Impact of comorbidity on headache-related disability

OBJECTIVE

To assess and compare the extent to which comorbid conditions explain the role disability associated with migraine and other severe headaches.

METHODS

A probability sample of US adults (n = 5,692) was interviewed. Presence of headaches, other chronic pain conditions, and chronic physical conditions was assessed in a structured interview administered by trained interviewers. Diagnostic criteria for migraine were based on the International Headache Society classification. Mental disorders were ascertained with the Composite International Diagnostic Interview that collected diagnostic criteria according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Role disability was assessed with World Health Organization Disability Assessment Schedule questions about days out of role and days with impaired role functioning.

RESULTS

Eighty-three percent of migraineurs and 79% of persons with other severe types of headache had some form of comorbidity. Compared with headache-free subjects, migraineurs were at significantly increased risk for mental disorders (odds ratio [OR] 3.1), other pain conditions (OR 3.3), and physical diseases (OR 2.1). Compared with headache-free subjects, persons with nonmigraine headache were also at significantly increased risk for mental disorders (OR 2.0), other pain conditions (OR 3.5), and physical diseases (OR 1.7). Migraineurs experienced role disability on 25.2% of the last 30 days compared with 17.6% of the days for persons with nonmigraine headaches and 9.7% of the days for persons without headache. Comorbid conditions explained 65% of the role disability associated with migraine and all of the role disability associated with other severe headaches.

CONCLUSIONS

Comorbidity is an important factor in understanding disability among persons with headache.

The contribution of GJB2 mutations to slight or mild hearing loss in Australian elementary school children

BACKGROUND

There is a lack of information on prevalence, cause and consequences of slight/mild bilateral sensorineural hearing loss (SNHL) in children. We report the first systematic genetic analysis of the GJB2 gene in a population-derived sample of children with slight/mild bilateral SNHL.

METHODS

Hearing tests were conducted in 6240 Australian elementary school children in Grades 1 and 5. 55 children (0.88%) were found to have a slight/mild sensorineural hearing loss. 48 children with slight/mild sensorineural hearing loss and a matched group of 90 children with normal hearing participated in a genetic study investigating mutations in the GJB2 gene, coding for connexin 26, and the presence of the del(GJB6-D13S1830) and del(GJB6-D13S1854) deletions in the GJB6 gene, coding for connexin 30.

RESULTS

Four of 48 children with slight/mild sensorineural hearing loss were homozygous for the GJB2 V37I change. The four children with homozygous V37I mutations were all of Asian background and analysis of SNPs in or near the GJB2 gene suggests that the V37I mutation arose from a single mutational event in the Asian population.

DISCUSSION

Based on the prevalence of carriers of this change we conclude that V37I can be a causative mutation that is often associated with slight/mild sensorineural hearing loss. No other children in the slight/mild hearing loss group had a hearing loss related to a GJB2 mutation. One child with normal hearing was homozygous for the R127H change and we conclude that this change does not cause hearing loss. Two children of Asian background were carriers of the V37I mutation. Our data indicate that slight/mild sensorineural hearing loss due to the GJB2 V37I mutation is common in people of Asian background.

Isochromosome of a deleted 20q: a rare but recurrent chromosome abnormality in myelodysplastic syndromes

Interstitial deletion of the long arm of chromosome 20, as the sole abnormality, is commonly observed in myeloid malignancies, including myeloproliferative disorder, myelodysplastic syndrome, and acute myeloid leukemia. The breakpoints of the deletion are typically located in the region 20q11.2 approximately q13.3, although smaller deletions within this region have also been reported. We present here 4 patients with myelodysplastic syndrome with an isochromosome of the deleted long arm of chromosome 20: ider(20)(q10)del(20)(q11q13). Fluorescence in situ hybridization studies were performed on the bone marrow samples from these patients to prove the identity of this unusual chromosome abnormality.

Deletion of chromosome arm 15q and hitherto unreported duplication of del(15q) in myeloid disorders

Deletion of the long arm of chromosome 15 has been described as a recurrent chromosomal abnormality in myeloid malignancies. We present here some additional case reports of deletion 15 including two cases with an extra copy of the deleted chromosome, a finding that has not previously been described. We compare our cases to those previously reported. Our findings show that, contrary to previous reports, this abnormality may not always be associated with an unfavorable prognosis. They also indicate that deletion 15q most frequently appears to be associated with myelomonocytic disease. Potential candidate genes on 15q that may be involved in the tumorigenesis of these cases are discussed.

