'PartBreCon' study. A UK multicentre retrospective cohort study to assess outcomes following PARTial BREast reCONstruction with chest wall perforator flaps

BACKGROUND

Partial breast reconstruction with a pedicled chest wall perforator flap (CWPF) enables breast conservation in a higher tumour: breast volume ratio scenario. Since there is limited evidence, this retrospective cohort study aimed to ascertain immediate (30-days) and medium-term (follow-up duration) surgical outcomes.

METHODS

STROBE-compliant protocol ascertained CWPF outcomes between March 2011-March 2021. UK centres known to perform CWPF were invited to participate if they performed at least 10 cases. Data were retrospectively collected, including patient demographics, tumour and treatment characteristics, and surgical and oncological outcomes. Statistical analysis (R™) included multivariable logistic regression and sensitivity analysis.

RESULTS

Across 15 centres, 507 patients with median age (54 years, IQR; 48-62), body mass index (25.4 kg/m2, IQR; 22.5-29), tumour size (26 mm, IQR; 18-35), and specimen weight (62 g, IQR; 40-92) had following flap types: LiCAP (54.1%, n = 273), MiCAP/AiCAP (19.6%, n = 99), LiCAP + LTAP (19.8%, n = 100) and TDAP (2.2%, n = 11). 30-days complication rates were in 12%: haematoma (4.3%, n = 22), wound infection (4.3%, n = 22), delayed wound healing (2.8%, n = 14) and flap loss (0.6%, n = 3; 1 full) leading to readmissions (2.6%, n = 13) and re-operations (2.6%, n = 13). Positive margins (n = 88, 17.7%) led to 15.9% (n = 79) re-excisions, including 7.5% (n = 37) at the planned 2nd of 2-stage surgery and 1.8% (n = 9) mastectomy. At median 23 months (IQR; 11-39) follow-up, there were 1.2% (n = 6) symmetrisations; recurrences: local (1%), regional/nodal (0.6%) and distant (3.2%).

CONCLUSIONS

This large multicentre cohort study demonstrates acceptable complication and margin re-excision rates. CWPF extends the range of breast conservation techniques. Further studies are required for long-term oncological outcomes.

Observational studies on the efficacy of carbamazepine and ascorbyl palmitate in managing trigeminal neuralgia

OBJECTIVE

Ascorbyl palmitate is a fat-soluble ester of vitamin C and is used as an antioxidant food additive. While literature reports that ascorbyl palmitate can prevent exacerbation of pain and improve the quality of life of patients suffering from pain, this is not yet supported by clinical trial data. Our study aimed to investigate the effectiveness of ascorbyl palmitate in managing trigeminal neuralgia.

PATIENTS AND METHODS

This study was carried out in a single-centre clinical trial in which subjects suffering from trigeminal neuralgia (N=11) were included. All patients were on carbamazepine when first included and, after washout period, received Ascorbyl palmitate. Eligible patients had the most severe trigeminal neuralgia pain in the oral cavity or pain on touching trigger zones, aged 20 years or older, were capable of proper assessment of the severity of pain and their condition, and had experienced multiple episodes of intraoral pain for at least 3 months with a pain intensity of more than 4 points on the numerical rating scale. The Brief Pain Questionnaire was used to evaluate patient's quality of life.

RESULTS

A total of 11 patients were included with a mean age 55.36±10.67 years (7 males, 4 females). Most patients had compression by the superior cerebellar artery and vascular loops upon magnetic resonance examination. The mean numerical rating scale score for carbamazepine after one month was 7.9±0.56 (95% CI 7.49, 8.30). Similarly, for ascorbyl palmitate was 5.5±1.50 (95% CI 4.42, 6.57) (p<0.001).

CONCLUSIONS

Ascorbyl palmitate can be used as an adjunct intervention in managing trigeminal neuralgia pain. According to the results, ascorbyl palmitate prevents frequent exacerbation of pain and improves patient quality of life.

A prospective evaluation of the American College of Surgeons Surgical Risk Calculator as a predictor of complications for breast surgery

BACKGROUND

The infection rates for operative management of breast cancer are often unpredictable and higher than average for a clean surgical procedure (0.8% and 28%). We aimed to assess the effectiveness of the American College of Surgeons (ACS) Surgical Risk Calculator (SRC), a preoperative scoring system to calculate the risk of surgical site infection (SSI) and serious complications following breast surgery.

METHODS

Prospective risk scoring using the SRC on 213 patients in the preoperative clinic and the incidence of SSI and serious complications within 30 days postoperatively was prospectively collected.

RESULTS

The overall SSI rate in our sample was 5% (n=11/210 patients). For a one-unit increase in SRC score, the odds of having SSI increased by a factor of 1.88 (95% CI 1.33 to 2.74). Odds of developing SSI were higher in patients with high Body Mass Index (OR 1.25; 95% 1.13 to 1.40) and American Society of Anesthesiologists score 3 (OR 11.54; 95% CI 2.98 to 43.65). The odds of developing an SSI were ∼19 times higher if a patient had an SRC score >3.0 versus those with an SRC score <3.0. Only 3% (n=4) of patients who had an SRC score of <3.0 experienced SSI, compared with 33% (n=7) for those with a risk score of >3.0. Out of 210 patients, 9 had serious complications (4.2%).

