple birth rate. One hundred and four clomiphene citrate cycles and 91 FSH cycles were evaluable. The relative risk and its 95% confidence interval were 1.17 (0.97-1.46) for HCG cycles with ovulation, 1.78 (0.92-3.54) for the pregnancy rate per woman, and 1.83 (0.79-4.40) for live births per woman in favour of FSH. The cumulative pregnancy rate after three treatment cycles was 43% with FSH and 24% with clomiphene citrate (P = 0.06). By logistic regression analysis, the factors predicting ovulation included female age, serum androstenedione and use of FSH. Predictors of pregnancy were duration of infertility and use of FSH. This randomized controlled trial suggests that low-dose recombinant FSH may be an effective alternative to clomiphene citrate in first-line treatment for anovulatory PCOS patients. Thus, further studies, possibly multi-centre, in order to avoid problems with patient recruitment, are warranted to confirm these results.     

Ulcerative keratitis caused by Serratia marcescens after laser in situ keratomileusis

We report 2 cases of severe corneal infections caused by Serratia marcescens after laser in situ keratomileusis (LASIK). Twenty-four hours after LASIK, 2 patients developed infectious keratitis, 1 bilaterally. In each eye, the corneal flap was edematous, ulcerated, and detached from the stromal bed. Treatment included removal of the necrotic flap and aggressive antibiotic therapy. Cultures from corneal exudates were positive for S marcescens. After 1 year, both patients had a loss of best corrected visual acuity (BCVA) ranging from 20/40 to 20/22 because of irregular astigmatism. Overrefraction with a hard contact lens resulted in a BCVA of 20/20 in the 3 affected eyes. Slitlamp examination showed trace subepithelial haze without severe corneal scarring. Videokeratography disclosed areas of paracentral inferior steepening resembling keratoconus. Refraction and videokeratography remained stable after 6 months of follow-up. Ulcerative keratitis caused by S marcescens is a potential complication of LASIK. Bilateral involvement may occur if bilateral simultaneous surgery is performed.     

Dietary nucleotides accelerate changes in intestinal lymphocyte maturation in weanling mice

OBJECTIVE: Nucleotides, the building blocks of nucleic acids, are normal components of the mammalian diet. These molecules have been implicated in biologic processes, such as the stimulation of the immunologic response. Nucleotides have also been considered as conditionally essential nutrients for infant formulas. The authors evaluated the influence of dietary nucleotides on the expression of several surface antigens by different intestinal lymphocyte populations in weanling mice. METHODS: Mice at weaning were fed a semipurified diet with or without 3 g/kg of each of the following nucleotides: adenosine monophosphate, cytosine monophosphate, guanosine monophosphate, and uridine monophosphate. Animals were killed at different times (0, 4, 7, 12, and 18 days) after weaning, and lymphocytes from intestinal Peyer's patches, epithelium, and lamina propria were isolated. The expression of different antigens (CD3, CD4, CD8alpha, CD8beta, TCRalphabeta, TCRgammadelta, CD5, CD22 and CD45R) was analyzed by flow cytometry. RESULTS: The expression of these antigens changed parallel to the maturation of the lymphocytes from Peyer's patches, epithelium, and lamina propria. However, developmental changes of expression for most of the antigens occurred sooner in the animals fed the diet supplemented with nucleotides. The expression of T and B antigens was different in the lymphocyte populations analyzed and also changed according to the diet within each population. In general, nucleotides promoted the expression of B- and T-helper cell antigens. CONCLUSIONS: The authors conclude that dietary nucleotides may affect the process of maturation and differentiation of intestinal lymphocytes, which usually takes place at weaning.     

Hemodynamic state and the role of angiotensin II in ovarian hyperstimulation syndrome in the rabbit

Objective: To investigate the hemodynamic state in the ovarian hyperstimulation syndrome (OHSS) in the rabbit model and to determine the role of angiotensin II in the pathophysiology of this syndrome.

Design: Experimental study.

Setting: Physiology laboratory.

Animal(s): Female New Zealand rabbits were studied; 16 rabbits were stimulated with gonadotropins, and 6 were controls. Six of the stimulated rabbits received additional treatment with captopril.

Main Outcome Measure(s): Cardiac index, blood pressure, and heart rate were recorded.

Result(s): Gonadotropin-stimulated rabbits had significant enlargement of ovaries that was not modified by captopril. Ascites was present in 80% of animals in the OHSS group; captopril significantly decreased the incidence and volume of ascites. The three groups did not differ in blood pressure, heart rate, cardiac index, and total peripheral resistance.

Conclusion(s): In rabbits with OHSS, ascites are a primary event. Such animals are normotensive and have normal vascular resistance and cardiac index. Angiotensin-converting enzyme inhibition decreases the incidence of OHSS in the rabbit model by 30%, suggesting that angiotensin II may play a role in the formation of ascites.