Consequences of vanishing twins in IVF/ICSI pregnancies

BACKGROUND: Spontaneous reductions are a possible cause of the increased morbidity in IVF singletons. The aim of this study was to assess incidence rates of spontaneous reductions in IVF/ICSI twin pregnancies and to compare short- and long-term morbidity in survivors of a vanishing co-twin with singletons and born twins. METHODS: We identified 642 survivors of a vanishing co-twin, 5237 singletons from single gestations and 3678 twins from twin gestations. All children originated from pregnancies detected by transvaginal sonography in gestational week 8. By cross-linkage with the national registries the main endpoints were prematurity, birth weight, neurological sequelae and mortality. RESULTS: Of all IVF singletons born, 10.4% originated from a twin gestation in early pregnancy. Multiple logistic regression analyses adjusted for maternal age, parity and ICSI treatment showed for birth weight <2500 g an odds ratio (OR) of 1.7 [95% confidence interval (CI) 1.2-2.2] and for birth weight <1500 g OR 2.1 (95% CI 1.3-3.6) in singleton survivors of a vanishing twin versus singletons from single gestations; corresponding figures were seen for preterm birth. This increased risk was almost entirely due to reductions that occurred at >8 weeks gestation. We found no excess risk of neurological sequelae in survivors of a vanishing co-twin versus the singleton cohort; however, OR of cerebral palsy was 1.9 (95% CI 0.7-5.2). Furthermore, we observed a correlation between onset of spontaneous reduction, i.e. the later in pregnancy the higher the risk of neurological sequelae (r = -0.09; P = 0.02). Adjusted OR of child death within the follow-up period was 3.6 (95% CI 1.7-7.6) in the survivor versus the singleton cohort. CONCLUSIONS: One in 10 IVF singletons originates from a twin gestation. Spontaneous reductions that occur at >8 weeks gestation are one of the causes for the higher risk of adverse obstetric outcome in IVF singletons.     

Typhus and typhuslike rickettsiae associated with opossums and their fleas in Los Angeles County, California.

The recent discovery of cat fleas (Ctenocephalides felis) infected with a typhuslike rickettsia (designated the ELB agent) raises the question of whether similar rickettsial infections exist in wild cat flea populations. We verified the presence of the ELB agent and Rickettsia typhi in urban and suburban areas of Los Angeles, Calif. Opossums trapped in close proximity to the residences of human murine typhus cases in Los Angeles county and other areas within the city of Los Angeles were tested for the presence of typhus group rickettsiae by the polymerase chain reaction (PCR). The presence of rickettsiae in the spleen tissues of three opossums (n = 9) and in 66 opossum fleas (n = 205) was determined by PCR and was verified by dot blot and Southern transfer hybridization. Further analysis of the amplified PCR products generated by a series of primer pairs derived from either the 17-kDa antigen gene or the citrate synthase gene revealed that both R. typhi and the ELB agent were present in the tested samples. Dual infection was not noted in the samples; however, the fleas were infected with either R. typhi or the ELB agent. The presence of the ELB agent in the cat flea population may have implications for public health. Whether this agent is responsible for the mild cases of human murine typhus in urban and suburban areas of Los Angeles or in other endemic foci remains to be determined.     

Molecular epidemiology of tuberculosis in Denmark in 1992.

The incidence of tuberculosis (TB) is increasing all over the world, including in countries with a high standard of living and good social security. Denmark represents such a region. Furthermore, it is a small country (5 million inhabitants) with a long tradition in TB control, including a centralization of the bacteriological diagnostic facility. The present study was intended to analyze the transmission of Mycobacterium tuberculosis in a country in which TB has low endemicity by a combination of conventional epidemiological approaches and DNA fingerprinting techniques, whereby individual bacterial strains can be traced. M. tuberculosis isolates from 92% of all new cases of bacteriologically verified TB in Denmark during 1992 were subjected to IS6110 DNA fingerprinting to visualize the DNA restriction fragment length polymorphism (RFLP) patterns of the isolated strains. The data obtained from the RFLP analyses were interpreted by using demographic data, such as age, sex, ethnicity, and residence, for the patients. The risk factors among the patients for being part of an active chain of transmission, as opposed to demonstrating reactivation of a previously acquired latent infection, were estimated by statistical analyses. The magnitude of TB transmission in 1992 in Denmark was determined, and transmitted infections were shown to comprise at least one quarter of the total number of cases. Almost half of the TB cases involved patients of foreign origin. However, most of these isolates showed unique DNA fingerprint patterns and were rarely part of an active chain of transmission. The major chains of recent transmission were localized to distinct geographical regions in the country.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of timing of iron supplementation on maternal and neonatal growth and iron status of iron-deficient pregnant rats

