Prenatal omega-3 LCPUFA and symptoms of allergic disease and sensitization throughout early childhood - a longitudinal analysis of long-term follow-up of a randomized controlled trial

Background

Randomized controlled trials of prenatal omega (ω-3) long chain polyunsaturated fatty acid (LCPUFA) supplementation are suggestive of some protective effects on allergic sensitization and symptoms of allergic disease in childhood. Due to the nature of the atopic march, investigation of any effects of this prenatal intervention may be most informative when consistently assessed longitudinally during childhood.

Methods

Follow-up of children (n = 706) with familial risk of allergy from the Docosahexaenoic Acid to Optimize Mother Infant Outcome (DOMInO) trial. The intervention group received fish oil capsules (900 mg of ω-3 LCPUFA) daily from <21 weeks' gestation until birth; the control group received vegetable oil capsules without ω-3 LCPUFA. This new longitudinal analysis reports previously unpublished data collected at 1 and 3 years of age. The allergic disease symptom data at 1, 3 and 6 years of age were consistently reported by parents using the "International Study of Asthma and Allergies in Childhood" (ISAAC) questionnaire. Sensitization was determined by skin prick test to age specific, common allergen extracts.

Results

Changes over time in symptoms of allergic disease with sensitization (IgE-mediated) and sensitization did not differ between the groups; interaction p = 0.49, p = 0.10, respectively. Averaged across the 1, 3 and 6-year assessments, there were no significant effects of prenatal ω-3 LCPUFA supplementation on IgE-mediated allergic disease symptoms (adjusted relative risk 0.88 (95% CI 0.69, 1.12), p = 0.29) or sensitization (adjusted relative risk 0.97 (95% CI 0.82, 1.15), p = 0.76). Sensitization patterns to common allergens were consistent with the atopic march, with egg sensitization at 1 year strongly associated with house dust mite sensitization at 6 years, (p < 0.0001).

Discussion

Although there is some evidence to suggest that maternal supplementation with 900mg ω-3 LCPUFA has a protective effect on early symptoms of allergic disease and sensitization in the offspring, we did not observe any differences in the progression of disease over time in this longitudinal analysis. Further investigation into the dose and timing of ω-3 LCPUFA supplementation, including long-term follow up of children using consistent outcome reporting, is essential to determine whether this intervention may be of benefit as a primary prevention strategy for allergic disease.

Conclusion

Maternal supplementation with 900 mg of ω-3 LCPUFA did not change the progression of IgE-mediated allergic disease symptoms or sensitization throughout childhood from 1 to 6 years.

Trial registration

Australian New Zealand Clinical Trials Registry (ACTRN); DOMInO trial ACTRN12605000569606, early childhood allergy follow up ACTRN12610000735055 and 6-year allergy follow up ACTRN12615000498594.

Effects of maternal dietary egg intake during early lactation on human milk ovalbumin concentration: a randomized controlled trial

BACKGROUND

There is limited understanding of how maternal diet affects breastmilk food allergen concentrations, and whether exposure to allergens through this route influences the development of infant oral tolerance or sensitization.

OBJECTIVE

To investigate how maternal dietary egg ingestion during early lactation influences egg protein (ovalbumin) levels detected in human breastmilk.

METHODS

In a randomized controlled trial, women were allocated to a dietary group for the first six weeks of lactation: high-egg diet (> 4 eggs per week), low-egg diet (one-three eggs per week) or an egg-free diet. Breastmilk samples were collected at 2, 4 and 6 weeks of lactation for the measurement of ovalbumin. The permeability of the mammary epithelium was assessed by measuring the breastmilk sodium : potassium ratio. Egg-specific IgE and IgG4 were measured in infant plasma at 6 weeks, and prior to the introduction of egg in solids at 16 weeks.

RESULTS

Average maternal egg ingestion was associated with breastmilk ovalbumin concentration. Specifically, for each additional egg ingested per week, there was an average 25% increase in ovalbumin concentration (95% CI: 5-48%, P = 0.01). Breastmilk ovalbumin concentrations were significantly higher in the 'high-egg' group (> 4 eggs per week) compared with the 'egg-free' group (P = 0.04). However, one-third of women had no breastmilk ovalbumin detected. No detectable associations were found between mammary epithelium permeability and breastmilk ovalbumin concentrations. Infant plasma egg-specific IgG4 levels were also positively associated with maternal egg ingestion, with an average 22% (95% CI: 3-45%) increase in infant egg-specific IgG4 levels per additional egg consumed per week (P = 0.02).

CONCLUSIONS AND CLINICAL RELEVANCE

Increased maternal egg ingestion is associated with increased breastmilk ovalbumin, and markers of immune tolerance in infants. These results highlight the potential for maternal diet to benefit infant oral tolerance development during lactation.

