Comparing surgeries to restore upper extremity function in tetraplegia: Impact on function during the perioperative period

CONTEXT/OBJECTIVE

To assess short-term changes in health outcomes in people with cervical-level spinal cord injury (SCI) who underwent upper extremity (UE) reconstruction via either novel nerve transfer (NT) or traditional tendon transfer (TT) surgery with individuals who did not undergo UE surgical reconstruction.

DESIGN

Prospective, comparative cohort pilot study.

PARTICIPANTS

34 participants with cervical SCI met the following inclusion criteria: age 18 or older, greater than 6 months post-injury, and mid-cervical level SCI American Spinal Injury Association Impairment Scale (AIS) A, B or C.

SETTING

Two tertiary academic hospitals and their affiliated veterans' hospitals.

METHODS

Health outcomes were assessed using two previously validated measures, the Spinal Cord Independence Measure (SCIM) and Short-Form Health Survey (SF-36). Demographic, surgical, and survey data were collected at the initial evaluation and one month postoperatively/post-baseline.

RESULTS

34 participants with cervical SCI were recruited across three cohorts: no surgery (n = 16), NT (n = 10), and TT (n = 8). The TT group had a decline in SCIM and SF-36 scores whereas the NT and no surgery groups experienced little change in independence or health status in the immediate perioperative period.

CONCLUSIONS

Surgeons and rehabilitation providers must recognize differences in the perioperative needs of people with cervical SCI who chose to have restorative UE surgery. Future work should focus on further investigation of health outcomes, change in function, and improving preoperative counseling and cross-disciplinary management.

Quantifying Tenodesis Hand Function in Cervical Spinal Cord Injury: Implications for Function

PURPOSE

Cervical spinal cord injury (SCI) has a profound effect on upper-extremity function. Individuals with stiffness and/or spasticity may have more, or less, useful tenodesis function. This study examined the variability present before any reconstructive surgery.

METHODS

Tenodesis pinch and grasp were measured with the wrist in maximal active extension. Tenodesis pinch was the contact point of the thumb with the index finger proximal phalanx (T-IF:P1), middle phalanx (T-IF:P2), distal phalanx (T-IF:P3), or absent (T-IF:absent). Tenodesis grasp was the distance from the long finger to the distal palmar crease (LF-DPC). Activities of daily living function was assessed using the Spinal Cord Independence Measure (SCIM).

RESULTS

The study included 27 individuals (4 females, 23 males; mean age 36 years, mean time since SCI 6.8 years). The mean International Classification for Surgery of the Hand in Tetraplegia (ICSHT) group classification was 3. In the dominant hand, individuals with a T-IF tenodesis pinch to P1 or P2 had significantly higher total SCIM scores (43.7 and 34.2, respectively) compared to those with absent T-IF tenodesis pinch (SCIM 17.8). Shorter LF-DPC distance with tenodesis grasp (improved finger closing) also correlated with improved SCIM mobility and total scores. No association was found between the ICSHT group and SCIM score or tenodesis measures.

CONCLUSIONS

Quantifying tenodesis with pinch (T-IF) and grasp (LF-DPC) is a simple method to characterize hand movement in individuals with cervical SCI. Better tenodesis pinch and grasp were associated with improved activities of daily living performance.

CLINICAL RELEVANCE

Differences in grasp function have implications for mobility, and differences in pinch function have implications for all functions, particularly self-care. These physical measurements could be used to assess movement changes after nonsurgical and surgical treatment in tetraplegia.

Beyond the Cubital Tunnel: Use of Adjunctive Procedures in the Management of Cubital Tunnel Syndrome

BACKGROUND

Our management of cubital tunnel syndrome has expanded to involve multiple adjunctive procedures, including supercharged end-to-side anterior interosseous to ulnar nerve transfer, cross-palm nerve grafts from the median to ulnar nerve, and profundus tenodesis. We also perform intraoperative brief electrical stimulation in patients with severe disease. The aims of this study were to evaluate the impact of adjunctive procedures and electrical stimulation on patient outcomes.

METHODS

We performed a retrospective review of 136 patients with cubital tunnel syndrome who underwent operative management from 2013 to 2018. A total of 38 patients underwent adjunctive procedure(s), and 33 received electrical stimulation. A historical cohort of patients who underwent cubital tunnel surgery from 2009 to 2011 (n = 87) was used to evaluate the impact of adjunctive procedures. Study outcomes were postoperative improvements in Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire scores, pinch strength, and patient-reported pain and quality of life.

RESULTS

In propensity score-matched samples, patients who underwent adjunctive procedures had an 11.3-point greater improvement in DASH scores than their matched controls (P = .0342). In addition, patients who received electrical stimulation had significantly improved DASH scores relative to baseline (11.7-point improvement, P < .0001), whereas their control group did not. However, when compared between treatment arms, there were no significant differences for any study outcome.

CONCLUSIONS

Patients who underwent adjunctive procedures experienced greater improvement in postoperative DASH scores than their matched pairs. Additional studies are needed to evaluate the effects of brief electrical stimulation in compression neuropathy.

Living With Cervical Spinal Cord Injury During the COVID-19 Pandemic: A Qualitative Study

Objective

To understand how COVID-19 has affected the daily lives of people living with cervical spinal cord injury (SCI).

Design

Cross sectional qualitative study.

Setting

Academic medical center in the Midwestern United States.

Participants

Ten community-dwelling individuals (8 men, 2 women), average 11.6 years post-mid-cervical level SCI (N=10).

Interventions

Not applicable.

Main Outcome Measures

Semistructured interviews were completed by phone. The research team used thematic analysis and inductive strategies to analyze the data in this exploratory investigation.

Results

People with cervical SCI living in the United States during the spring of 2020 experienced changes to their daily lives. Participants described how interactions with caregivers for activities of daily living were complicated by fear about contracting and/or transmitting COVID-19. The pandemic limited this population's access to medical care and adversely affected their mental and physical health. Telemedicine was seen as a helpful alternative to in-person visits. Some participants felt that their previous life-altering experience (SCI) better prepared them to cope with the pandemic and “roll with things.”

Conclusions

Learning about how people with SCI cope, persevere, and survive to overcome adversity during the pandemic should inform future research to support those with SCI. Improving telemedicine and rewarding and recognizing caregivers for their role in maintaining health are important first steps. We must continue to be creative about improving our health care systems and access for people with disabilities, particularly during this and future public health crises.

P06.03 Child, parent, and clinician selection of patient-reported outcome measures to use in pediatric neuro-oncology outpatient follow-up clinics

BACKGROUND

Survivors of childhood brain tumours are at risk of poor health-related quality of life (HRQoL). Appropriate and relevant measures can be used to monitor HRQoL so that timely interventions may be made for issues thus identified. We had previously selected patient-reported outcome measures (PROMs) with good psychometric properties that had emerged as well-suited for this use in two systematic reviews. The aim of the present study was to ascertain the views of families regarding the suitability of the selected measures for use in paediatric neuro-oncology follow-up clinics. These views were then used to inform the choice of PROMs for use on the KLIK PROM portal, a website designed to gather HRQoL information from families.

MATERIAL AND METHODS

As part of the PROMOTE study, we used a multi-centre, multi-informant, cross-sectional, qualitative methods research design. Using ‘think aloud’ audio-recorded interviews, children aged 8–17 years diagnosed within the previous five years with a brain tumour, off treatment and receiving outpatient care, and their parents, were shown a total of nine PROMs and asked to express their views on which they preferred. Detailed notes were made of all audio-recordings by two independent researchers. The final choice of PROMs to be included on the KLIK PROM portal was agreed through discussion of the PROMs selected by families with an expert panel of clinicians, researchers, and parent representatives.