Qualitative analysis of parents' experience with early detection of hearing loss

AIMS

To determine key themes from parents' comments on paths to diagnosis and intervention for their children with hearing loss, following introduction of at-risk neonatal hearing screening and modification of distraction test screening for infants not at-risk.

METHODS

Parents of children born in 1993 in Victoria, Australia, who were eligible for screening via the Victorian Infant Hearing Screening Program and who were subsequently diagnosed with a permanent congenital hearing loss and fitted with hearing aids prior to the year 2000 were asked to complete a semi-structured questionnaire shortly after aid fitting. Two researchers independently analysed parent comments using the constant comparative method.

RESULTS

Parents of 82 children (61%) replied to the questionnaire. Themes analysis revealed a generally positive response to neonatal ABR screening, with a mixed response to the distraction test; powerful emotions experienced by parents at diagnosis including denial and shock; frustration arising from delays in diagnosis, and communication difficulties with providers. Special difficulties testing children with other medical and developmental problems, confusion about tympanostomy tube insertion, and difficulty with wearing hearing aids were also reported. Some children had experienced problems in the school setting. Experience of post-diagnostic services was generally positive.

CONCLUSIONS

Parents need greater support both during the testing of screen failures and at the time of diagnosis. Providers need more training in how to communicate findings to parents, particularly at times when parents are experiencing strong emotions. Parents need more strategies to enable hearing aid wearing in very young children. Some children with additional medical, developmental, and behavioural problems need specialised approaches to testing.

The influence and interactions of hydrostatic and osmotic pressures on the intracellular milieu of chondrocytes

The intracellular milieu of chondroctyes is regulated by an array of proteins in the cell membrane which operate as transport pathways, allowing ions and nutrients such as glucose and amino acids and metabolites such as lactate to cross the plasma membrane. Here we investigated the influence of hydrostatic pressure on intracellular calcium concentrations ([Ca(2+)](i)) in isolated bovine articular chondrocytes. We found that short applications of high hydrostatic pressures led to a significant increase in [Ca(2+)](i). The pressure-induced rise was abolished for long (240 sec) but not short (30 sec) pressure applications by removal of extracellular Ca(2+). The rise in pressure was also blocked by the inhibitors neomycin and thapsigargin confirming that pressure, by generating IP(3), led to an increase in [Ca(2+)](i) by mobilising the pool of Ca(2+) ions contained within intracellular stores. We also found that intracellular [Na(+)] was affected by a rise in osmotic pressure and further affected by application of hydrostatic pressure. The effect of hydrostatic pressure on sulphate incorporation depended strongly on extracellular osmolality. Since significant gradients in extracellular osmolality exist across intact cartilage, the results imply that responses of chondrocytes to the same pressure will vary depending on location in the joint. The results also indicate that hydrostatic pressures can affect several different transporter systems thus influencing the intracellular milieu and chondrocyte metabolism.

Mosaic trisomy 2 in myelodysplastic syndromes and acute myeloblastic leukemias

We present a short report here of two more patients with trisomy 2 as the sole chromosomal abnormality in a hematologic malignancy. Although trisomy 2 is a recognized abnormality in neoplasms, particularly hepatoblastomas, to the best of our knowledge only three other cases have been reported with trisomy 2, in patients with a hematologic malignancy. The two cases presented here of myelodysplastic syndrome transforming to acute myeloblastic leukemia and chronic myelomonocytic leukemia showed trisomy 2 as the sole abnormality.

Six year effectiveness of a population based two tier infant hearing screening programme

AIMS

To determine whether a two tier universal infant hearing screening programme (population based risk factor ascertainment and universal distraction testing) lowered median age of diagnosis of bilateral congenital hearing impairment (CHI) >40 dB HL in Victoria, Australia.