Randomized controlled trial of fish oil supplementation in pregnancy on childhood allergies

BACKGROUND

Diets high in n-3 long chain polyunsaturated fatty acids (LCPUFA) may modulate the development of IgE-mediated allergic disease and have been proposed as a possible allergy prevention strategy. The aim of this study was to determine whether n-3 LCPUFA supplementation of pregnant women reduces IgE-mediated allergic disease in their children.

METHODS

Follow-up of children (n = 706) at hereditary risk of allergic disease in the Docosahexaenoic Acid to Optimise Mother Infant Outcome randomized controlled trial. The intervention group (n = 368) was randomly allocated to receive fish oil capsules (providing 900 mg of n-3 LCPUFA daily) from 21 weeks' gestation until birth; the control group (n = 338) received matched vegetable oil capsules without n-3 LCPUFA. The diagnosis of allergic disease was made during medical assessments at 1 and 3 years of age.

RESULTS

No differences were seen in the overall percentage of children with IgE-mediated allergic disease in the first 3 years of life between the n-3 LCPUFA and control groups (64/368 (17.3%) vs 76/338 (22.6%); adjusted relative risk 0.78; 95% CI 0.58-1.06; P = 0.11). Eczema was the most common allergic disease; 13.8% of children in the n-3 LCPUFA group had eczema with sensitization compared with 19.0% in the control group (adjusted relative risk 0.75; 95% CI 0.53-1.05; P = 0.10).

CONCLUSIONS

Overall, n-3 LCPUFA supplementation during pregnancy did not significantly reduce IgE-associated allergic disease in the first 3 years of life. Further studies should examine whether the nonsignificant reductions in IgE-associated allergies are of clinical and public health significance.

Effect of n-3 long chain polyunsaturated fatty acid supplementation in pregnancy on infants' allergies in first year of life: randomised controlled trial

OBJECTIVE

To determine whether dietary n-3 long chain polyunsaturated fatty acid (LCPUFA) supplementation of pregnant women with a fetus at high risk of allergic disease reduces immunoglobulin E associated eczema or food allergy at 1 year of age.

DESIGN

Follow-up of infants at high hereditary risk of allergic disease in the Docosahexaenoic Acid to Optimise Mother Infant Outcome (DOMInO) randomised controlled trial.

SETTING

Adelaide, South Australia.

PARTICIPANTS

706 infants at high hereditary risk of developing allergic disease whose mothers were participating in the DOMInO trial.

INTERVENTIONS

The intervention group (n=368) was randomly allocated to receive fish oil capsules (providing 900 mg of n-3 LCPUFA daily) from 21 weeks' gestation until birth; the control group (n=338) received matched vegetable oil capsules without n-3 LCPUFA.

MAIN OUTCOME MEASURE

Immunoglobulin E associated allergic disease (eczema or food allergy with sensitisation) at 1 year of age.

RESULTS

No differences were seen in the overall percentage of infants with immunoglobulin E associated allergic disease between the n-3 LCPUFA and control groups (32/368 (9%) v 43/338 (13%); unadjusted relative risk 0.68, 95% confidence interval 0.43 to 1.05, P=0.08; adjusted relative risk 0.70, 0.45 to 1.09, P=0.12), although the percentage of infants diagnosed as having atopic eczema (that is, eczema with associated sensitisation) was lower in the n-3 LCPUFA group (26/368 (7%) v 39/338 (12%); unadjusted relative risk 0.61, 0.38 to 0.98, P=0.04; adjusted relative risk 0.64, 0.40 to 1.02, P=0.06). Fewer infants were sensitised to egg in the n-3 LCPUFA group (34/368 (9%) v 52/338 (15%); unadjusted relative risk 0.61, 0.40 to 0.91, P=0.02; adjusted relative risk 0.62, 0.41 to 0.93, P=0.02), but no difference between groups in immunoglobulin E associated food allergy was seen.

CONCLUSION

n-3 LCPUFA supplementation in pregnancy did not reduce the overall incidence of immunoglobulin E associated allergies in the first year of life, although atopic eczema and egg sensitisation were lower. Longer term follow-up is needed to determine if supplementation has an effect on respiratory allergic diseases and aeroallergen sensitisation in childhood.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12610000735055 (DOMInO trial: ACTRN12605000569606).

Effect of maternal egg consumption on breast milk ovalbumin concentration

BACKGROUND

Maternal dietary avoidance of egg has been recommended to treat egg allergy in breastfed infants. However, only one of three randomized controlled trials have produced evidence in favour of this recommendation.

OBJECTIVE

Our objective was to assess human milk ovalbumin (OVA) concentration after daily maternal ingestion of one cooked egg for 3 weeks.

METHODS

Mothers with egg-sensitive, eczematous breastfed infants were randomly allocated to consume one muffin per day containing one egg (egg group, n=16) or a similar egg-free muffin (control group, n=16) for 21 days (Days 3-23). All mothers and infants followed an egg-free diet. Breast milk samples were collected at two hourly intervals for 6 h after eating the test muffins on Days 3, 12 and 23 and breast milk OVA concentration measured. Infant eczema was assessed at the commencement and completion of the trial.

