35 years of autologous serum skin test in chronic spontaneous urticaria: what we know and what we do not know

Summary

The autologous serum skin test (ASST) has been used in patients with chronic spontaneous urticaria (CSU) as a means to detect an autoreactivity state for thirty-five years now. Nonetheless, several aspects of this old diagnostic test are still insufficiently defined. Particularly, the nature of the factor(s) responsible for the appearance of the wheal-and-flare skin reaction is still poorly characterized. This article will review our current knowledge about the clinical significance of the ASST and the factors possibly associated with the occurrence of the skin reaction following the intradermal administration of autologous serum that are known so far.

Mollusk allergy in shrimp-allergic patients: Still a complex diagnosis. An Italian real-life cross-sectional multicenter study

Introduction

Shellfish allergy is an important cause of food allergies worldwide. Both in vivo and in vitro diagnostics failure nowadays is caused by the poor quality of the extracts associated with the scarce availability of allergenic molecules in the market. It is known that not all patients with shellfish allergies experience adverse reactions to mollusks. It is still unclear how to detect and diagnose these patients correctly.

Aim

To investigate the features of shrimp-allergic patients either reactive or tolerant to mollusks, with the currently available diagnostic methods.

Methods

Nineteen centers, scattered throughout Italy, participated in the real-life study, enrolling patients allergic to shrimp with or without associated reactions to mollusks. Patients underwent skin tests using commercial extracts or fresh raw and cooked shrimp and mollusks, and IgE reactivity to currently available allergenic extracts and molecules was measured in vitro.

Results

Two hundred and forty-seven individuals with a self reported adverse reactions to shrimp participated in the study; of these 47.8% reported an adverse reaction to mollusks ingestion (cephalopod and/or bivalve). Neither of the tests used, in vivo nor in vitro, was able to detect all selected patients. Accordingly, a great heterogeneity of results was observed: in vivo and in vitro tests agreed in 52% and 62% of cases. Skin tests were able to identify the mollusk reactors (p < 0.001), also using fresh cooked or raw food (p < 0.001). The reactivity profile of mollusk reactors was dominated by Pen m 1, over Pen m 2 and Pen m 4 compared to tolerant subjects, but 33% of patients were not detected by any of the available molecules. Overall, a higher frequency of IgE rectivity to shrimp was recorded in northern Italy, while mollusk reactivity was more frequent in the center-south.

Conclusion

The current diagnostic methods are inadequate to predict the cross-reactivity between crustaceans and mollusks. The detection of mollusks hypersensitivity should still rely on skin tests with fresh material. The exclusion of mollusks from shrimp allergic patients’ diets should occur when clinical history, available diagnostic instruments, and/or tolerance tests support such a decision.

1

Current diagnostic methods are inadequate to predict cross-reactivity between crustaceans and mollusks;

2.

The detection of mollusks hypersensitivity must still rely on skin tests with fresh material (and oral challenges where possible);

3.

Clinically, there is no need to exclude a priori mollusks from shrimp allergic patients' diets;

Peanut allergy in Italy: A unique Italian perspective

Background

Peanut allergy has not been well characterized in Italy.

Objective

Our aim was to better define the clinical features of peanut allergy in Italy and to detect the peanut proteins involved in allergic reactions.

Methods

A total of 22 centers participated in a prospective survey of peanut allergy over a 6-month period. Clinical histories were confirmed by in vivo and/or in vitro diagnostic means in all cases. Potential risk factors for peanut allergy occurrence were considered. Levels of IgE to Arachis hypogea (Ara h) 1, 2, 3, 6, 8, and 9 and profilin were measured.

Results

A total of 395 patients (aged 2-80 years) were enrolled. Of the participants, 35% reported local reactions, 38.2% reported systemic reactions, and 26.6% experienced anaphylaxis. The sensitization profile was dominated by Ara h 9 (77% of patients were sensitized to it), whereas 35% were sensitized to pathogenesis-related protein 10 (PR-10) and 26% were sensitized to seed storage proteins (SSPs). Sensitization to 2S albumins (Ara h 2 and Ara h 6) or lipid transfer protein (LTP) was associated with the occurrence of more severe symptoms, whereas profilin and PR-10 sensitization were associated with milder symptoms. Cosensitization to profilin reduced the risk of severe reactions in both Ara h 2- and LTP-sensitized patients. SSP sensitization prevailed in younger patients whereas LTP prevailed in older patients (P < .01). SSP sensitization occurred mainly in northern Italy, whereas LTP sensitization prevailed in Italy's center and south. Atopic dermatitis, frequency of peanut ingestion, peanut consumption by other family members, or use of peanut butter did not seem to be risk factors for peanut allergy onset.

Conclusions

In Italy, peanut allergy is rare and dominated by LTP in the country's center and south and by SSP in the north. These 2 sensitizations seem mutually exclusive. The picture differs from that in Anglo-Saxon countries.

Systemic allergic reactions induced by labile plant-food allergens: Seeking potential cofactors. A multicenter study

BACKGROUND

Heat-and-pepsin-sensitive plant food allergens (PR-10 and profilin) sometimes cause systemic reaction.

OBJECTIVE

To detect the risk factors for systemic reactions induced by labile food allergens.

METHODS

A retrospective multicenter study was performed on patients with a documented history of systemic allergic reaction to labile plant food allergens and on age-matched controls with a history of oral allergy syndrome (OAS) induced by the same foods. Offending foods, their amount, and state (solid or liquid), and potential cofactors (nonsteroidal anti-inflammatory drugs, protonic pump inhibitors, exercise, alcohol, and fasting) were considered.

