Adaptation of sea turtles to climate warming: Will phenological responses be sufficient to counteract changes in reproductive output?

Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a "middle of the road" scenario (SSP2-4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26-43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present-day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from -20 to -191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.

Increased incidence of Persistent Pulmonary Hypertension of the Newborn following third trimester maternal COVID-19 infection

Background

Novel coronavirus (COVID-19) has been a world concern since December 2019. The knowledge about vertical transmission and fetal morbidity and mortality from maternal COVID-19 infection is limited. We detected an increase in the number of cases of term and near-term neonates with persistent pulmonary hypertension (PPHN) during the COVID-19 pandemic in 2020.

Methods and results

We collected data on all newborns with PPHN born between 2018 and 2020. We excluded premature infants (<34+0 weeks) and infants with other significant pathology or genetic syndromes. Compared to 5 cases of PPHN of 22930 live births in 2018, and 6 cases of PPHN of 22270 live births in 2019 (2-year average 0.02%, 95% CI 0.013%-0.043%), there were 16 PPHN cases from 22323 live births in 2020 (0.07%, 95% CI 0.044%-0.12%), a 3 fold increase (p<0.01). We report 5 cases of term and near-term neonates born to mothers who had highly suspected (2) and PCR proven (3) COVID-19 infection during the third trimester of pregnancy, who presented with PPHN during COVID-19 pandemic in 2020. All had otherwise unexplained pulmonary hypertension, right ventricular hypertrophy (RVH) and dilatation. Two patients needed endotracheal intubation, one was supported by nasal continuous positive airway pressure (CPAP) without intubation, two needed O2 support by nasal cannula only ant two newborns (one of them was intubated) needed Nitric oxide (NO) as pulmonary vasodilator therapy. No patient required Extracorporeal membrane oxygenation (ECMO) or died, and no prolonged residual cardiovascular or pulmonary morbidity was recorded during a median follow up of 4.8 months (range 4–6 months).

Conclusions

The increase in the incidence of PPHN during the COVID-19 pandemic, and the cases presented, suggest an intrauterine effect of maternal COVID-19 infection on the fetal pulmonary circulation. It is possible that the maternal infection affected the fetal pulmonary vascular resistance, or altered the normal decline in the resistance after birth. The right ventricular hypertrophy and dilatation with reduced function may be secondary to this hypothetical increased afterload or a direct effect of the infection. Further studies are warranted to elucidate the pathogenesis and clinical implications of this phenomenon.

Funding Acknowledgement

Type of funding sources: None.

Tele-rehabilitation for people with dementia in the COVID-19 pandemic: A case-study

Introduction

The Promoting Activity, Independence and Stability in Early Dementia (PrAISED) is delivering an exercise programme for people with dementia. The Lincolnshire partnership NHS foundation Trust successfully delivered PrAISED through a video-calling platform during the COVID-19 pandemic.

Objectives

This qualitative case-study identified participants that video delivery worked for, and highlighted its benefits and challenges.

Methods

Interviews were conducted with participants with dementia, caregivers and therapists, and analysed through thematic analysis.

Results

Video delivery worked best when participants had a supporting carer, when therapists showed enthusiasm and had an established rapport with the client. Benefits included time-efficiency of sessions, enhancing participants’ motivation, caregivers’ dementia awareness and therapists’ creativity. Limitations included users’ poor IT skills and resources.

Conclusions

The COVID-19 pandemic required innovative ways of delivering rehabilitation. This study supports that people with dementia can use tele rehab, but success is reliant on having a caregiver and an enthusiastic and known therapist.

Age and Ageing to introduce a new category of paper: healthcare improvement science

Age and Ageing is now inviting papers on healthcare improvement for older people. In this article we outline the nature and scope of healthcare improvement and reference improvement models and the tools and methods of improvement science. We emphasise the issues of sustainability, including scale and spread; evaluation - including associated ethical consideration and the involvement of patients and the public in healthcare improvement and associated research. Throughout we refer to resources the authors have found useful in their own work, and provide a bibliography of sources and web-links which will provide essential guidance and support for potential contributors to this new category of submission to Age and Ageing.

Development and content validation of measures assessing adherence barriers and behaviors for use in clinical care

BACKGROUND

Providers are often unaware of poor adherence to prescribed medications for their patients with chronic diseases.

OBJECTIVE

To develop brief, computer-administered patient-reported measures in English and Spanish assessing adherence behaviors and barriers. Design, Participants, and Main Measures: Item pools were constructed from existing measures of medication adherence behaviors and barriers, which informed development of a patient concept elicitation interview guide to identify medication adherence behavior and barrier-related concepts. Two hundred six patients either living with HIV (PLWH) or without were interviewed. Interviews were coded, concepts matched to item pool content, and new items were developed for novel concepts. A provider/investigator team highlighted clinically relevant items. Cognitive interviews were conducted with patients on final candidate items (n = 37). The instruments were administered to 2081 PLWH.

KEY RESULTS

Behavioral themes from concept elicitation interviews included routines incorporating time of day, placement, visual cues, and intentionality to miss or skip doses. Barrier themes included health-related (e.g. depressed mood, feeling ill), attitudes/beliefs (e.g., need for medication), access (e.g., cost/insurance problems), and circumstantial barriers (e.g., lack of privacy, disruption of daily routine). The final instruments included 6 behavior items, and 1 barrier item with up to 23 response options. PLWH endorsed a mean (SD) of 3.5 (1.1) behaviors. The 201 PLWH who missed ≥2 doses in the previous week endorsed a mean (SD) of 3.1 (2.5) barriers. The intraclass correlation coefficient (ICC) for the numbers of behaviors endorsed in 61 PLWH after 4-16 days was 0.54 and for the number of barriers for the 20 PLWH with ≥2 missed doses the ICC was 0.89, representing fair and excellent test-retest reliability.