CONCLUSIONS

ACS SRC Score of more than 3 was associated with a higher likelihood of SSI. SRC was able to predict the risk of SSI and serious complications and can be used preoperatively for identification and risk minimisation.

Innovations for the future of breast surgery

BACKGROUND

Future innovations in science and technology with an impact on multimodal breast cancer management from a surgical perspective are discussed in this narrative review. The work was undertaken in response to the Commission on the Future of Surgery project initiated by the Royal College of Surgeons of England.

METHODS

Expert opinion was sought around themes of surgical de-escalation, reduction in treatment morbidities, and improving the accuracy of breast-conserving surgery in terms of margin status. There was emphasis on how the primacy of surgical excision in an era of oncoplastic and reconstructive surgery is increasingly being challenged, with more effective systemic therapies that target residual disease burden, and permit response-adapted approaches to both breast and axillary surgery.

RESULTS

Technologies for intraoperative margin assessment can potentially half re-excision rates after breast-conserving surgery, and sentinel lymph node biopsy will become a therapeutic procedure for many patients with node-positive disease treated either with surgery or chemotherapy as the primary modality. Genomic profiling of tumours can aid in the selection of patients for neoadjuvant and adjuvant therapies as well as prevention strategies. Molecular subtypes are predictive of response to induction therapies and reductive approaches to surgery in the breast or axilla.

CONCLUSION

Treatments are increasingly being tailored and based on improved understanding of tumour biology and relevant biomarkers to determine absolute benefit and permit delivery of cost-effective healthcare. Patient involvement is crucial for breast cancer studies to ensure relevance and outcome measures that are objective, meaningful, and patient-centred.

Cytomegalovirus Infection and Rates of Antiviral Resistance Following Intestinal and Multivisceral Transplantation

BACKGROUND

Cytomegalovirus (CMV) disease is a common and clinically significant complication following intestinal or multivisceral transplantation. CMV disease is more common in cases of serologic mismatch between donor and recipient. Though in some cases it may be asymptomatic, in the immunosuppressed population it often manifests with evidence of systemic infection or end-organ disease.

METHODS

We conducted a retrospective review of all patients undergoing intestinal or multivisceral transplantation over 8 years at our institution.

RESULTS

Forty-eight transplantations were performed, with 40% of the patients (19/48) having ≥1 episode of CMV viremia, which rose to 90% in the "donor-positive, recipient-negative" (DPRN) serologic mismatch group. The median time to 1st episode following transplantation was 22.3 weeks (range, 1-78) and median duration of each episode was 4.9 weeks (range, 1.6-37.4). Six of the 19 viremic patients (31.6%) developed virologic resistance with 4 of these occurring in the DPRN group. Four of the 6 patients with drug-resistant CMV died with CMV viremia. All patients with drug resistance acquired ganciclovir resistance; these patients were more challenging to manage with second-line toxicity-limited treatments, including foscarnet, cidofovir, and leflunomide. CMV immunoglobulin has been used and we briefly discuss the use of CMV-specific adoptive T-lymphocyte transfer in the management of 1 case.

CONCLUSIONS

Post-transplantation CMV disease continues to be challenging to manage, and there is little consensus on optimal management strategies in this patient group, with a significant requirement for novel therapies; these may be pharmacologic or cell based. Extensive multidisciplinary discussion is important for most cases, but particularly for those patients who acquire virologic resistance.

Abstract LB-205: Genome-wide copy number analysis of pediatric hepatocellular carcinomas: Identification of characteristic aberrations

Hepatocellular carcinomas (HCC) of childhood are rare neoplams. Their pathogenesis is believed to be different from HCC in adulthood. The differential diagnosis from hepatoblastoma (HBL)is important because of worse prognosis of pediatric HCC (pHCC) and different treatment approaches. However, the diagnosis by conventional histological analysis may be difficult in some cases. Informations on chromosomal alterations in pHCC are lacking.

The aim of this study was to identify recurrent chromosomal aberrations in a larger cohort of pHCC and compare it to a previously published cohort of HBL (Weber et al., American Journal of Pathology, 2000) to identify characteristic chromosomal alterations of pHCC. Genomic DNA was extracted from FFPE samples of a cohort of 34 pHCC including 4 cases of the fibrolamellar subtype and 3 cases with partial fibrolamellar differentiation from the archives of the German Pediatric Tumor Registry, University of Kiel. Genome-wide copy analysis was performed by molecular inversion profiling. GISTIC analysis was done to identify significant large and focal aberrations.

Most frequent copy number alterations were gains of chromosome 1q (65%), 2q (35%), 6p (35%), 20 (35%), 19q (32%) and 8q (29%) and losses of chromosomal regions 1p (56%) and 4q (38%). In addition, GISTIC analysis identified several significant fokal alterations including losses of the AXIN1 tumor suppressor locus on 15q26 in 53% of cases. 6/34 pHCC lacked any larger chromosomal imbalances. Of note, 5 of these 6 genomically stable tumors showed fibrolamellar differentiation. When pHCC with fibrolamellar differentiation were compared to the other pHCC, loss of 1p and 4q and gains of 1q, 2q, 6q and 20 occurred significantly more frequent in the latter. When pHCC were compared to HBL, both entities shared similar alterations including gains if 1q and 2q, but losses of 1p (56% vs. 3%), and gains of 6p (35% vs. 3%) and 19q (32% vs. 0%) were significantly more frequent in pHCC.