RESULTS

Women in the egg group had higher OVA concentrations in breast milk than the control group at all time-points. Within each dietary group, OVA excretion did not change with time. OVA was not detected in breast milk of 25% of women in the egg group. In contrast, infant eczema symptom scores significantly reduced with time for both groups.

CONCLUSION

Human milk OVA is related to maternal dietary egg intake, but a significant proportion of women either have a delayed excretion or may not excrete OVA in their breast milk.

Helper-dependent adenoviral gene therapy mediates long-term correction of the clotting defect in the canine hemophilia A model

BACKGROUND

Adenoviral vector-mediated gene therapy might have potential for long-term correction of the monogenic disease hemophilia A.

OBJECTIVE

In this study, we tested the efficacy of administering a helper-dependent adenoviral vector (HDV) designed for maximal liver-restricted canine factor VIII (cFVIII) expression on three out-bred hemophilia A dogs.

METHODS

Three FVIII-deficient animals from the University of North Carolina colony were injected with 1 x 10(12) (Dog A), and 3 x 10(12) (Dog B and C) vp kg(-1) helper-dependent adenoviral vector, and we performed systematic analysis of toxicity, persistence of therapeutic gene expression, and molecular analysis of gene transfer.

RESULTS

We observed acute dose-dependent elevation in liver enzymes and thrombocytopenia after injection, although both were transient and resolved within 2 weeks. The whole blood clotting time (WBCT), plasma FVIII concentration, FVIII activity, and activated partial thromboplastin time in all animals improved significantly after treatment, and two animals receiving a higher dose reached near normal WBCT with low-level FVIII activity until terminal sacrifice at 3 months, and 2 years. Importantly, the treated dogs suffered no bleeding events after injection. Moreover, we observed persistent vector-specific DNA and RNA in liver tissue collected from one high-dose animal at days 18 and 79, and could not detect the formation of inhibitory antibodies.

CONCLUSION

Although vector-associated toxicity remains an obstacle, a single injection of HDV led to long-term transgene expression and vector persistence in two FVIII-deficient animals with conversion of their severe phenotype to a moderate one.

Gene delivery to human sweat glands: a model for cystic fibrosis gene therapy

Gene therapy vectors are mostly studied in cultured cells, rodents, and sometimes in non-human primates, but it is useful to test them in human tissue prior to clinical trials. In this study, we investigated the possibility of using human sweat glands as a model for testing cystic fibrosis (CF) gene therapy vectors. Human sweat glands are relatively easy to obtain from skin biopsy, and can be tested for CFTR function. Using patients' sweat glands could provide a safe model to study the efficacy of CF gene therapy. As the first step to explore using sweat glands as a model for CF gene therapy, we examined various ex vivo gene delivery methods for a helper-dependent adenovirus (HD-Ad) vector. Gene delivery to sweat glands in skin organ culture was studied by topical application, intradermal injection or submerged culture. We found that transduction efficiency can be enhanced by pretreating isolated sweat glands with dispase, which suggests that the basement membrane is a critical barrier to gene delivery by adenoviral vectors. Using this approach, we showed that Cftr could be efficiently delivered to and expressed by the epithelial cells of sweat glands with our helper-dependent adenoviral vector containing cytokeratin 18 regulatory elements. Based on this study we propose that sweat glands might be used as an alternative model to study CF gene therapy in humans.

Effect of cooked and raw egg consumption on ovalbumin content of human milk: a randomized, double-blind, cross-over trial

BACKGROUND

Maternal avoidance of egg intake has been recommended to treat egg allergy in breastfed infants.

OBJECTIVE

To determine if the concentration of ovalbumin (OVA) in human milk is directly related to the quantity and form of egg consumed by breastfeeding mothers.

METHODS

Randomized, blinded, cross-over, intervention trial. Breastfeeding women (n = 41) attended four clinic days between 11 and 14 weeks of lactation and on each day were randomly allocated to receive a test breakfast, identical except for the egg content (no egg, one raw egg, half a cooked egg or one cooked egg). Breast milk samples were collected at two hourly intervals for 8 h and their OVA concentration measured by ELISA.

RESULTS

There was a direct, dose-response between the amount of cooked egg ingested and the peak OVA concentration (no egg 0.05 ng/mL [95% confidence interval (CI), 0.01-0.11], half a cooked egg 2.24 ng/mL [95% CI, 0.57-3.91], one cooked egg 3.16 ng/mL [95% CI, 1.41-4.91], n = 41, P<0.05) as well as the total OVA excretion (no egg 0.18 ng/mL/h [95% CI, 0.04-0.39], half a cooked egg 4.93 ng/mL/h [95% CI, 1.40-8.46], one cooked egg 9.14 ng/mL/h [95% CI, 4.25-14.03], n = 41, P<0.05). The peak concentration and total OVA excretion in response to one raw egg did not differ from ingesting half a cooked egg. There was no detectable OVA in the breast milk of 24% (10/41) women up to 8 h after any egg challenge.