RESULTS

We studied 89 patients and 81 controls. Sensitization to PR-10 or profilin, IgE to Bet v 1 and/or Bet v 2, and foods causing OAS were similar in the two groups. Twenty patients experienced >1 systemic allergic reaction. Tree nuts, Rosaceae, Apiaceae, and soymilk were the main offending foods. Seventeen (19%) patients were taking a PPI when the systemic reaction occurred (vs 5% in controls; P < .025). The ingestion of the offending food in liquid form (soymilk) was frequent among patients (15%) but unusual among controls (2%; P < .025). Soy milk-induced systemic reactions were independent of PPI treatment. Fasting and excess of allergen, but not NSAID and exercise, were other relevant cofactors for systemic reactions. Systemic reactions occurred without any identifiable cofactor in 39 (44%) cases.

CONCLUSION

PR-10- and profilin-induced systemic reactions are facilitated by PPI, ingestion of large amounts of unprocessed foods, and fasting. Soybean beverages represent a risk for PR-10 hypersensitive patients and should be avoided.

Genetic deletion of TRPA1 receptor attenuates amyloid beta- 1-42 (Aβ1-42)-induced neurotoxicity in the mouse basal forebrain in vivo

Amyloid β 1-42 peptide (Aβ_1-42) accumulates in Alzheimer's disease (AD) that is toxic to the basal forebrain cholinergic (BFC) neurons in substantia innominata-nucleus basalis magnocellularis complex (SI-NBM). Transient Receptor Potential Ankyrin1 (TRPA1) receptor is present in murine brain, however its role in neurotoxic processes is unclear. We investigated the Aβ_1-42-induced neurotoxicity in TRPA1 wild-type (TRPA1^+/+) and knockout (TRPA1^-/-) mice. Expression and neuroanatomical localization of TRPA1 receptor were examined using RT qPCR. Cholinergic fibre loss was determined on acetylcholinesterase (AChE) stained brain slices, and choline acetyltransferase (ChAT) immunohistochemistry was used to assess the cholinergic cell loss. Novel object recognition (NOR), radial arm maze (RAM) and Y-maze tests were used to investigate memory loss. Aβ_1-42-injected WT mice showed marked loss of cholinergic fibres and cell bodies, which was significantly attenuated in TRPA1^-/- animals. According to the NOR and RAM tests, pronounced memory loss was detected in Aβ_1-42-injected TRPA1^+/+ mice, but not in TRPA1^-/- group. Our findings demonstrate that TRPA1 KO animals show substantially reduced morphological damage and memory loss after Aβ_1-42 injection in the SI-NBM. We conclude that TRPA1 receptors may play an important deteriorating role in the Aβ_1-42-induced cholinergic neurotoxicity and the consequent memory loss in the murine brain.

Evaluation of two commercial peach extracts for skin prick testing in the diagnosis of hypersensitivity to lipid transfer protein. A multicenter study

Summary

The clinical usefulness of two commercial peach extracts for SPT (by Lofarma SpA and ALK-Abellò, respectively) was compared in a multicenter study carried out in Italy. Peach allergic patients were tested with the two extracts in parallel and underwent the detection of IgE specific for all three peach allergens currently available (Pru p1, Pru p3, and Pru p4, respectively). The two extracts were almost identical in terms of sensitivity and specificity, being able to detect virtually all patients sensitized to stable peach allergens (lipid transfer protein (LTP) and, presumably, peamaclein) but scoring negative in patients exclusively sensitive to labile allergens (either PR-10 and/or profilin). Thus, the two extracts represent an excellent tool to carry out a preliminary component-resolved diagnosis of peach allergy at the first patient visit.

Acquired cow's milk sensitization after liver transplant in an adult: "clinical implications" and future strategies

Background

Identifying the mechanisms responsible for the development of food allergy in liver transplant recipients is more complex as there are several different clinical scenarios related to the immunological function of the liver.

Case presentation

We describe the first case of Transplant Acquired Food Allergy (TAFA) to cow milk in an adult following LT from a donor dead because of anaphylactic shock. A 67-year-old woman with primary biliary cirrhosis was referred to the Transplant Center of our hospital because of an acute-on-chronic liver failure. The donor was a 15-year-old girl deceased for anoxic encephalopathy due to food induced anaphylaxis after eating a biscuit. In the donor's history food allergies to cow milk and eggs were present.

Conclusion

This case emphasizes the need for a standardized assessment of both solid-organ donors and recipients including donor allergy history in order to detect recipients at risk for anaphylaxis due to passive IgE transfer. Despite several reports of TAFA after solid organ, especially liver, an appropriate protocol to avoid risk for the recipient doesn't exist at the moment. The SPT (skin prick test) or specific IgE level are not enough to ensure a correct management in these cases and a correct education of the patients and the medical staff involved is absolutely necessary. It is the first case of milk allergy sensitization after solid organ transplant by passive transfer of IgE.

TRPV1 antagonists that cause hypothermia, instead of hyperthermia, in rodents: Compounds' pharmacological profiles, in vivo targets, thermoeffectors recruited and implications for drug development

AIM

Thermoregulatory side effects hinder the development of transient receptor potential vanilloid-1 (TRPV1) antagonists as new painkillers. While many antagonists cause hyperthermia, a well-studied effect, some cause hypothermia. The mechanisms of this hypothermia are unknown and were studied herein.

METHODS

Two hypothermia-inducing TRPV1 antagonists, the newly synthesized A-1165901 and the known AMG7905, were used in physiological experiments in rats and mice. Their pharmacological profiles against rat TRPV1 were studied in vitro.