RESULTS

16 children and 17 parents participated and of these 2 children and 2 parents did not express a preference. The Pediatric Quality of Life Inventory (PedsQL) Core module was the most popular among the children and parents with 7/14 (50%) of children selecting it as either their 1st or 2nd choice citing that they liked the questions and felt them to be most relevant to them, and 8/15 (53%) of parents citing that it was easy, quick and simple, the wording was easy, and they liked the questions about emotional, social, and school functioning. The least popular questionnaires, with no participants selecting them as first choices, were the Kidscreen-10 and the Health Utilities Index. The latter 2 were selected only as 2nd or lower choices by 1 child and 3 parents respectively.

CONCLUSION

The PROMs that were finally selected for the KLIK PROM portal were the parent- and child-report PedsQL-Core measures of HRQoL due to their good psychometric properties, family and clinician preference and perceived relevance to follow-up care, and for clinical utility on the KLIK PROM portal.

Evaluation for Late Nerve Transfer Surgery in Spinal Cord Injury: Predicting the Degree of Lower Motor Neuron Injury

PURPOSE

Nerve transfer surgery is used to restore upper extremity function following cervical spinal cord injury (SCI) with substantial variation in outcomes. The injury pattern in SCI is complex and can include isolated upper motor neuron (UMN) and combined UMN/lower motor neuron (LMN) dysfunction. The purpose of the study was to determine the most effective diagnostic technique for determining suitable candidates for nerve transfer surgery in SCI.

METHODS

Medical records were reviewed of patients who had nerve transfers to restore upper extremity function in SCI. Data collected included (1) preoperative clinical examination and electrodiagnostic testing; (2) intraoperative neuromuscular stimulation (NMS); and (3) nerve histopathology. Preoperative, intraoperative, and postoperative data were compared to identify predictors of isolated UMN versus combined UMN/LMN injury patterns.

RESULTS

The study sample included 22 patients with 50 nerve transfer surgeries and included patients ranging from less than 1 year to over a decade post-SCI. Normal recipient nerve conduction studies (NCS) before surgery corresponded to the intraoperative presence of recipient NMS and postoperative histopathology that showed normal nerve architecture. Conversely, abnormal recipient NCS before surgery corresponded with the absence of recipient NMS during surgery and patterns of denervation on postoperative histopathology. Normal donor preoperative manual muscle testing corresponded with the presence of donor NMS during surgery and normal nerve architecture on postoperative histopathology. An EMG of corresponding musculature did not correspond with intraoperative donor or recipient NMS or histopathological findings.

CONCLUSIONS

NCS better predict patterns of injury in SCI than EMG. This is important information for clinicians evaluating people for late nerve transfer surgery even years post-SCI.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Does difficulty functioning in the surrogate role equate to vulnerability in critical illness research? Use of path analysis to examine the relationship between difficulty providing substituted judgment and receptivity to critical illness research participation

PURPOSE

Individuals who struggle to provide substitute judgment for the critically ill often find it challenging to engage in decision making for therapeutic interventions. Although essential to the conduct of research, how these individuals respond to requests for clinical trial participation is poorly understood.

METHODS

Survey data collected to examine surrogate attitudes toward research provided the conceptual framework to explore influences on decision making. Path analysis was used to derive the final model (nonlatent, fully recursive, 1 indicator/variable).

RESULTS

Surrogates with list-wise complete records (406) were analyzed. The following variables were not retained in the final model: education, income, religiosity, decision-making experience, discussion of patient's wishes, number of individuals assisting with decision making, trust in care providers, difficulty making decisions, and responsibility for decision making. Being white and having experience making treatment decisions for the patient during the current intensive care unit encounter affected the likelihood the surrogate would permit participation in research positively (parameter estimates, 0.281 and 0.06, respectively). No variable reflecting difficulty functioning in the surrogate role was associated with permitting research participation.

CONCLUSIONS

We were unable to demonstrate a relationship between perceived difficulty in decision making in the surrogate role and receptivity to clinical trial participation.

Surrogate receptivity to participation in critical illness genetic research: aligning research oversight and stakeholder concerns

BACKGROUND

Collection of genetic biospecimens as part of critical illness investigations is increasingly commonplace. Oversight bodies vary in restrictions imposed on genetic research, introducing inconsistencies in study design, potential for sampling bias, and the possibility of being overly prohibitive of this type of research altogether. We undertook this study to better understand whether restrictions on genetic data collection beyond those governing research on cognitively intact subjects reflect the concerns of surrogates for critically ill patients.

METHODS

We analyzed survey data collected from 1,176 patients in nonurgent settings and 437 surrogates representing critically ill adults. Attitudes pertaining to genetic data (familiarity, perceptions, interest in participation, concerns) and demographic information were examined using univariate and multivariate techniques.

RESULTS

We explored differences among respondents who were receptive (1,333) and nonreceptive (280) to genetic sample collection. Whereas factors positively associated with receptivity to research participation were "complete trust" in health-care providers (OR, 2.091; 95% CI, 1.544-2.833), upper income strata (OR, 2.319; 95% CI, 1.308-4.114), viewing genetic research "very positively" (OR, 3.524; 95% CI, 2.122-5.852), and expressing "no worry at all" regarding disclosure of results (OR, 2.505; 95% CI, 1.436-4.369), black race was negatively associated with research participation (OR, 0.410; 95% CI, 0.288-0.585). We could detect no difference in receptivity to genetic sample collection comparing ambulatory patients and surrogates (OR, 0.738; 95% CI, 0.511-1.066).

CONCLUSIONS

Expressing trust in health-care providers and viewing genetic research favorably were associated with increased willingness for study enrollment, while concern regarding breach of confidentiality and black race had the opposite effect. Study setting had no bearing on willingness to participate.

Perspectives of Decisional Surrogates and Patients Regarding Critical Illness Genetic Research

BACKGROUND

Critical illness research is challenging due to disease severity and because patients are frequently incapacitated. Surrogates called upon to provide consent might not accurately represent patient preferences. Though commonplace, genetic data collection adds complexity in this context. We undertook this investigation to understand whether surrogate decision makers would be receptive to permitting participation in a critical illness genetics study and whether their decision making was consistent with that of the patient represented.

METHODS

We invited individuals identified as surrogates for critically ill adults, if required, as well as patients once recovered to participate in a survey designed to understand attitudes about genetic research. Associations between dependent (receptivity to participation, concordance of responses) and independent variables were tested using bivariate and multivariate logistic regression analyses.

RESULTS

Most of the entire surrogate sample (n=439) reported familiarity with research, including genetic research; tended to view research as useful; and were receptive to allowing their family member participate (with 39.6% and 38.1% stating that this would be "very" and "somewhat likely," respectively) even absent direct benefit. Willingness to participate was similar comparing genetic and non-genetic studies (χ² [1,n=439]=0.00127, p=0.972), though respondents expressed worry regarding lack of confidentiality of genetic data. Responses were concordant in 70.8% of the 192 surrogate-patient pairs analyzed. In multivariate analysis, African American race was associated with less receptivity to genetic data collection (p<0.05). No factors associated with concordance of surrogate-patient response were identified.

CONCLUSIONS

Surrogates' receptivity to critical illness research was not influenced by whether the study entailed collection of genetic data. While more than two-thirds of surrogate-patient responses for participation in genetics research were concordant, concerns expressed regarding genetic data often related to breach of confidentiality. Emphasizing safeguards in place to minimize such breeches might prove an effective strategy for enhancing recruitment.