CONCLUSION

OVA was detected in the breast milk of lactating women up to 8 h after a controlled intake of egg. A dose-response correlation was indicated. As excretion of OVA in human milk appears to be a normal phenomenon, further studies need to determine the threshold of OVA excretion that leads to symptoms in egg-allergic breastfed infants.

B cell- and monocyte-activating chemokine (BMAC), a novel non-ELR alpha-chemokine

A novel alpha-chemokine, designated KS1, was identified from an EST database of a murine immature keratinocyte cDNA library. The EST has 94% similarity to a recently cloned human gene, BRAK, that has no demonstrated function. Northern analysis of mouse and human genes showed detectable mRNA in brain, intestine, muscle and kidney. Tumour panel blots showed that BRAK was down-regulated in cervical adenocarcinoma and uterine leiomyoma, but was up-regulated in breast invasive ductal carcinoma. KS1 bound specifically to B cells and macrophages, as well as two B cell lines, CESS and A20, and a monocyte line, THP-1. KS1 showed no binding to naive or activated T cells. In addition, KS1 stimulated the chemotaxis of CESS and THP-1 cells but not T cells. The s.c. injection of KS1 creates a mixed inflammatory response in Nude and C3H/HeJ mice. The above data indicates that KS1 and its human homologue represents a novel non-ELR alpha-chemokine that may have important roles in trafficking of B cells and monocytes. We propose the name B cell- and monocyte-activating chemokine (BMAC) for this molecule to reflect the described biological functions.

Localization of the noradrenaline transporter in rat adrenal medulla and PC12 cells: evidence for its association with secretory granules in PC12 cells

The noradrenaline transporter (NAT) is present in noradrenergic neurons and a few other specialized cells such as adrenal medullary chromaffin cells and the rat pheochromocytoma (PC12) cell line. We have raised antibodies to a 49-residue segment (NATM2) of the extracellular region (residues 184-232) of bovine NAT. Affinity-purified NATM2 antibodies specifically recognized an 80-kDa band in PC12 cell membranes by western blotting. Bands of a similar size were also detected in membranes from human neuroblastoma (SK-N-SH) cells expressing endogenous NAT and human embryonic kidney (HEK293) cells stably expressing bovine NAT. Immunocytochemistry of rat adrenal tissue showed that NAT staining was colocalized with tyrosine hydroxylase in medullary chromaffin cells. Most NAT immunoreactivity in rat adrenal chromaffin and PC12 cells was present in the cytoplasm and had a punctate appearance. Cell surface biotinylation experiments in PC12 cells confirmed that only a minor fraction of the NAT was present at the cell surface. Subcellular fractionation of PC12 cells showed that relatively little NAT colocalized with plasma membrane, synaptic-like microvesicles, recycling endosomes, or trans-Golgi vesicles. Most of the NAT was associated with [3H]noradrenaline-containing secretory granules. Following nerve growth factor treatment, NAT was localized to the growing tip of neurites. This distribution was similar to the secretory granule marker secretogranin I. We conclude that the majority of NAT is present intracellularly in secretory granules and suggest that NAT may undergo regulated trafficking in PC12 cells.

The effects of maternal protein deprivation on the fetal rat pancreas: major structural changes and their recuperation

There is evidence that low birth weight and poor growth in early life cause a long-term predisposition to non-insulin-dependent diabetes. Morphological changes were assessed in fetal rat pancreas subjected to both pre- and post-natal maternal protein deprivation (LP). Further groups were subjected to purely prenatal maternal protein deprivation (preLP) and purely postnatal maternal protein deprivation (postLP), as well as a control group. The results show that the LP and postLP groups had fewer but larger islets than the control group, while the preLP group had more numerous, smaller islets. All three low protein groups had more irregularly shaped islets than the control group. There was a reduction in the amount of beta cells within each islet in all three protein-deprived groups. The LP and postLP groups showed a reduction in the percentage of islet tissue and beta cells per pancreas, but the percentage of islet tissue expressed per unit body weight was similar in all four groups. These results show that in maternal protein deprivation, homeostatic mechanisms ensure a constant amount of pancreatic endocrine tissue per unit of body weight. However, there remain major structural changes in the size, shape, and composition of the islets. These results support the theory that early development profoundly affects the structure of the pancreas and may play a role in the later development of adult diseases, such as non-insulin-dependent diabetes mellitus.

Transscleral diode laser cyclophotocoagulation on autopsy eyes with abnormally thinned sclera

BACKGROUND AND OBJECTIVE

To determine, using autopsy eyes, whether diode laser energy adjustments are indicated in patients with thin sclera.

