Diversity of immunoglobulin E-encoding transcripts in sinus mucosa of subjects diagnosed with non-allergic fungal eosinophilic sinusitis

BACKGROUND

The role of allergy in the aetiopathogenesis of chronic rhinosinusitis (CRS) remains controversial. For example, in some cases with sinus fungal infections allergy can be demonstrated by standard tests. In other cases, such signs can be absent despite elevated levels of IgE-positive cells in sinus tissue and the presence of IgE and eosinophils in the sinus mucous.

OBJECTIVE

To define the nature of molecular diversity in antibodies of the IgE isotype at the site of local inflammation in subjects diagnosed with non-allergic fungal eosinophilic sinusitis (NAFES).

METHODS

The local occurrence and sequence characteristics of IgE-encoding transcripts in NAFES patients were investigated and compared with sequences found in subjects diagnosed with CRS featuring systemic allergy. These sequences have also been compared with other reported IgE-encoding transcriptomes. Results IGHV genes derived from major subgroups 1, 3, 4 and 5 and a diverse set of IGHD and IGHJ genes were shown to create the IgE repertoire in patients diagnosed with NAFES and CRS. The average lengths of the third hypervariable loop in these populations were 15.8 and 14.6 residues. The sequences showed evidence of extensive somatic hypermutation (mutation frequency: NAFES, 6.4 ± 3.2%; CRS, 7.0 ± 4.4%) with substitutions targeted to complementarity-determining regions. These sequence collections thus show extensive similarities to those found in other polyclonal Ig repertoires including those encoding IgE.

CONCLUSION AND CLINICAL RELEVANCE

We conclude that sinus IgE-encoding transcripts in subjects diagnosed with NAFES show evidence of conventional IgE responses and we suggest that allergens with characteristics of classical antigens should be investigated for a role in the local response occurring in NAFES. This investigation illustrates that assessment of local immunity might be an important diagnostic tool in conditions like NAFES with no systemic signs of allergy to identify or rule out an allergic component of the patient's disease.

A single early postnatal estradiol injection affects morphology and gene expression of the ovary and parametrial adipose tissue in adult female rats

Events during early life can affect reproductive and metabolic functions in adulthood. We evaluated the programming effects of a single early postnatal estradiol injection (within 3h after birth) in female rats. We assessed ovarian and parametrial adipose tissue morphology, evaluated gene expression related to follicular development and adipose tissue metabolism, and developed a non-invasive volumetric estimation of parametrial adipose tissue by magnetic resonance imaging. Estradiol reduced ovarian weight, increased antral follicle size and number of atretic antral follicles, and decreased theca interna thickness in atretic antral follicles. Adult estradiol-injected rats also had malformed vaginal openings and lacked corpora lutea, confirming anovulation. Estradiol markedly reduced parametrial adipose tissue mass. Adipocyte size was unchanged, suggesting reduced adipocyte number. Parametrial adipose tissue lipoprotein lipase activity was increased. In ovaries, estradiol increased mRNA expression of adiponectin, complement component 3, estrogen receptor α, and glucose transporter 3 and 4; in parametrial adipose tissue, expression of complement component 3 was increased, expression of estrogen receptor α was decreased, and expression of leptin, lipoprotein lipase, and hormone-sensitive lipase was unaffected. These findings suggest that early postnatal estradiol exposure of female rats result in long-lasting effects on the ovary and parametrial adipose tissue at adult age.

Implementing public health regulations in developing countries: lessons from the OECD countries

Developing country efforts to enforce basic public health standards are often hindered by limited agency resources and poorly designed enforcement mechanisms, including excessive reliance on slow and erratic judicial systems. Traditional public health regulation can therefore be difficult to implement. This article examines innovative approaches to the implementation of public health regulations that have emerged in recent years within the OECD countries. These approaches aim to improve compliance with health standards among the different actors while reducing dependence on the legal system and the administrative resources of public health agencies in developing countries. Developing countries may find some useful lessons from these approaches that can be adapted for use in their own institutional settings.