CONCLUSION

Measures of medication adherence behaviors and barriers were developed for use with patients living with chronic diseases focusing on clinical relevance, brevity, and content validity for use in clinical care.

Medication understanding among patients living with multiple chronic conditions: Implications for patient-reported measures of adherence

BACKGROUND

Low health literacy is associated with poor medication adherence and poor health outcomes. Limited understanding of prescribed medications may decrease validity of patient-reported adherence measures.

OBJECTIVES

To assess knowledge of names and purposes of prescribed medications among patients with multiple chronic conditions.

METHODS

Individual interviews were conducted with a convenience sample of patients from six U.S. primary care clinics. Participants (n = 57) were English and/or Spanish-speaking patients prescribed 3+ medications for chronic conditions, for which non-adherence may lead to disability or death. In individual interviews, patients were asked to name their medications, explain the purpose of each, and to explain how they distinguish them from one another. Interviews were audio recorded, transcribed, and coded; coded content was quantified by 1) whether or not the patient could name medications; 2) method of categorizing medications; 3) whether or not the purpose of the medication was understood. Descriptive statistics were compiled using Fisher's exact test to determine the relationship between patient knowledge and medication characteristics.

RESULTS

Thirty percent of patients could not name at least one of their medications; 19% did not know their purpose; 30% held misconceptions about the purpose of one or more medications. There was no significant difference in ability to name medications or state their medication's purpose between patients using medi-sets, pre-packaged rolls, or blister packs, and patients who stored pills in their original containers (p = 0.56 and p = 0.73, respectively), or across demographic groups (p = 0.085 to 0.767).

CONCLUSIONS

Many patients demonstrated difficulty identifying the name and purpose of prescribed medications; this did not differ by demographic group or medication storage type. Patients may benefit from routine review of medications with their provider in order to improve health literacy, outcomes, and patient-reported adherence measurement.

Chip-based quantum key distribution

Improvement in secure transmission of information is an urgent need for governments, corporations and individuals. Quantum key distribution (QKD) promises security based on the laws of physics and has rapidly grown from proof-of-concept to robust demonstrations and deployment of commercial systems. Despite these advances, QKD has not been widely adopted, and large-scale deployment will likely require chip-based devices for improved performance, miniaturization and enhanced functionality. Here we report low error rate, GHz clocked QKD operation of an indium phosphide transmitter chip and a silicon oxynitride receiver chip—monolithically integrated devices using components and manufacturing processes from the telecommunications industry. We use the reconfigurability of these devices to demonstrate three prominent QKD protocols—BB84, Coherent One Way and Differential Phase Shift—with performance comparable to state-of-the-art. These devices, when combined with integrated single photon detectors, pave the way for successfully integrating QKD into future telecommunications networks.

Quantum key distribution has not been widely adopted in part due to technical hurdles preventing it being fully integrated in classical communication networks. Here the authors report quantum key distribution between two photonic chips manufactured with state-of-the-art telecoms industry processes.

A randomised controlled trial of complete denture impression materials

Objectives

There is continuing demand for non-implant prosthodontic treatment and yet there is a paucity of high quality Randomised Controlled Trial (RCT) evidence for best practice. The aim of this research was to provide evidence for best practice in prosthodontic impressions by comparing two impression materials in a double-blind, randomised, crossover, controlled, clinical trial.

Methods

Eighty-five patients were recruited, using published eligibility criteria, to the trial at Leeds Dental Institute, UK. Each patient received two sets of dentures; made using either alginate or silicone impressions. Randomisations determined the order of assessment and order of impressions. The primary outcome was patient blinded preference for unadjusted dentures. Secondary outcomes were patient preference for the adjusted dentures, rating of comfort, stability and chewing efficiency, experience of each impression, and an OHIP-EDENT questionnaire.

Results

Seventy-eight (91.8%) patients completed the primary assessment. 53(67.9%) patients preferred dentures made from silicone impressions while 14(17.9%) preferred alginate impressions. 4(5.1%) patients found both dentures equally satisfactory and 7 (9.0%) found both equally unsatisfactory. There was a 50% difference in preference rates (in favour of silicone) (95%CI 32.7–67.3%, p < 0.0001).

Conclusion

There is significant evidence that dentures made from silicone impressions were preferred by patients.

Clinical significance

Given the strength of the clinical findings within this paper, dentists should consider choosing silicone rather than alginate as their material of choice for secondary impressions for complete dentures.

Trial Registration: ISRCTN 01528038.



This article forms part of a project for which the author (TPH) won the Senior Clinical Unilever Hatton Award of the International Assocation for Dental Research, Capetown, South Africa, June 2014.

Introducing structured caregiver training in stroke care: findings from the TRACS process evaluation study

OBJECTIVE

To evaluate the process of implementation of the modified London Stroke Carers Training Course (LSCTC) in the Training Caregivers After Stroke (TRACS) cluster randomised trial and contribute to the interpretation of the TRACS trial results. The LSCTC was a structured competency-based training programme designed to help develop the knowledge and skills (eg, patient handling or transfer skills) essential for the day-to-day management of disabled survivors of stroke. The LSCTC comprised 14 components, 6 were mandatory (and delivered to all) and 8 non-mandatory, to be delivered based on individual assessment of caregiver need.

DESIGN

Process evaluation using non-participant observation, documentary analysis and semistructured interviews.

PARTICIPANTS

Patients with stroke (n=38), caregivers (n=38), stroke unit staff (n=53).

SETTINGS

10 of the 36 stroke units participating in the TRACS trial in four English regions (Yorkshire, North West, South East and South West, Peninsula).

RESULTS

Preparatory cascade training on delivery of the LSCTC did not reach all staff and did not lead to multidisciplinary team (MDT) wide understanding of, engagement with or commitment to the LSCTC. Although senior therapists in most intervention units observed developed ownership of the LSCTC, MDT working led to separation rather than integration of delivery of LSCTC elements. Organisational features of stroke units and professionals' patient-focused practices limited the involvement of caregivers. Caregivers were often invited to observe therapy or care being provided by professionals but had few opportunities to make sense of, or to develop knowledge and stroke-specific skills provided by the LSCTC. Where provided, caregiver training came very late in the inpatient stay. Assessment and development of caregiver competence was not commonly observed.