MATERIALS AND METHODS

In the laboratory, the superior 180 degrees of sclera at the limbus was dissected to the level of barely visible anterior uvea and the opposite 180 degrees of sclera served as the control in three human cadaver eyes. A contact G-probe was placed at the limbus, and settings of a diode laser were increased in increments from 1.0 to 9.0 J at 4 burns per setting in each location.

RESULTS

On gross examination, circular hypopigmented lesions were seen in the ciliary body (CB) beginning at 3.0 J in thin sclera and at 5.0 J in normal sclera. On light microscopic examination of thin scleral sections, CB damage began at 2.9 J and CB/ciliary body epithelium (CBE) damage occurred beginning at 3.5 J. In normal sclera, minimal CB/CBE changes occurred at 6.0 to 7.5 J. No scleral damage was visible in either the experimental or the control groups.

CONCLUSION

Cycloablation energy adjustments are indicated on eyes with abnormally thin sclera to achieve similar histologic end points using the diode laser.

Pathogenesis of Sendai virus infection in the Syrian hamster

Young adult male Syrian hamsters were inoculated intranasally with Sendai virus, then killed and examined at postinoculation days (PID) 3, 5, 7, 9, 12, 16, and 21. Evaluation included clinical assessment, histologic examination, immunohistochemistry, viral isolation, and antibody response. Inoculated and control hamsters remained asymptomatic throughout the study. There was a focal to segmental rhinitis involving respiratory tract epithelium lining the dorsal and ventral meatus and nasal septum, and segmental lesions involving all regions of the trachea. At PID 5 and 7, there was focal bronchitis and bronchioloalveolitis, respectively. In general, most lesions had resolved by PID 12, although in hamsters examined at PID 21, residual lesions were present in the nasal passages in one of three, and in the trachea in two of three animals. In immunoperoxidase-stained preparations, viral antigen was present in the respiratory tract epithelium of the nasal passages and trachea beginning at PID 3, with extension to scattered bronchi at PID 5. Sendai virus was recovered from the lungs of inoculated animals at PID 5. Antibodies to Sendai virus were first detected at PID 7, and titers remained high throughout the remainder of the 21-day study. This report provides additional evidence that Syrian hamsters are susceptible to Sendai virus infection, and that the lesions and sites of replication in the upper and lower portions of the respiratory tract are similar to those observed in susceptible strains of laboratory mice.

Localization of ATP-gated ion channels in cerebellum using P2x2R subunit-specific antisera

The distribution of the P2x2 purinoceptor subunit protein, which forms ATP-gated ion channels by homo- and hetero-multimeric assembly, was examined in the adult rat and guinea-pig cerebellum using two novel antisera generated against separate 18 amino acid sequences located in the predicted extracellular domain of this subunit. These antisera, the first available for labelling the P2x2R subunit protein, were validated by selective labelling of a fusion protein containing the target amino acid sequences, and in cerebellum, by peptide specific block of immunoreactivity and by comparison with the distribution of P2x2R mRNA. P2x2R-like immunoreactivity was seen in Purkinje cells, specifically the soma and dendrites, neurons in the granular and molecular layers and deep cerebellar nuclei. The identification of P2x2R-like immunoreactivity within the cerebellar neural circuitry is consistent with a role for extracellular ATP acting as a fast neurotransmitter in motor learning and coordination of movement. Additionally, labelling of neuroglia and fibre tracts supports a diverse role for extracellular ATP in CNS homeostasis.

Effectiveness of apraclonidine and acetazolamide in preventing postoperative intraocular pressure spikes after extracapsular cataract extraction

We studied the effectiveness of two prophylactic agents in controlling early postoperative intraocular pressure (IOP) increases after cataract surgery. Fifty-four nonglaucomatous patients received either topical 1% apraclonidine, one drop before and after surgery, or sustained-release acetazolamide, 500 mg, or no medication at the completion of planned extracapsular cataract extraction (ECCE). Mean baseline IOPs were similar among patients randomized to the apraclonidine, acetazolamide, and control groups: 15.29 mm Hg, 15.33 mm Hg, and 14.26 mm Hg, respectively. At 3 hours postoperatively, IOPs were significantly lower in the apraclonidine group (11.13 mm Hg, P = .035), nonsignificantly lower in the acetazolamide group (13.3 mm Hg, P = .17), and significantly increased in the control group (21.32 mm Hg, P = .003). One eye in the apraclonidine group and six in the control group had IOPs greater than 30 mm Hg. At 24 hours, the only statistically significant difference was in the control group, whose mean IOPs remained elevated (21.83 mm Hg, P = .0008). One eye in the apraclonidine group, two in the acetazolamide group, and five in the control group had IOPs greater than 30 mm Hg. We found a significant early IOP reduction with apraclonidine given topically preoperatively and at the completion of planned ECCE.