METHODS

Comparison of whole population birth cohorts pre and post introduction of the Victorian Infant Hearing Screening Program (VIHSP). All babies surviving the neonatal period born in Victoria in 1989 (pre-VIHSP) and 1993 (post-VIHSP) were studied. (1) Pre-1992: distraction test at 7-9 months. (2) Post-1992: infants with risk factors for CHI referred for auditory brain stem evoked response (ABR) assessment; all others screened by modified distraction test at 7-9 months.

RESULTS

Of the 1989 cohort (n = 63 454), 1.65/1000 were fitted with hearing aids for CHI by end 1995, compared with 2.09/1000 of the 1993 cohort (n = 64 116) by end 1999. Of these, 79 cases from the 1989 cohort (1.24/1000) and 72 cases from the 1993 cohort (1.12/1000) had CHI >40 dB HL. Median age at diagnosis of CHI >40 dB HL for the 1989 birth cohort was 20.3 months, and for the 1993 cohort was 14.2 months. Median age at diagnosis fell significantly for severe CHI but not for moderate or profound CHI. Significantly more babies with CHI >40 dB HL were diagnosed by 6 months of age in 1993 than in 1989 (21.7% v 6.3%). Compared to the six years pre-VIHSP, numbers aided by six months were consistently higher in the six years post-VIHSP (1.05 per 100 000 births versus 13.4 per 100 000 births per year).

CONCLUSIONS

VIHSP resulted in very early diagnosis for more infants and lowered median age of diagnosis of severe CHI. However, overall results were disappointing.

Costs of care for irritable bowel syndrome patients in a health maintenance organization

OBJECTIVES

The aims of this study were: 1) to determine the total costs of care and costs related to lower GI-related problems for patients who received a diagnosis of irritable bowel syndrome (IBS), and 2) to compare them to age- and sex-matched population controls and patients treated for inflammatory bowel disease (IBD) or gastroesophageal reflux disease (GERD).

METHODS

Use and cost data were obtained through the computerized information systems of a large staff-model health maintenance organization on three groups of patients diagnosed in 1994 or 1995 with IBS, IBD, or GERD; and an age- and sex-matched control group of patients without any of these listed diagnoses. The IBS patient group was compared to the three comparison groups on components of total and IBS-related costs.

RESULTS

Total costs of care for IBS patients were 49% higher than population controls during the year starting with the visit at which IBS patients were identified. In the index year, every component of total costs except inpatient care was significantly higher for IBS patients than for population controls. The costs of care for lower GI problems were significantly higher for patients with IBS than for population controls across a range of services. However, only 33% of the difference in total costs of care between IBS patients and population controls was due to lower GI-related services in the index year. In the subsequent years, lower GI-related services accounted for 18% and 20% of the total cost difference between IBS patients and population controls. The total costs of care as well as the components of costs of care were generally higher for IBD patients than for IBS patients, but were comparable for GERD and IBS patients.

CONCLUSIONS

Patients with IBS show sustained increases in health care costs relative to population controls for both lower GI services and care unrelated to lower GI problems. However, the majority of the excess in health care costs resulted from medical care not directly related to lower GI problems.

Prevalence and nature of connexin 26 mutations in children with non-syndromic deafness

OBJECTIVE

To determine (1) the prevalence and nature of connexin 26 mutations in a cohort of Australian children with non-syndromic hearing loss, and (2) the carrier frequency of the common connexin 26 mutation (35delG) in the general population.

DESIGN

A cohort, case-finding study. Mutation analysis was performed on DNA extracted from white blood cells, buccal cells, or Guthrie blood spots.

SETTING

A hearing loss investigation clinic and a deafness centre in two Australian capital cities, 1 January 1998 to 31 October 2000.

PARTICIPANTS

(1) 243 children (age range, 4 weeks to 16 years; median, 4 years), attending hearing loss clinics in Sydney and Melbourne; (2) 1000 blood samples obtained from anonymous Guthrie card blood spots collected in 1984 [corrected] by the Victorian Clinical Genetics Service as part of the newborn screening program.

MAIN OUTCOME MEASURES

(1) The prevalence and types of connexin 26 mutations in a cohort of children with prelingual deafness; (2) the carrier frequency of the common connexin 26 mutation, 35delG, in the general population.