CONCLUSIONS

Contextual factors including service improvement pressures and staff perceptions of the necessity for and work required in caregiver training impacted negatively on implementation of the caregiver training intervention. Structured caregiver training programmes such as the LSCTC are unlikely to be practical in settings with short inpatient stays. Stroke units where early supported discharge is in place potentially offer a more effective vehicle for introducing competency based caregiver training.

LINKED TRACS CLUSTER RANDOMISED CONTROLLED TRIAL NUMBER

ISRCTN49208824.

The molecular genetics of Marfan syndrome and related disorders

Marfan syndrome (MFS), a relatively common autosomal dominant hereditary disorder of connective tissue with prominent manifestations in the skeletal, ocular, and cardiovascular systems, is caused by mutations in the gene for fibrillin-1 (FBN1). The leading cause of premature death in untreated individuals with MFS is acute aortic dissection, which often follows a period of progressive dilatation of the ascending aorta. Recent research on the molecular physiology of fibrillin and the pathophysiology of MFS and related disorders has changed our understanding of this disorder by demonstrating changes in growth factor signalling and in matrix-cell interactions. The purpose of this review is to provide a comprehensive overview of recent advances in the molecular biology of fibrillin and fibrillin-rich microfibrils. Mutations in FBN1 and other genes found in MFS and related disorders will be discussed, and novel concepts concerning the complex and multiple mechanisms of the pathogenesis of MFS will be explained.

In frame fibrillin-1 gene deletion in autosomal dominant Weill-Marchesani syndrome

Weill-Marchesani syndrome (WMS) is a connective tissue disorder characterised by short stature, brachydactyly, joint stiffness, and characteristic eye anomalies including microspherophakia, ectopia of the lenses, severe myopia, and glaucoma. Both autosomal recessive (AR) and autosomal dominant (AD) modes of inheritance have been described and a gene for AR WMS has recently been mapped to chromosome 19p13.3-p13.2. Here, we report on the exclusion of chromosome 19p13.3-p13.2 in a large AD WMS family and show that, despite clinical homogeneity, AD and AR WMS are genetically heterogeneous entities. Because two AD WMS families were consistent with linkage to chromosome 15q21.1, the fibrillin-1 gene was sequenced and a 24 nt in frame deletion within a latent transforming growth factor-beta1 binding protein (LTBP) motif of the fibrillin-1 gene was found in a AD WMS family (exon 41, 5074_5097del). This in frame deletion cosegregated with the disease and was not found in 186 controls. This study strongly suggests that AD WMS and Marfan syndrome are allelic conditions at the fibrillin-1 locus and adds to the remarkable clinical heterogeneity of type I fibrillinopathies.

Prevention: developing a framework for conceptualizing and evaluating outcomes of preventive services for older people

There is growing preoccupation among policy makers and commissioners in developing preventive strategies and services. There is simultaneous concern with evidence-based purchasing and provision, within health and social care. In social care the evidence base regarding prevention is neither extensive nor robust. As the review of recent policy documents indicates, the concept of prevention is extremely slippery. What preventive services are and whether they are effective depends on the specific policy context, the overall service objectives and the perspective on outcomes adopted (user, carer, professional, service). Focusing on older people, the paper seeks a way through the confusion, locating prevention within a theoretical model of successful ageing. This conceptualizes ageing as involving adaptation to the changing balance between gains and losses over the life course. Successful ageing is perceived as the attainment of valued goals, the minimisation of losses and maximization of gains through the linked processes of selective compensation and optimisation. The paper then identifies necessary elaborations of the model to take into account the wider cultural and socio-economic context. This shapes and constrains the goals pursued and the resources available in adopting particular adaptation strategies. Within this model, preventive services may be conceived as resources to be drawn upon to support compensatory strategies. Similarly, outcomes and effectiveness of services may be evaluated in terms of whether they facilitate/allow older people to achieve valued goals. In developing and evaluating preventive services in social care the question of interest is reformulated: what contribution do specific services make in optimising gains and compensating for the losses that accompany ageing? This framework is explored in respect of two substantive areas ripe for secondary prevention services and strategies - bereavement and instrumental support in the home.

Classic, atypically severe and neonatal Marfan syndrome: twelve mutations and genotype-phenotype correlations in FBN1 exons 24-40

Mutations in the gene for fibrillin-1 (FBN1) cause Marfan syndrome, an autosomal dominant disorder of connective tissue with prominent manifestations in the skeletal, ocular, and cardiovascular system. There is a remarkable degree of clinical variability both within and between families with Marfan syndrome as well as in individuals with related disorders of connective tissue caused by FBN1 mutations and collectively termed type-1 fibrillinopathies. The so-called neonatal region in FBN1 exons 24-32 comprises one of the few generally accepted genotype-phenotype correlations described to date. In this work, we report 12 FBN1 mutations identified by temperature-gradient gel electrophoresis screening of exons 24-40 in 127 individuals with Marfan syndrome or related disorders. The data reported here, together with other published reports, document a significant clustering of mutations in exons 24-32. Although all reported mutations associated with neonatal Marfan syndrome and the majority of point mutations associated with atypically severe presentations have been found in exons 24-32, mutations associated with classic Marfan syndrome occur in this region as well. It is not possible to predict whether a given mutation in exons 24-32 will be associated with classic, atypically severe, or neonatal Marfan syndrome.