Golgi coatomer binds, and forms K(+)-selective channels gated by, inositol polyphosphates

Coatomer is a distinct type of coat protein complex involved in the formation of specific Golgi intercisternal transport vesicles. Direct binding studies using purified coatomer isolated from bovine liver cytosol show that coatomer specifically binds both inositol 1,3,4,5-tetrakisphosphate ((1,3,4,5)IP4) and inositol hexakisphosphate (IP6) with subnanomolar affinities (0.1 and 0.2 nM, respectively). Diphosphoinositol pentakisphosphate (PP-IP5) is an efficient competitor for both (1,3,4,5)IP4 and IP6 binding to coatomer. Inositol 1,3,4,5,6-pentakisphosphate ((1,3,4,5,6)IP5) is a poor inhibitor of IP6 binding, whereas little or no competition is detected with inositol 1,4,5-trisphosphate ((1,4,5)I-P3). Coatomer displays ion channel activity when reconstituted into planar bilayers which is preferentially permeable to K+. Permeability ratios of the channel are PK+/PCl- approximately 8.0 and PK+/PNa+ approximately 7.1, indicating a cation-selective channel with selectivity of K+ over Na+. In symmetrical 500 mM KCl, the smallest observable unitary channel conductance is 8.3 picosiemens. The coatomer channel activity is normally active with long open times (0.1 to several seconds) and is selectively blocked by 10 microM (1,3,4,5)IP4, 1 microM IP6, and 0.27 microM PP-IP5; even lower concentrations are sufficient to induce channel flicker. The channel activity is not affected by (1,4,5)IP3, or (1,3,4,5,6)IP5. Thus, the channel activity of coatomer is modulated by the inositol polyphosphates which exhibit tight binding to the complex.

Abdominal symptoms, hypercalcaemia and apathetic hyperthyroidism: treatment with pamidronate

A 24-year-old man with anorexia, repeated bouts of vomiting, and wasting was found to have florid thyrotoxicosis and hypercalcaemia. Pamidronate promptly reduced the serum calcium concentration to normal, and simultaneously abated the abdominal symptoms, which did not recur in spite of continuing severe hyperthyroidism, which was eventually controlled by radioactive iodine ablation of thyroid activity.

Coated vesicle assembly in the Golgi requires only coatomer and ARF proteins from the cytosol

Transport vesicles derived from the Golgi apparatus are thought to mediate biosynthetic transport across the Golgi stack. These vesicles are surrounded by a protein coat whose principal constituents are coatomer (a complex of seven distinct subunits or COPs) and ADP-ribosylation factor (ARF, an N-myristylated small GTP-binding protein). The coat proteins of the COP-coated vesicles were originally defined by ultrastructural criteria, however, and it is possible that important but minor coat proteins or cytoplasmic proteins needed for coat assembly may have been overlooked. Here we show that coatomer and ARF are the only cytoplasmic proteins needed for the assembly and budding of COP-coated vesicles. COP-coated buds may therefore form essentially by self-assembly from Golgi cisternae after an initial step in which GTP is used to allow ARF binding.

Binding of coatomer to Golgi membranes requires ADP-ribosylation factor

Coatomer, a complex of seven proteins, appears to be the precursor of the coat structure of non-clathrin-coated Golgi-derived vesicles. Another component of this vesicle coat is the cytosolic protein ADP-ribosylation factor (ARF). Like coatomer, ARF appears to reversibly associate with Golgi membranes. We now report that ARF is required for coatomer binding to Golgi membranes and that myristoylated, but not non-myristoylated, ARF is the required species. We utilize an antibody directed against the beta-subunit of coatomer (beta-COP) to follow coatomer binding. ARF and beta-COP bind stoichiometrically to Golgi membranes. ARF-dependent beta-COP binding requires a membrane-associated protein, is saturable, and is enhanced in the presence of stable GTP analogues like guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S). ARF and beta-COP bind sequentially to Golgi membranes, since beta-COP can be bound to reisolated membranes that had been previously incubated with ARF and GTP gamma S. We conclude that membrane-bound ARF confers to Golgi membranes all of the requirements for specific beta-COP binding.

Two distinct populations of ARF bound to Golgi membranes

ADP-ribosylation factor (ARF) is a small molecular weight GTP-binding protein (20 kD) and has been implicated in vesicular protein transport. The guanine nucleotide, bound to ARF protein is believed to modulate the activity of ARF but the mechanism of action remains elusive. We have previously reported that ARF binds to Golgi membranes after Brefeldin A-sensitive nucleotide exchange of ARF-bound GDP for GTP gamma S. Here we report that treatment with phosphatidylcholine liposomes effectively removed 40-60% of ARF bound to Golgi membranes with nonhydrolyzable GTP, presumably by competing for binding of activated ARF to lipid bilayers. This revealed the presence of two different pools of ARF on Golgi membranes. Whereas total ARF binding did not appear to be saturable, the liposome-resistant pool is saturable suggesting that this pool of ARF is stabilized by interaction with a Golgi membrane-component. We propose that activation of ARF by a guanine nucleotide-exchange protein results in association of myristoylated ARF GTP with the lipid bilayer of the Golgi apparatus. Once associated with the membrane, activated ARF can diffuse freely to associate stably with a target protein or possibly can be inactivated by a GTPase activating protein (GAP) activity.