The role of hypoxia in atherosclerosis

PURPOSE OF REVIEW

It is important to address the factors involved in the progression of atherosclerosis because advanced atherosclerotic lesions are prone to rupture, leading to disability or death. Hypoxic areas are known to be present in human atherosclerotic lesions, and lesion progression is associated with the formation of lipid-loaded macrophages and increased local inflammation. Here we summarize the role of hypoxia in the development of advanced atherosclerotic lesions by promoting lipid accumulation, inflammation, ATP depletion, and angiogenesis.

RECENT FINDINGS

A recent study clearly demonstrated the presence of hypoxia in macrophage-rich regions of advanced human carotid atherosclerotic lesions. We showed that hypoxia increases the formation of lipid droplets in macrophages and promotes increased secretion of inflammatory mediators, and recent evidence indicates that lipid droplets may play a role in mediating the inflammatory response. Hypoxia also promotes lesion progression by exacerbating ATP depletion and lactate accumulation, and the presence of hypoxia in human carotid atherosclerotic lesions correlates with angiogenesis.

SUMMARY

Recent studies indicate that hypoxia may play a key role in the progression to advanced lesions by promoting lipid accumulation, increased inflammation, ATP depletion, and angiogenesis. Further understanding of the effects of hypoxia in atherosclerotic lesions could indicate potential therapeutic targets.

Association between Gc genotype and susceptibility to TB is dependent on vitamin D status

Group-specific component (Gc) variants of vitamin D binding protein differ in their affinity for vitamin D metabolites that modulate antimycobacterial immunity. We conducted studies to determine whether Gc genotype associates with susceptibility to tuberculosis (TB). The following subjects were recruited into case-control studies: in the UK, 123 adult TB patients and 140 controls, all of Gujarati Asian ethnic origin; in Brazil, 130 adult TB patients and 78 controls; and in South Africa, 281 children with TB and 182 controls. Gc genotypes were determined and their frequency was compared between cases versus controls. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were obtained retrospectively for 139 Gujarati Asians, and case-control analysis was stratified by vitamin D status. Interferon (IFN)-gamma release assays were also performed on 36 Gujarati Asian TB contacts. The Gc2/2 genotype was strongly associated with susceptibility to active TB in Gujarati Asians, compared with Gc1/1 genotype (OR 2.81, 95% CI 1.19-6.66; p = 0.009). This association was preserved if serum 25(OH)D was <20 nmol.L(-1) (p = 0.01) but not if serum 25(OH)D was > or =20 nmol.L(-1) (p = 0.36). Carriage of the Gc2 allele was associated with increased PPD of tuberculin-stimulated IFN-gamma release in Gujarati Asian TB contacts (p = 0.02). No association between Gc genotype and susceptibility to TB was observed in other ethnic groups studied.

CD44-deficiency on hematopoietic cells limits T-cell number but does not protect against atherogenesis in LDL receptor-deficient mice

OBJECTIVE

Vascular and inflammatory cells express adhesion molecule CD44. We demonstrated previously that enhanced CD44 localizes in human atherosclerotic lesions. Apolipoprotein E/cd44 double-deficient mice and apolipoprotein E-deficient mice transplanted with CD44-deficient bone marrow (BM) exhibit reduced atherosclerosis. Since CD44 is a novel factor in atherogenesis, it is imperative that it is investigated in more than one animal model to conclusively determine its role in this particular disease pathology. To test the hypothesis that CD44 expressed by hematopoietic cells plays a critical role in atherogenesis in the low density lipoprotein (LDL) receptor-deficient mouse model, we performed BM reconstitution experiments.

METHODS

Lethally irradiated LDL receptor-deficient mice were transplanted with either CD44-deficient or wild-type BM. Beginning 10 weeks after successful reconstitution, mice consumed a cholesterol-enriched atherogenic diet for 6 or 11 weeks.

