The effect of costimulatory and interleukin 2 receptor blockade on regulatory T cells in renal transplantation.

Regulatory T cells (Treg) are critical regulators of immune tolerance. Both IL-2 and CD28-CD80/CD86 signaling are critical for CD4(+)CD25(+)FOXP3(+) Treg survival in mice. Yet, both belatacept (a second-generation CTLA-4Ig) and basiliximab (an anti-CD25 monoclonal antibody) are among the arsenal of current immunotherapies being used in kidney transplant patients. In this study, we explored the direct effect of basiliximab and belatacept on the Tregs in peripheral blood both in the short term and long term and in kidney biopsies of patients with acute rejection. We report that the combined belatacept/basiliximab therapy has no long-term effect on circulating Tregs when compared to a calcineurin inhibitor (CNI)-treated group. Moreover, belatacept-treated patients had a significantly greater number of FOXP3(+) T cells in graft biopsies during acute rejection as compared to CNI-treated patients. Finally, it appears that the basiliximab caused a transient loss of both FOXP3(+) and FOXP3(-) CD25(+) T cells in the circulation in both treatment groups raising important questions about the use of this therapy in tolerance promoting therapeutic protocols.

Cellular and molecular aspects of Lyme arthritis.

Lyme disease is a multisystem illness initiated upon infection with the spirochete Borrelia burgdorferi. Whereas the majority of patients who develop Lyme arthritis may be successfully treated with antibiotic therapy, about 10% go on to develop arthritis which persists for months to years, despite antibiotic therapy. Development of what we have termed treatment-resistant Lyme arthritis has previously been associated with both the presence of particular major histocompatibility complex class II alleles and immunoreactivity to the spriochetal outer surface protein A (OspA). Recently, we showed that patients with treatment-resistant Lyme arthritis, but not patients with other forms of arthritis, generate synovial fluid T cell responses to an immunodominant epitope of OspA and a highly homologous region of the human-lymphocyte-function-associated antigen-1alphaL chain. Identification of a bacterial antigen capable of propagating an autoimmune response against a self-antigen provides a model of molecular mimicry in the pathogenesis of treatment-resistant Lyme arthritis.

Identification of LFA-1 as a candidate autoantigen in treatment-resistant Lyme arthritis.

Treatment-resistant Lyme arthritis is associated with immune reactivity to outer surface protein A (OspA) of Borrelia burgdorferi, the agent of Lyme disease, and the major histocompatibility complex class II allele DRB1*0401. The immunodominant epitope of OspA for T helper cells was identified. A homology search revealed a peptide from human leukocyte function-associated antigen-1 (hLFA-1) as a candidate autoantigen. Individuals with treatment-resistant Lyme arthritis, but not other forms of arthritis, generated responses to OspA, hLFA-1, and their highly related peptide epitopes. Identification of the initiating bacterial antigen and a cross-reactive autoantigen may provide a model for development of autoimmune disease.

T helper 1 response is dominant and localized to the synovial fluid in patients with Lyme arthritis.

Cytokines produced by subsets of CD4+ T helper cells responding to an infection influences the efficiency with which the host is able to mount a protective immune response. In an attempt to elucidate the population of active cells involved in the propagation of Lyme arthritis we have utilized intracellular cytokine staining to analyze the polyclonal immune response at the single cell level. We have determined the Th phenotype in the synovial fluid of patients with a variety of chronic inflammatory arthritides, including patients representative of the spectrum of Lyme arthritis. Th1 cells dominate the immune response in the synovial fluid of patients with Lyme as well as those with rheumatoid or other types of chronic inflammatory arthritis. In addition, the severity of Lyme arthritis directly correlates with the ratio of Th1 to Th2 cells in the synovial fluid, such that the larger the effusion, the higher the ratio (r = 0.67, p < 0.05). These results suggest that Th1 cells play a direct role in the pathogenesis of the inflammatory process seen in Lyme arthritis, and that Th2 cells modulate the pro-inflammatory response generated by Th1 cells in the joint. Finally, we identify Th1 cells specific for outer surface protein A of Borrelia burgdorferi, the agent of Lyme disease. These cells are restricted to patients with Lyme arthritis and are localized to the joint. Furthermore, they persist in patients with prolonged antibiotic treatment-resistant Lyme arthritis, suggesting the possibility of an autoimmune process.