RESULTS

Administered peripherally, A-1165901 caused hypothermia in rats by either triggering tail-skin vasodilation (at thermoneutrality) or inhibiting thermogenesis (in the cold). A-1165901-induced hypothermia did not occur in rats with desensitized (by an intraperitoneal dose of the TRPV1 agonist resiniferatoxin) sensory abdominal nerves. The hypothermic responses to A-1165901 and AMG7905 (administered intragastrically or intraperitoneally) were absent in Trpv1^-/- mice, even though both compounds evoked pronounced hypothermia in Trpv1^+/+ mice. In vitro, both A-1165901 and AMG7905 potently potentiated TRPV1 activation by protons, while potently blocking channel activation by capsaicin.

CONCLUSION

TRPV1 antagonists cause hypothermia by an on-target action: on TRPV1 channels on abdominal sensory nerves. These channels are tonically activated by protons and drive the reflectory inhibition of thermogenesis and tail-skin vasoconstriction. Those TRPV1 antagonists that cause hypothermia further inhibit these cold defences, thus decreasing body temperature.

SIGNIFICANCE

TRPV1 antagonists (of capsaicin activation) are highly unusual in that they can cause both hyper- and hypothermia by modulating the same mechanism. For drug development, this means that both side effects can be dealt with simultaneously, by minimizing these compounds' interference with TRPV1 activation by protons.

The clinical relevance of lipid transfer protein

Despite a huge number of studies, many aspects of the lipid transfer protein (LTP) syndrome, the most frequent primary food allergy in Mediterranean countries, remain unclear. Its peculiar geographical distribution, along with the extreme variability of its clinical expression, makes this type of food allergy something unique in the panorama of IgE-mediated food-induced allergic reactions. This review article tried to summarize the current knowledge about the most important aspects of LTP sensitization and allergy, along with the importance of positive and negative co-factors in the clinical expression of the syndrome as well as the issues regarding the cross-reactivity between LTPs present in botanically related and unrelated foods. Further, the possible absence of the protein from some plant foods is discussed.

Environmental interventions for mite-induced asthma: a journey between systematic reviews, contrasting evidence and clinical practice

House dust mites (HDM) are one of the most important sources of indoor allergens worldwide. Exposure to high environmental levels of dust mite allergen is associated with an increased risk of sensitization, asthma and deterioration of lung function. On the basis of these data, it would be logical to assume that asthmatic patients with mite allergy could benefit from a reduction of exposure to these allergens. Several environmental prophylactic actions against HDM, either physical or chemical have been tried, alone or in different combinations. However, a recent Cochrane Systematic Review did not detect specific clinical benefits from the use of prophylactic environmental measures in asthmatic patients sensitive to HDM and concluded that such measures can no longer be recommended as they are ineffective. This paper presents the results of a web-based questionnaire, administered to more than 200 Italian paediatricians, and shows that physicians' behaviour in real life is very far from SR conclusions. It also summarizes the indications of the most authoritative guidelines, highlighting some contrasting evidence and some significant weaknesses of the SR, that could make the final conclusions at least uncertain. In the light of these findings, it seems that the recent Cochrane SR cannot be considered the definitive document on the uselessness of environmental prevention of mite-related asthma.

NK cell activity controls human herpesvirus 8 latent infection and is restored upon highly active antiretroviral therapy in AIDS patients with regressing Kaposi's sarcoma

Kaposi's sarcoma (KS) develops upon reactivation of human herpesvirus 8 (HHV8) infection and virus dissemination to blood and tissue cells, including endothelial and KS spindle cells where the virus is mostly present in a latent form. However, this may likely require the presence of compromised host immune responses and/or the evasion of infected cells from the host immune response. In this regard, mechanisms of evasion of productively infected cells from both CTL and NK cell responses, and resistance of latently infected cells from specific CTL, have already been shown. Here we show that cells which are latently infected by HHV8 are indeed efficiently lysed by NK cells from individuals with a normal immune response. Notably, NK cell-mediated immunity was found to be significantly reduced in AIDS patients with progressing KS as compared to both HIV-negative patients with indolent classic KS or normal blood donors. However, it was restored after treatment with the highly active antiretroviral therapy (HAART) in AIDS-KS patients, that showed regression and clearance of HHV8 from PBMC. By contrast, AIDS-KS patients with a more aggressive disease and no clinical response had persistent HHV8 viremia associated with reduced NK cell cytotoxicity. These results suggest a key role for NK cells in the control of HHV8 latent infection, KS development, and in disease remission upon HAART.

[Prophylaxis with tercef of infection-related complications after cesarean section]

The purpose of this prospective and case controlled study is to determine the effectiveness and safety of antibiotic prophylaxis with Tercef (ceftriaxone) in women undergoing cesarean section and to compare the results with those of 24 hours regiment of Cefazolin and also with a group without prophylaxis. The study includes 122 cases of elective and emergency CS: 41 with a single intravenous dose of 1.0 g Tercef after clamping of the umbilical cord; 41 cases of antibiotic prophylaxis with Cefazolin three times 2.0 g for 24 hours and 40 low infectious risk CS without antibiotic prophylaxis. We take in account the existing before the CS risk factors for postoperative infectious complications as: hours of PROM; length of labor, number of vaginal examinations before CS, previous sections, duration of the operation, anemia, bacteriuria and diabetes. For post CS infection-related complications we take: febrile morbidity, endometritis, wound infections, infection of urinary tract. The results show infection complication in the three groups as follow: 14.6% for tercef, 17.1% for cefazolin and 20.0% for the group without antibiotic. There is not statistically significant difference. According our study in cases of CS with increased risk of post-operative infectious complications the antibiotic prophylaxis reduce the rate of infection-related complications even below that of CS with low infectious risk. The single dose of 1 g tercef i.v. is effective and suitable in comparison with 24 hours regiment of cefazolin.

