Ethical issues in preventing mother-to-child transmission of hepatitis B by immunisation

Without intervention, a pregnant woman who is a chronic hepatitis B carrier is at risk of transmitting hepatitis B and of her infant becoming a chronic carrier and having a significantly increased lifetime risk of developing liver cancer or cirrhosis. Hepatitis B vaccine and immunoglobulin reduce the risk of the baby becoming a carrier, but with only a short window period after birth to deliver this potentially life-saving intervention. We reviewed the evidence on the magnitude of the risk. If the carrier mother is e antigen positive (highly infective), the calculated risk to the infant without intervention is 75.2%, reduced to 6.0% by giving vaccine and immunoglobulin at birth. If the mother is surface antigen positive but e antigen negative, the risk to the infant without intervention is 10.3%, reduced to 1.0% by giving vaccine and immunoglobulin. If vaccine is accepted but immunoglobulin refused, as for example by some Jehovah's Witnesses, the risk to babies of e antigen positive mothers is reduced to 21.0% and to babies of e antigen negative mothers to 2.6%. These figures can be used to inform parents and as a possible basis for child protection proceedings if parents decline vaccine and/or immunoglobulin. We argue from the perspective of the best interests of the child that the severity of the condition justifies initiating child protection proceedings whenever a baby is born to a hepatitis B carrier mother and, despite concerted attempts to persuade them, the parents refuse vaccine and/or immunoglobulin.

Lesions of the dorsomedial striatum disrupt prepulse inhibition

Prepulse inhibition (PPI) of startle is an experimentally tractable measure of sensorimotor gating that can be readily evaluated in mice, rats, monkeys, and humans. PPI is the inhibitory effect of a low-intensity stimulus, the prepulse, on the startle response to a subsequent high-intensity stimulus. PPI has garnered great interest as a marker of clinically relevant information processing abnormalities, because it is impaired in such neuropsychiatric conditions as schizophrenia, Tourette syndrome, and obsessive compulsive disorder (OCD). Pathology of the basal ganglia has been described in all three of these disorders, and it is therefore of great interest to determine the role of the basal ganglia in PPI. Previous work in rats described a PPI deficit after excitotoxic ventral striatal lesions and a more subtle attenuation after caudodorsal lesion, but no effect of other large lateral dorsal lesions. However, previous studies have not specifically investigated the role of the dorsomedial striatum in PPI. We investigated this issue using excitotoxic lesions in mice. We describe a marked reduction in PPI, at a variety of prepulse intensities, after bilateral lesions of dorsomedial striatum. There was no effect of lesion on baseline startle or habituation. In contrast, comparably sized lesions of the central dorsal striatum had no effect on PPI. These results reveal a role for the dorsomedial striatum in prepulse inhibition, which may have relevance for the abnormalities observed in this region in such disorders as Tourette syndrome and OCD.

The design and development of fesoterodine as a prodrug of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of tolterodine

This review highlights the design and development of fesoterodine (Toviaz) as a prodrug of 5-hydroxymethyl tolterodine (5-HMT), which is also the active metabolite of tolterodine, for the treatment of overactive bladder (OAB). Tolterodine and 5-HMT are both potent antimuscarinic agents. A prodrug approach was necessary for systemic bioavailability of 5-HMT after oral administration. Fesoterodine was selected amongst a series of ester analogues of 5-HMT to develop an advanced OAB treatment with an optimum biopharmaceutics profile, while maintaining a pharmacological link to tolterodine. While tolterodine and 5-HMT have similar antimuscarinic activity, the logD value, a determinant of lipophilicity and permeability across biological interfaces such as the gut wall and blood-brain barrier, is considerably lower for 5-HMT (0.74) versus tolterodine (1.83). In contrast to the cytochrome P450 (CYP) 2D6-mediated metabolism of tolterodine, 5-HMT formation from fesoterodine occurs via ubiquitous nonspecific esterases. Consequently, treatment with fesoterodine results in consistent, genotype-independent exposure to a singular active moiety (5-HMT); treatment with tolterodine results in CYP2D6 genotype-dependent exposure to varying proportions of two active moieties (5-HMT and tolterodine). At least partially due to the avoidance of variations in pharmacokinetic exposures observed with tolterodine, it was possible to develop fesoterodine with the flexibility of two efficacious and well-tolerated dosage regimens of 4 and 8 mg daily.

Mutational analysis of parkin and PINK1 in multiple system atrophy

Multiple system atrophy (MSA) and Parkinson's disease (PD) are progressive neurodegenerative disorders with overlapping clinical, biochemical and genetic features. To test the hypothesis that the PD genes parkin and PINK1 also play a role in the pathogenesis of MSA, we performed a mutational screening study involving 87 pathologically proven MSA cases. In parkin we identified eight sequence variants and four heterozygous deletions and in PINK1 we identified nine variants of which two silent mutations have not been previously reported (p.Gly189Gly and p.Arg337Arg). The frequencies of the observed variants were not significantly different from previously published control data and none of the possibly pathogenic variants were found in a homozygous state. Our results indicate that genetic variants at the parkin and PINK1 loci do not play a critical role in the pathogenesis of MSA.