Critical illness research involving collection of genomic data: the conundrum posed by low levels of genomic literacy among surrogate decision makers for critically ill patients

Critical illness clinical trials that entail genomic data collection pose unique challenges. In this qualitative study, we found that surrogate decision makers (SDMs) for critically ill individuals, such as those who would be approached for study participation, appeared to have a limited grasp of genomic principles. We argue that low levels of genomic literacy should neither preclude nor be in conflict with the conduct of ethically rigorous clinical trials.

Factors affecting stress experienced by surrogate decision makers for critically ill patients: implications for nursing practice

OBJECTIVES

This study explores surrogate decision-makers' (SDMs) challenges making decisions related to the care of patients in critical care, to (1) characterise the SDM stress, (2) identify personal, social, care-related factors influencing stress and (3) consider implications of findings to improving critical care practice.

METHODOLOGY

Semi-structured interviews were conducted with SDMs of critically ill patients receiving care in two tertiary care institutions. Transcripts were analysed using a grounded theory approach. Domains explored were: stress characteristics, stress mitigators, coping strategies, social networks, SDM decision-making role, decision-making concordance, knowledge of patient's preferences, experience with provider team, SDM-provider communication, patient outcome certainty.

MAIN OUTCOMES

We interviewed 34 SDMs. Most were female and described long-term relationships with patients. SDMs described the strain of uncertain outcomes and decision-making without clear, consistent information from providers. Decision-making anxiety was buffered by SDMs' active engagement of social networks, faith and access to clear communication from providers.

CONCLUSION

Stress is a very real factor influencing SDMs confidence and comfort making decisions. These findings suggest that stress can be minimised by improving communication between SDMs and medical providers. Nurses' central role in the ICU makes them uniquely poised to spearhead interventions to improve provider-SDM communication and reduce SDM decision-making anxiety.

Real-time perspectives of surrogate decision-makers regarding critical illness research: findings of focus group participants

OBJECTIVE

We undertook the current investigation to explore how the pressures of serving as a surrogate decision-maker (SDM) for an acutely ill family member influence attitudes regarding clinical investigation.

METHODS

We conducted a prospective study involving SDMs for critically ill patients cared for in the ICUs of two urban hospitals. Measurements included participation in focus groups designed to explore perceptions of ICU care and clinical research. Audiotapes were transcribed and analyzed to identify common patterns and themes using grounded theory. Demographic and clinical data were summarized using standard statistical methods.

RESULTS

Seventy-four SDMs (corresponding to 24% of eligible patients) participated. Most SDMs were women and described long-term relationships with the patients represented. SDMs described their role as "overwhelming," their emotions were accentuated by the fatigue of the ICU experience, and they relied on family members, social contacts, and religion as sources of support. Altruism was reported as a common motivation for potential study participation, a sentiment often strengthened by the critical illness episode. Although research was viewed as optional, some SDMs perceived invitation for research participation as tacit acknowledgment of therapeutic failure. SDMs expressed a preference for observational studies (perceived as low risk) over interventional designs (perceived as higher risk). Trust in the ICU team and the research enterprise seemed tightly linked.

CONCLUSIONS

Despite significant emotional duress, SDMs expressed interest in investigation and described multiple factors motivating participation. Consent processes that minimize the effects of anxiety may be one strategy to enhance recruitment.

Neurocognitive effects of CNS tumors

There is ample evidence that many children treated for brain tumors experience long-term neurocognitive deficits. The severity of those deficits is determined by a complex interaction of the child's genetic make-up and age, neuroanatomical damage caused by tumor and surgery, radiotherapy and chemotherapy, the psychosocial environment, and the intensity of targeted rehabilitation. The consequences of neurocognitive deficits are moderated by the number and severity of other deficits, including neurological and endocrine impairments, and this wider context must be considered. The impact of intellectual decline on academic functioning is evident, and underlies, for example, poor reading, writing, and mathematical skills. The effects of early brain damage on development are cumulative as more functions are expected to mature. Many survivors of CNS tumors can be expected to grow into deficits that have far-reaching consequences not only for academic achievement but also for their psychological and social development and their ability to be self-sufficient. Because the problems typically only become apparent over time, surveillance for their detection is an essential prerequisite for early educational and other interventions to support learning and successful transition to independent adult life.

Considerations in the construction of an instrument to assess attitudes regarding critical illness gene variation research

Clinical studies conducted in intensive care units are associated with logistical and ethical challenges. Diseases investigated are precipitous and life-threatening, care is highly technological, and patients are often incapacitated and decision-making is provided by surrogates. These investigations increasingly involve collection of genetic data. The manner in which the exigencies of critical illness impact attitudes regarding genetic data collection is unstudied. Given interest in understanding stakeholder preferences as a foundation for the ethical conduct of research, filling this knowledge gap is timely. The conduct of opinion research in the critical care arena is novel. This brief report describes the development of parallel patient/surrogate decision-maker quantitative survey instruments for use in this environment. Future research employing this instrument or a variant of it with diverse populations promises to inform research practices in critical illness gene variation research.

Ethical considerations in the collection of genetic data from critically ill patients: what do published studies reveal about potential directions for empirical ethics research?

Critical illness trials involving genetic data collection are increasingly commonplace and pose challenges not encountered in less acute settings, related in part to the precipitous, severe and incapacitating nature of the diseases involved. We performed a systematic literature review to understand the nature of such studies conducted to date, and to consider, from an ethical perspective, potential barriers to future investigations. We identified 79 trials enrolling 24 499 subjects. Median (interquartile range) number of participants per study was 263 (116.75-430.75). Of these individuals, 16 269 (66.4%) were Caucasian, 1327 (5.4%) were African American, 1707 (7.0%) were Asian Pacific Islanders and 139 (0.6%) were Latino. For 5020 participants (20.5%), ethnicity was not reported. Forty-eight studies (60.8%) recruited subjects from single centers and all studies examined a relatively small number of genetic markers. Technological advances have rendered it feasible to conduct clinical studies using high-density genome-wide scanning. It will be necessary for future critical illness trials using these approaches to be of greater scope and complexity than those so far reported. Empirical research into issues related to greater ethnic inclusivity, accuracy of substituted judgment and specimen stewardship may be essential for enabling the conduct of such trials.

Large scale calcium channel gene rearrangements in episodic ataxia and hemiplegic migraine: implications for diagnostic testing

BACKGROUND

Episodic ataxia type 2 (EA2) and familial hemiplegic migraine type 1 (FHM1) are autosomal dominant disorders characterised by paroxysmal ataxia and migraine, respectively. Point mutations in CACNA1A, which encodes the neuronal P/Q-type calcium channel, have been detected in many cases of EA2 and FHM1. The genetic basis of typical cases without CACNA1A point mutations is not fully known. Standard DNA sequencing methods may miss large scale genetic rearrangements such as deletions and duplications. The authors investigated whether large scale genetic rearrangements in CACNA1A can cause EA2 and FHM1.

METHODS

The authors used multiplex ligation dependent probe amplification (MLPA) to screen for intragenic CACNA1A rearrangements.

RESULTS

The authors identified five previously unreported large scale deletions in CACNA1A in seven families with episodic ataxia and in one case with hemiplegic migraine. One of the deletions (exon 6 of CACNA1A) segregated with episodic ataxia in a four generation family with eight affected individuals previously mapped to 19p13. In addition, the authors identified the first pathogenic duplication in CACNA1A in an index case with isolated episodic diplopia without ataxia and in a first degree relative with episodic ataxia.

CONCLUSIONS

Large scale deletions and duplications can cause CACNA1A associated channelopathies. Direct DNA sequencing alone is not sufficient as a diagnostic screening test.

Reading and communication skills after universal newborn screening for permanent childhood hearing impairment

BACKGROUND

Birth in periods with universal newborn screening (UNS) for permanent childhood hearing impairment (PCHI) and early confirmation of PCHI have been associated with superior subsequent language ability in children with PCHI. However their effects on reading and communication skills have not been addressed in a population-based study.