RESULTS

Connexin 26 mutations were identified and characterised in 52 (21%) of the 243 children; 14 different mutations, including four previously unreported mutations (135S, C53R, T123N and R127C), were identified. The common 35delG mutation was found in 56 of the 104 alleles (ie, 86 of the connexin 26 alleles in which a mutation was positively identified). The mutations V371 and M34T were also relatively common. The carrier frequency of connexin 26 mutations and of the common 35delG connexin 26 mutation in the Victorian population was estimated to be 1 in 54 and 1 in 100, respectively.

CONCLUSIONS

Mutations in the connexin 26 gene (especially the 35delG mutation) are a common cause of prelingual hearing loss in Australia.

Identification of dna components required for induction of cotton leaf curl disease

Cotton leaf curl disease (CLCuD) is a major constraint to cotton production in Pakistan. Infectious clones of the monopartite begomovirus cotton leaf curl virus (CLCuV), associated with diseased cotton, are unable to induce typical symptoms in host plants. We have identified and isolated a single-stranded DNA molecule approximately 1350 nucleotides in length which, when coinoculated with the begomovirus to cotton, induces symptoms typical of CLCuD, including vein swelling, vein darkening, leaf curling, and enations. This molecule (termed DNA beta) requires the begomovirus for replication and encapsidation. The CLCuV/DNA 1/DNA beta complex, together with a similar complex previously identified in Ageratum conyzoides, represent members of an entirely new type of infectious, disease-causing agents. The implications of this finding to our understanding of the evolution of new disease-causing agents are discussed.

Outcome in the second year of life after in-vitro fertilisation by intracytoplasmic sperm injection: a UK case-control study

BACKGROUND

There have been reports suggesting that children born after in-vitro fertilisation by intracytoplasmic sperm injection (ICSI) are at increased risk of neurodevelopmental delay. We have undertaken a case-control study of this issue.

METHODS

We studied 208 singleton children conceived by ICSI and a control group of 221 normally conceived singleton children. Children were recruited from 22 fertility centres and local nurseries throughout the UK. Controls were selected to match cases as closely as possible for social class, maternal educational attainment, region, sex, and race. The primary outcome measure was neurodevelopmental scoring; secondary measures were perinatal outcomes, postnatal health, and congenital abnormalities. A single examiner assessed all the children.

FINDINGS

A follow-up rate of 90% for the ICSI group was achieved at a mean age of 17 months. No difference between the study children and controls was found in mean neurodevelopmental scores (98.08 [SD 10.93] vs 98.69 [9.99]) or any subscales on the Griffiths' scales of mental development. Perinatal outcome was similar apart from a higher rate of caesarean section (73 [35.1%] vs 53 [24.0%], p=0.015) and a lower mean birthweight (3163 [SD 642] vs 3341 [606] g, p=0.013) in the study group. Rates of major congenital abnormality were also similar overall (ten [4.8%] study vs ten [4.5%] control), although there were significantly more congenital anomalies among children born to fathers with oligozoospermia than in other children.

INTERPRETATION

This population study did not show any significant difference between children conceived after ICSI and their naturally conceived peers in terms of physical health and development.

Correlation of collagen organization with polarization sensitive imaging of in vitro cartilage: implications for osteoarthritis

OBJECTIVE

Optical coherence tomography (OCT), a new method of high resolution imaging, has shown feasibility for assessing articular cartilage to identify early changes in osteoarthritis (OA) and monitor therapy. OCT is analogous to ultrasound, measuring the intensity of backreflected infrared light rather than sound. The resolution of this technology is up to 25 times higher than existing methods. We investigated the correlation between changes observed by OCT and the degree of collagen organization in OA cartilage.

METHODS

Polarization sensitive OCT (PSOCT) imaging was used to assess changes in cartilage collagen organization in vitro.

RESULTS

The presence (or absence) of PSOCT changes correlated with collagen organization (or disorganization) on histology as assessed by picrosirius polarization microscopy (no significant difference). In multiple cases, cartilage was abnormal by both PSOCT and polarization microscopy, but was grossly normal by routine staining, showing cartilage thickness > 2 mm and no fibrillations.

CONCLUSION

This in vitro study suggests PSOCT changes in cartilage are due to the state of collagen organization. The combination of high resolution structural imaging and birefringence detection make OCT a potentially powerful technology for early assessment of OA.