Human infection with Cryptosporidium felis: case report and literature review

An infection with Cryptosporidium felis in an HIV-positive man from Italy was successfully treated with paromomycin, despite the patient's having a CD4+ cell count of 31/mL. Fourteen cases of human infection with C. felis have been described, all in the past 3 years, emphasizing the public health importance of Cryptosporidium parasites other than C. parvum.

Hyperglycemia-induced vasculopathy in the murine conceptus is mediated via reductions of VEGF-A expression and VEGF receptor activation

Major congenital malformations, including those affecting the cardiovascular system, remain the leading cause of mortality and morbidity in infants of diabetic mothers. Interestingly, targeted mutations of several genes (including VEGF and VEGF receptors) and many teratogenic agents (including excess D-glucose) that give rise to embryonic lethal phenotypes during organogenesis are associated with a failure in the formation and/or maintenance of a functional vitelline circulation. Given the similarities in the pathology of the abnormal vitelline circulation in many of these conditions, we hypothesized that the hyperglycemic insult present in diabetes could cause the resultant abnormalities in the vitelline circulation by affecting VEGF/VEGF receptor signaling pathway(s). In this study we report that hyperglycemic insult results in reduced levels of VEGF-A in the conceptus, which in turn, leads to abnormal VEGF receptor signaling, ultimately resulting in embryonic (vitelline) vasculopathy. These findings and our observation that addition of exogenous rVEGF-A(165) within a defined concentration range blunts the hyperglycemia-induced vasculopathy in the conceptus support the concept that VEGF levels can be modulated by glucose levels. In addition, these findings may ultimately lead to novel therapeutic approaches for the treatment of selected congenital cardiovascular abnormalities associated with diabetes.

Decreased T cell apoptosis and T cell recovery during highly active antiretroviral therapy (HAART)

T cell apoptosis represents a common mechanism of T cell depletion in HIV-1-infected individuals reflecting maturational and functional T cell abnormalities either directly or indirectly induced by the virus. In the present study, the effects of highly active antiretroviral therapy (HAART) on the spontaneous apoptosis of distinct T cell subsets were investigated during a 6-month follow-up in a cohort of HIV-1-infected individuals with CD4(+) cell counts between 100 and 500 cells/microliter and plasma HIV-1 RNA levels >/=10, 000 copies/ml. We determined that the rapid and sustained increase of both naive (CD45RA(+)CD62L(+)) and memory (CD45R0(+) and CD45RA(+)/CD62L(-)) CD4(+) and, to as lesser extent, CD8(+) T cells in peripheral blood was associated with a significant decrease of apoptotic CD4(+) and CD8(+) as well as CD3(+)CD4(-)CD8(-) T cells. Among CD4(+) lymphocytes, at enrollment, the highest frequency of apoptotic cells was observed within the memory compartment, as defined by CD45R0 expression. During HAART, however, the frequency of CD4(+)CD45R0(+) apoptotic T cells progressively decreased in association with a significant downregulation of surface activation markers that indicated decreased levels of systemic immune stimulation. These results indicate that effective viral suppression can contribute to progressive normalization of maturational and functional T cell abnormalities responsible for the high levels of T cell apoptosis in HIV-1-infected individuals. This, in turn, may contribute to a reduced rate of T cell loss and immune reconstitution during HAART.

Platelet-endothelial cell adhesion molecule-1 (CD31), a scaffolding molecule for selected catenin family members whose binding is mediated by different tyrosine and serine/threonine phosphorylation

Platelet-endothelial cell adhesion molecule (PECAM)-1 is a 130-kDa glycoprotein commonly used as an endothelium-specific marker. Evidence to date suggests that PECAM-1 is more than just an endothelial cell marker but is intimately involved in signal transduction pathways. This is mediated in part by phosphorylation of specific tyrosine residues within the ITAM domain of PECAM-1 and by recruitment of adapter and signaling molecules. Recently we demonstrated that PECAM-1/beta-catenin association functions to regulate beta-catenin localization and, moreover, to modulate beta-catenin tyrosine phosphorylation levels. Here we show that: 1) not only beta-catenin, but also gamma-catenin is associated with PECAM-1 in vitro and in vivo; 2) PKC enzyme directly phosphorylates purified PECAM-1; 3) PKC-derived PECAM-1 serine/threonine phosphorylation inversely correlates with gamma-catenin association; 4) PECAM-1 recruits gamma-catenin to cell-cell junctions in transfected SW480 cells; and 5) gamma-catenin may recruit PECAM-1 into an insoluble cytoskeletal fraction. These data further support the concept that PECAM-1 functions as a binder and modulator of catenins and provides a molecular mechanism for previously reported PECAM-1/cytoskeleton interactions.

Clinical and immunologic response without decrease in virus load in patients with AIDS after 24 months of highly active antiretroviral therapy

This study reports an analysis of clinical, virological, and immunologic outcomes in a cohort of 77 multidrug-experienced AIDS patients during 24 months of highly active antiretroviral therapy (HAART). Our results have shown a reduced risk of AIDS complications, prolonged survival, and immunologic benefit even in the absence of sustained virus suppression. The degree of immunodepression, the risk factors for HIV-1 infection, the use of 2 drugs instead of 3, and a change in protease inhibitor were independently correlated with virological failure. In the majority of studied patients, an increase in CD4+ T cells was observed after HAART. However, the increase was more pronounced in patients who showed a decrease in virus load than in those who did not. Moreover, we observed an absence of relapses among patients who permanently discontinued prophylaxis for Cytomegalovirus retinitis and atypical mycobacterial infections. Peripheral lipodystrophy developed in the majority of patients, regardless of treatment used and virological outcome.