Two novel fibrillin-2 mutations in congenital contractural arachnodactyly

Congenital contractural arachnodactyly (CCA) is an autosomal dominant connective tissue disorder, comprising marfanoid habitus, flexion contractures, severe kyphoscoliosis, abnormal pinnae, and muscular hypoplasia. It is now known that mutations in the gene encoding fibrillin-2 cause CCA. Interestingly, mutations described to date cluster in the fibrillin-2 region homologous to the so-called neonatal Marfan syndrome region of fibrillin-1. Thus, it has been hypothesized that the relative infrequency of CCA compared with the Marfan syndrome is due to the limited region of the gene targeted for mutations. In support of the above hypothesis, we report here the finding of two additional FBN2 mutations in CCA, C1141F (exon 26) and C1252W (exon 29). In addition, a new 3' UTR polymorphism is also described.

Partial cloning and sequencing of chick fibrillin-1 cDNA

The recent identification of numerous matrix genes and gene products has allowed a detailed examination of their roles in development. Two of these extracellular matrix proteins, fibrillin-1 and fibrillin-2, are components of the elastin-associated microfibrils. Given what is known about the distribution of the fibrillins in normal tissues and the abnormalities that result when mutations occur, a basic hypothesis has emerged: fibrillin-1 is primarily responsible for load bearing and providing structural integrity, whereas fibrillin-2 may be a director of elastogenesis. Nevertheless, examination of phenotypes in disorders caused by mutations in fibrillin-1 or fibrillin-2 suggests some common functions. To better understand these similar and diverse roles, it would be helpful to examine these proteins during chick development. To accomplish this goal, it is first necessary to characterize the chick homologs of the known fibrillins. In this study, the partial chick FBN1 cDNA was identified by polymerase chain reaction-aided cloning as a first step toward elucidating these goals. Sequence analysis indicated that there is striking conservation between chick and mammalian fibrillin-1 at the DNA and protein levels. Antisense and sense riboprobes were synthesized and used in in situ hybridization in stage 14 chick embryos and high levels of FBN1 transcripts were observed in the heart.

The molecular genetics of Marfan syndrome and related microfibrillopathies

Mutations in the gene for fibrillin-1 (FBN1) have been shown to cause Marfan syndrome, an autosomal dominant disorder of connective tissue characterised by pleiotropic manifestations involving primarily the ocular, skeletal, and cardiovascular systems. Fibrillin-1 is a major component of the 10-12 nm microfibrils, which are thought to play a role in tropoelastin deposition and elastic fibre formation in addition to possessing an anchoring function in some tissues. Fibrillin-1 mutations have also been found in patients who do not fulfil clinical criteria for the diagnosis of Marfan syndrome, but have related disorders of connective tissue, such as isolated ectopia lentis, familial aortic aneurysm, and Marfan-like skeletal abnormalities, so that Marfan syndrome may be regarded as one of a range of type 1 fibrillinopathies. There appear to be no particular hot spots since mutations are found throughout the entire fibrillin-1 gene. However, a clustering of mutations associated with the most severe form of Marfan syndrome, neonatal Marfan syndrome, has been noted in a region encompassing exons 24 to 32. The gene for fibrillin-2 (FBN2) is highly homologous to FBN1, and mutations in FBN2 have been shown to cause a phenotypically related disorder termed congenital contractural arachnodactyly. Since mutations in the fibrillin genes are likely to affect the global function of the microfibrils, the term microfibrillopathy may be the most appropriate to designate the spectrum of disease associated with dysfunction of these molecules. The understanding of the global and the molecular functions of the fibrillin containing microfibrils is still incomplete and, correspondingly, no comprehensive theory of the pathogenesis of Marfan syndrome has emerged to date. Many, but not all, fibrillin-1 gene mutations are expected to exert a dominant negative effect, whereby mutant fibrillin monomers impair the global function of the microfibrils. In this paper we review the molecular physiology and pathophysiology of Marfan syndrome and related microfibrillopathies.

Prenatal diagnosis in congenital contractural arachnodactyly

Congenital contractural arachnodactyly (CCA) is a heritable connective tissue disorder caused by defects in the gene encoding fibrillin-2 (FBN2). People with CCA typically have a marfanoid habitus, flexion contractures, severe kyphoscoliosis, abnormal pinnae, and muscular hypoplasia. Because of the relative infrequency of the syndrome and its generally mild to moderate severity, prenatal diagnosis had not previously been sought. Here we report prenatal diagnosis in a family with CCA. Because the course of the disease in the proband was rather severe, she had requested genetic counseling as early as age 17. She delayed childbearing until prenatal diagnosis for CCA became possible. This decision was supported by her mother and later her husband. Because she shared the same genotype with her husband, genetic linkage analysis of this family did not alter the a priori 50% risk of having an affected child. The possibility of unambiguously ascertaining the affected status of a fetus homozygous for the tested FBN2 marker was sufficient for the family to pursue prenatal diagnosis. This case strongly points to the importance of informed decisions now that genetic testing is becoming commonplace.

Maternal, but not fetal, administration of corticosteroids restricts fetal growth

OBJECTIVE

Previous studies have shown that repeated doses of corticosteroids given to pregnant sheep improve postnatal lung function, but restrict fetal growth. Repeated administration of corticosteroids directly to the fetus also enhances postnatal lung function. The purpose of the present study was to investigate and characterize the relative effects on growth of repeated maternal and fetal treatments by study of body, organ, and placental weights.

METHODS

Date-bred pregnant sheep were given intramuscular betamethasone or saline to either the mother or fetus on three occasions at weekly intervals commencing at 104 days gestation, followed by cesarean section at 125 days. Twenty-two animals which had received three doses of betamethasone were compared with 21 which had received a single dose at 104 days and with 12 saline-treated controls.

RESULTS

Repeated maternal doses of betamethasone resulted in reductions in birthweight and weights of the placenta and major organs. Direct fetal injection did not affect birthweight, placental weight, placental/ birthweight ratio, or weights of the major organs with the exception of the liver.

CONCLUSIONS

Administration of repeated doses of betamethasone directly to the sheep fetus does not produce the growth-restricting effects induced by maternal administration and does not affect the placental/birthweight ratio.