RESULTS

Surprisingly, CD44-deficiency on BM-derived inflammatory cells did not affect lesion size. Additionally, neither group displayed differences in smooth muscle cell, macrophage, collagen, or elastin content as well as lipoprotein levels. However, lesions in CD44-deficient BM-recipient mice contained fewer T-cells compared to wild-type BM mice. Interestingly, CD44-deficient T-cells expressed less chemokine receptor-5 mRNA. Furthermore, in vivo leukocyte adhesion decreased in CD44-deficient mice compared to wild-type mice.

CONCLUSION

This study surprisingly revealed that atherogenesis does not require CD44 expression on hematopoietic cells in the LDL receptor-deficient mouse model. However, CD44 promotes T-cell recruitment, downregulates chemokine receptor-5, and participates critically in leukocyte adhesion in vivo. Consequently, the anti-atherogenic role of CD44 may require CD44-deficiency on cell types other than inflammatory cells in the LDL receptor-deficient mouse model.

Tail regeneration in Xenopus laevis as a model for understanding tissue repair

Augmentation of regenerative ability is a powerful strategy being pursued for the biomedical management of traumatic injury, cancer, and degeneration. While considerable attention has been focused on embryonic stem cells, it is clear that much remains to be learned about how somatic cells may be controlled in the adult organism. The tadpole of the frog Xenopus laevis is a powerful model system within which fundamental mechanisms of regeneration are being addressed. The tadpole tail contains spinal cord, muscle, vasculature, and other terminally differentiated cell types and can fully regenerate itself through tissue renewal--a process that is most relevant to mammalian healing. Recent insight into this process has uncovered fascinating molecular details of how a complex appendage senses injury and rapidly repairs the necessary morphology. Here, we review what is known about the chemical and bioelectric signals underlying this process and draw analogies to evolutionarily conserved pathways in other patterning systems. The understanding of this process is not only of fundamental interest for the evolutionary and cell biology of morphogenesis, but will also generate information that is crucial to the development of regenerative therapies for human tissues and organs.

Peliosis hepatis following treatment with androgen-steroids in patients with bone marrow failure syndromes

Androgens widely used in the treatment of bone marrow failure syndromes can in rare cases cause hepatic peliosis, a pathological entity characterized by multiple blood-filled cavities in the liver parenchyma. Bone marrow failure syndromes per se are associated with a low coagulation status, which is further magnified by bone marrow transplantation for aplastic anaemia due to deep thrombocytopenia. Both these conditions can cause bleeding; their combination is especially dangerous. We describe two cases of aplastic anaemia due to paroxysmal nocturnal hemoglobinuria and Fanconi syndrome, in which patients developed peliosis hepatis after prolonged treatment with androgens. One patient developed severe subcapsular bleeding, successfully treated with catheterization of the right hepatic artery and embolization of the bleeding site. The second patient bridged over deep post-transplant aplasia with high frequency platelet transfusions, and demonstrated an uncomplicated post-BMT course. We suggest avoiding or interrupting treatment with androgens in patients preparing for BMT.

Haplotypic diversity in human CEACAM genes: effects on susceptibility to meningococcal disease

Adhesion between the opacity-associated adhesin (Opa) proteins of Neisseria meningitidis and human carcino-embryonic antigen cell adhesion molecule (CEACAM) proteins is an important stage in the pathogenesis of meningococcal disease, a globally important bacterial infection. Most disease is caused by a small number of meningococcal genotypes known as hyperinvasive lineages. As these are also carried asymptomatically, acquisition of them alone cannot explain why only some hosts develop meningococcal disease. Our aim was to determine whether genetic diversity in CEACAM is associated with susceptibility to meningococcal disease. Frequency distributions of alleles, genotypes and haplotypes were compared in four CEACAM genes in 384 case samples and 190 controls. Linkage disequilibrium among polymorphic sites, haplotype structures and relationships were also analysed. A number of polymorphisms were observed in CEACAM genes but the diversity of CEACAM1, to which most Opa proteins bind, was lower, and a small number of high-frequency haplotypes were detected. Dose-dependent associations of three CEACAM haplotypes with meningococcal disease were observed, with the effect of carrying these haplotypes amplified in homozygous individuals. Two haplotypes were protective while one haplotype in CEACAM6 was associated with a twofold increase in disease susceptibility. These data imply that human CEACAM may be one determinant of human susceptibility to meningococcal disease.