In this genome-wide copy number analysis of a large cohort of pHCC we were able to identify for the first time characteristic alterations which may indicate a specific pathogenesis of these neoplasms, may help to subclassify pHCC and to differentiate these tumors from HBL.

Supported by the German Childhood Cancer Foundation.

Citation Format: Torsten Pietsch, A. Carmichael, Christian Vokuhl, Ivo Leuschner. Genome-wide copy number analysis of pediatric hepatocellular carcinomas: Identification of characteristic aberrations. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-205. doi:10.1158/1538-7445.AM2014-LB-205

Critical dependence of acetate thermal mattress on gel activation temperature

BACKGROUND

Sodium acetate gel mattresses provide an active method of warming patients through release of latent heat of crystallisation. They can be used as an adjunct to incubator care or as an exclusive heat source.

OBJECTIVE

To determine activation temperatures of the Transwarmer mattress needed to achieve plateau temperatures of 38-42 degrees C.

DESIGN AND SETTING

In vitro testing of mattress temperature.

METHODS AND OUTCOME MEASURES

Transwarmer mattresses were activated at initial temperatures ranging from 5 to 40 degrees C. Mattress temperature was recorded up to 4 h to determine peak and plateau temperatures. Peak and plateau temperatures achieved by the mattress were related to the initial starting temperature.

RESULTS

The starting temperature of the mattress was strongly correlated with peak and plateau temperature (r = 0.99, p<0.001). To achieve the target temperature of 38-42 degrees C, the Transwarmer mattress requires activation between 19.2 degrees C and 28.3 degrees C. A temperature of 37 degrees C could be generated by activation at 17 degrees C.

CONCLUSIONS

Safe use of this device is critically dependent on gel temperature at the point of activation. To ensure warming of a hypothermic neonatal patient without running any risk of burns, the mattress should be activated with a gel temperature between 19 degrees C and 28 degrees C.

Endotracheal tube position in neonates requiring emergency interhospital transfer

A malpositioned endotracheal tube (ETT) is common following initial intubation. This study assessed ETT position in 53 orotracheally intubated neonates referred for interhospital transfer during a 3-month period. Position of the ETT on first chest radiograph (CXR) after intubation was assessed and related to radiographic lung expansion, with documentation that the final ETT length had achieved a satisfactory position. At the time of first CXR, median ETT length at the lips was 7.0 cm (range, 5 to 12 cm) with median tip position at T3.0 (range, C7 to T6). The ETT required repositioning in 58% of patients. Most malpositioned tubes were too low (26 were withdrawn and only four were advanced; p < 0.001), with lung expansion more closely related to vertebral than clavicular position of the ETT. Final ETT length correlated well with corrected gestation ( r = 0.83; p < 0.01) and marginally less well with weight ( r = 0.79; p < 0.01). From the regression analysis, we provide a table of recommended tube lengths by gestation.

FMR1 alleles in Tasmania: a screening study of the special educational needs population

The distribution of fragile X mental retardation-1 (FMR1) allele categories, classified by the number of CGG repeats, in the population of Tasmania was investigated in 1253 males with special educational needs (SEN). The frequencies of these FMR1 categories were compared with those seen in controls as represented by 578 consecutive male births. The initial screening was based on polymerase chain reaction analysis of dried blood spots. Inconclusive results were verified by Southern analysis of a venous blood sample. The frequencies of common FMR1 alleles in both samples, and of grey zone alleles in the controls, were similar to those in other Caucasian populations. Consistent with earlier reports, we found some (although insignificant) increase of grey zone alleles in SEN subjects compared with controls. The frequencies of predisposing flanking haplotypes among grey zone males FMR1 alleles were similar to those seen in other Caucasian SEN samples. Contrary to expectation, given the normal frequency of grey zone alleles, no premutation (PM) or full mutation (FM) allele was detected in either sample, with only 15 fragile X families diagnosed through routine clinical admissions registered in Tasmania up to 2002. An explanation of this discrepancy could be that the C19th founders of Tasmania carried few PM or FM alleles. The eight to ten generations since white settlement of Tasmania has been insufficient time for susceptible grey zone alleles to evolve into the larger expansions.

A differing pattern of association between dietary fish and allergen-specific subgroups of atopy

BACKGROUND

We examined the role of fish intake in the development of atopic disease with particular reference to the possibility of differential effects on allergen-specific subgroups of sensitization.

METHODS

The exposure of interest was parental report of fish intake by children aged 8 years at the 1997 Childhood Allergy and Respiratory Health Study (n = 499). The outcomes of interest were subgroups of atopy: house dust mite (HDM)-pure sensitization [a positive skin-prick test (SPT) > or = 2 mm to Der p or Der f only], ryegrass-pure sensitization (a positive SPT > or = 2 mm to ryegrass only); asthma and hay fever by allergen-specific sensitization.