METHODS

In a follow-up study of a large birth cohort in southern England, we measured reading by direct assessment and communication skills by parent report in 120 children with bilateral moderate, severe or profound PCHI aged 5.4-11.7 years, of whom 61 had been born in periods with UNS, and in a comparison group of 63 children with normal hearing.

RESULTS

Compared with birth during periods without UNS, birth during periods with UNS was associated with better reading scores (inter-group difference 0.39 SDs, 95% CI 0.02 to 0.76, p = 0.042) and communication skills scores (difference 0.51 SDs, 95% CI 0.06 to 0.95, p = 0.026). Compared with later confirmation, confirmation of PCHI by age 9 months was also associated with better reading (difference 0.51 SDs, 95% CI 0.15 to 0.87, p = 0.006) and communication skills (difference 0.56 SDs, 95% CI 0.12 to 1.00, p = 0.013). In the children with PCHI, reading, communication and language ability were highly correlated (r = 0.62-0.84, p<0.001).

CONCLUSION

Birth during periods with UNS and early confirmation of PCHI predict better reading and communication abilities at primary school age. These benefits represent functional gains of sufficient magnitude to be important in children with PCHI.

Human immature oocytes grow during culture for IVM

BACKGROUND

Oocyte competence for maturation and embryogenesis is associated with diameter in many mammals. We aimed to test whether this relationship exists in humans and to quantify its impact upon in vitro maturation (IVM).

METHODS

We used computer-assisted image analysis daily to measure average diameter, zona thickness and other parameters in oocytes. Immature oocytes originated from unstimulated patients with polycystic ovaries, and from stimulated patients undergoing intracytoplasmic sperm injection (ICSI). Some were cultured with meiosis activating sterol (FF-MAS). Matured oocytes were inseminated using ICSI and embryo development was monitored. In vivo matured oocytes were also measured.

RESULTS

Immature oocytes were smaller at collection than in vivo matured oocytes. Maturation was related to oocyte diameter and many oocytes grew in culture. FF-MAS stimulated growth in oocytes derived from ICSI patients, but only stimulated growth in PCO derived oocytes if they matured in vitro. Degenerating oocytes showed cytoplasmic shrinkage. Neither zona thickness, perivitelline space, nor the total diameter of the oocyte plus zona were informative regarding maturation capacity.

CONCLUSIONS

Immature oocytes grow during maturation culture. FF-MAS promotes oocyte growth in vitro. Oocytes from different sources have different growth profiles in vitro. Measuring oocytes in clinical IVM may provide additional non-invasive information that could potentially avoid the use of growing oocytes.

Risk management in IVF

Patient safety incidents occur in approximately 10% of hospital admissions in the UK. Although robust data are not available, assisted conception is unlikely to be any less prone to adverse incidents; indeed there have been several high-profile cases which have drawn attention to this problem. Recently established national reporting systems for adverse events are collecting data which will inform trends in patient safety. Because of the nature of the work undertaken in assisted conception, there is the potential to affect not only future generations but also many patients simultaneously because of storage of biological material. It is therefore important to implement strategies to reduce the likelihood of patient safety incidents. Established methodologies exist for the reactive (root cause analysis) and the proactive assessment of risk (failure mode effects analysis). Furthermore, establishing the detail of a process and its context through process mapping is an important prerequisite for understanding its risk. The knowledge gained through these enquiries enables the implementation of an effective risk management programme which this chapter examines in detail.

The pathogenic helminth parasites of eels

Although 63 and 55 species of helminths have been reported from each species of Atlantic eel and from 29 to 19 for each species of Pacific eel only the monogeneans Pseudodactylogyrus bini and P. anguillae and the nematode Anguillicola crassus, originally specific to species of Pacific eels, can be considered serious pathogens. None of the three are normally pathogenic to their preferred natural eel host species in the wild. Pseudodactylogyrus spp. only cause serious local gill damage when present on a host in large numbers under optimal conditions that facilitate transmission. This is the case in eel aquaculture, where infections can be controlled by drugs. Anguillicola crassus is only pathogenic to Anguilla anguilla and A. rostrata when Atlantic eels are introduced to the far east or when the parasites have been introduced to Europe. Here the parasite life cycle differs in that A. crassus can infect a wide range of intermediate hosts, employ paratenic hosts and survive as larvae for months in the swimbladder wall. This makes it an excellent colonizer. Its major pathogenic effects on eels result from haemorrhaging in, and thickening of, the swimbladder wall. It reduces the oxygen concentration in the swimbladder, reducing its ability to function as a hydrostatic organ, and increases the stress response of eels. In shallow lakes at warm temperatures this can result in mass mortalities. It is also feared that the parasite affects the ability of eels to migrate to the Sargasso Sea and so contributes to the decline in eel populations. Control by drug treatment is possible in culture, but not in the wild.

How old is too old for fertility treatment?

Women are delaying starting their families. High-profile women such as Cherie Blair and Madonna are having successful pregnancies with healthy babies in their forties. Is this sending out messages to women that delaying conception during their twenties and thirties is a good idea? Fertility treatment can overcome certain age-related hurdles but is certainly not the magic wand some expect it to be.

Utilization of brown troutSalmo truttabyAcanthocephalus clavulain an Irish lake: is this evidence of a host shift?

The population biology of the fish acanthocephalanAcanthocephalus clavulawas described from 161 wild brown trout,Salmo truttasampled over a two-year period in Clogher Lake in the west of Ireland. Overall prevalence of the parasite was 86% and the mean abundance was 53 worms per fish. Despite the presence of large numbers of worms in the trout very few females (2%) attained full reproductive maturity. This suggests that trout is an accidental host. A sample of yellow eels,Anguilla anguillawas examined at a different time from the same lake. The prevalence ofA. clavulawas 97% and the average abundance was 8 worms per fish. In contrast to the situation in trout, the proportion of female worms attaining full reproductive maturity was 61% fulfilling the expected characteristic of a preferred definitive host. The possible explanations for the very high abundance ofA. clavulain trout are discussed and include the influence of fluctuations in host populations, host diet and the absence of a potential competitor.

Dynamics and predicted decline of Anguillicola crassus infection in European eels, Anguilla anguilla, in Neusiedler See, Austria

The eel population in Neusiedler See has been maintained by regular massive stocking since 1958. After the establishment of the National Park Neusiedler See-Seewinkel in 1993, eel stocking was prohibited and the population, together with the specific parasites of eels, was predicted to decline to extinction within 10 years. This investigation was undertaken to document the decline and extinction of the Anguillicola crassus population in eels. From 1994 to 2001, 720 eels were collected from two sites in the lake. Prevalence and abundance of A. crassus were lower in spring than in summer and autumn and larger eels harboured more parasites than smaller ones. Neither year of study nor sampling site were correlated with parasite infection levels. No significant trend in the population parameters of A. crassus was detected over the 8 years of the survey. This suggested that there had been no significant decline in the eel population. This suggestion was confirmed by investigations of the fishery, which also found evidence of regular illegal stocking. The stability of the A. crassus population over the past decade seems to reflect the lack of change in eel population density. No mass mortalities of eels occurred over the period despite the many similarities between Neusiedler See and Lake Balaton in Hungary. Differences in eel size, eel diet and the lack of large-scale insecticide use are discussed as possible explanations for the absence of eel mass mortalities in Neusiedler See.