Randomised controlled trial of the efficacy of a metered dose inhaler with bottle spacer for bronchodilator treatment in acute lower airway obstruction

BACKGROUND

Inhaled bronchodilator treatment given via a metered dose inhaler (MDI) and spacer is optimal for relief of bronchoconstriction. Conventional spacers are expensive or unavailable in developing countries, but there is little information on the efficacy of low-cost spacers in young children.

OBJECTIVE

To compare the response to bronchodilator treatment given via a conventional or a low-cost bottle spacer

METHODS

A randomised controlled trial of the efficacy of a conventional spacer compared with a bottle spacer for bronchodilator treatment in young children with acute lower airway obstruction. Bronchodilator treatment was given from an MDI via an Aerochamber or a bottle spacer. Clinical score and oximetry recording were carried out before and after 15 min of treatment. MDI-spacer treatment was repeated up to three times, depending on clinical response, after which nebulisation was used. The primary outcome was hospitalisation.

RESULTS

400 children, aged (median (25th-75th centile)) 12 (6-25) months, were enrolled. The number of children hospitalised (n = 60, 15%) was identical in the conventional and bottle spacer groups (n = 30, 15% in each). Secondary outcomes including change in clinical score (-2 (-3 to -1)), oxygen saturation (0 (-1 to 1)) and number of bronchodilator treatments (2 (1 to 3)) were similar in both groups. Oral corticosteroids, prescribed for 78 (19.5%) children, were given to a similar number in the conventional (37 (18.5%)) and bottle spacer groups (41 (20.5%)).

CONCLUSION

A low-cost bottle spacer is as effective as a conventional spacer for bronchodilator treatment in young children with acute obstruction of the lower airways.

Interferon-gamma therapy in two patients with progressive chronic pulmonary aspergillosis

Infection by Aspergillus species causes a wide spectrum of pulmonary disease in humans. In two patients with semi-invasive Aspergillus-induced lung disease, significantly reduced levels of interferon-gamma secretion by peripheral blood mononuclear cells were found after in vitro stimulation with the T-cell mitogen phytohaemagglutinin. Despite anti-fungal therapy, both patients exhibited progressive disease, and adjunctive interferon-gamma therapy was associated with significant clinical improvement. The data suggest that impaired production of interferon-gamma can be seen in patients with chronic pulmonary aspergillosis. Adjunctive cytokine therapy with interferon-gamma may be useful in patients with progressive disease despite adequate anti-fungal therapy.

An Outbreak of Rocky Mountain Spotted Fever Associated with a Novel Tick Vector, Rhipicephalus sanguineus, in Arizona, 2004: Preliminary Report

This study describes preliminary results of an investigation of RMSF in Arizona associated with the brown dog tick, Rhipicephalus sanguineus. High numbers of dogs and heavy infestations of ticks created a situation leading to human disease.

Separation of human adipocytes by size: hypertrophic fat cells display distinct gene expression

Enlarged adipocytes are associated with insulin resistance and are an independent predictor of type 2 diabetes. To understand the molecular link between these diseases and adipocyte hypertrophy, we developed a technique to separate human adipocytes from an adipose tissue sample into populations of small cells (mean 57.6+/-3.54 microm) and large cells (mean 100.1+/-3.94 microm). Microarray analysis of the cell populations separated from adipose tissue from three subjects identified 14 genes, of which five immune-related, with more than fourfold higher expression in large cells than small cells. Two of these genes were serum amyloid A (SAA) and transmembrane 4 L six family member 1 (TM4SF1). Real-time RT-PCR analysis of SAA and TM4SF1 expression in adipocytes from seven subjects revealed 19-fold and 22-fold higher expression in the large cells, respectively, and a correlation between adipocyte size and both SAA and TM4SF1 expression. The results were verified using immunohistochemistry. In comparison with 17 other human tissues and cell types by microarray, large adipocytes displayed by far the highest SAA and TM4SF1 expression. Thus, we have identified genes with markedly higher expression in large, compared with small, human adipocytes. These genes may link hypertrophic obesity to insulin resistance/type 2 diabetes.