RESULTS

A significant association between fish intake and ryegrass-pure [adjusted odds ratio (AOR) 0.37 (0.15-0.90)] but not HDM-pure sensitization [AOR 0.87 (0.36-2.13)] was found. Fish consumption significantly decreased the risk for ryegrass-pure sensitization in comparison with HDM-pure sensitization [AOR 0.20 (0.05-0.79)].

CONCLUSIONS

We have demonstrated a differential effect of fish intake for sensitization to different aeroallergens. This may be due to the different timing of allergen exposure during early life. Further investigation of the causes of atopic disease should take into account allergen-specific subgroups.

Lentivirus-mediated gene transfer of viral interleukin-10 delays but does not prevent cardiac allograft rejection

Human immunodeficiency virus (HIV)-based lentiviral vectors expressing viral interleukin-10 (vIL-10) were used to transduce rat cardiac allografts with the aim of extending graft survival. vIL-10 expression was first shown, by RT-PCR, to persist in transduced heart isografts for at least 28 days after transduction. Cardiac transplants were performed in a fully allogeneic rat strain combination (Lewis to DA); allografts transduced by vectors expressing vIL-10 showed significantly prolonged survival (14.5 vs 7.5 days median survival time). Mixed lymphocyte reactions (MLRs) were used to determine the influence, in vitro, of vIL-10 on alloantigen-induced T-cell proliferation. Bioactive vIL-10, produced by DA rat aortic endothelial cells transduced with HIV-PGK-vIL-10, was added to MLRs at different time points and lymphocyte proliferation was assessed by uptake of [3H]thymidine. T-cell proliferation was inhibited by >80% when vIL-10 was added to the MLR at day 1, 2 or 3 of coculture. The inhibitory effect was significantly decreased when addition of vIL-10 was delayed until day 4 or 5 (47 and 35% inhibition, respectively). The extended graft survival time is comparable to that using adenoviral vectors delivering vIL-10 in a similar rat strain combination. The limited improvement in survival may be due to lack of inhibition of the early phase of the alloimmune response as suggested by in vitro studies confirming that maximum suppression of the MLR by vIL-10 can only be achieved if the cytokine is present at the initiation of alloimmune recognition. The delay in expression of vIL-10 from the lentiviral vector means that protocols must be developed to suppress the early stages of alloimmune stimulation before vIL-10 is produced.

Cerebral Vasculitis Caused by Aspergillus Species in an Immunocompetent Adult

We describe a case of cerebral vasculitis due to Aspergillus infection in an immunocompetent adult, in whom the probable source was paranasal sinus infection. At postmortem there was widespread endovascular Aspergillus infection of the cerebral arteries with occlusion of the basilar artery. We review the literature regarding intracranial Aspergillus infection and new approaches to diagnosis.

A prospective association between cocoon use in infancy and childhood asthma

There is increasing evidence for a role for bedding items in the development of asthma. The use of some forms of synthetic bedding, such as foam mattresses and pillows, is associated with a significantly increased risk of childhood wheeze. Our aim was to examine prospectively whether the use of synthetic cocoon/baby nests in infancy is associated with the subsequent development of wheeze in childhood. Data collected in 1988 as part of the Tasmanian Infant Health Survey were linked to the cross-sectional Childhood Asthma Survey conducted in 1995 in Tasmania, Australia. We were able to match 863 records out of the 1111 in the 1988 survey. Information including parental, child-care, and the infant's sleeping environment was collected at home interview in 1988 when the infant was 1 month of age. Data including sleep environment and asthma symptoms were available for each child at age 7 years. A generalised linear model was used to calculate the adjusted relative risk (RR) estimates for symptoms of wheeze and infant cocoon use. For children who were placed in a cocoon in infancy, there was an increased risk of recent wheeze (adjusted RR = 4.33 [95% CI 2.08, 9.02]) and night wheeze (adjusted RR = 3.35 [95% CI 1.52, 7.39]) at age 7 years. In view of the increasing prevalence of childhood asthma, the identification of potentially modifiable environmental factors which might operate in infancy is of importance. The present findings implicate infant bedding choice as a significant factor and further studies on the infant sleeping environment are indicated.

The use of thalidomide in the treatment of intracranial tuberculomas in adults: two case reports

We present two cases of tuberculous meningitis (TBM) in adults complicated by focal neurological deficits which showed progression whilst on steroids. In case 1 an MRI demonstrated multiple ring-enhancing lesions compressing the optic chiasm leading to a bitemporal hemianopia. After the introduction of thalidomide serial imaging and field perimetry at 6, 9, 12 and 24 months into treatment showed progressive improvement. In case 2, two months into anti-tuberculous treatment with steroids, the patient developed fluctuating right sided paralysis with the MRI demonstrating a large ring-enhancing mass encasing the left internal carotid and middle cerebral arteries. Thalidomide was introduced as an immunomodulatory adjunct and subsequently the patient made a complete neurological recovery. The immunomodulatory effects of thalidomide may have a role in the acute and chronic management of TBM complicated by intracranial tuberculomas.