Long-term evaluation of T-cell subsets and T-cell function after HAART in advanced stage HIV-1 disease

OBJECTIVES

Evaluation of immunological reconstitution after 2 years of highly active antiretroviral therapy (HAART) in AIDS patients.

DESIGN

Previous data showed the effectiveness of HAART but conflicting evidence of immune reconstitution has been found in severely immunocompromised patients. Therefore, T-cell subsets and functions were analysed during 24 months of HAART in 21 AIDS patients (mean baseline CD4 cell count, 20 x 10(6)/l).

METHODS

Subjects were tested at baseline and after 4, 12 and 24 months of therapy for clinical symptoms and the following investigations were carried out: plasma HIV RNA, T-cell subsets and lymphoproliferative responses to mitogens (phytohaemagglutinin, anti-CD3), and recall antigens (Candida mannoprotein, tetanus toxoid and recombinant glycoprotein 160).

RESULTS

Increase in body weight, improvement of Karnofsky's score and reduction of opportunistic infections were observed. All patients showed an initial increase in the CD4 memory subset, whereas naive CD4 cells consistently increased only after 1 year. The magnitude of immune recovery was stronger in patients showing a significant reduction in viral load. However seven out of 21 patients who did not reach a sustained suppression of viral load showed also an increase in T-cell subsets. The majority of patients recovered lymphoproliferative responses to mitogens, whereas only four subjects showed a functional response to Candida mannoprotein. No patients showed a response to HIV recombinant glycoprotein 160 or tetanus toxoid.

CONCLUSIONS

The immune recovery observed is slower and not complete in severely immunocompromised patients. Our data suggest that HAART may be continued also in the absence of a significant HIV RNA decrease if alternative drugs are not available.

Hyperglycemia-induced vasculopathy in the murine vitelline vasculature: correlation with PECAM-1/CD31 tyrosine phosphorylation state

Maternal diabetes mellitus is associated with an increased incidence of congenital abnormalities as well as embryonic and perinatal lethality. In particular, a wide range of cardiovascular abnormalities have been noted in children of diabetic mothers and in the offspring of diabetic animals. The vascular system is the first organ system to develop in the embryo and is critical for normal organogenesis. The organization of mesodermal cells into endothelial and hematopoietic cells and into a complex vascular system is, in part, mediated by a series of specific cell-cell, cell-extracellular matrix, and cell-factor interactions. PECAM-1 expression has been observed during the earliest stages of vasculogenesis, and changes in PECAM-1 tyrosine phosphorylation have been associated with endothelial cell migration, vasculogenesis, and angiogenesis both in vitro and in vivo. In this report we demonstrate that exposure to hyperglycemia during gastrulation causes yolk sac and embryonic vasculopathy in cultured murine conceptuses and in the conceptuses of streptozotocin-induced diabetic pregnant mice. In addition, we correlate the presence of yolk sac and embryonic vasculopathy with the failure of PECAM-1 tyrosine dephosphorylation during the formation of blood islands/vessels from clusters of extra-embryonic and embryonic angioblasts in the murine conceptus using both in vitro and in vivo models. The importance of these findings in the development of vasculopathy in the offspring of diabetic mothers and the potential effects and benefits of glucose regulation during the periods of vasculogenesis/angiogenesis in embryonic development are discussed.

Inhaled nitric oxide therapy in a critically ill neonate with Ebstein's anomaly

The successful use of nitric oxide (NO) inhalation in a critically ill neonate with Ebstein's anomaly of the tricuspid valve is reported for the first time. This use of inhaled NO therapy suggests a therapeutic intervention that directly addresses the pathophysiologic process of severe neonatal Ebstein's anomaly.

Fetal lung mRNA levels of Hox genes are differentially altered by maternal diabetes and butyrate in rats

Diabetes is known to be associated with delayed lung development in humans and in experimental animals. This includes delayed expression of surfactant apoproteins. An important component of the metabolic abnormalities in diabetes is elevated levels of analogs of butyric acid, and the effects of diabetes on surfactant apoproteins can be reproduced by exposure of fetal rat lung explants to butyrate. Dexamethasone has the opposite effects on lung development. In humans, antenatal exposure to dexamethasone results in a lower incidence of RDS, whereas in experimental animals, dexamethasone increases the expression of surfactant apoproteins. A subset of Hox genes are expressed in developing lung, and their level of expression decreases with advancing gestation. We hypothesized that: 1) lungs of fetuses of rats with streptozotocin-induced diabetes would have altered levels of expression of Hox genes, 2) the effect would be mediated in part through elevated levels of butyrate, and 3) dexamethasone would reverse the effect. We tested our hypotheses in vivo using fetuses from streptozotocin-treated rats and in vitro by treating lung explants from normal rats with sodium butyrate. Streptozotocin treatment increased expression of Hoxb-5 at 18 d of gestation, but did not affect Hoxa-5 expression. This was associated with a 20-fold increase in alpha-aminobutyrate levels. Dexamethasone tended to reverse this effect. In contrast, butyrate treatment of explants decreased the expression of Hoxa-5 and Hoxb-5. We conclude that diabetes alters expression of Hox genes, but that the effect of butyrate on lung development, and in particular on surfactant apoprotein expression, is independent of its effects on Hox genes.