Novel exon skipping mutation in the fibrillin-1 gene: two 'hot spots' for the neonatal Marfan syndrome

The Marfan syndrome is an autosomal dominant heritable disorder of connective tissue that involves principally the skeletal, ocular, and cardiovascular systems. The most severe end of the phenotypic spectrum, the neonatal Marfan syndrome (nMFS), is characterized by pronounced atrioventricular valve dysfunction, and death often occurs within the first year of life due to congestive heart failure. Mutations in the gene coding for fibrillin-1, FBN1, are known to cause Marfan syndrome, and have been identified in almost all exons of FBN1. Here, we describe a novel mutation affecting the invariant + 1 position of the splice donor site in intron 31, associated with skipping of exon 31, in a patient with nMFS. Published reports of nMFS are reviewed and a strict definition for nMFS is suggested. If this definition is used, all nMFS mutations reported to date lie in one of two hot spots, comprising mainly missense mutations in FBN1 exons 24-27 and mutations causing skipping of exon 31 or 32.

Repeated antenatal corticosteroids: size at birth and subsequent development

OBJECTIVE

The objective was to study the effects of repeated antenatal corticosteroids on birth size, growth, and development in preterm infants.

STUDY DESIGN

This observational study followed up for 3 years a prospective geographic cohort in the state of Western Australia of 477 singleton infants born at <33 weeks' gestation.

RESULTS

Birth weight ratio decreased with increasing number of corticosteroid courses (P =.001), and multivariate analyses confirmed a reduction in birth weight of as much as 9% (P =.014) and a reduction in head circumference of as much as 4% (P =.0024). There were no additional benefits in mortality or respiratory outcomes, and there was a trend toward more severe chronic lung disease. At age 3 years growth and severe disability outcomes did not appear to be related to increasing number of corticosteroid courses.

CONCLUSIONS

In this cohort study repeated corticosteroid courses were associated with adverse effects on size at birth without apparent benefits. These changes have the potential to affect later development.

Renal handling of circulating nitrates in anesthetized dogs

Nitric oxide (NO) is rapidly oxidized to nitrite (NO-2) and then to nitrate (NO-3) in biological tissues. Although urinary excretion rates of NO-3 are often used as an index of NO production in the body, very little is known regarding the kidney's ability to excrete circulating NO-3. We have evaluated the renal responses to systemic administration of sodium nitrate (NaNO3) in eight anesthetized dogs treated with the NO synthase inhibitor, nitro-L-arginine (NLA; 50 microg . kg-1 . min-1), intrarenally to minimize renal production of NO. Urinary and plasma concentrations of NO-3/NO-2 (NOX) were determined by the Greiss reaction after enzymatic reduction of NO-3 to NO-2. NLA treatment alone resulted in reductions in urinary NOX excretion rates (UNOXV, 1.13 +/- 0.2 to 0.53 +/- 0.1 nmol . min-1 . g-1) and an increase in fractional reabsorption of NOX (FRNOX, 93.8 +/- 0.6 to 97 +/- 0.6%) without changes in arterial plasma concentrations (ANOX, 18.7 +/- 1.4 to 21.2 +/- 3.7 microM). Administration of NaNO3 (10, 20, 30, and 40 microg . kg-1 . min-1) resulted in dose-dependent increases in ANOX (34.5 +/- 8.0, 46.4 +/- 7.3, 60.7 +/- 6.3, and 78.1 +/- 6.3 microM), UNOXV (1.8 +/- 0.7, 4.2 +/- 1.8, 7.0 +/- 2.0, and 11.4 +/- 3.3 nmol . min-1 . g-1), and decreases in FRNOX (93.8 +/- 2.3, 90.3 +/- 3.5, 88.6 +/- 3.2, and 84.6 +/- 3.5%). Absolute net tubular reabsorption of NO-3 showed a linear relationship with filtered loads, with no evidence of a transport maximum. These data show that, in the absence of additions from intrarenal sources, urinary excretion rates of nitrate increases progressively in response to increases in its circulating levels without exhibiting a transport maximum but with progressive decreases in fractional reabsorption.

Efficacy of intravaginal misoprostol in second-trimester pregnancy termination: a randomized controlled trial

A prospective randomized, double-blind, controlled clinical trial to compare the clinical efficacy and side effects of intravaginal misoprostol with the traditional prostaglandin, gemeprost, in second-trimester pregnancy interruption was conducted. A sample size of 100 women was calculated to demonstrate that misoprostol was as effective as gemeprost in achieving delivery within 24 hours (alpha = 0.1, 80% power). Women were recruited with fetal death in utero, severe fetal anomaly, or psychosocial pregnancy termination between 14 and 28 weeks gestation and randomized to receive either 1 mg gemeprost 3 hourly for 5 doses, or 200 mcg misoprostol 6 hourly for 4 doses, intravaginally. The therapeutic regimens were repeated if undelivered by 24 hours. Those undelivered after 48 hours received an extra-amniotic PGF2 alpha infusion. The median gestation at recruitment was identical: gemeprost 19 weeks (IQ 17-22 weeks) vs. misoprostol 19 weeks (IQ 17-21 weeks), P = 0.887. Delivery within 24 hours occurred in 75.1% of women receiving gemeprost and 74.9% receiving misoprostol (P = 1.0). The median time from prostaglandin commencement to delivery was similar: gemeprost 13.7 hours (IQ 9.0-23.5 hours) vs. misoprostol 16.9 hours (IQ 10.3-23.5 hours), P = 0.769. A significant reduction in the incidence of vomiting in women randomized to misoprostol occurred (34% vs. 13.2%, P = 0.017). There was no significant difference in the incidence of maternal fever > 37.5 degrees C, nausea, diarrhea, or placental retention. A 200-fold pharmaceutical cost advantage was observed with the use of misoprostol compared with gemeprost. Intravaginal misoprostol performs as effectively as gemeprost in achieving delivery in the second trimester without increase in adverse effects and displaying a significant cost advantage.