Composition of coronary plaques obtained by directional atherectomy in stable angina: its relation to serum lipids and statin treatment

OBJECTIVES

The stability and inflammatory activity in atherosclerotic plaques may be modulated by lipids and lipoproteins as well as the pleiotropic effects of statins. The aim of this study was to analyse the effect of statin treatment as well as the relation of plasma lipids and lipoproteins to tissue composition in atherosclerotic plaques.

DESIGN

Patients with stable angina and coronary plaques suitable for directional coronary atherectomy (DCA) were randomized to atorvastatin (80 mg once daily) or placebo (29 randomized, 22 underwent DCA, 11/group). After an average treatment of 10 weeks, patients underwent DCA, tissue specimens were obtained, and the tissue composition was determined by immunohistochemistry.

RESULTS

Atorvastatin reduced the T-cell content, but did not change lipid, collagen, smooth muscle cell, or macrophage content. Plasma levels of apolipoprotein AI (apoAI) correlated positively with tissue collagen and inversely with metalloproteinase-9 and macrophage content. About half the specimens contained neutrophil granulocytes.

CONCLUSIONS

Short-term atorvastatin treatment tended to reduce the T-cell content of atherosclerotic plaques, indicating modulation of cell-mediated immunity. High plasma levels of apoAI correlated with increased collagen content and reduced inflammation, supporting the notion that plasma apoAI stabilizes atherosclerotic plaques. The significance of neutrophils in the lesions merits further study.

ATP depletion in macrophages in the core of advanced rabbit atherosclerotic plaques in vivo

The cores of rabbit plaques in vivo are hypoxic, suggesting that ATP depletion due to an insufficient supply of oxygen and nutrients could contribute to macrophage death in atherosclerotic plaques. During hypoxia, however, macrophages maintain ATP levels by anaerobic glycolysis. To directly assess ATP and glucose metabolites in plaques in vivo, we used bioluminescence imaging to map the concentrations of ATP, glucose, glycogen, and lactate in normal and atherosclerotic rabbit aortas in vivo. Hypoxia was assessed with NITP (7-(4'-(2-nitroimidazol-1-yl)-butyl)-theophylline). Normal aortas and plaques <500 microm thick were not hypoxic and had homogenous concentrations of energy metabolites. In plaques >500 microm thick, however, the cores were characterized by ATP depletion, low concentrations of glucose and glycogen, and a high concentration of lactate. A majority of ATP-depleted macrophages within the core were viable but severely hypoxic and glucose depleted. Hyperoxia in vitro reversed the ATP depletion in macrophages in viable areas of the core. Our findings suggest that ATP depletion contributes to the death of macrophages in atherosclerotic lesions and to the formation of a necrotic core.

Adenosine concentration in the porcine coronary artery wall and A2A receptor involvement in hypoxia-induced vasodilatation