Platelet-endothelial cell adhesion molecule-1 (PECAM-1/CD31) tyrosine phosphorylation state changes during vasculogenesis in the murine conceptus

Vasculogenesis, the differentiation of mesodermal cells to angioblasts and the subsequent formation of blood islands and blood vessels by angioblasts in the conceptus, is a dynamic process modulated, in part, by cell-extracellular matrix and cell-cell interactions in the presence of a variety of growth factors and morphogens. In this report we demonstrate differential tyrosine phosphorylation of platelet-endothelial cell adhesion molecule-1 (PECAM-1) during the formation of blood islands and vessels from clusters of extraembryonic and embryonic angioblasts in the murine conceptus. In addition, we identify the phosphorylation of a particular tyrosine residue in the PECAM-1 cytoplasmic domain, Tyr686, which has the potential of mediating binding to Src homology 2 domain-containing proteins, affecting PECAM-1 cellular localization and endothelial cell migration.

Semen analysis in HIV seropositive men and in subjects at high risk for HIV infection

The main purpose of this research was (i) to perform a comparative study of sperm parameters in human immunodeficiency virus (HIV) seropositive and high risk subjects in order to identify any possible alterations in the semen which specifically result from HIV infection and (ii) to study the p24 antigen as an early diagnostic marker of infection in high risk subjects. HIV seropositive subjects showed no significant variations regarding sperm densities, motility and viscosity compared to high risk subjects and controls. On the other hand, these HIV seropositive subjects showed (a) a significantly higher percentage of cytoplasmic droplet forms and immature germ cells, perhaps caused by an early failure of epididymal function and/or by a condition of stress affecting spermatogenesis after HIV infection and (b) a significantly higher level of spermiophage cells, suggesting that HIV activates mechanisms that increase spermiophagy. In addition, HIV seropositive men showed a significant positive correlation between blood CD4+ and sperm motility as well as a significant inverse correlation between CD4+ and sperm abnormalities. This is perhaps due to a decrease in testosteronaemia leading to defective epididymal sperm maturation. To date, p24 has not been found in the serum or seminal plasma of high risk subjects. The longitudinal study in progress should provide further information on this point.

Immunologic aspects of hyperimmunoglobulinemia E-like syndrome in patients with AIDS

In this study we describe a series of nine patients affected by acquired immunodeficiency syndrome (AIDS) or AIDS-related complex who had hypereosinophilia and hyperimmunoglobulinemia E (hyper-IgE) with chronic dermatitis and recurrent staphylococcal infections. These patients had features similar to those present in hyper-IgE syndrome, a primary immunodeficiency disease. In addition, immunologic characterization of these patients with human immunodeficiency virus (HIV) infection, compared with 51 HIV-positive patients without hyper-IgE, both atopic and nonatopic, and three patients affected by the primary hyper-IgE syndrome, also revealed an increase in IgA and a severe decrease in B and CD4+ lymphocytes. Spontaneous in vitro synthesis of IgE by peripheral blood mononuclear cells was confirmed in both hyper-IgE conditions, together with increased levels of circulating eosinophil cationic protein. Serum-soluble CD23, usually increased in atopic conditions and hyper-IgE, was similar to that of normal control subjects in the HIV-positive patients with hyper-IgE. On the basis of our findings, we conclude that a hyper-IgE-like syndrome represents a distinct aspect of the clinical manifestations associated with HIV infection and that the immunologic mechanisms in this condition seem to differ from those known in primary hyper-IgE syndrome, because CD4+ TH2 type cells, which are currently believed to have a role in IgE production, are severely depleted in HIV-positive patients.

Immunological, Clinical and Epidemiological Aspects of an HIV-1 Positive Drug Abuser Cohort

We analyzed a cohort of intravenous drug abusers with HIV-1 disease attending our institute in the years 1985–1993. We focused particular attention on the epidemiological analysis of patients, and their clinical, immunological and infectious conditions. The significance of biological markers, particulary CD4+ lymphocyte count and the occurence of other viral infections such as Cytomegalovirus, Epstein-Barr virus, Herpes Simplex virus and Hepatitis B and C viruses in the progress of HIV-1 disease were evaluated. At least two-thirds of the patients at different stages of HIV-1 were treated with antiretroviral drugs: zidovudine (AZT) from 1987 up to the present and more recently didanosine (DDI) alone or in combination with AZT. Psychological and behavioral aspects of our HIV-1 infected drug abusers, in particular needle exchange and condom use, were analyzed.

Lack of evidence for a superantigen in lymphocytes from HIV-discordant monozygotic twins

OBJECTIVE

An HIV-associated superantigen (SAg) has been hypothesized. Here we test whether an SAg is functionally detectable in peripheral blood mononuclear cells (PBMC) from monozygotic twins discordant for HIV infection.

DESIGN AND METHODS

The V beta selective T-cell depletion found in minor lymphocyte stimulation (Mls)-positive mice is caused by an SAg encoded by the mouse mammary tumour virus. Mls is a locus whose gene product stimulates a mixed lymphocyte reaction (MLR) in mice strains identical at the major histocompatibility complex locus. If an SAg is present in PBMC and/or sorted CD4+ cells from one HIV-infected monozygotic twin, it would stimulate PBMC from the corresponding healthy monozygotic twin in an MLR. In addition, if an SAg causes V beta-selective T-cell depletion in AIDS patients, a differential proliferation to a panel of staphylococcal enterotoxins (SE) of T lymphocytes from healthy and HIV-infected monozygotic twins should become measurable.

RESULTS

No positive MLR or significant differences in the SE-driven proliferation between the healthy and the HIV-infected twins were observed.

CONCLUSIONS

Our results suggest that PBMC from the two HIV-infected twins do not express a functionally detectable SAg.