Budding from Golgi membranes requires the coatomer complex of non-clathrin coat proteins

Do the coats on vesicles budded from the Golgi apparatus actually cause the budding, or do they simply coat buds (Fig. 1)? One view (the membrane-mediated budding hypothesis) is that budding is an intrinsic property of Golgi membranes not requiring extrinsic coat proteins. Assembly of coats from dispersed subunits is super-imposed upon the intrinsic budding process and is proposed to convert the tips of tubules into vesicles. The alternative view (the coat-mediated budding hypothesis) is that coat formation provides the essential driving force for budding. The membrane-mediated budding hypothesis was inspired by the microtubule-dependent extension of apparently uncoated, 90-nm-diameter membrane tubules from the Golgi apparatus and other organelles in vivo after treatment with brefeldin A, a drug that inhibits the assembly of coat proteins onto Golgi membranes. This hypothesis predicts that tubules will be extended when coat proteins are unavailable to convert tubule-derived membrane into vesicles. Here we use a cell-free system in which coated vesicles are formed from Golgi cisternae to show that, on the contrary, when budding diminishes as a result of immunodepletion of coat protein pools, tubules are not formed at the expense of vesicles. We conclude that coat proteins are required for budding from Golgi membranes.

Identification of molecular aggregates containing glycoproteins III, J, K (carboxypeptidase H), and H (Kex2-related proteases) in the soluble and membrane fractions of adrenal medullary chromaffin granules

An investigation of the molecular properties of glycoprotein III has shown this to be a major component of molecular aggregates present in the membrane and soluble fractions of secretory vesicles from bovine adrenal medulla. These aggregates also contain components identified as glycoproteins H, J, and K which are molecular forms of Kex2-related proteases (glycoprotein H) and carboxypeptidase H (glycoprotein components J and K) and which have functions concerned with the processing of prohormones. A number of experiments indicated that these glycoproteins were associated. These components were coimmunoprecipitated from the soluble and membrane fractions of chromaffin granules. Purification of soluble glycoprotein III using wheat germ agglutinin-Sepharose resulted in the recovery of similar proportions of glycoproteins H, J, and K and gel filtration of the eluted material in combination with immunoprecipitation revealed the presence of heteroaggregates containing all of the glycoproteins. Similar results were obtained following octylglucoside solubilization of chromaffin granule membranes. Glycoprotein components III, H, J, and K were also found to have identical distributions following fractionation of chromaffin granule membranes with Triton X-114. It was concluded that the aggregates seen in the soluble fraction reflect an association of these components in the chromaffin granule membrane. This raises the possibility that these interactions are important for the targetting of these glycoproteins to secretory granules.

Identification of kex2-related proteases in chromaffin granules by partial amino acid sequence analysis

We have characterized glycoprotein H (GpH) from bovine adrenal medullary chromaffin granules. Two-dimensional gel electrophoresis was used to purify GpH from an insoluble fraction obtained following extraction of chromaffin granule membranes with lithium diiodosalicylate. The GpH material was recovered from two-dimensional gel spots by concentration and recovery on a one-dimensional gel followed by electro-blotting to a poly(vinylidene difluoride) membrane. This material was subjected to in situ tryptic digestion. The released peptides were purified by microbore high performance liquid chromatography and sequenced. The peptide sequences revealed extensive similarity to the mammalian kex2/subtilisin-related proteases (PC2 and PC3) which have been characterized recently by molecular cloning and sequence analysis (Smeekens, S. P., and Steiner, D. F. (1990) J. Biol. Chem. 265, 2997-3000; Smeekens, S. P., Avruch, A. S., LaMendola, J., Chan, S. J., and Steiner, D. F. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 340-344). The sequence similarity included regions that contain residues equivalent to the aspartic acid and histidine residues which are involved in the active site of the subtilisin family of serine proteases. The sequence data revealed the presence of tryptic peptides derived from both PC2 and PC3. NH2-terminal sequence analysis of GpH gave two sequences which were aligned with residues 110-121 of PC2 and PC3. It is likely that these sequences represent the mature form of PC2 and PC3 in chromaffin granules. These forms would be generated by cleavage at a site which is conserved in mammalian kex2-related enzymes and which would result in the release of approximately 80-residue propeptides. It was concluded that the spot identified as GpH by two-dimensional gel electrophoresis contains the bovine counterparts of both PC2 and PC3. The direct identification of these components in chromaffin granules supports their role in the processing of protein precursors.