Index matching to improve optical coherence tomography imaging through blood

BACKGROUND

Most myocardial infarctions are caused by the rupture of small rather than large plaques in the arteries of the heart that are beyond the detection limit of current technologies.

METHODS AND RESULTS

Recently, optical coherence tomography (OCT) has demonstrated considerable potential as a method for high-resolution assessment of vulnerable plaque. However, intravascular OCT imaging is complicated by the need to remove blood from the imaging field because blood results in substantial signal attenuation. This work examines index matching as a method for increasing penetration. Index matching is based on the hypothesis that the predominant source of scattering in blood is the difference in refractive index between the cytoplasm of erythrocytes and serum. By increasing the refractive index of serum to a value near that of the cytoplasm, or index matching, scattering can be substantially reduced. The concept was tested with a system that pumped blood in vitro through transparent tubing. The test compounds, dextran and intravenous contrast agent, both led to significant improvements in penetration (69+/-12% and 45+/-4%). No significant effect was seen with the saline control. For dextran, the effect could not be attributed to reductions of red cell number or volume because changes in these parameters were not different from the control. In the case of intravenous contrast, a small but significant relative reduction in red cell volume was seen.

CONCLUSIONS

This study demonstrates the feasibility of index matching for improving OCT imaging through blood. Future studies are required to identify compounds for effective index matching in vivo.

Pathogenicity of a natural recombinant associated with ageratum yellow vein disease: implications for geminivirus evolution and disease aetiology

Yellow vein disease of Ageratum conyzoides is caused by a viral DNA complex consisting of the genomic component (DNA A) of the monopartite begomovirus Ageratum yellow vein virus (AYVV, family: Geminiviridae) and a small satellite-like DNA beta component. AYVV DNA A is unable to induce symptoms in this host alone but can systemically infect A. conyzoides in which it accumulates to low levels. Here, we demonstrate that the yellow vein phenotype can also be produced by co-inoculating A. conyzoides with AYVV DNA A and recDNA-Abeta17, a naturally occurring recombinant of approximately the same size as DNA beta that contains sequences from both DNA A and DNA beta. Symptoms induced by DNA A and recDNA-Abeta17 in A. conyzoides and Nicotiana glutinosa are qualitatively similar to those associated with DNA A and DNA beta although milder. Recombination between DNA A and DNA beta to produce a chimera resembling recDNA-Abeta17 was observed after whitefly transmission of the disease in A. conyzoides. Hence, such recombination events are likely to occur frequently, implying that recombinants will normally be associated with this type of disease complex in the field. Possible implications of these findings for the evolution of begomoviruses and the aetiology of their diseases are discussed.

A discotic disguised as a smectic: A hybrid columnar bragg glass

We show that discotics, lying deep in the columnar phase, can exhibit an x-ray scattering pattern which mimics that of a somewhat unusual smectic liquid crystal. This exotic, new glassy phase of columnar liquid crystals, which we call a "hybrid columnar Bragg glass," can be achieved by confining a columnar liquid crystal in an anisotropic random environment of, e.g., strained aerogel. Long-ranged orientational order in this phase makes single-domain x-ray scattering possible, from which a wealth of information could be extracted. We give detailed quantitative predictions for the scattering pattern in addition to exponents characterizing anomalous elasticity of the system.

Effect of sleep state on the flash visual evoked potential. A case study

Controversy exists regarding the influence of sleep state on the flash visual evoked potential. This study recorded the visual evoked potential in a new-born infant in four different sleep states; wakefulness. drowsiness, active sleep and quiet sleep over a five hour period. The infant's heart rate, breathing rate and breathing regularity were also recorded. It was clear that when this subject was awake the VEPs recorded differed substantially from those recorded when sleeping. Two of the four main components had shorter peak latencies, one component was prolonged and one of the peak to trough amplitudes was consistently smaller when alert. This study highlights an important and often overlooked aspect of developmental research that the state of the infant may affect developmental measures.