The yolk sac theory: closing the circle on why diabetes-associated malformations occur

OBJECTIVE

The purpose of this article is to examine the role of yolk sac failure during organogenesis in the development of diabetes-associated embryopathy.

METHODS

The current literature regarding congenital malformations in diabetic pregnancies was reviewed to elucidate the precise role of the yolk sac in embryonic development and the relation between yolk sac injury and embryopathy.

RESULTS

We and others have demonstrated that hyperglycemia produces a teratogenic effect during organogenesis. In addition, we have shown that the yolk sac appears to be the target site of injury induced by hyperglycemia. We have also presented evidence that cell membrane dysfunction leads to failed vitelline vessel formation and that arachidonic acid supplementation prevents many of the morphologic and biochemical alterations observed under hyperglycemic conditions.

CONCLUSIONS

These data strongly support the teratogenic effect of hyperglycemia, the arachidonic acid deficiency state, the resultant maldevelopment of vitelline vessels, and the ability to prevent these changes by arachidonic acid supplementation. These studies have made significant inroads in explaining why diabetes-associated anomalies occur, and suggest a potential future role for prophylaxis against these organogenetic malformations using dietary polyunsaturated fatty acid supplementation.

Silent HIV infection

The period of latency between infection by the human immunodeficiency virus type-1 (HIV-1) and the production of specific antibodies to viral antigens may be prolonged and, occasionally, may last for years. This condition of seronegative infection could represent a serious risk of viral transmission from subjects who are unaware of their status. However, whether these individuals are actually infectious, especially through body fluids, has not been clarified. We have performed a prospective study in 65 high-risk individuals seronegative for HIV-1 antibodies for a prolonged period of time. Twelve of them (18%) were shown to be carriers of HIV-1 proviral sequences by the polymerase chain reaction (PCR). The virus was isolated from mitogen-stimulated peripheral blood lymphocytes in five out of ten subjects tested since the first positive PCR. In two of them, virus could also be isolated from cell-free plasma, subsequently they remained seronegative during 10 months of follow-up. These data indicate that delayed seroconversions may be associated with productive infection, suggesting that mechanism(s) other than viral latency may be responsible for the absence of antibody responses to HIV-1 proteins. Furthermore, our findings suggest that prolonged seronegative individuals can transmit HIV infection through their body fluids.

Predictive value of neurological abnormalities in HIV 1 patients in the early stages of the infection

A longitudinal clinical neurological and electrophysiological follow-up study was carried out on 31 HIV1 seropositive outpatients in the asymptomatic or LAS stages of the infection (CDC II-III). The results of clinical examination and multimodal evoked potentials (EP) recording showed a high percentage of abnormalities (42% and 39% of cases respectively); in a statistically significant number of subjects these abnormalities were predictive of subsequent immunological deterioration, thus demonstrating the close relationship between neurological and immunological functions in HIV1 infection.

Effects of maternal diabetes on fetal rat lung ion transport. Contribution of alveolar and bronchiolar epithelial cells to Na+,K(+)-ATPase expression

Fetuses of streptozotocin-induced diabetic rats exhibited delayed lung maturation and a 40% reduction in the steady-state level of lung Na+,K(+)-ATPase alpha 1 subunit mRNA and Na+,K(+)-ATPase activity at 21 d of gestation. In in situ hybridization experiments the signal specific for Na(+)-pump alpha 1 subunit message was strongest above columnar epithelial cells of air-conducting structures. Strong labeling was also present above cuboidal cells lining the forming alveoli, but not above mesenchymal cells. Immunocytochemical localization of the protein paralleled the distribution of the mRNA. Mesenchymal cells were more abundant in fetal lungs of diabetic mothers, and thus the decreased overall levels of Na+,K(+)-ATPase may result from the observed morphological pulmonary immaturity. One day after birth there was no apparent difference in lung morphology at the light microscopic level, in the localization or the steady-state level of Na+,K(+)-ATPase alpha 1 isoform mRNA, or in enzyme activity. Na+,K(+)-ATPase has a likely role in the active phase of fluid absorption in the airways of newborns before the onset of breathing. Decreased fluid clearance and lack of thinning of the lung's connective tissue may contribute to the increased risk for respiratory distress in infants of diabetic mothers.

Yolk sac failure in embryopathy due to hyperglycemia: horseradish peroxidase uptake in the assessment of yolk sac function

We described previously the morphologic alterations of the visceral endodermal yolk sac cells of rat conceptuses cultured under hyperglycemic conditions which occurred concomitantly with major embryonic malformations. To determine whether the transport function of the yolk sac was impaired simultaneously as a result of these hyperglycemic conditions, horseradish peroxidase was used as a tracer protein to assess the transport function of the visceral endodermal yolk sac cells of conceptuses cultured in both control and hyperglycemic media. Cellular uptake of peroxidase, which was added to the culture medium for 3 or 24 hours, was observed in controls. This differed from the marked diminution in peroxidase uptake seen in conceptuses cultured in hyperglycemic medium. These results demonstrate that during hyperglycemia-induced embryopathy, there is concomitant yolk sac failure evidenced by morphologic alterations and impaired endocytosis. These findings therefore strengthen our hypothesis that diabetes-related malformations, as demonstrated experimentally in rat conceptuses, are associated with impairment in the structure and functions of the visceral yolk sac cells during a critical period of organogenesis.