Adaptive changes in HIV-1 subtype C proteins during early infection are driven by changes in HLA-associated immune pressure

It is unresolved whether recently transmitted human immunodeficiency viruses (HIV) have genetic features that specifically favour their transmissibility. To identify potential "transmission signatures", we compared 20 full-length HIV-1 subtype C genomes from primary infections, with 66 sampled from ethnically and geographically matched individuals with chronic infections. Controlling for recombination and phylogenetic relatedness, we identified 39 sites at which amino acid frequency spectra differed significantly between groups. These sites were predominantly located within Env, Pol and Gag (14/39, 9/39 and 6/39 respectively) and were significantly clustered (33/39) within known immunoreactive peptides. Within 6 months of infection, we detected reversion-to-consensus mutations at 14 sites and potential CTL escape mutations at seven. Here we provide evidence that frequent reversion mutations probably allows the virus to recover replicative fitness which, together with immune escape driven by the HLA alleles of the new hosts, differentiate sequences from chronic infections from those sampled shortly after transmission.

SNCA variants are associated with increased risk for multiple system atrophy

To test whether the synucleinopathies Parkinson's disease and multiple system atrophy (MSA) share a common genetic etiology, we performed a candidate single nucleotide polymorphism (SNP) association study of the 384 most associated SNPs in a genome-wide association study of Parkinson's disease in 413 MSA cases and 3,974 control subjects. The 10 most significant SNPs were then replicated in additional 108 MSA cases and 537 controls. SNPs at the SNCA locus were significantly associated with risk for increased risk for the development of MSA (combined p = 5.5 x 10(-12); odds ratio 6.2) [corrected].

Respiratory health in pre-school and school age children following extremely preterm birth

RATIONALE

Increasing survival at extremely low gestational ages is associated with very high rates of bronchopulmonary dysplasia (BPD) but is rarely quantified.

OBJECTIVES

To identify respiratory morbidity and risk factors in the EPICure cohort over the first 6 years of life.

METHODS

308 babies born at < or =25 weeks' gestation in 1995 were followed up at 30 months and 6 years of age. Respiratory outcome was evaluated using clinical assessment, parental questionnaire and peak expiratory flow (PEF) at 6 years.

RESULTS

74% of this population received supplemental oxygen at 36 weeks postmenstrual age and 36% were discharged with supplemental oxygen which continued for a median of 2.5 months (75th percentile: 8.5 months). 236 children were followed to 6 years. Respiratory symptoms and medication use were more prevalent at 30 months and 6 years in children with BPD compared to those without. Children without BPD (n = 56) were not significantly different from their classmates but had consistently higher prevalence of poor respiratory health. Symptoms, need for hospital admission and medication use declined between 30 months and 6 years. 200 index children completed three PEF measures; PEF was lower than in classmates (mean adjusted difference: 39 l/min (95% CI 30 to 47)) and was lowest in children discharged home with oxygen and in those with BPD. Gestational age, BPD and maternal smoking at home and in pregnancy were independent risk factors for symptoms, but BPD was the only independent associate of PEF.

CONCLUSION

Extremely preterm children have a continuum of poor respiratory health over the first 6 years, which is exacerbated by smoking during pregnancy and in the home.

In vitro allergen challenge of peripheral blood induces differential gene expression in mononuclear cells of asthmatic patients: inhibition of cytosolic phospholipase A2alpha overcomes the asthma-associated response

BACKGROUND

Existing treatments for asthma are not effective in all patients and disease exacerbations are common, highlighting the need for increased understanding of disease mechanisms and novel treatment strategies. The leukotriene pathway including the enzyme responsible for arachidonic acid release from cellular phospholipids, cPLA(2)alpha, is a major contributor to asthmatic responses and an attractive target in asthma therapies.

OBJECTIVE

The study reported here investigates (a) the differential effects of in vitro exposure of peripheral blood mononuclear cells (PBMCs) to allergen between asthma and healthy subjects, and (b) the contribution of cPLA(2)alpha to these differences in gene expression.

METHODS

In vitro responses of asthma (N=26) and healthy (N=11) subject PBMC samples to allergen stimulation in the presence and absence of cPLA(2)alpha inhibition or 5-lipoxygenase inhibition were compared at the gene expression level using oligonucleotide arrays and at the protein level using ELISA.

RESULTS

Subject samples within both asthma and healthy groups showed allergen-dependent cytokine production and allergen-dependent gene expression changes, although transcriptional profiling identified 153 genes that were modulated significantly differently by allergen between asthma and healthy subjects. Among these were genes previously associated with asthma, but the majority (about 80%) have not previously been associated with asthma.

CONCLUSIONS

Transcriptional profiling elucidated novel gene expression differences between the asthmatic and healthy subject samples. Although 5-lipoxygenase inhibition did not significantly affect allergen-modulated gene expression, the inhibition of cPLA(2)alpha activity affected many of the allergen-dependent, asthma-associated gene expression changes.

The detection of microsatellite instability in blind endometrial samples--a potential novel screening tool for endometrial cancer in women from hereditary nonpolyposis colorectal cancer families?