Breast cancer risk among the survivors of atomic bomb and patients exposed to therapeutic ionising radiation

Radiation induced breast cancer is a highly complex phenomenon, which most likely involves the accumulation of several genetic and epigenetic events. Studies of atomic bomb survivors, patients who underwent multiple fluoroscopic examinations during treatment for pulmonary tuberculosis, those who received therapeutic radiation for benign breast disease, such as acute post-partum mastitis, or those with an enlarged thymus or skin haemangioma and patients with Hodgkin's disease treated by mantle radiotherapy established that the risk of breast cancer increases with exposure to ionising radiation. The carcinogenic effect of therapeutic or accidental radiation is highest when exposure occurs during childhood and exposure after age 40 imparts low or minimal risk. The risk of bilateral breast cancer is not significantly increased in the survivors of atomic bomb and therapeutic radiations. Fractionated exposures for therapeutic radiation are similar to a single exposure of the same total dose in their ability to induce breast cancer; this risk remains high for many years after exposure. Younger age at first full term pregnancy confers a protective effect against the risk of breast cancer in the survivors of atomic bomb but long-term data on this beneficial effect after therapeutic radiation is not available.

Prolonged survival in AIDS-related progressive multifocal leucoencephalopathy following anti-retroviral therapy and cidofovir

We describe the case of a 44-year-old man who developed sub-acute cerebellar ataxia due to AIDS-related progressive multifocal leucoencephalopathy (PML) caused by JC virus. Following treatment with highly active anti-retroviral therapy (HAART) and cidofovir, he made a marked neurological improvement and is leading an independent life 18 months after the diagnosis of PML. Early recognition of AIDS-related PML and treatment with HAART improves prognosis. Cidofovir, an inhibitor of viral DNA polymerase, appears to have an additive beneficial effect and should be considered especially in patients who fail to improve despite treatment with HAART and in patients who have a high JC virus load in CSF.

An association between plastic mattress covers and sheepskin underbedding use in infancy and house dust mite sensitization in childhood: a prospective study

BACKGROUND

Higher house dust mite (HDM) allergen exposure during infancy has been associated with increased HDM sensitization. Infant bedding has been associated with the accumulation of varying levels of HDM. Prospective data on the relationship between infant bedding and the development of HDM sensitization has not been previously examined.

OBJECTIVES

To determine if particular types of bedding used in infancy are associated with increased risk of house dust mite sensitization in childhood.

METHODS

A population-based sample (n = 498) of children born in 1988 or 1989, and who were resident in Northern Tasmania in 1997, participated in this study. These children were part of a birth cohort study (1988-95), the Tasmanian Infant Health Survey. Data on infant underbedding and mattresses was available on 460 and 457 children, respectively. The main outcome measure was HDM sensitization defined as a skin prick test (SPT) reaction of 3 mm or more to the allergens of Dermatophagoides pteronyssinus and/or Dermatophagoides farinae.

RESULTS

The use of either sheepskin underbedding or plastic mattress covers in infancy was associated with an increased risk of sensitization to HDM allergens at age 8 years. The adjusted risk ratio (RR) for sensitization to HDM with sheepskin in infancy was 2.27 (95% CI: 1.14, 4.55), P = 0.020. The adjusted RR for sensitization to HDM with the use of plastic mattress covers in infancy was 2.06 (95% CI: 1.22, 3.51), P = 0.007. The use of a foam mattress in infancy was not related to subsequent HDM sensitization.

CONCLUSION

Infant's bedding plays a role in the development of HDM sensitization in childhood. Intervention studies to examine mite allergen levels and the role of underbedding on the development of HDM sensitization are required.

A prospective study of the association between home gas appliance use during infancy and subsequent dust mite sensitization and lung function in childhood

BACKGROUND

Home gas appliance use has been associated with child respiratory illness but prospective data on the relationship between infant exposure and the development of child allergic disease has not been readily available.

OBJECTIVES

(a) To determine if home gas appliance use is associated with increased risk of house dust mite (HDM) sensitization. (b) To examine whether any association between current home gas use and airway obstruction is influenced by HDM sensitization.

METHODS

DESIGN

an 8-year follow-up birth cohort study of children born during 1988 and 1989.

PARTICIPANTS

a population-based sample (n = 498) of children who participated in the Tasmanian Infant Health Survey (TIHS) and resided in Northern Tasmania in 1997 (84% of eligible children).

MAIN OUTCOME MEASURES

(a) Skin prick test reaction to nine allergens, including Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1). (b) Spirometric lung function indices, including forced expiratory volume in one second (FEV(1)) and forced vital capacity (FVC).

RESULTS

The relative risk for home gas appliance use at 1 month of age and HDM sensitization was 1.98 (1.04, 3.79) in a cohort analysis with confounder matching. Current home gas use was also associated with HDM sensitization (ARR 1.73 (1.43, 2.76)). Current home gas use was related to a stronger (P = 0.006) reduction in the FEV(1) : FVC ratio among HDM-sensitive children (adjusted difference - 6.2% (- 10.0 to - 2.4)) than non-HDM-sensitive children (adjusted difference - 0.3% (- 2.5 to 1.8)).

CONCLUSION

Indoor pollutants from gas combustion may increase the likelihood of initial sensitization to HDM and play a role in the development of atopic asthma. HDM-sensitized children may be more vulnerable to indoor pollutant-induced airway obstruction. The ability of this study to detect such effects may partly reflect unflued gas appliance use among this sample.