We tested whether hypoxia-induced coronary artery dilatation could be mediated by an increase in adenosine concentration within the coronary artery wall or by an increase in adenosine sensitivity. Porcine left anterior descendent coronary arteries, precontracted with prostaglandin F(2alpha) (10(-5) M), were mounted in a pressure myograph and microdialysis catheters were inserted into the tunica media. Dialysate adenosine concentrations were analysed by HPLC. Glucose, lactate and pyruvate were measured by an automated spectrophotometric kinetic enzymatic analyser. The exchange fraction of [(14)C]adenosine over the microdialysis membrane increased from 0.32 +/- 0.02 to 0.46 +/- 0.02 (n = 4, P < 0.01) during the study period. At baseline, interstitial adenosine was in the region of 10 nM which is significantly less than previously found myocardial concentrations. Hypoxia (P(O(2)) 30 mmHg for 60 min, n = 5) increased coronary diameters by 20.0 +/- 2.6% (versus continuous oxygenation -3.1 +/- 2.4%, n = 6, P < 0.001) but interstitial adenosine concentration fell. Blockade of adenosine deaminase (with erythro-9-(2-hydroxy-3-nonyl-)-adenine, 5 microM), adenosine kinase (with iodotubericidine, 10 microM) and adenosine transport (with n-nitrobenzylthioinosine, 1 microM) increased interstitial adenosine but the increase was unrelated to hypoxia or diameter. A coronary dilatation similar to that during hypoxia could be obtained with 30 microM of adenosine in the organ bath and the resulting interstitial adenosine concentrations (n = 5) were 20 times higher than the adenosine concentration measured during hypoxia. Adenosine concentration-response experiments showed vasodilatation to be more pronounced during hypoxia (n = 9) than during normoxia (n = 9, P < 0.001) and the A(2A) receptor antagonist ZM241385 (20 nM, n = 5), attenuated hypoxia-induced vasodilatation while the selective A(2B) receptor antagonist MRS1754 (20 nM, n = 4), had no effect. The lactate/pyruvate ratio was significantly increased in hypoxic arteries but did not correlate with adenosine concentration. We conclude that hypoxia-induced coronary artery dilatation is not mediated by increased adenosine produced within the artery wall but might be facilitated by increased adenosine sensitivity at the A(2A) receptor level.

Postnatal constriction, ATP depletion, and cell death in the mature and immature ductus arteriosus

After birth, constriction of the full-term ductus arteriosus induces oxygen, glucose and ATP depletion, cell death, and anatomic remodeling of the ductus wall. The immature ductus frequently fails to develop the same degree of constriction or anatomic remodeling after birth. In addition, the immature ductus loses its ability to respond to vasoconstrictive agents, like oxygen or indomethacin, with increasing postnatal age. We examined the effects of premature delivery and postnatal constriction on the immature baboon ductus arteriosus. By 6 days after birth, surrogate markers of hypoxia (HIF1alpha/VEGF mRNA) and cell death [dUTP nick-end labeling (TUNEL)-staining] increased, while glucose and ATP concentrations (bioluminescence imaging) decreased in the immature ductus. TUNEL-staining was significantly related to the degree of glucose and ATP depletion. Glucose and ATP depletion were directly related to the degree of ductus constriction; while TUNEL-staining was logarithmically related to the degree of ductus constriction. Extensive cell death (>15% TUNEL-positive cells) occurred only when there was no Doppler flow through the ductus lumen. In contrast, HIF1alpha/VEGF expression and ATP concentrations were significantly altered even when the immature ductus remained open after birth. Decreased ATP concentrations produced decreased oxygen-induced contractile responses in the immature ductus. We hypothesize that ATP depletion in the persistently patent immature newborn ductus is insufficient to induce cell death and remodeling but sufficient to decrease its ability to constrict after birth. This may explain its decreasing contractile response to oxygen, indomethacin, and other contractile agents with increasing postnatal age.

ATP depletion and cell death in the neonatal lamb ductus arteriosus

Postnatal constriction of the full-term ductus arteriosus produces cell death and remodeling of the ductus wall. Using a bioluminescence imaging technique, we found that after birth, the lamb ductus develops ATP, glucose, and glycogen depletion in addition to hypoxia. In vitro studies showed that cell death correlates best with ATP depletion and is most marked when both glucose and oxygen are severely depleted; in addition, the degree of ATP depletion found in vivo is sufficient to account for the extensive degree of cell death that occurs after birth. Under hypoxic conditions, the immature ductus is more capable of preserving its ATP supply than the mature ductus as a result of increased glucose availability, glycogen stores, and glucose utilization. However, the immature ductus is just as susceptible as the mature ductus to ATP depletion when glucose supplies are restricted. The extensive degree of cell death that occurs in the newborn ductus after birth is associated primarily with ATP depletion. The increased glycolytic capacity of the immature ductus may enable it to tolerate episodes of hypoxia and nutrient shortage, making it more resistant to developing postnatal cell death and permanent closure.