Upregulation of adiponectin receptor 1 and 2 mRNA and protein in adipose tissue and adipocytes in insulin-resistant women with polycystic ovary syndrome

AIMS/HYPOTHESIS

Polycystic ovary syndrome (PCOS) is a multifaceted metabolic disease linked with insulin resistance (IR) and obesity. Adiponectin, which is lower in IR states, exerts its glucose-lowering and anti-inflammatory effects by activating two receptors, ADIPOR1 and ADIPOR2. There are no data on the relative expression of these receptors in adipose tissue of PCOS women.

METHODS

We investigated the expression of adiponectin receptors from corresponding s.c. and omental (o.m.) adipose tissue in women with PCOS compared with matched non-PCOS women. As there is a disturbance in the steroid milieu in PCOS women, we also assessed the effects of testosterone and oestradiol on adiponectin receptors using adipocytes and adipocyte explants. Real-time RT-PCR and western blotting were used to assess the relative adiponectin receptor mRNA expression and protein production, respectively. Biochemical measurements were performed in our hospital's laboratory.

RESULTS

We are the first to describe adiponectin receptor expression and production, in corresponding s.c. and o.m. human adipose tissues at the mRNA and protein level. We demonstrate the upregulation of mRNA expression and protein production of adiponectin receptors in women with PCOS, in s.c. and o.m. adipose tissue. Treatment of adipose tissue explants and adipocytes with testosterone and oestradiol induced the expression of adiponectin receptor mRNA and protein. There was a significant positive association between ADIPOR1/R2 expression and homeostasis model assessment, testosterone, oestradiol and triglycerides and a negative relationship with sex hormone-binding globulin.

CONCLUSIONS/INTERPRETATION

The precise reason for the upregulation of adiponectin receptors seen in PCOS women, a pro-diabetic state, is unknown, but it appears that sex steroids may play a role in their regulation in adipose tissue.

The presenting features of brain tumours: a review of 200 cases

OBJECTIVE

To determine the presenting features of brain tumours in children.

DESIGN

Retrospective case note review.

SETTING

Paediatric and neurosurgical services at the Wessex Neurology Centre and Southampton General Hospital, UK.

PATIENTS

200 patients presenting with a CNS tumour between 1988 and 2001.

RESULTS

The commonest first presenting symptoms were headache (41%), vomiting (12%), unsteadiness (11%), visual difficulties (10%), educational or behavioural problems (10%), and seizures (9%). The commonest symptoms occurring at any time were headache (56%), vomiting (51%), educational or behavioural problems (44%), unsteadiness (40%), and visual difficulties (38%). Neurological signs were present at diagnosis in 88%: 38% had papilloedema, 49% cranial nerve abnormalities, 48% cerebellar signs, 27% long tract signs, 11% somatosensory abnormalities, and 12% a reduced level of consciousness. The median symptom interval was 2.5 months (range 1 day to 120 months). A short symptom interval was significantly associated with high grade tumours and patient age of 3 years or younger.

CONCLUSIONS

The well known predominance of headache in children with CNS tumours is confirmed. Visual, behavioural, and educational symptoms were also prominent. With the exception of seizures, every initial symptom was accompanied by other symptoms or signs by the time of diagnosis. Questions about visual symptoms and educational or behavioural difficulties, as well as the more widely recognised symptoms of raised intracranial pressure and motor dysfunction, are important in the diagnosis of brain tumours, as are vision assessment and the appropriate plotting of growth and head size.

Genetic research and testing in critical care: surrogates' perspective

OBJECTIVE

Genetic testing is increasingly a component of clinical research in critical illness and has potential for integration into routine care. This study explored the perspectives of surrogate decision-makers (SDMs) for acutely ill patients with respect to social, legal, and ethical aspects of genetic testing.

SETTING

Medical and surgical intensive care units in an urban tertiary care hospital.

INTERVENTION

Questionnaires administered to SDMs for critically ill patients over a 12-month period.

MEASUREMENTS AND MAIN RESULTS

A majority of eligible SDMs participated (117/146; 80.8%). SDMs were more likely to permit genetic testing for purposes of diagnosing a treatable life-threatening disease (114/117; 97.4%) or chronic disease (111/117; 94.9%) than for an untreatable life-threatening illness (95/117; 81.2%) (p < .001). SDMs were receptive to testing to explain familial traits (112/117; 95.7%) or ethnic traits (105/117; 89.7%) (p = .131). SDMs were concerned about potential for economic discrimination, with a majority expressing reluctance to permit testing if employers (93/117; 79.5%), health insurers (90/117; 76.9%), or life insurers (92/117; 78.6%) could access results. There was a greater willingness to allow participation in studies in which data were collected anonymously (90/117; 76.9%) vs. nonanonymously (75/117; 64.1%) (p = .04). Finally, SDMs placed greater trust in universities and nonprofit organizations (107/117; 91.4%) than either the federal government (75/117; 64.1%) or pharmaceutical companies (46/117; 39.3%) to perform genetic research (p < .01).

CONCLUSIONS

SDMs expressed concerns regarding economic discrimination, confidentiality of data, and trust in entities conducting clinical investigation that may represent barriers both to performing studies in which genetic information is collected and to implementation of gene-based technologies in the critical care environment.

European eels, Anguilla anguilla (L.), infected with Anguillicola crassus exhibit a more pronounced stress response to severe hypoxia than uninfected eels

The parasite, Anguillicola crassus is a non-native species that infects naive European eels, Anguilla anguilla, and causes pathological damage to the swimbladder, potentially compromising their ability to cope with hypoxic conditions. This study aimed to elucidate whether anguillicolosis exacerbates the stress responses to exposure to hypoxic water, conditions that have been implicated in mass mortalities of wild infected European eels. Blood parameters in infected and uninfected eels were measured during exposure to severe hypoxia over an 8-h period. Infected fish showed significantly higher levels of plasma cortisol compared with uninfected eels after 4 h of hypoxia. Uninfected fish showed an almost twofold increase in plasma glucose after 8-h exposure to hypoxia but infected fish showed no significant change, so that the plasma glucose concentration was significantly higher in uninfected eels than in infected eels. Both groups showed similar elevations in blood haematocrit, suggesting a similar catecholamine response in infected and uninfected eels. The lack of a hyperglycaemic response in infected eels, despite indirect evidence of a catecholamine response to hypoxia, may reflect an increase in glucose turnover. The data suggest that anguillicolosis results in a significantly greater corticosteroid stress response to hypoxia accompanied by a higher metabolic cost.

The life cycle of Paraquimperia tenerrima: a parasite of the European eel Anguilla anguilla

Previous studies on the life history of the nematode eel specialist Paraquimperia tenerrima (Nematoda: Quimperiidae) have failed to determine whether an intermediate host is required in the life cycle. In the laboratory, eggs failed to hatch below 10 degrees C, hatching occurring only at temperatures between 11 and 30 degrees C. Survival of the free-living second stage larvae (L2) was also temperature dependent, with maximal survival between 10 and 20 degrees C. Total survival of the free-living stages (eggs and L2) is unlikely to exceed a month at normal summer water temperatures, confirming that parasite could not survive the 6 month gap between shedding of eggs in spring and infection of eels in early winter outside of a host. Eels could not be infected directly with L2, nor could a range of common freshwater invertebrate species. Third stage larvae (L3) resembling P. tenerrima were found frequently and abundantly in the swimbladder of minnows Phoxinus phoxinus from several localities throughout the year and were able to survive in this host in the laboratory for at least 6 months. Third stage larvae identical to these larvae were recovered from minnows experimentally fed L2 of P. tenerrima, and eels infected experimentally with naturally and experimentally infected minnows were found to harbour fourth stage larvae (L4) and juvenile P. tenerrima in their intestines. Finally, the whole life cycle from eggs to adult was completed in the laboratory, confirming that minnows are an obligate intermediate host for P. tenerrima.