Cognitive-behavioral treatment for severe anger in posttraumatic stress disorder.

With a randomized group design, a 12-session anger treatment was evaluated with severely angry Vietnam War veterans suffering combat-related posttraumatic stress disorder (PTSD). Eight participants in anger treatment and 7 in a routine clinical care control condition completed multiple measures of anger control, anger reaction, and anger disposition, as well as measures of anxiety, depression, and PTSD at pre- and posttreatment. Controlling for pretreatment scores, significant effects were found on anger reaction and anger control measures but not on anger disposition or physiological measures. Eighteen-months follow-up (for both completers and dropouts) supported the posttreatment anger control findings. The challenges of treatment research with this refractory population are discussed.

Anger regulation deficits in combat-related posttraumatic stress disorder.

We describe a typology of regulatory deficits associated with anger in combat-related posttraumatic stress disorder (PTSD). Cognitive, arousal, and behavioral domain deficits in anger regulation were observed clinically in PTSD patients with high levels of anger who were participating in a multi-year trial of a structured anger treatment. We also describe a category of patients whose anger type we have termed "ball of rage." These patients exhibit regulatory deficits in all three domains of anger regulation. We offer a conceptual framework to advance the understanding of anger associated with PTSD and to guide its effective treatment.

Differences in semantic event-related potentials in learning-disabled, normal, and gifted children.

Cortical event-related potentials (ERP) were recorded over FZ, CZ, and PZ scalp sites in 15 learning-disabled (LD), 14 gifted (G), and 13 normal control (N) children of ages 8-12. The common stimulus consisted of nouns presented 80 percent of the time; the target stimulus of animal names presented 20 per cent of the time. ERPs were averaged over subjects from 180 msec pre-stimulus to 900 msec post-stimulus. Principal components analysis was used to determine if there were amplitude differences at different post-stimulus latencies as a function of condition. Differences in ERP's between groups (LD, gifted, and controls), scalp locations, and common versus target stimuli were analyzed by ANOVAs. P3, Late, P2, and N1 components represented by four factors were identified. Significant differences between G and LD and the N and LD groups were found target stimulus at all central locations for the P3 component. Differences were found centrally between G and LD, G and N, and N and LD groups for the P2 component centrally. Other differences were found for the N1 and late components. These differences could be interpreted as a deficit in either attentional mechanisms or information processing for the LD group.

Severe perinatal Marfan syndrome.

The cardiovascular manifestations of the Marfan syndrome in older children and adults have been well described. Clinical, radiographic, and echocardiographic data regarding three patients with severe perinatal Marfan syndrome are described. Two of these patients had the syndrome at birth and died in infancy. The syndrome was diagnosed in the third patient at 6 months of age and the child is still alive at 3 years of age. The possible relationship among the Marfan syndrome, Ehlers-Danlos syndrome, and osteogenesis imperfecta is considered. Patients with Marfan syndrome and severe cardiorespiratory problems early in life tend to have a limited life expectancy.

Echocardiographic abnormalities in the mucopolysaccharide storage diseases.

The mucopolysaccharide storage diseases express themselves clinically with a wide variety of abnormalities, including growth and mental retardation, skeletal abnormalities, clouded corneas, nerve compression syndromes, upper airway obstruction and cardiovascular involvement, to name the most common. In most cases the cause of early death is cardiorespiratory failure secondary to cardiovascular involvement and upper airway obstruction. The findings of cardiac ultrasound examination in 29 children, adolescents and young adults are presented. In addition to the previously well-described abnormalities of the mitral and aortic valves in several types of mucopolysaccharide storage disease, we report patchy involvement in some cases, 3 instances of asymmetric septal hypertrophy not previously reported in mucopolysaccharide storage diseases, cardiac involvement in half of our patients with Sanfilippo syndrome and a lack of age-related severity of cardiac involvement even within the specific syndromes.