Heritable connective tissue disorders in cervical artery dissections: a prospective study

We prospectively evaluated 15 consecutive patients with spontaneous cervical artery dissections. Three patients (20%) had a heritable connective tissue disorder, each with a unique phenotype. None of these patients met the criteria of any of the named syndromes, and collagen and fibrillin analyses were normal. Heritable connective tissue disorders are common among patients with spontaneous cervical artery dissections, but, despite intensive investigations, the type of disorder usually cannot be identified. The underlying arteriopathy in cervical artery dissections is likely to be heterogeneous.

Factors influencing the selection of analgesia in spontaneously labouring nulliparous women at term

We investigated the maternal characteristics, labour performance and delivery mode of 497 nulliparas entering labour spontaneously at term to identify the obstetric factors which influenced their choice of analgesia; 51.7% of these women used epidural analgesia. They were shorter (163 versus 165 cm, p = 0.002) and the mean gestation was 3 days greater than those not using epidural analgesia (40.2 versus 39.6 weeks, p = 0.0007). Median birth-weight in the epidural group was greater by 155 g (3,450 versus 3,295 gs, p = 0.0001). Analysis of the labour characteristics showed a lesser cervical dilatation on admission, significantly longer latent and active phases of labour and second stage length in the epidural cohort. The need for oxytocin augmentation was significantly greater in the epidural group, both prior to and after insertion. Oxytocin augmentation was strongly associated with an increased risk of operative intervention regardless of analgesia. Selection of intrapartum analgesia is not a random event and epidural analgesia appears to be an indicator of abnormal labour patterns. To further investigate the impact of analgesic methods on nulliparous labour we are currently conducting a prospective randomized controlled trial.

Antenatal patterns of uterine activity in low-risk women: a longitudinal study

There is a surprising lack of information on antenatal patterns of uterine activity in the normal obstetric population, with the majority of research having focussed on women at high-risk for preterm birth. We conducted a prospective longitudinal study to investigate patterns of uterine activity in women with singleton gestations at low-risk for preterm birth. Twenty pregnant women were recruited and their uterine activity was recorded using ambulatory tocodynamometry twice weekly throughout the latter half of pregnancy. The collected data were transmitted to a central receiving station for analysis. As gestation advanced there was a progressive increase in the median number of contractions detected per hour, peaking and stablizing at 37-40 weeks (median of 0 contractions/hour at 20-24 weeks rising to 5.4 contractions/hour at 37-40 weeks). In those women with uterine activity, contraction duration and amplitude of deflection significantly increased as gestation advanced. There was a progressive increase in the number of higher amplitude contractions throughout the third trimester. Increasing parity was not associated with increasing antenatal uterine contraction frequency. No association between normal daily physical activity and uterine contraction frequency was evident throughout gestation. In normal human pregnancy there is a steady, progressive increase in the frequency, duration and amplitude of antenatal uterine activity throughout the latter half of gestation. The uterine contractile profile alters from one of a low amplitude, low frequency pattern in the second trimester to a higher amplitude, higher frequency pattern at term.

Pressure natriuresis and renal medullary blood flow in dogs

In the present study, we evaluated the effects of changes in arterial pressure on regional renal blood flows and sodium excretion in anesthetized dogs during control conditions and after 5% volume expansion with isotonic saline. Medullary and cortical blood flow responses were determined with laser-Doppler needle flow probes inserted into the midmedullary and midcortical regions, and whole-kidney blood flow was assessed with an electromagnetic flow probe. Volume expansion in six dogs caused marked increases in urine flow (20.2 +/- 5.5 to 82.5 +/- 22.7 microL.min-1.g-1) and sodium excretion (3.2 +/- 0.5 to 11.1 +/- 2.7 mumol.min-1.g-1), with slight increases in glomerular filtration rate (0.92 +/- 0.03 to 1.01 +/- 0.02 mL.min-1.g-1) but no significant changes in total renal blood flow (4.7 +/- 0.3 to 5.2 +/- 0.6 mL.min-1.g-1), medullary blood flow (+6 +/- 9%), or cortical blood flow (+12 +/- 10%). During stepwise reductions in renal arterial pressure (150 to 75 mm Hg) elicited with a renal arterial occluder, both before and after volume expansion, medullary, cortical, and total renal blood flows as well as glomerular filtration rate exhibited efficient autoregulation, with slopes not significantly different from zero over this range of arterial pressure. Ther were marked increases in the slopes of the relationships between arterial pressure and urine flow (0.18 +/- 0.05 to 0.78 +/- 0.27 microL.min-1.g-1.mm Hg-1) as well as sodium excretion (0.03 +/- 0.004 to 0.10 +/- 0.03 mumol.min-1.g-1.mm Hg-1) during volume expansion. These data demonstrate that medullary blood flow is efficiently autoregulated in dogs during control and volume-expanded states and indicate that the mechanism responsible for the arterial pressure-induced changes in sodium excretion does not depend on coincident alterations in medullary blood flow.

A validation study of home uterine activity monitoring technology in Western Australia

Home uterine activity monitoring has been developed as an 'early warning' device to detect premature uterine activity, thereby encouraging earlier referral and tocolysis of women at risk of preterm delivery. This ambulatory monitoring system, utilizing a ring-guard tocodynamometer, was piloted in Western Australia to determine if it can reliably record and transmit antenatal uterine activity data in an Australian environment. Pregnant women were readily able to correctly apply and use the ambulatory monitoring device. The information collected was able to be transmitted using standard Australian telecommunications systems within our hospital environment. Validation studies with the ambulatory monitor and current external tocodynamometry hardware were performed. The ring-guard tocodynamometer detected more uterine activity at gestations less than 32 weeks compared with conventional external tocodynamometers. As term approached, however, the sensitivity of the ring-guard tocodynamometer decreased. A cross-sectional profile of antenatal uterine activity was developed for women at low risk of delivering preterm. A gradual increase in the number, duration and amplitude of uterine contractions as pregnancy advanced was observed.