An exploratory study of the structure and validity of pediatric examination of educational readiness (PEER) factors

The Pediatric Examination of Educational Readiness (PEER) is an assessment instrument specifically designed for use by pediatricians in assessing the development of preschool children. The present study investigated the psychometric properties of the PEER. Specifically, factor analyses of items from the Developmental Attainment and Associated Observation components of the test were performed. The PEER was administered to 69 preschool children. Three major factors were identified as making up the Developmental Attainment portion of the test: perceptual-motor, verbal-cognitive, and gross motor. The Associated Observations component was found to be composed of only one factor, attention. Children's performance on only two of these four factors was associated with their performance on the McCarthy Scales, the Woodcock-Johnson skills cluster, and the Minnesota Child Development Inventory. Discussion focused on the validity and utility of the PEER.

The primary structure of glycoprotein III from bovine adrenal medullary chromaffin granules. Sequence similarity with human serum protein-40,40 and rat Sertoli cell glycoprotein

Glycoprotein III (GpIII) was purified from the soluble fraction of bovine chromaffin granules, the secretory vesicles of the adrenal medulla, by chromatography using wheat germ agglutinin-Sepharose followed by reverse-phase high performance liquid chromatography (HPLC). Characterization of this glycoprotein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, reverse-phase HPLC, amino acid analysis and partial NH2-terminal sequence analysis indicated that GPIII was a disulfide-linked heterodimer with 37-kDa subunits. Analysis of in vitro translation products of adrenal medullary poly(A)+ RNA by immunoprecipitation using an anti-GpIII serum and sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggested that both subunits are synthesized from a single precursor. Partial NH2-terminal sequence analysis allowed construction of oligonucleotides which were used as primers for a polymerase chain reaction to generate a GpIII-specific DNA probe. This probe was used to isolate a cDNA clone encoding the GpIII precursor from a bovine adrenal medullary cDNA library. The predicted amino acid sequence of GpIII has greater than 80% similarity to human serum protein-40,40, a protein implicated in the complement system, and to a major secretory product of Sertoli cells, glycoprotein 2, which is thought to play a role in spermatogenesis. Northern blot analysis confirmed that RNA encoding GpIII is also abundant in liver, testis, and brain.

A comparison of depressed and nondepressed disturbed children on measures of attributional style, hopelessness, life stress, and temperament

Upon admission to a hospital treatment program, clinically depressed and nondepressed children (aged 9-17 years) were assessed on measures of attributional style, hopelessness, depression, life stress, and child temperament. The depressed group tended to attribute positive events to specific and unstable factors when compared with the nondepressed sample. Group differences also were found on child temperament measures. However, no differences were reported between the diagnostic groups on self-reported depression, hopelessness, or life stress. The findings suggested that there may not be a unique constellation of cognitive characteristics in depressed children when compared with a nondepressed clinical sample. For both depressed and nondepressed groups, treatment did appear to affect self-reported depression and overall ratings of depressogenic attributional style.

A comparison of two dose regimens of epsilon aminocaproic acid in the prevention and management of secondary traumatic hyphemas

Fifty-nine patients who sustained hyphema following blunt trauma were randomly assigned prospectively to either of two dose regimens of epsilon aminocaproic acid (Amicar). Twenty-six took an oral dosage of 50 mg/kg ("half dose") every four hours for five days, up to a maximum of 30 g/day, and 33 patients received 100 mg/kg ("full-dose") every four hours up to a maximum of 30 g/day. Five patients in the full-dose group experienced dizziness, hypotension, and syncope. Half-dose Amicar substantially reduced such serious side effects (P = 0.063), had no adverse effect on the reduced rate of recurrent hemorrhages (P = 0.22), and was more cost effective than the full-dose regimen. When the two patients in the half-dose group receiving 30 g/day of Amicar were deleted, however, the comparison of dizziness and hypotension in the two groups became more significant (P = 0.050). The incidence of nausea and vomiting was approximately the same in both groups (P = 0.52). Serum Amicar levels were within the range of plasminogen inhibition at both dose levels. Prior aspirin ingestion appeared to have no influence on the rate of rebleeding (P = 0.58).

Preparation of desulphated bovine fibrinopeptide B and demonstration of its sulphation in vitro by an enzyme system from neuroblastoma-glioma hybrid cells

A method is described for isolating bovine fibrinopeptide B (bFPB) in a highly purified form from crude bovine fibrinogen, using ion-exchange chromatography on DEAE cellulose. Desulphated bFPB (designated DSbFPB) was prepared by treatment of the product with acid. After incubating DSbFPB with [35S]PAPS, in the presence of a particulate preparation from neuroblastoma-glioma hybrid cells, radioactivity was incorporated into a product identified as [35S]bFPB from its position of elution on reverse-phase HPLC. The possible significance of this observation is discussed.

An attributional perspective on labeling

Drawing extensively from the attributional investigations of Bernard Weiner and his colleagues in the area of achievement motivation, this review addresses attribution theory and its implications for labeling. Specifically, findings concerning attributional taxonomies, antecedents, and consequents are presented and related to labeling effects. In addition, a relationship between informal labeling and attributional processes is proposed. It is concluded that attributions, not the presence or absence of formal labels, may be the critical variable of concern.