Atrial rupture in a child from cardiac massage by his parent.

A 4-year-old boy presented with a single seizure following a viral syndrome. He had a pericardial effusion on admission, and this increased suddenly on the third day of hospitalization, producing cardiac tamponade. After blood was aspirated from the child's pericardial cavity, the father revealed that he performed cardiac massage on his son following the seizure. A laceration of the right atrium was repaired at operation, and the boy made a good recovery. Cardiopulmonary resuscitation by lay persons is not without hazard, and patients with such a history should be watched carefully for the possibility of damage to intrathoracic structures.

Adaptation of a fluorescent immunoassay for canine haptoglobin.

The development and adaptation of a fluorescent immunoassay for determining changes in canine haptoglobin levels is described. Levels of canine haptoglobin determined by the fluorescent immunoassay from a group of healthy dog sera (68.0 mg/dl) compared favorably to the haptoglobin levels determined by a spectrophotometric method (74.5 mg/dl). The fluorescent immunoassay offered several advantages over currently used methods for determining levels of canine haptoglobin in serum.

Unique use of a tip-deflecting guide wire in removing a catheter embolus from an infant.

An umbilical catheter fragment embolus in a neonate was difficult to approach due to fixation of both ends, in the left atrial appendage and the ductus venosus, respectively. A tip-deflecting guide wire was used in unique fashion to free the catheter fragment and allow its percutaneous removal via the femoral vein approach.

Beta 1-selective adrenoceptor antagonists: examples of the 2-[4-[3-(substituted amino)-2-hydroxypropoxy]phenyl]imidazole class. 2.

An attempt to develop a highly cardioselective beta-adrenoceptor antagonist devoid of intrinsic sympathomimetic activity (ISA) focused on exploring structure-activity relationships around (S)-[p-[3-[[2-(3,4-dimethoxyphenyl)ethyl]amino]-2-hydroxypropoxy] phenyl]-4-(2-thienyl)imidazole. Strategies to reduce or eliminate ISA centered on structural changes that could influence activation of the receptor by the drug itself or by a metabolite. The approaches involved (a) eliminating the acidic imidazole N-H proton, (b) incorporating substituents ortho to the beta-adrenergic blocking side chain, (c) increasing steric bulk around the N-H moiety, (d) decreasing lipophilicity, (e) introducing intramolecular hydrogen bonding involving the imidazole N-H, and (f) displacing the imidazole ring from an activating position by the incorporation of a spacer element. The compounds were investigated in vitro for beta-adrenoceptor antagonism and in vivo for ISA. From these studies, the most successful variation involved the insertion of a spacer between the imidazole and aryl rings. (S)-4-Acetyl-2-[[4-[3-[[2-(3, 4-dimethoxyphenyl)ethyl]amino]-2-hydroxypropoxy]phenyl]methyl] imidazole (S-51) was demonstrated to be highly cardioselective (dose ratio beta 2/beta 1 greater than 9333) and devoid of ISA.

Early elective senning repair: optimal operative strategy for simple transposition of the great arteries.

After the inception of a new pediatric cardiovascular service, we reviewed the management of the first eight consecutive neonatal patients with simple transposition of the great arteries who underwent successful balloon atrial septostomy. Immediate cardiac catheterization and septostomy were performed, and all were discharged in good condition. Each returned at about 6 months of age for elective Senning repair in which the hypothermic arrest technique was used. All survived and are doing well at follow-up that now averages 20 months, and is over 1 year in every instance. While late follow-up is not yet available, it appears that this approach of early, elective repair of simple transposition can give optimal results, even within the context of a new clinical program.