Fatty acid content of yolk sac and embryo in hyperglycemia-induced embryopathy and effect of arachidonic acid supplementation

Using the postimplantation rat conceptus model, we analyzed with gas-liquid chromatography, the fatty acid composition in major lipid groups (phospholipids, triglycerides, nonesterified fatty acids, and cholesterol esters) of yolk sacs and embryos cultured for 48 hours under control, hyperglycemic, and arachidonic acid-supplemented hyperglycemic conditions. In all experimental conditions the yolk sacs had greater fatty acid content than the embryos in all lipid groups except in nonesterified fatty acids. The fatty acid level in embryonic nonesterified fatty acids was significantly higher (p less than 0.05) in hyperglycemia-exposed embryos than found with arachidonic acid supplementation. Total yolk sac triglycerides were greater with added glucose (p less than 0.05) than with the addition of arachidonic acid to the same medium. Oleic acid, a fatty acid associated with essential fatty acid deficiency, was increased in the embryonic phospholipids and nonesterified fatty acids of conceptuses exposed to excess glucose, as well as in the culture media of this group, compared with the control or arachidonic acid-supplemented, hyperglycemic group (p less than 0.05). The results of this study demonstrate that diabetes-related embryopathy is associated with quantitative and qualitative abnormalities in major lipid groups. Furthermore, the elevation in embryonic oleic acid level suggests that the teratogenic mechanism could be related to a deficiency in essential fatty acids. The pattern of essential fatty acid deficiency and embryopathy was preventable with arachidonic acid supplementation in this experimental model.

Prognostic significance of the human yolk sac assessed by ultrasonography

Ultrasonographic examinations were conducted between 6 and 12 weeks' gestation in 77 first-trimester pregnancies with normal fetal outcome. Each examination consisted of measurements of the secondary yolk sac diameter and the fetal crown-rump length. The yolk sac was seen in all cases, and whereas its measurements demonstrated wide biologic variability, it correlated weakly (R2 = 0.39) with gestational age as confirmed by crown-rump length measurements. Growth of the yolk sac diameter, although slight, assumed a curvilinear relationship with gestational age. Such a growth profile is best described by a second-degree polynomial regression equation. The yolk sac performs important functions for embryonic development during organogenesis and the remnant of the secondary yolk sac seen on ultrasonography is often considered to be a potential predictor of fetal outcome. Our findings indicate that the size of this remnant in pregnancies with normal karyotypes and normal fetal outcomes is extremely variable. Additionally, the yolk sac size in patients with karyotypic abnormalities and spontaneous abortion were equally variable and almost all were within the normal range. In light of these findings, the secondary yolk sac size does not appear to be a sensitive predictor of embryonic integrity and pregnancy outcome.

Behavioral momentum in the treatment of noncompliance

Behavioral momentum refers to the tendency for behavior to persist following a change in environmental conditions. The greater the rate of reinforcement, the greater the behavioral momentum. The intervention for noncompliance consisted of issuing a sequence of commands with which the subject was very likely to comply (i.e., high-probability commands) immediately prior to issuing a low-probability command. In each of five experiments, the high-probability command sequence resulted in a "momentum" of compliant responding that persisted when a low-probability request was issued. Results showed the antecedent high-probability command sequence increased compliance and decreased compliance latency and task duration. "Momentum-like" effects were shown to be distinct from experimenter attention and to depend on the contiguity between the high-probability command sequence and the low-probability command.

A hypothesis concerning the general basis of organogenetic congenital anomalies

Evidence supports the idea that it is the degree of metabolic imbalance present in diabetic gravid women during the period of organogenesis that accounts for organogenetic congenital defects. In light of the proved and inferred metabolic instability occurring during early pregnancy, we propose that metabolic imbalances may occur that result in organogenetic congenital defects in offspring of apparently normal gravid women.

Arachidonic acid prevents hyperglycemia-associated yolk sac damage and embryopathy

Light microscopic, electron microscopic, and morphometric studies were performed on rat conceptuses cultured between day 10 and day 12 in normal, hyperglycemic, arachidonic acid-supplemented normal, and arachidonic acid-supplemented hyperglycemic rat serum. The results were compared with those of 12-day-old conceptuses grown in utero. No major differences were observed between in vivo and in vitro control conceptuses. Arachidonic acid supplementation of control culture medium resulted in an improvement of conceptus development. Addition of 20 micrograms/ml of arachidonic acid to an otherwise teratogenic hyperglycemic serum medium (950 mg/dl of D-glucose) prevented the malformations induced by hyperglycemic conditions: open neural tube, advanced neuropil formation in the neuroepithelium, significant reduction of rough endoplasmic reticulum, decreased size and number of lipid droplets, and increased number of lysosome-like structures in the visceral endodermal yolk sac cells.

Yolk sac failure in embryopathy due to hyperglycemia: ultrastructural analysis of yolk sac differentiation associated with embryopathy in rat conceptuses under hyperglycemic conditions

Diabetes mellitus in pregnancy is associated with an increased incidence of various congenital anomalies that occur during organogenesis. Because a well functioning yolk sac is crucial to embryonic growth and development during this period, we performed an ultrastructural study of the effects of excess glucose (total glucose 750 mg/dl, osmolality 305 mOsm/kg) on pregnancy day 10 (Witschi stage 13) rat conceptuses cultured for 48 hr in heat-inactivated male rat serum with and without added d- or l-glucose. Embryos exposed to excess d-glucose demonstrated decreased conceptus size (P less than 0.001), and gross malformations in a dose-related fashion. The visceral yolk sac capillaries and vitelline vessels of conceptuses in excess d-glucose were sparse, patchy, and nonuniformly located. Ultrastructurally, the visceral yolk sac endodermal cells had reduced numbers of rough endoplasmic reticulum, ribosomes, and mitochondria. These obvious defects in yolk sac structure suggest that hyperglycemia during organogenesis has a primary deleterious effect on yolk sac function with resultant embryopathy.