Multiple and independent cessation of recombination between avian sex chromosomes

Birds are characterized by female heterogamety; females carry the Z and W sex chromosomes, while males have two copies of the Z chromosome. We suggest here that full differentiation of the Z and W sex chromosomes of birds did not take place until after the split of major contemporary lineages, in the late Cretaceous. The ATP synthase alpha-subunit gene is now present in one copy each on the nonrecombining part of the W chromosome (ATP5A1W) and on the Z chromosome (ATP5A1Z). This gene seems to have evolved on several independent occasions, in different lineages, from a state of free recombination into two sex-specific and nonrecombining variants. ATP5A1W and ATP5A1Z are thus more similar within orders, relative to what W (or Z) are between orders. Moreover, this cessation of recombination apparently took place at different times in different lineages (estimated at 13, 40, and 65 million years ago in Ciconiiformes, Galliformes, and Anseriformes, respectively). We argue that these observations are the result of recent and traceable steps in the process where sex chromosomes gradually cease to recombine and become differentiated. Our data demonstrate that this process, once initiated, may occur independently in parallel in sister lineages.

Asthma, inhaled corticosteroid use, and bone mass in prepubertal children

The aim of this cross-sectional study was to describe the role of asthma, asthma severity, and medication usage in bone mineralization of prepubertal children. Asthma severity, medication usage, and physical activity were assessed by questionnaire and objective measures in 330 children. Bone densitometry and body composition were measured by dual-energy x-ray absorptiometry. Asthma ever was reported by 110 subjects (33%). A diagnosis of asthma was not associated with any deficit in bone mass, whereas usage of inhaled corticosteroids (ICS) in the last year (but not past use) was associated with deficits in bone in the total body (only after adjustment for confounders), particularly for doses of > or =400 microg/day. These observations support current recommendations with regard to ICS usage in children, but require confirmation in longitudinal studies.

The relation between infant indoor environment and subsequent asthma

Our aim was to examine the contribution of an infant's indoor environment to childhood asthma using prospective data. We conducted a cross-sectional asthma survey in 1995 on 92% (6,378/6,911) of 7-year-olds in Tasmania, Australia. We linked these data with data collected in 1988 as part of the Tasmanian Infant Health Survey, which was designed to investigate sudden infant death. We were able to match 863 records out of the 1,111 in the 1988 survey and the 6,378 in the 1995 survey. The former group was interviewed at home at 1 month of age. In homes where at least one adult smoked in 1988, reported infant exposure to smoking in the same room in 1988 was associated with increased asthma by 1995 (relative risk = 1.52; 95% confidence interval = 1.01-2.29) after adjustment for confounders. The associations between infant exposure to environmental tobacco smoke and asthma were not consistent, however. Gas heater use in 1988 was associated with asthma (relative risk = 1.92; 95% confidence interval = 1.33-2.76). Markers of aeroallergen exposure at 1 month of age were not materially associated with asthma or wheeze. In some settings, air circulation practice with regard to bedroom door closure appeared important. Poor indoor air quality may play an important role in the development of childhood asthma.

Identical or overlapping sequences in the primary structure of human alpha(2)-macroglobulin are responsible for the binding of nerve growth factor-beta, platelet-derived growth factor-BB, and transforming growth factor-beta

alpha(2)-Macroglobulin (alpha(2)M) functions as a proteinase inhibitor and as a carrier of diverse growth factors. In this study, we localized binding sites for platelet-derived growth factor-BB (PDGF-BB) and nerve growth factor-beta (NGF-beta) to a linear sequence in the 180-kDa human alpha(2)M subunit which includes amino acids 591-774. A glutathione S-transferase fusion protein containing amino acids 591-774 (FP3) bound PDGF-BB and NGF-beta in ligand blotting assays whereas five other fusion proteins, which collectively include amino acids 99-590 and 775-1451 did not. The K(D) values for PDGF-BB and NGF-beta binding to immobilized FP3 were 300 +/- 40 and 180 +/- 30 nM, respectively; these values were comparable with those determined using methylamine-modified alpha(2)M, suggesting that higher-order alpha(2)M structure is not necessary for PDGF-BB and NGF-beta binding. PDGF-BB and NGF-beta blocked the binding of transforming growth factor-beta1 (TGF-beta1) to FP3. Furthermore, murinoglobulin, which is the only known member of the alpha-macroglobulin family that does not bind TGF-beta, also failed to bind PDGF-BB and NGF-beta. These results support the hypothesis that either a single linear sequence in human alpha(2)M or overlapping sequences are responsible for the binding of TGF-beta, PDGF-BB, and NGF-beta, even though there is minimal sequence identity between these three growth factors. FP3 blocked the binding of PDGF-BB to a purified chimeric protein, in which the extracellular domain of the PDGF beta receptor was fused to the IgG(1) Fc domain, and to PDGF receptors on NIH 3T3 cells. Thus, FP3 may inhibit the activity of PDGF-BB.