Microsatellite instability (MSI) is the phenotypic molecular characteristic of the majority of tumors associated with the hereditary nonpolyposis colorectal cancer syndrome (HNPCC). Women in this group have an increased risk of endometrial cancer (EC). This study aimed to determine whether MSI could be demonstrated in blind endometrial samples from women with EC, HNPCC kindreds undergoing screening for EC, and women with normal endometrium. Twenty-four women with EC, 20 women from HNPCC kindreds, and 20 women undergoing gynecological surgery for benign indications underwent blind sampling. MSI analysis was performed by conventional polymerase chain reaction using fluorescent-labeled primers and automated analysis. Twelve microsatellites were studied with MSI defined as evident when novel alleles were seen in endometrial biopsy samples compared to genomic DNA. Of the 24 EC samples obtained, sufficient DNA for analysis was extracted in 17 cases. Three cases had evidence of MSI in at least 7/12 loci. None of the endometrium from the two other study groups revealed evidence of MSI. This is the first demonstration of MSI in blind endometrial biopsies. The ability to demonstrate MSI in heterogeneous endometrial samples suggests potential for the development of a novel EC screening tool for women in HNPCC kindreds.

Phenotypic homogeneity of the Huntington disease-like presentation in a SCA17 family

We describe clinical and genetic analysis of a family with spinocerebellar ataxia 17 (SCA17) presenting with a Huntington disease-like (HDL) syndrome. Clinically diagnosed, HD is genetically heterogeneous. Differential diagnosis includes SCA17. However, SCA17 HDL presentation has been observed only sporadically or in solitary individuals within a family. HDL phenotypic homogeneity in SCA17 has not been described. SCA17 can present with a HDL syndrome in multiple family members.

Plant use of the Maasai of Sekenani Valley, Maasai Mara, Kenya

Traditional plant use is of tremendous importance in many societies, including most rural African communities. This knowledge is however, rapidly dwindling due to changes towards a more Western lifestyle, and the influence of modern tourism.In case of the Sekenani Maasai, the recent change from a nomadic to a more sedentary lifestyle has not, thus far lead to a dramatic loss of traditional plant knowledge, when compared to other Maasai communities. However, in Sekenani, plants are used much less frequently for manufacturing tools, and for veterinary purposes, than in more remote areas. While the knowledge is still present, overgrazing and over-exploitation of plant resources have already led to a decline of the plant material available.This paper examines the plant use of the Maasai in the Sekenani Valley, North of the Masaai Mara National Reserve. The Maasai pastoralists of Kenya and Tanzania use a large part of the plants in their environment for many uses in daily life. The plant use and knowledge of the Sekenani Maasai is of particular interest, as their clan, the "Il-Purko", was moved from Central Kenya to this region by the British Colonial Administration in 1904.The results of this study indicate that despite their relocation 100 years ago, the local population has an extensive knowledge of the plants in their surroundings, and they ascribe uses to a large percentage of the plants found. One-hundred-fifty-five plant species were collected, identified and their Maa names and traditional uses recorded. Although fifty-one species were reported as of "no use", only eighteen of these had no Maasai name. Thirty-three were recognized by a distinctive Maa name. Thirty-nine species had a medicinal use, and 30 species served as fodder for livestock. Six species could not be identified. Of these plants five were addressed by the Maasai with distinct names. This exemplifies the Sekenani Maasai's in-depth knowledge of the plant resources.Traditionally, the Maasai attribute most illnesses to the effect of pollutants that block or inhibit digestion. These pollutants can include "polluted" food, contact with sick people and witchcraft. In most cases the treatment of illness involves herbal purgatives to cleanse the patient. There are also frequent indications of plant use for common problems like wounds, parasites, body aches and burns.

The detection of microsatellite instability in blind endometrial samples—a potential novel screening tool for endometrial cancer in women from hereditary nonpolyposis colorectal cancer families?

Microsatellite instability (MSI) is the phenotypic molecular characteristic of the majority of tumors associated with the hereditary nonpolyposis colorectal cancer syndrome (HNPCC). Women in this group have an increased risk of endometrial cancer (EC). This study aimed to determine whether MSI could be demonstrated in blind endometrial samples from women with EC, HNPCC kindreds undergoing screening for EC, and women with normal endometrium. Twenty-four women with EC, 20 women from HNPCC kindreds, and 20 women undergoing gynecological surgery for benign indications underwent blind sampling. MSI analysis was performed by conventional polymerase chain reaction using fluorescent-labeled primers and automated analysis. Twelve microsatellites were studied with MSI defined as evident when novel alleles were seen in endometrial biopsy samples compared to genomic DNA. Of the 24 EC samples obtained, sufficient DNA for analysis was extracted in 17 cases. Three cases had evidence of MSI in at least 7/12 loci. None of the endometrium from the two other study groups revealed evidence of MSI. This is the first demonstration of MSI in blind endometrial biopsies. The ability to demonstrate MSI in heterogenous endometrial samples suggests potential for the development of a novel EC screening tool for women in HNPCC kindreds.