Marfan Database (second edition): software and database for the analysis of mutations in the human FBN1 gene

Fibrillin is the major component of extracellular microfibrils. Mutations in the fibrillin gene on chromosome 15 (FBN1) were described at first in the heritable connective tissue disorder, Marfan syndrome (MFS). More recently, FBN1 has also been shown to harbor mutations related to a spectrum of conditions phenotypically related to MFS. These mutations are private, essentially missense, generally non-recurrent and widely distributed throughout the gene. To date no clear genotype/phenotype relationship has been observed excepted for the localization of neonatal mutations in a cluster between exons 24 and 32. The second version of the computerized Marfan database contains 89 entries. The software has been modified to accomodate new functions and routines.

The real problem

I really was dismayed to see the basic cause of all our planet's problems buried in the September/October 96 issue: "...religious zealots might wreck the family planning needs of a billion people...." Let's face hard facts: all these problems would go away if the planet's population were small enough. What we really need to establish is what the population of the earth should be, and then set out to achieve that population as soon as possible. All of our efforts to reduce automobile pollution, the amount of reactor waste, the number of species being obliterated, etc., are just postponing the inevitable. What we need to look at, and keep track of, are those factors that encourage expanding population and discourage population control. For example, most businesses like to see the population expand so they can have a growing customer base. I truly appreciate your efforts. But if we are going to get anywhere we have to clearly identify the real problem. And then we have to break it down into manageable pieces and go to work on them. Otherwise we are going to keep looking at the graphs and wringing our hands as this accumulation of problems builds until it sweeps over us like a giant tsunami.

Pressure natriuresis and autoregulation of inner medullary blood flow in canine kidney

We have evaluated the responses to changes in arterial pressure on regional blood flows in the renal medulla and sodium excretion simultaneously in denervated kidneys of six anesthetized sodium-replete dogs. Renal regional blood flow responses were determined using laser-Doppler needle flow probes and whole-kidney blood flow was assessed using an electromagnetic flow probe. The responses to stepwise reductions in renal arterial pressure (140 to 70 mm Hg) were examined first with a laser-Doppler needle probe inserted in the outer medulla and then repeated after advancing the same probe in the inner medulla. There were no differences in the control values of total renal blood flow (4.4 +/- 0.7 to 4.5 +/- 0.5 mL.min-1.g-1), glomerular filtration rate (0.89 +/- 0.7 to 0.94 +/- 0.9 mL.min-1.g-1), sodium excretion (3.6 +/- 0.6 to 3.4 +/- 0.5 mumol.min-1.g-1), and urinary excretion rate of nitric oxide metabolites (nitrate/nitrite, 1.6 +/- 0.2 to 1.5 +/- 0.2 nmol.min-1.g-1) at the start of both experimental periods. During changes in renal arterial pressure, inner medullary blood flow exhibited efficient autoregulation similar to that in outer medullary blood flow. Usual excretory responses to reductions in renal arterial pressure as well as autoregulation of cortical and whole-kidney blood flows and glomerular filtration rate were observed in these dogs. The slopes of the relationship between arterial pressure and sodium excretion (0.046 +/- 0.007 to 0.044 +/- 0.009 mumol.min-1.g-1.mm Hg-1) or nitrate/nitrite excretion (0.014 +/- 0.003 to 0.013 +/- 0.003 nmol.min-1.g-1.mm Hg-1) were similar in both experimental periods. These data indicate that blood flow to the inner medulla is efficiently autoregulated as in outer medulla and cortex of the kidney in anesthetized dogs and demonstrate further that the arterial pressure-induced natriuretic responses do not require associated changes in medullary blood flow.

Delivery of a hammerhead ribozyme specifically down-regulates the production of fibrillin-1 by cultured dermal fibroblasts

The hammerhead ribozyme is a small catalytic RNA molecule. Potential hammerhead ribozymes that possess a catalytic domain and flanking sequence complementary to a target mRNA can cleave in trans at a putative cleavage site within the target molecule. We have investigated the potential of hammerhead ribozymes to down-regulate the product of the fibrillin-1 gene (FBN1). Fibrillin is a 347 kDa glycoprotein that is a major constituent of the elastin-associated microfibrils. Mutations in the FBN1 gene are responsible for Marfan syndrome (MFS), a common systemic disorder of the connective tissue. Many FBN1 mutations responsible for MFS appear to act in a dominant-negative fashion, raising the possibility that reduction of the amount of product from the mutant FBN1 allele might be a valid therapeutic approach for MFS. A trans-acting hammerhead ribozyme (FBN1-RZ1) targeted to the 5' end of the human FBN1 mRNA has been designed and synthesized, and shown to cleave its target efficiently in vitro. FBN1-RZ1 cleavage is magnesium dependent and efficient at both 37 and 50 degrees C. Delivery of the FBN1-RZ1 ribozyme into cultured dermal fibroblasts, by receptor-mediated endocytosis of a ribozyme-transferrin-polylysine complex, specifically reduces both cellular FBN1 mRNA and the deposition of fibrillin in the extracellular matrix. These results suggest that the use of hammerhead ribozymes is a valid approach to the study of fibrillin gene expression and possibly to the development of a therapeutic approach to MFS.