A phase I trial in HIV negative healthy volunteers evaluating the effect of potent adjuvants on immunogenicity of a recombinant gp120W61D derived from dual tropic R5X4 HIV-1ACH320

Thirty healthy HIV negative volunteers were randomised to receive 200 micrograms of rgp120W61D in either: 3D-MPL and QS21, with an oil and water emulsion (SBAS-2) (13); or 3D-MPL and QS21 (SBAS-1) (11); or alum (six). Immunizations were given at 0, 4 and 28 weeks and 23 (77%) participants completed the schedule. Adverse events were more frequent (P < 0.001) and more severe (P < 0.001) in the SBAS-2 group. Binding antibodies to the homologous rgp120W61D were detected after the first immunisation only in those receiving SBAS-1 and SBAS-2, were maximal after the third immunization in all three groups, and persisted to week 84 only in the novel adjuvant groups. These differences were significant (p = 0.02). Neutralising antibodies to TCLA-strains of HIV-1 were observed after the second immunization in all three groups, were maximal after the third immunization, but did not neutralise homologous or heterologous PBMC derived primary HIV-1 isolates. Proliferative T-cell responses to rgp120W61D were maximal after the second immunization and reached very high values in the SBAS-2 group. HIV-1 specific CD8+ MHC Class I restricted cytotoxic T-lymphocytes were not seen in a subset of participants tested at a single timepoint. SBAS-2 with rgp120W61D induced antibody titres as high as those seen in HIV infection, but the quality of the antibodies remained different in that there was no evidence of primary isolate neutralisation. Although cell-mediated immunity was enhanced by SBAS-2 in terms of lymphoproliferative responses, HIV-1 specific CD8+ cytotoxicity was not demonstrated.

Relationship between early life respiratory illness, family size over time, and the development of asthma and hay fever: a seven year follow up study

BACKGROUND

The timing and mechanism of the inverse association between increasing sibling number and atopic disease are not yet understood. A study was undertaken to examine how family size at birth predicts early respiratory illness, to report the association between infant respiratory illness and childhood atopic disease, and to determine whether the protective effect of large family size operates during infancy or later childhood.

METHODS

A prospective follow up study was carried out on 863 children (78%) of 1111 participants in the Tasmanian Infant Health Survey performed in 1988. In 1988 household size and history of respiratory illness were obtained by parental interview at home (median age 35 days) and later by telephone (median age 85 days). In 1995 asthma, hay fever, and household size were assessed by parental questionnaire in a large cross sectional survey.

RESULTS

In 1988 increasing resident number (per resident) (adjusted odds ratio (AOR) 1.17 (95% CI 1.05 to 1.31)) and resident density (AOR 1.77 (95% CI 1.07 to 2.94)) were related to parental report of an upper respiratory tract infection (URTI) by one month of age. Children with a reported URTI by home interview were more likely to have subsequent asthma (adjusted relative risk (ARR) 1.27 (95% CI 1.05 to 1.53)). The association between lower respiratory tract infection (LRTI) at telephone interview (relative risk (RR) 1.34 (95% CI 1.02 to 1.75) and asthma was reduced after adjustment for family history of asthma (ARR 1.27 (95% CI 0.98 to 1.66)). Antibiotic use by home interview was not associated with subsequent asthma or hay fever. Indicators of family size in 1988 were associated with hay fever but not asthma but, in contrast, resident number in 1995 was inversely associated with asthma (AOR 0.82 (95% CI 0.72 to 0.92) per resident) and hay fever (AOR 0.82 (95% CI 0.71 to 0.96) per resident). Children with no siblings were at risk for current asthma, particularly if symptoms began after the age of four (RR 2.81 (95% CI 1.36 to 5.84)).

CONCLUSIONS

The apparent protective effect of large household size and asthma could not be explained by an increase in reported early respiratory illness. The first year of life may not be the most critical time for the protective effect of large household size to be mediated in relation to asthma, but this effect occurred by the seventh year of life.

Progressive loss of IL-2-expandable HIV-1-specific cytotoxic T lymphocytes during asymptomatic HIV infection

In HIV-1 infection, circulating HIV-1-specific cytotoxic T lymphocytes (CTL) exist in different states of activation, including activated cytotoxic cells and memory cells. We report that a subpopulation of HIV-1-specific CTL is capable of clonal expansion upon culture with IL-2 without exogenous antigen. The IL-2-expandable HIV-1-specific CTL precursor frequency was reduced in patients with advancing infection, although HIV-1-specific memory CTL could still be detected by stimulation in vitro with allele-specific HIV-1 peptide. Longitudinal analysis during advancing infection showed a progressive decline in the IL-2-expandable HIV-1-specific CTL precursor (CTLp) frequency without a decline in Epstein-Barr virus (EBV)-specific or allo-specific CTLp frequencies. To address mechanisms that may contribute to the decline in the IL-2-expandable HIV-specific CTL response, the requirements for in vitro generation of HIV-1-specific and EBV-specific effector CTL were examined. In the absence of exogenous IL-2 in limiting dilution, generation of EBV-specific CD8+ effector CTL was dependent upon help from CD4+ cells. CD4+ help for EBV-specific CD8+ CTL was observed in asymptomatic HIV infection but not in advanced infection. In the presence of exogenous IL-2, CD4+ cells could also provide help for the optimal generation of HIV-1 peptide-specific CD8+ CTL, because in vitro depletion of CD4+ cells prior to culture using stimulation with an MHC class I-restricted HIV-1 peptide reduced the peptide-specific CD8+ CTL response. We conclude that there is a decline in the IL-2-expandable HIV-1-specific CTL response during advancing infection. There are a number of possible mechanisms for this decline, including a reduction in CD4+ T cell help for in vivo antigen-activated CD8+ T cells.