Long-term investigation of the composition and richness of intestinal helminth communities in the stocked population of eel, Anguilla anguilla, in Neusiedler See, Austria

Data from a long-term study of the intestinal helminth parasite community of eels, Anguilla anguilla, stocked into the shallow eutrophic Neusiedler See, Austria, were collected over an 8 year period (1994–2001). In total, 720 eels from 2 sampling sites were examined. The parasite community showed characteristics similar to those in the natural eel populations in rivers of the UK and mainland Europe: it was species poor, with only 5 species (Acanthocephalus lucii, Acanthocephalus anguillae, Raphidascaris acus, Proteocephalus macrocephalus, Bothriocephalus claviceps) comprising the component community and a maximum infracommunity richness of 4 species. Over the period, the intestinal parasite community of the sampling site in Illmitz, which was originally dominated by A. lucii, changed. As levels of A. anguillae increased to a point at which it dominated the community, diversity increased whilst dominance of a single species decreased. By contrast the community in the southern sampling site remained rather constant with a continuous high infection level of A. anguillae and low abundance of A. lucii. Both acanthocephalan species exhibited higher infection levels in larger eels and in different seasons of the year and the infection parameters were significantly different between the years of study. The significant differences in the infection levels of the 2 acanthocephalan species at the 2 sampling sites were surprising as both acanthocephalan species use the same intermediate host, Asellus aquaticus, and the sampling sites were in close proximity and were similar in terms of water quality, host size and invertebrate abundance. Differences in the fish communities of the 2 sampling sites and eel movements rather than interspecific competition are discussed as possible explanations for the differences in the parasite communities of the 2 sampling sites.

Should cryopreserved epididymal or testicular sperm be recovered from obstructive azoospermic men for ICSI?

OBJECTIVE

To determine the effect of the anatomical site of sperm recovery on intracytoplasmic sperm injection (ICSI) embryo implantation, pregnancy and live birth rates in couples with isolated obstructive azoospermia as the sole cause of infertility.

DESIGN

Controlled, single centre, retrospective clinical study.

SETTING

University Hospital, Centre for Reproductive Medicine.

SAMPLE

One hundred and fifty-one cycles of ICSI were performed, using surgically recovered sperm, between August 1996 and March 2002.

METHODS

The outcome of ICSI, with surgically recovered sperm, was compared between epididymal (Group E) and testicular (Group T) derived sperm. Inclusion was limited to couples undergoing their first treatment cycle, where female age was < or =39 years and a minimum of five oocytes were available for injection. Women with a history of ovarian surgery, ultrasonic evidence of polycystic ovaries, uterine anomalies or hydrosalpinx were excluded.

MAIN OUTCOME MEASURES

Clinical pregnancy, implantation and live birth rate.

RESULTS

Forty-two of 151 cycles met the strict inclusion criteria. Groups E and T were comparable with respect to age, basal serum FSH, ovarian response; number of oocytes injected and number of embryos available and transferred. No difference existed between Groups E and T in implantation, clinical pregnancy or live birth rate (28.8% vs 25.8%, 42.9% vs 42.9% and 39.3% vs 42.9%, respectively).

CONCLUSIONS

Cryopreserved epididymal and testicular sperm, from men with obstructive azoospermia, appear equally effective in ICSI. Epididymal recovery should remain the method of first choice for obstructive azoospermic men but further study of sperm DNA damage rates in different testicular sites is required.

Comparison of morphological characters in Irish and English populations of the acanthocephalan Pomphorhynchus laevis (Müller, 1776)

Pomphorhynchus laevis is believed on ecological evidence to exist as three strains in the British Isles. However, the strains have never been shown to be capable of being distinguished using morphological characters. A morphological comparison was made between a sample of P. laevis from Salmo trutta in L. Feeagh in the west of Ireland and a sample from Leuciscus cephalus in R. Culm in the south of England. The length and width of the trunk, neck, bulb, proboscis and hooks were measured. The number of hooks per row, the number of rows and the positions of the stoutest and longest hooks were also recorded. A Principal Components Analysis based on the morphological measurements confirmed the separation of the two populations and showed that two characters successfully identified the populations: the position of the stoutest hook and the ratio of numbers of anterior to posterior hooks.

Evidence for the hypothesis of strain formation inPomphorhynchus laevis(Acanthocephala): an investigation using mitochondrial DNA sequences

A hypothesis has been erected stating that in the British Isles the acanthocephalan,Pomphorhynchus laeviscan be separated into 3 strains, an English, Irish and marine strain. Ecological and morphological evidence exists in support of this hypothesis. An investigation at the molecular level was conducted in order to test the validity of the existing evidence. A mitochondrial gene, subunit I of cytochrome c oxidase was partially sequenced from 3 Irish populations ofP. laevis, 1 Scottish population and 3 English populations.P. laevissequences from brown trout from Ireland, England and Scotland were very similar, showing a mean sequence divergence of 0·7%. Sequences from two populations ofP. laevisfrom English chub and bullhead were also similar to each other (0·35% divergence). These two groups of sequences, the brown trout group and the chub/bullhead group were 2·2% different. These data confirm the existence of at least 2 strains in Ireland and Britain, although there is evidence to suggest that these strains are defined by their host species rather than by their geographical distributions.

Interspecific interactions between Acanthocephala in the intestine of brown trout: are they more frequent in Ireland?

The aim of this paper was to test the hypothesis that when the 2 species of Acanthocephalan Pomphorhynchus laevis and Acanthocephalus clavula are found concurrently within the intestine of brown trout under field conditions, they have the potential to interact negatively. Evidence has shown that Acanthocephala are more likely to exhibit negative interactions with their own and other species, under both field and experimental conditions. Furthermore, the likelihood of these interactions is increased in Ireland because of the absence of certain definitive hosts and the fact that concurrent infections by two or more species of Acanthocephala are more commonly observed in fish. Data collected from wild and stocked brown trout and from 2 lakes provided an opportunity to compare the 2 potentially interacting helminth species in their fundamental and realized niche and several pieces of convincing evidence are provided here to support the hypothesis. A significant negative association between the numbers of each species found in individual fish was reported and this was consistent for both wild and stocked trout. Furthermore, an analysis of the proportions of low, moderate and high intensity infections in single and concurrent infections revealed a significant reduction in increasing intensities in concurrent infections compared to single infections. Finally, strikingly different patterns of niche inhabitation were observed, particularly for P. laevis in the presence of A. clavula in wild trout. Results from the niche width analysis also support the observations on average position in single and concurrent infections. The niche width of P. laevis when it co-occurred with A. clavula decreased markedly in high intensity infections compared to low intensity infections.

Long-term stability in the richness and structure of helminth communities in eels, Anguilla anguilla, in Lough Derg, River Shannon, Ireland

A data set on intestinal helminth parasites was collected in the course of an 18 year investigation into the biology of eels in Meelick Bay, Lough Derg, River Shannon. This was used to test two hypotheses relating to the composition and structure of intestinal helminth communities, namely that eels in large rivers do not harbour richer and more diverse communities than those in small rivers but that community composition and structure are more stable over time than in small rivers. The helminth community was species poor, with only six species comprising the component community and a maximum infracommunity richness of three species. The community was overwhelmingly dominated by the acanthocephalan Acanthocephalus lucii, reflecting the importance of its intermediate host Asellus aquaticus in the eels' diet. The remaining helminth species contributed to species richness but made very little contribution to community diversity. Population levels of Acanthocephalus lucii fell and remained low between 1992 and 2000, probably reflecting increased movement of eels from other parts of the lough into Meelick Bay. Diversity values were low, but similar to those reported from other rivers in Britain and Europe. The results provided support for both hypotheses and indicated that in respect of richness, diversity and dominance, the helminth communities of eels in the River Shannon were typical of, and comparable to, those of other large rivers throughout Europe.