Familial occurrence of typical and severe lethal congenital contractural arachnodactyly caused by missplicing of exon 34 of fibrillin-2

Genetic linkage studies have linked congenital contractural arachnodactyly (CCA), a usually mild heritable connective-tissue disorder, to FBN2, the fibrillin gene on chromosome 5. Recently, FBN2 mutations in two patients with CCA have been described. Here we report an A-->T transversion at the -2 position of the consensus acceptor splice site, resulting in the missplicing of exon 34, a calcium-binding epidermal growth factor-like repeat in fibrillin-2 in a mother and daughter with CCA. Significantly, the mother exhibited a classic CCA phenotype with arachnodactyly, joint contractures, and abnormal pinnae, whereas her daughter exhibited a markedly more severe CCA phenotype, which included cardiovascular and gastrointestinal anomalies that led to death in infancy. Analysis of cloned fibroblasts showed that the mother is a somatic mosaic for the exon 34 missplicing mutation, whereas all the daughter's cells harbored the mutation.

Weill-Marchesani syndrome--possible linkage of the autosomal dominant form to 15q21.1

Weill-Marchesani syndrome comprises short stature, brachydactyly, microspherophakia, glaucoma, and ectopia lentis is regarded as an autosomal recessive trait (McKusick 277600). We present two families each with affected individuals in 3 generations demonstrating autosomal dominant inheritance of Weill-Marchesani syndrome. Linkage analysis in these 2 families suggests a gene for Weill-Marchesani syndrome maps to 15q21.1. The dislocated lenses and connective tissue disorder in these families suggests that fibrillin-1 and microfibril-associated protein 1, which both map to 15q21.1, are candidate genes for Weill-Marchesani syndrome. Immunohistochemistry staining of skin sections from family 1 showed an apparent decrease in fibrillin staining compared to control individuals.

Double mutant fibrillin-1 (FBN1) allele in a patient with neonatal Marfan syndrome

It is now well established that defects in fibrillin-1 (FBN1) cause the variable and pleiotropic features of Marfan syndrome (MFS) and, at the most severe end of its clinical spectrum, neonatal Marfan syndrome (nMFS). Patients with nMFS have mitral and tricuspid valve involvement and aortic root dilatation, and die of congestive heart failure, often in the first year of life. Although mutations in classical MFS have been observed along the entire length of the FBN1 mRNA, mutations in nMFS appear to cluster in a relatively small region of FBN1, approximately between exons 24 and 34. Here we describe the appearance of two FBN1 mutations in a single allele of an infant with nMFS. The changes were within six bases of each other in exon 26. One was a T3212G transversion resulting in an I1071S amino acid substitution and the second was an A3219T transversion resulting in an E1073D amino acid substitution. This is the first reported double mutant allele in FBN1.

An accurate method for comparing transcript levels of two alleles or highly homologous genes: application to fibrillin transcripts in Marfan patients' fibroblasts

We introduce here a novel and generally applicable, solid-phase minisequencing-based approach for rapid estimation of relative levels of transcripts with high sequence homology. This study was undertaken to screen for the consequences of different fibrillin-1 mutations on the transcript levels in patients with the Marfan syndrome (MFS). This dominantly inherited, connective tissue disorder is characterized by pleiotrophic symptoms in cardiovascular, skeletal, and ocular systems. A spectrum of disease mutations in the gene encoding fibrillin-1 (FBN1), a glycoprotein component of extracellular matrix microfibrils, has been identified in MFS patients, but the mechanisms by which mutations result in different phenotypic manifestations are still unknown to a large extent. Our data from the quantitation of FBN1 transcripts provide support for the hypothesis that mutations causing premature stop codons result in a milder phenotype than classical MFS by reducing the stability of the mutant transcript and, consequently, decreasing the interference of mutant polypeptide in the formation of fibrillin fibers. We also applied this mRNA quantitation method to determine the relative ratio between transcripts from the genes coding for two highly homologous microfibrillar components, FBN1 and FBN2, in control fibroblast cultures as well as in fibroblasts from MFS patients. Interestingly, these data show large variations between the levels of the two transcripts in fibroblast cultures, but these variations do not correlate either with the nature of the disease mutation or to the clinical MFS phenotype.

Low dose aspirin for the treatment of fetal growth restriction: a randomized controlled trial

The purpose of this study was to investigate the hypothesis that maternal administration of 100mg aspirin each day will improve birth-weight and other measures of neonatal size when given as a treatment to pregnancies complicated by fetal growth restriction and umbilical-placental insufficiency. A randomized, double-blind, placebo controlled study design was employed; 51 pregnant women were enrolled. The entry criteria were a fetal abdominal circumference < 10th per centile together with an umbilical artery Doppler systolic/diastolic ratio > 95th per centile between 28 and 36 weeks' gestation. Compliance was assessed by serial measurement of maternal serum thromboxane B2 levels. The mean gestational age at enrolment was 32 weeks and at delivery was 36 weeks. There were no differences between the 2 groups in gestational age at birth; birth-weight or birth-weight ratio; circumferences of the head, chest or abdomen; skin fold thicknesses; or neonatal morbidity. Low dose aspirin therapy did not alter Doppler systolic/diastolic ratios. After 14 days therapy, mean thromboxane B2 levels fell more than 80% from baseline values; 10.5% of women did not demonstrate biochemical confirmation of aspirin ingestion, despite verbal confirmation of compliance. We conclude that low dose aspirin therapy is not of benefit in the treatment of pregnancies complicated by fetal growth restriction and umbilical-placental insufficiency between 28 and 36 weeks' gestation.

Prenatal and presymptomatic diagnosis of the Marfan syndrome using fluorescence PCR and an automated sequencer

The Marfan syndrome (MFS) is a heritable connective tissue disorder characterized by skeletal, ocular, and cardiovascular abnormalities. Defects in fibrillin, an elastin-associated microfibrillar protein, are now known to cause MFS. Since the discovery of fibrillin as the gene responsible for MFS, requests for prenatal and presymptomatic diagnosis have become common-place. Here we report the use of the polymerase chain reaction (PCR), using fluorescence labelled primers and an automated sequencer, to establish linkage data for 'molecular diagnosis'. The mistaken clinical diagnosis of MFS based on the appearance of a common cardiovascular manifestation, mitral valve prolapse, and a positive family history is also discussed.