A unique virus complex causes Ageratum yellow vein disease

Ageratum conyzoides L., a weed species widely distributed throughout southeast Asia, frequently exhibits striking yellow vein symptoms associated with infection by Ageratum yellow vein virus (AYVV), a member of the Geminiviridae (genus Begomovirus). Most begomoviruses have bipartite genomes (DNAs A and B), but only a DNA A has been identified for AYVV. We demonstrate that yellow vein disease of A. conyzoides results from co-infection by AYVV DNA A (2,741 nt) and a circular DNA that is approximately half its size (1,347 nt) that we designate DNA beta. Apart from the sequence TAATATTAC, common to all geminiviruses and containing the initiation site of rolling circle replication, DNA beta shows negligible sequence homology either to AYVV DNA A or to DNA B associated with bipartite begomoviruses. DNA beta depends on DNA A for replication and is encapsidated by DNA A-encoded coat protein and so has characteristics of a DNA satellite. However, systemic infection of A. conyzoides by DNA A alone is sporadic and asymptomatic, and DNA A accumulation is reduced to 5% or less of its accumulation in the presence of DNA beta. Therefore, DNA A and DNA beta together form a previously unrecognized disease-inducing complex. Our data also demonstrate that the nanovirus-like DNA 1 component associated with infected A. conyzoides plays no essential role in the disease and represents a satellite-like DNA. Furthermore, the satellite DNA previously found associated with tomato leaf curl virus is probably a defective DNA beta homologue.

High frequency hearing loss correlated with mutations in the GJB2 gene

Genetic hearing impairment affects approximately 1/2000 live births. Mutations in one gene, GJB2, coding for connexin 26 cause 10%-20% of all genetic sensorineural hearing loss. Mutation analysis in the GJB2 gene and audiology were performed on 106 families presenting with at least one child with congenital hearing loss. The families were recruited from a hospital-based multidisciplinary clinic, which functions to investigate the aetiology of sensorineural hearing loss in children and which serves an ethnically diverse population. In 74 families (80 children), the aetiology was consistent with non-syndromic recessive hearing loss. Six different connexin 26 mutations, including one novel mutation, were identified. We show that GJB2 mutations cause a range of phenotypes from mild to profound hearing impairment and that loss of hearing in the high frequency range (4000-8000 Hz) is a characteristic feature in children with molecularly diagnosed connexin 26 hearing impairment. We also demonstrate that this type of audiology and high frequency hearing loss is found in a similar-sized group of deaf children in whom a mutation could only be found in one of the connexin 26 alleles, suggesting connexin 26 involvement in the aetiology of hearing loss in these cases. In our study of the M34T mutation, only compound heterozygotes exhibited hearing loss, suggesting autosomal recessive inheritance.

A nanovirus-like DNA component associated with yellow vein disease of Ageratum conyzoides: evidence for interfamilial recombination between plant DNA viruses

Yellow vein disease of Ageratum conyzoides, a weed species that is widely distributed throughout Asia, has been attributed to infection by the geminivirus Ageratum yellow vein virus (AYVV). In addition to a single AYVV genomic component (DNA A), we have previously demonstrated that infected plants contain chimeric defective viral components, comprising DNA A and nongeminiviral sequences, that act as defective interfering DNAs. A database search has revealed that the nongeminiviral sequences of one such defective component (def19) show significant homology with sequences of nanovirus components that encode replication-associated proteins (Reps). Primers designed to hybridise to the nongeminiviral DNA were used to PCR-amplify a full-length nanovirus-like component, referred to as DNA 1, from an extract of infected A. conyzoides. DNA 1 is unrelated to AYVV DNA A but resembles nanovirus components that encode Reps and is most closely related (73% identity) to a nanovirus-like DNA recently isolated from geminivirus-infected cotton. DNA 1 is dependent on AYVV DNA A for systemic infection of A. conyzoides and Nicotiana benthamiana and can systemically infect N. benthamiana in the presence of the bipartite geminivirus African cassava mosaic virus. A. conyzoides plants coinfected with AYVV DNA A and DNA 1 remain asymptomatic, indicating that additional factors are required to elicit yellow vein disease. Our results provide direct evidence for recombination between distinct families of plant single-stranded DNA viruses and suggest that coinfection by geminivirus and nanovirus-like pathogens may be a widespread phenomenon. The ability of plant DNA viruses to recombine in this way may greatly increase their scope for diversification.