Cross sectional study of the relation between sibling number and asthma, hay fever, and eczema

OBJECTIVES

To document the relation between sibling number and atopic disease, and to assess the contribution of possible confounding factors to the protective effect of siblings in relation to asthma and hay fever.

DESIGN AND SUBJECTS

Cross sectional survey by parental questionnaire in Tasmania, Australia, on 6378 children (92% of those eligible) who reached 7 years of age during 1995.

METHODS

Exercise challenge lung function testing was conducted on 428 children. Analyses reported were conducted on singleton births only (n = 6158).

RESULTS

The prevalences of a history of asthma ever, hay fever, and eczema were 27%, 19%, and 22%, respectively. Asthma and hay fever, but not eczema, were inversely related to sibling number, with evidence of a dose-response trend. The mean age at onset for asthma or wheezy breathing decreased as the number of siblings increased. The inverse association between sibling number and asthma or hay fever persisted after adjustment for several confounders, such as parental smoking or breast feeding, but did not persist after adjustment for household size in 1995.

CONCLUSIONS

The protective effect of high sibling number could not be separated from household size at age 7, and it appears to be operating after birth and influences the age at onset of asthma symptoms. Further work to increase knowledge of how the protective effect of the presence of siblings works might have important implications for the understanding of the pathogenesis of asthma.

Analysis of the human env-specific cytotoxic T-lymphocyte (CTL) response in natural human immunodeficiency virus type 1 infection: low prevalence of broadly cross-reactive env-specific CTL

Major histocompatibility complex-restricted cytotoxic T lymphocytes (CTL) are part of the cellular immune response to persistent virus infections. Candidate vaccines against human immunodeficiency virus type 1 (HIV-1) should elicit broad cross-reactive immunity to confer protection against different strains of HIV-1. As it is likely that candidate vaccines will include the envelope gene product Env, we determined the proportion of CTL clones which recognized variable and conserved determinants in three env variants during natural infection. Limiting dilution analysis was used to characterize numerous short-term CTL clones derived from peripheral blood of HIV-1-infected subjects, using split-well analysis to assay cytotoxicity against target cells expressing gp160env of HIV-1 strains IIIB, MN, and RF. In 9 of 12 HIV-1-infected subjects, at the clonal level most env-specific CTL recognized determinant(s) within one env variant but not in the other variants. In some subjects, CTL recognized multiple nonconserved determinants in different variants. The pattern of recognition of different env variants was relatively stable over time. In most of the patients studied, the proportion of CTL which showed cross-recognition of conserved determinants shared among the three strains was low. Two novel CTL epitopes within gp41 were identified by using 15-mer peptides of the HIV-SF2 sequence. When specific peptide was used to stimulate CTL precursors in vitro, the frequency of peptide-specific CTL precursors was very high, but the CTL elicited by this stimulation were highly strain specific. We conclude that the use of a single HIV env variant to detect CTL activity can underestimate the magnitude and complexity of the env-specific CTL response. The low prevalence of CTL clones which show cross-recognition of conserved determinants may have implications for immunization strategies based solely on env; to elicit broadly cross-reactive CTL other, more conserved viral antigens are likely to be needed in addition to env. Because of its capacity to distinguish CTL responses against different virus strains, limiting dilution analysis is particularly appropriate to quantitate the immune responses generated by candidate env-based vaccines.

Exercise-induced bronchial hyperresponsiveness and parental ISAAC questionnaire responses

The predictive value of parental questionnaire responses for exercise-induced bronchoconstriction in childhood asthma has not been fully clarified. The aim of this study was to compare exercise-induced bronchial hyperresponsiveness in 7 year old children with parental responses to core questions in the International Study of Asthma and Allergies in Childhood (ISAAC) study. A cross-sectional study was conducted on 191 (91% of eligible) children from seven randomly selected schools in Southern Tasmania. Study measurements included a parental questionnaire and exercise challenge testing, using a recently validated 6 min free-running protocol. The response to exercise was assessed using forced expiratory volume in one second (FEV1) measurement. The median percentage fall in FEV1 was significantly higher in children whose parents responded positively to ISAAC questions on a history of wheeze (p = 0.0031) or asthma (p = 0.0005), recent wheeze (p = 0.0005), sleep disturbance due to wheeze (p = 0.0005), or exercise-induced wheeze (p = 0.0015). Receiver operating characteristic (ROC) curve analysis showed exercise-induced bronchial hyperresponsiveness to be a good indicator of current asthma status. Using a 12% or greater fall in FEV1 postexercise as a positive test response, the exercise challenge had sensitivity and specificity estimates for current asthma and exercise-induced wheeze of (0.58 and 0.77) and (0.60 and 0.77), respectively. In conclusion, the respiratory response to exercise was consistent with parental responses to the ISAAC questionnaire in a population-based sample of 7 year old children. These findings will assist interpretation of large ISAAC studies in terms of asthma prevalence.

Monitoring environmental hazards in the workplace

This paper, the fifth in a series, looks at the importance of monitoring the environment. A number of case studies are used to illustrate specific points.