Evidence for the co-existence of separate strains or species of Ligula in Lough Neagh, Northern Ireland

LIGULA (Cestoda: Pseudophyllidea) infections in gudgeon (Gobio gobio) and roach (Rutilus rutilus) differ markedly in the pathology that is observed in the host, particularly with respect to a tissue response and the extent of inhibition of gonadal development. The entire internal transcribed spacer (ITS) region (ITS-1, 5.8S and ITS-2) and the large subunit domains D1-D3 were sequenced and compared in parasites from these fish from Lough Neagh, Northern Ireland, together with a single specimen from minnow (Phoxinus phoxinus) from Wales. Sufficient differences were observed between parasites from R. rutilus and G. gobio to support the suggestion that they may represent different strains/species. In contrast, Ligula from P. phoxinus closely resembled those from R. rutilus. Ligula infections in G. gobio were recorded prior to the introduction of R. rutilus. The co-existence of separate strains or species of Ligula in Lough Neagh probably resulted from the introduction of R. rutilus to these waters, correlated with an increase in the number of great crested grebes (Podiceps cristatus).

Comparison of the macroparasite communities of wild and stocked brown trout (Salmo trutta L.) in the west of Ireland

The aim of the present study was to compare the helminth infra and component communities of wild and stocked brown trout in Lough Feeagh, in the west of Ireland, and also to examine the establishment and development of helminth communities in stocked brown trout. Fish were sampled in May, August and November 1997 and 1998 and an additional sample of wild brown trout was examined in April 1997. In total 217 wild trout and 122 stocked trout were examined. The acanthocephalans Acanthocephalus clavula and Pomphorhynchus laevis were the first parasite species to infect stocked trout in May 1997. In May 1998 both acanthocephalan species along with the trout specialists Eubothrium crassum and Crepidostomumfarionis were the first to infect trout. Mean species richness values for stocked trout increased from May to November, in 1997 and 1998. For wild trout, mean species richness values increased from April to November, in 1997 and decreased from May to November in 1998. The parasite communities of wild trout were richer than those of stocked trout in May of both years. In August the parasite communities recorded for wild and stocked trout were similar in terms of the number of species present but differed in terms of structure, and in November the parasite communities of stocked trout were richer than those of wild trout.

The osmotic relationship of the swimbladder nematode Anguillicola crassus with seawater eels

The study was designed to test the hypothesis that the majority of individuals in a population of Anguillicola crassus can tolerate seawater by osmoconformation with the blood plasma of the eel host. The osmolality of the pseudocoelomic fluid of pre-adult and adult A. crassus was compared to the osmolality of eel plasma after eels were maintained in laboratory freshwater for 2 weeks (short-term transfer) or 3 months (long-term transfer) or in natural seawater for 2 h (acute transfer), 2 weeks or 3 months. The majority of A. crassus (at least 90% of the tested population) osmoconform with their hosts in seawater within +/-30 mOsm/kg of host osmolality. Some pre-adults and adults (15-21% of the total population) were unable to withstand osmotic stress resulting in vacuolation of the hypodermis and intestinal wall, and cuticular detachment. The reasons for variation in the tissue tolerance of A. crassus to increased osmolality of host plasma are unknown and are not related to maturity, sex or conditions in the swimbladder. Osmoconformation in the majority of the population, however, enables parasites to survive and reproduce for long periods in seawater eels. The adaptation of A. crassus to its euryhaline host has played an important part in the rapid spread of the swimbladder nematode in populations of the European eel.

Randomized, controlled trial of acetazolamide and furosemide in posthemorrhagic ventricular dilation in infancy: follow-up at 1 year

OBJECTIVE

Posthemorrhagic ventricular dilation (PHVD) is a complication of intraventricular hemorrhage in preterm infants and is associated with a high risk of long-term disability. Furosemide and acetazolamide are used widely in the treatment of PHVD in the hope of avoiding the need for placement of a ventriculoperitoneal shunt, but these drugs have not been evaluated in a controlled trial. This article reports a multicenter, randomized, controlled trial designed to test the hypothesis that these drugs would reduce the rate of shunt placement (or death) and increase survival to 1 year of age without disability.

METHODS

Between 1992 and 1996, 177 infants who were less than 3 months past term and had ventricular width >4 mm above the 97th centile following intraventricular hemorrhage were assigned randomly to either standard therapy or standard therapy plus drug therapy with acetazolamide (100 mg/kg/d) plus furosemide (1 mg/kg/d). Infants who were enrolled in the trial had a median gestational age of 28.6 weeks and were enrolled at a mean postnatal age of 3.6 weeks. Forty-four percent were reported to have a cerebral parenchymal lesion on ultrasound scan at randomization. The primary outcome measure of death or shunt placement (known in all but 1 infant) occurred in 56 of 88 infants who were allocated to drug plus standard therapy compared with 46 of 88 who were allocated to standard therapy. The risk ratio was 1.23 (95% confidence interval: 0.95-1.59). Neurodevelopmental outcome information at a corrected age of 1 year (known in all but 3 of 149 surviving infants) included disability or neuromotor impairment in 54 of 67 infants (81%) who were allocated to drug plus standard therapy and 52 of 69 infants (66%) who were allocated to standard therapy. Seventy-two of 85 infants (85%) who were allocated to drug therapy either died or were disabled or impaired at 1 year compared with 62 of 89 infants (70%) who were treated with standard therapy (risk ratio: 1.22; 95% confidence interval: 1.03-1.4376). The excess risk of these adverse outcomes was greater among infants who did not have a cerebral parenchymal lesion seen on ultrasound examination at trial entry.

CONCLUSIONS

These results suggest that the use of acetazolamide and furosemide in preterm infants with PHVD is ineffective in decreasing the rate of shunt placement and is associated with increased neurologic morbidity. This treatment therefore cannot be recommended.

Long-term dynamics of Ligula intestinalis and roach Rutilus rutilus: a study of three epizootic cycles over thirty-one years

Data are presented on 2 full epizootic cycles and the start of a third of Ligula intestinalis in roach Rutilus rutilus in a small lake, and the relationships of these cycles to the densities of rudd, Scardinius erythrophthalmus, and Great Crested Grebes, Podiceps cristatus, over 31 years. The parasite was introduced to the lake by P. cristatus in 1973 at a time when the roach population had increased in response to eutrophication to a level at which individual fish growth was stunted and the hithero dominant rudd population had declined in numbers as a consequence of inter-specific competition with roach. Ligula prevalence peaked at 28% in only 2 years: thereafter parasite-induced host mortality caused a decline in the roach population, releasing fish from stunting and allowing the rudd population to recover. The consequent improved growth of roach individuals and their short life-span reduced Ligula transmission rates and prevalence levels declined to approximately 1% although Ligula nevertheless persisted for a further 10 years. Following a massive winter-kill of the fish populations in 1984-1985, fish and Ligula numbers declined to barely detectable levels and the parasite disappeared from samples. Rudd recovered first, then roach and interspecific competition again led to a decline in rudd numbers. This increase in roach numbers led to a decrease in roach growth rates, which coincided with the re-colonization of the lake by Ligula. This second epizootic of Ligula peaked within 2 years in 1991-1992, when up to 78% of roach were infected with a maximum abundance of 2.2 parasites and intensity of 21 parasites. Heavy parasite-induced mortality of roach led to a decline in numbers, an improvement in individual growth rate and a reduction of Ligula transmission rates such that the epizootic died out in 1996. Similar conditions of roach numbers and growth prevailed at the start of a third cycle in 1998. The course of events over the second cycle was so similar to that of the first that it confirms the interpretations of that cycle. Comparison with other localities shows that epizootics of Ligula always coincide with rapid increases in roach numbers, for whatever cause, and stunted growth, which together attract piscivorous birds. At the start of a cycle Ligula is a major determinant of the population dynamics of the roach, but at the end of the cycle the fish population dynamics determine those of the parasite. The cycles are not regulated and the roach-Ligula system is inherently unstable.