We have previously shown that maternal iron (Fe) deficiency not only reduces fetal size, but also increases blood pressure in the offspring when they are adults. In this paper we examine whether there are critical periods when supplementation reverses or fails to reverse the effect both on size and on expression of genes of Fe metabolism. We made dams Fe deficient, mated them and provided supplements of Fe in the diet from the beginning of gestation (0.5 days), from 7.5 days or from 14.5 days. Within 12 h of birth, dams and neonates were killed and tissues taken and examined. Fe deficiency throughout pregnancy reduces neonatal size. Supplementation from the beginning of the first, second or third week all reduced the effect. Maternal haematocrit was restored to normal levels only in animals given supplements for at least 2 weeks. In contrast, the neonates' Fe levels were normal in all supplemented groups. These results were mirrored in liver Fe levels and in transferrin receptor mRNA. Iron-responsive element (IRE)-regulated divalent metal transporter 1 (DMT1) increased in maternal and neonatal liver. Non-IRE-regulated DMT1 levels did not change in the maternal liver, but decreased in the neonatal liver. H and L ferritin mRNA levels also showed different patterns in the mother and her offspring. Finally, the neonatal size correlated with maternal Fe stores, and not with those of the fetus. The data demonstrate that Fe supplementation during pregnancy is most effective when given early, rather than later, in gestation.     

Evaluation of a communication and stress management training programme for infertile couples

OBJECTIVE: This study evaluates a patient education programme focussed on improving communication and stress management skills among couples in fertility treatment. METHODS: In total, 37 couples completed the intervention. Two teachers conducted all the five courses offered. The effectiveness regarding communication and infertility-related stress was assessed by questionnaires immediately before (time T1) and after the intervention (time T2). Seeking of information and professional support was assessed at a 12-month follow-up (time T3); response rates were: T1, 93.2%; T2, 85.1%; T3, 74.3%. Data were compared at baseline (T1) and at the 12-month follow-up (T3) with a prospective cohort of Danish people in fertility treatment. RESULTS: There were no differences in infertility-related stress at base line between the two groups studied. We estimated the bi-directional changes in communication, e.g., changes from talking often to talking less frequently and vice versa. More intervention participants started to talk often with their partner about infertility and its treatment after the intervention compared to those who stopped to talk often. Women and men changed occurrence, frequency and content of communication with close other people. Among women marital benefit increased significantly. Infertility-related stress was not reduced significantly. Significantly more intervention participants than in the comparison group had contacted support groups, a psychologist and/or agencies for adoption at the 12-month follow-up. CONCLUSION: The intervention resulted in important perceived improvement in the participants' competence to actively manage changes in marital communication and in communication in different social arenas. PRACTICE IMPLICATIONS: We recommend fertility clinics to develop and evaluate different interventions for those fertility couples who ask for more psychosocial support.     

Gram-negative bacteria induce proinflammatory cytokine production by monocytes in the absence of lipopolysaccharide (LPS)

Tumour necrosis factor-alpha (TNF-alpha), IL-1alpha and IL-6 production by human monocytes in response to a clinical strain of the Gram-negative encapsulated bacteria Neisseria meningitidis and an isogenic lpxA- strain deficient in LPS was investigated. Wild-type N. meningitidis at concentrations between 105 and 108 organisms/ml and purified LPS induced proinflammatory cytokine production. High levels of these cytokines were also produced in response to the lpxA- strain at 107 and 108 organisms/ml. The specific LPS antagonist bactericidal/permeability-increasing protein (rBPI21) inhibited cytokine production induced by LPS and wild-type bacteria at 105 organisms/ml but not at higher concentrations, and not by LPS-deficient bacteria at any concentration. These data show that proinflammatory cytokine production by monocytes in response to N. meningitidis does not require the presence of LPS. Therapeutic strategies designed to block LPS alone may not therefore be sufficient for interrupting the inflammatory response in severe meningococcal disease.     