Headache in giant cell arteritis and other arteritides

Giant cell arteritis remains the most common systemic vasculitis in patients over the age of 50. Headache is the most common symptom, but is not invariably present. The headache may take almost any form, and may resemble any of the primary headaches, even cluster. Prompt diagnosis is important to prevent the well known serious complications. Accurate diagnosis allows appropriate therapy. Other forms of vasculitis may also cause headaches so correct diagnosis is essential as therapies may differ.

Formation of multicellular epithelial structures

The kidney is primarily comprised of highly polarized epithelial cells. Much has been learned recently about the mechanisms of epithelial polarization. However, in most experimental systems the orientation of this polarity is determined by external cues, such as growth of epithelial cells on a filter support. When Madin-Darby canine kidney (MDCK) cells are grown instead in a three-dimensional (3D) collagen gel, the cells form hollow cysts lined by a monolayer of epithelial cells, with their apical surfaces all facing the central lumen. We have found that expression of a dominant-negative (DN) form of the small GTPase Rac1 causes an inversion of epithelial polarity, such that the apical surface of the cells instead faces the periphery of the cyst. This indicates that the establishment of polarity and the orientation of polarity can be experimentally separated by growing cells in a 3D collagen gel, where there is no filter support to provide an external cue for orientation. DN Rac1 causes a defect in the assembly of laminin into its normal basement membrane network, and addition of a high concentration of exogenous laminin rescues the inversion of polarity caused by DN Rac1.

The relationship between serum cobalamin concentration and mean red cell volume at varying concentrations of serum folate

There is concern that exposure of patients to folic acid may prevent the development of the macrocytosis of cobalamin deficiency and thus delay the detection of the neurological complications. We examined the relationship between low cobalamin levels and mean cell volume (MCV) at different serum folate concentrations in 63,472 blood samples tested in a community pathology laboratory over 2 years. We found no evidence that high serum folate levels masked the macrocytosis of cobalamin deficiency in this population with similar increases in MCV regardless of whether the serum folate was low, normal or high. Macrocytosis appears to retain its value as a marker of cobalamin deficiency in people with serum folate concentrations above the population average.

Evolution of an adenovirus outbreak in a multidisciplinary children's hospital

OBJECTIVE

To describe the course of an evolving adenovirus outbreak in a multidisciplinary children's hospital with a high-risk patient population.

METHODS

Observational study in a 280-bed university hospital during June 2002. Active case finding identified children with adenovirus infection. Data are median (interquartile range) or n (%). Adenovirus infection was diagnosed in 49 children, median age 12 months (4-33).

RESULTS

New cases were diagnosed over 26 days and peaked on day 17 (n = 15). Total infected inpatients peaked on days 17-21 (n = 36). Twenty-three infections (47%) were community-acquired and 26 (53%) hospital-acquired. Thirty-three children (67%) had a coexistent high-risk condition. Median hospital stay before and after diagnosis was 9 days (3-18) and 9 days (4-29), respectively. Twenty-two children (45%) were admitted to PICU. Overall hospital mortality was 22% (n = 11) and mortality attributed to adenoviral disease 12% (n = 6). Hospital mortality was similar between community- and hospital-acquired infections (22% compared to 23%) (P = 1.0). Twenty children (41%) received intravenous immunoglobulin (IVIG). Children treated with IVIG had a longer hospital stay (median 40 days vs 14 days) than those who did not receive IVIG (P = 0.01). Neither PICU mortality (29% vs 12%), nor hospital mortality (35% vs 14%), differed significantly between IVIG treated and untreated children (P = 0.76 and P = 0.16, respectively).