Interspecific interactions between larval digeneans in the eyes of perch, Perca fluviatilis

The changes in prevalence and abundance of the three species of metacercariae in the humour of the eyes of perch Perca fluviatilis in Slapton Ley, Devon, have been monitored over a period of 29 years. Earlier studies had revealed that Diplostomum gasterostei was originally the sole occupant of this niche, but Tylodelphys clavata colonised in 1973 and T. podicipina in 1976. A decline in the number of perch with heavy infections of D. gasterostei was significantly negatively correlated with population abundance of T. clavata and a decline in recruitment rate of D. gasterostei coincided with the population increase in T. podicipino over the period 1976-1979. It was suggested that the decline in population size of D. gasterostei was due to inter-specific competition, but this hypothesis could not be tested experimentally. Subsequent investigations, reported here, confirmed the decline when the data set was extended to 1985. A severe decline in the perch population over the winter of 1984/1985 resulted in the disappearance of D. gasterostei and T. podicipina and this was followed by a slow recovery from 1990 onwards. This natural experiment provided an opportunity to test the hypothesis. Only T. clavata survived throughout the perch crash and the population continued at pre-crash levels up to 1999. Its congener T. podicipina did not re-appear until 1994 and was probably a re-introduction: it did not attain pre-crash levels until 1999. It is likely that D. gasterostei survived the crash as it re-appeared in 1991, but was confined to young of the year fish and barely approached pre-crash levels even in 1999. Its continual low levels cannot be explained by changes in the lake or in densities of snail intermediate or bird definitive hosts. New data revealed that the suspensory ligaments of the eye were the preferred site of all three species and that the eye was partitioned out between them. The data from the post-crash period do not refute but rather confirm earlier conclusions that inter-specific competition is responsible for the decline in D. gasterostei and this remains the preferred hypothesis.

Colonisation and extinction in relation to competition and resource partitioning in acanthocephalans of freshwater fishes of the British Isles

This paper challenges two paradigms long held in relation to the ecology of parasites in freshwater systems: (1) autogenic species are poorer colonisers than allogenic ones; and (2) parasites with direct life cycles are more successful colonisers than those with complex life cycles. Using new and existing data for Acanthocephala in freshwater fish from the British Isles, it is suggested that all six species present have been able to colonise and persist successfully, in spite of the supposed limitations of their autogenic life-style. It is proposed that these parasites have overcome these limitations by a variety of means, which apply equally to all species considered. Foremost among these is the utilisation of a migratory fish host as either a preferred or a suitable host in their life cycle, allowing colonisation of new areas and rescue effects in established areas, whilst equally important is the use of a common and widespread crustacean as the intermediate host. In addition, all six species appear to exhibit resource partitioning by host at either or both the larval and adult stages, thus reducing the potential for competition and further facilitating colonisation and survival. This hypothesis is supported by data from previous studies both on acanthocephalans from Europe and North America and on other autogenic parasites. It also provides an explanation for the apparently atypical host utilisation patterns of some acanthocephalan species in areas on the edge of their distributions, notably in Ireland.

Metapopulation and community dynamics of helminth parasites of eels anguilla Anguilla in the River Exe system

The possibility that much of the spatial and temporal variation in helminth communities in freshwater fish can be explained in terms of metapopulation theory was tested by examining helminth component communities of eels sampled from 3 localities in the River Exe and 5 of its tributaries on 2 occasions at an interval of 3 years. Four specific predictions of metapopulation theory in relation to community dynamics were tested. The prediction that parasite species could be recognized as common and rare and that this was sensitive to scale was met. The prediction that core species would be more widely distributed and have a higher dispersal ability was met only in part. The prediction that similarity between communities would increase with connectivity and decrease with distance apart was not met. The final prediction that species would go locally extinct and be replaced by rescue effects was not met. There was evidence of local extinctions; not of eel specialists but of species using other fish species as their principal definitive hosts. Eel helminth communities were heavily dominated by 3 species of eel specialists which were relatively stable and responsible for most of the similarity and its changes in space and time. It was concluded that metapopulation theory did not provide a very satisfactory explanation for the changes in the helminth communities in eels and reasons for this included the inherent difficulty of applying metapopulation theory to parasites and the fact that the helminth communities in eels in the River Exe were atypical in being dominated by eel specialists.

The effects of meiosis activating sterol on in-vitro maturation and fertilization of human oocytes from stimulated and unstimulated ovaries

The object of this study was to assess functional maturation in vitro by obtaining data on the fertilization and embryonic competence of human oocytes with or without exposure to meiosis activating sterol (MAS) during maturation in vitro. Immature oocytes were either collected from unstimulated patients with polycystic ovaries (PCO) during gynaecological surgery, or were donated by patients undergoing a cycle of intracytoplasmic sperm injection (ICSI) treatment including ovarian stimulation with gonadotrophins. PCO oocytes had variable cumulus cover, which was retained during culture while those from ICSI patients were cultured without cumulus. The study included 119 oocytes from PCO patients and 72 from ICSI patients. The oocytes were allowed to mature in vitro for up to 46 h in the presence or absence of MAS. Mature oocytes were inseminated by ICSI with fertile donor spermatozoa and embryo development was monitored in vitro. MAS (30 microg/ml) significantly increased the survival of oocytes from PCO patients (P < 0.01) but did not significantly affect the proportion completing maturation in vitro. For the ICSI patients, >90% of oocytes survived in all culture groups, regardless of MAS addition, however MAS (10 or 30 microg/ml) significantly increased the proportion of oocytes maturing in vitro (P < 0.05). The apparent tendency towards improved subsequent development in vitro will require larger numbers of oocytes for evaluation. Oocytes from ICSI patients matured more rapidly in vitro than those from PCO patients. Our results show positive effects of MAS on human oocytes, confirming previous data in mice. This work may have implications for the future clinical application of IVM.

Helminth communities in eels Anguilla anguilla from Adriatic coastal lagoons in Italy

The composition and diversity of the total and intestinal component and infra-communities were determined in eels Anguilla anguilla from three shallow lagoons on the Adriatic coast of Italy to determine whether the helminth communities would differ in composition and structure from those in eels from lagoons on the Tyrrhenian coast. The lagoons differed in respect of their management regimes and the extent of freshwater influx. Both freshwater and marine species of helminths were found in the eels in all three lagoons, but the freshwater component was richer in Valle Figheri. A suite of three digenean eel specialist species occurred in all three lagoons, of which any two members dominated each community. This conferred a high degree of similarity between the communities of the three lagoons. The same three species also dominated helminth communities in eels in lagoons along the Tyrrhenian coast of Italy, and compositional similarity levels were similar within and between western and eastern groups. Species richness was higher in the component communities of the eels of the Adriatic lagoons when compared to the Tyrrhenian ones, but diversity and dominance indices were of a similar order of magnitude and range. Intestinal helminth communities were richer and more diverse in two of the Adriatic lagoons because the proportion of eels with zero or one helminth species was, unusually, in the minority. It was nevertheless concluded that infracommunity structure was similar in eels from both western and eastern lagoons and that the hypothesis that it would differ in Adriatic lagoons could not be supported. The findings provide further evidence of the similarity in composition and structure of helminth communities in eels from coastal lagoons throughout Europe.