Micropatterned surfaces modified with select peptides promote exclusive interactions with osteoblasts

Microcontact printing techniques were used to pattern circles (diameters 10. 50, 100, and 200 microm) of N1[3-(trimethoxysilyl)-propyl]diethylenetriamine (DETA) surrounded by octadecyltrichlorosilane (OTS) borders on borosilicate glass, a model substrate. The DETA regions were further modified by immobilization of either the cell-adhesive peptides Arginine-Glycine-Aspartic Acid-Serine (RGDS) and Lysine-Arginine-Serine-Arginine (KRSR) or the non-adhesive peptides Arginine-Aspartic Acid-Glycine-Serine (RDGS) and Lysine-Serine-Serine-Arginine (KSSR). After four hours under standard cell culture conditions but in the absence of serum, adhesion of either osteoblasts or fibroblasts on surfaces patterned with the non-adhesive peptides RDGS and KSSR was random and low. In contrast, both osteoblasts and fibroblasts adhered and formed clusters onto circles modified with the adhesive peptide RGDS, whereas only osteoblasts adhered and formed clusters onto the circles modified with KRSR, a peptide that selectively promotes adhesion of osteoblasts. These results provide evidence that patterning of select peptides can direct adhesion of specific cell lines exclusively to predetermined regions on material surfaces.     

Capillary supply of the quadriceps femoris muscle of man: adaptive response to exercise

1. Five subjects trained for 8 weeks on a bicycle ergometer for an average of 40 min/day, four times a week at a work load requiring 80% of the maximal oxygen uptake (V(O2 max.)). V(O2 max.) determinations were performed, and muscle biopsies from the quadriceps femoris muscle (vastus lateralis) were taken before, as well as repeatedly during, the training period. The muscle biopsies were histochemically stained for fibre-types (myofibrillar ATPase) and capillaries (amylase-PAS method), and analysed biochemically for succinate dehydrogenase and cytochrome oxidase activities.2. The training programme resulted in a 16% increase in V(O2 max.), a 20% increase in capillary density, a 20% increase in mean fibre area, and an approximately 40% increase in the activities of succinate dehydrogenase and cytochrome oxidase.3. The capillary supply to type I, IIA and IIB fibres, expressed as the mean number of capillaries in contact with each fibre-type, relative to fibre-type area, increased equally.4. The present study shows that endurance training constitutes a powerful stimulus for capillary proliferation in human skeletal muscle.     

Association of tuberculin-boosted antibody responses with pathology and cell-mediated immunity in cattle vaccinated with Mycobacterium bovis BCG and infected with M. bovis

Vaccine development and our understanding of the pathology of bovine tuberculosis in cattle would be greatly facilitated by definition of the immunological correlates of protection and/or pathology. In this study we analyzed humoral immune responses in Mycobacterium bovis BCG-vaccinated and control cattle (in particular, the relationship between the intradermal comparative tuberculin skin test and serum immunoglobulin G [IgG] responses) against a range of mycobacterial antigens (MPB59, MPB64, MPB70, MPB83, ESAT-6, CFP-10, Acr1, and PstS-1) by multiantigen print immunoassay and conventional enzyme-linked immunosorbent assay. Following M. bovis infection, the comparative tuberculin skin test strongly boosted IgG, IgG1, and IgG2 antibody responses, particularly against MPB83 and MPB70, in unvaccinated cattle but failed to boost these responses, or did so only weakly, in BCG-vaccinated calves. In addition, the skin test-induced increases in MPB83-specific IgG responses correlated positively with bacterial loads and ESAT-6-induced in vitro gamma interferon responses. In conclusion, both the negative correlation of skin test-enhanced MPB83-specific antibody responses with BCG-induced protection and their positive correlation with bacterial loads can serve as useful markers for vaccine efficacy after challenge.