CONCLUSION

The rapid spread of hospital-acquired adenovirus underlines the importance of effective infection control measures. Despite nosocomial infection amongst high-risk patients, mortality was similar to that of community-acquired infection. Administration of immunoglobulin was not associated with demonstrable benefit. A prospective randomized trial would be required to resolve this issue.

Circulating aldosterone levels are unexpectedly low in children with acute meningococcal disease

The incidence of meningococcal disease in childhood has risen over the past decade. Mortality remains high for those who develop septic shock and purpura fulminans. Poor perfusion, hypotension, and loss of intravascular circulating volume may be expected to influence both mineralocorticoid and glucocorticoid secretion. The aim of the study was to define adrenocortical hormone status at presentation. Sixty children admitted to the pediatric intensive care unit were studied. Children were divided into two groups: group A (n = 31), with meningococcal sepsis, mean age 4.4 yr (range 0.5-14.4), predicted risk of mortality mean 32.3% (range 0.5-99.3%); and group B (n = 29), with other diagnoses (post major surgery and with severe respiratory infections), mean age 4.1 yr (range 0.3-16.3), predicted risk of mortality mean 9.4% (range 0.2-83%). The groups were not significantly different for age. Plasma levels of aldosterone and cortisol were determined by RIA. The mean plasma aldosterone concentration on admission in group A was 427.5 +/- 88.1 pg/ml, with 96.7% of values within the normal range for age for healthy children and were significantly lower than group B mean, 1489.2 +/- 244.2 pg/ml (P < 0.0001), with 59.3% of values above the normal range. In group A there was no correlation with plasma concentrations of sodium, potassium, or volume of colloid infused in the previous 8 h. In group A mean serum cortisol mean values were 799.5 +/- 75.9 nmol/liter and in group B cortisol levels were 703.4 +/- 78.6 nmol/liter (P = n.s.). We conclude that children with meningococcal disease present with lower plasma aldosterone concentrations than other patients in the pediatric intensive care unit, for which there is no clear explanation. Further work is needed to elucidate the mechanisms underlying this finding and to examine its clinical implications.

Circulating aldosterone levels are unexpectedly low in children with acute meningococcal disease

The incidence of meningococcal disease in childhood has risen over the past decade. Mortality remains high for those who develop septic shock and purpura fulminans. Poor perfusion, hypotension, and loss of intravascular circulating volume may be expected to influence both mineralocorticoid and glucocorticoid secretion. The aim of the study was to define adrenocortical hormone status at presentation. Sixty children admitted to the pediatric intensive care unit were studied. Children were divided into two groups: group A (n = 31), with meningococcal sepsis, mean age 4.4 yr (range 0.5-14.4), predicted risk of mortality mean 32.3% (range 0.5-99.3%); and group B (n = 29), with other diagnoses (post major surgery and with severe respiratory infections), mean age 4.1 yr (range 0.3-16.3), predicted risk of mortality mean 9.4% (range 0.2-83%). The groups were not significantly different for age. Plasma levels of aldosterone and cortisol were determined by RIA. The mean plasma aldosterone concentration on admission in group A was 427.5 +/- 88.1 pg/ml, with 96.7% of values within the normal range for age for healthy children and were significantly lower than group B mean, 1489.2 +/- 244.2 pg/ml (P < 0.0001), with 59.3% of values above the normal range. In group A there was no correlation with plasma concentrations of sodium, potassium, or volume of colloid infused in the previous 8 h. In group A mean serum cortisol mean values were 799.5 +/- 75.9 nmol/liter and in group B cortisol levels were 703.4 +/- 78.6 nmol/liter (P = n.s.). We conclude that children with meningococcal disease present with lower plasma aldosterone concentrations than other patients in the pediatric intensive care unit, for which there is no clear explanation. Further work is needed to elucidate the mechanisms underlying this finding and to examine its clinical implications.