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.

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.

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.

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.

Ultrastructural analysis of malformations of the embryonic neural axis induced by in vitro hyperglycemic conditions

Neural tube defects are the most common malformations associated with diabetic pregnancies. Although the teratogenic effects of excess glucose have been investigated in in vivo and in vivo studies, a cellular basis for neural tube defects has not been elucidated. We used rat embryo culture to study the organogenesis period of development, with excess d-glucose added to the serum medium to induce neural tube anomalies. Light and electron microscopic examination of control 12-day-old embryos grown 48 hours in culture revealed blastlike cells with few organelles or cellular processes. Twelve-day-old embryos cultured in excess d-glucose had advanced cellular maturation with differentiation, including the presence of free polysomes and copious cell processes, regardless of whether they had an open neural tube. Cytoarchitectural changes such as decreased numbers of mitotic figures with mitotic cells in the mantle layer were focally distributed throughout the neural epithelium but with predominance at the site of failed closure. In vivo studies failed to demonstrate neural processes in day 12 normal embryos. Fourteen-day-old embryos grown in utero also had foci of cell processes in the neural tube but to a much lesser degree than that observed in the in vitro day 12 glucose-exposed embryos. The cellular aberrations in the excess d-glucose-treated embryos are characteristic of a premature maturational change. Since they are present in excess d-glucose-exposed embryos with or without failure of neural tube closure, these maturational and cytoarchitectural changes may contribute to the cellular basis for neural tube defects.

Divorce and remarriage in a 65-year-old male following transphenoidal surgery and bromocriptine of hyperprolactinemic impotence: a dilemma

Hyperprolactinemia, hypogonadotropinism, and subnormal plasma testosterone were found in a 65-year-old patient who had an enlarged sella turcica, complained of fatigue, and addmitted to decreased sexual interest and potency. Selective nontotal tumorectomy followed by bromocriptine therapy resulted in normoprolactinemia, increased plasma testosterone, and "rejuvenation difficult to follow" according to his wife. This patient described his sexual status as comparable to that of age 24 when he fathered his only child. Both wife and husband attributed the changes to bromocriptine and requested discontinuation (wife) and continuation (husband) of the treatment; because of the clinical indications, treatment was continued. Legally, a medical certification of a normal state of health was required before divorce--and subsequent marriage to a young woman--were permitted.

THE SELECTIVE PROTEOLYTIC ENZYME INHIBITORY ACTION OF BENZETHONIUM CHLORIDE

Acute hemorrhagic pancreatitis in humans is thought to be perpetuated by the autolytic processes catalyzed by trypsin and lipase. This study is an integral part of our search for trypsin and lipase inhibitors to be used in the treatment of this disease.Benzethonium chloride was found to inhibit tryptic activity in vitro. The proteolytic activity of rabbit's serum was inhibited, and the inhibition was most pronounced 6 to 12 hours after the subcutaneous injection of the compound. Fibrinolysin was also inhibited in vitro but benzethonium chloride had no inhibitory action on chymotrypsin, pepsin, or lipase.Serum proteins in vitro were precipitated only with very high concentrations of the compound. No significant protein changes were observed in sera of rabbits after the subcutaneous injection of the compound.

THE SELECTIVE PROTEOLYTIC ENZYME INHIBITORY ACTION OF BENZETHONIUM CHLORIDE

Acute hemorrhagic pancreatitis in humans is thought to be perpetuated by the autolytic processes catalyzed by trypsin and lipase. This study is an integral part of our search for trypsin and lipase inhibitors to be used in the treatment of this disease.Benzethonium chloride was found to inhibit tryptic activity in vitro. The proteolytic activity of rabbit's serum was inhibited, and the inhibition was most pronounced 6 to 12 hours after the subcutaneous injection of the compound. Fibrinolysin was also inhibited in vitro but benzethonium chloride had no inhibitory action on chymotrypsin, pepsin, or lipase.Serum proteins in vitro were precipitated only with very high concentrations of the compound. No significant protein changes were observed in sera of rabbits after the subcutaneous injection of the compound.