Discovery, purification and characterization of the angiotensin converting enzyme inhibitor, L-681,176, produced by Streptomyces sp. MA 5143a.

L-681,176, an inhibitor of angiotensin converting enzyme was found in the culture filtrate of Streptomyces sp. MA 5143. The I50 of the crystalline inhibitor is about 1.3 micrograms/ml and the inhibition is reversed by zinc sulfate. In rats, L-681,176 exhibits a dose-related inhibition of the pressor response to angiotensin I with an ID50 of 142 mg/kg when administered intravenously. The structure of L-681,176 is similar to that of marasmine but lacking one carboxyl group. The maximum yield of L-681,176 occurs after three to four days growth at 28 degrees C.

R-enantiomer of timolol: a potential selective ocular antihypertensive agent.

Various studies were conducted to evaluate the effects of timolol, an S-enantiomer, relative to its R-enantiomer upon intraocular pressure and related ocular systems in the rabbit. The R-enantiomer was about one-third as potent as timolol in displacing 3H-dihydroalprenolol binding to iris-ciliary body tissue, reducing aqueous humor formation, and lowering intraocular pressure of alpha-chymotrypsin hypertensive eyes. In contrast, the R-enantiomer was 50 to 90 times less potent than timolol in antagonizing the effects of isoproterenol on pulmonary and atrial beta-adrenergic receptors. The data indicate that the R-enantiomer may lower intraocular pressure in man at concentrations less likely than timolol to block extraocular beta-adrenergic receptors. Finally, to account for the differential effect of the R-enantiomer upon ocular as opposed to extraocular beta-adrenergic receptors, it is tentatively suggested that this agent may also act upon a population of ocular beta-adrenergic receptors showing relatively poor stereoselectively.

Beta-adrenergic receptor subtypes in iris-ciliary body of rabbits.

Direct comparison of drug interaction with intraocular relative to extraocular beta-adrenergic receptors was used to test the hypothesis that the receptors in ocular tissues are of the beta 2-subtype. Potencies for the displacement of 3H-dihydroalprenolol radioligand binding to membranes obtained from rabbit-iris ciliary bodies by beta-adrenoceptor agonists was in the order: isoproterenol greater than or equal to epinephrine greater than salbutamol greater than terbutaline greater than tazolol greater than norepinephrine. Similar radioligand displacement by beta-adrenoceptor antagonists was in the order of potency: alprenolol greater than or equal to bupranolol = oxprenolol = timolol = propranolol greater than ICI 118,551 = IPS 339 much greater than betaxolol greater than metoprolol. Finally, for the above beta-adrenoceptor antagonists, a highly significant correlation was obtained for displacement of radioligand to ocular tissues (pKi values) relative to antagonism (pA2 values) of isoproterenol-induced guinea-pig tracheal relaxation but not guinea-pig atrial chronotropic effects. Consequently, the above three observations reinforce the notion that rabbit-iris ciliary bodies contain beta-adrenergic receptors predominantly of the beta 2-subtype.

The effect of atrial pacing-induced tachycardia on left ventricular contractile function in conscious newborn and adult sheep.

In order to determine if an increase in heart rate is associated with an increase of left ventricular contractile function during the neonatal period we recorded phasic and mean aortic blood pressure, left atrial mean or left ventricular end diastolic pressure, phasic left ventricular blood pressure, aortic blood flow velocity and the instantaneous first derivatives of left ventricular blood pressure (dP/dt) and aortic blood flow velocity (dV/dt) during pacing-induced tachycardia in conscious newborn and adult sheep. There was a significant positive linear correlation between heart rate and both indices of contractility (dP/dt and dV/dt) in both age groups. Left ventricular end diastolic pressure was unchanged except for a decrease at the most rapid heart rate in the newborns. There was no change in aortic mean blood pressure during the study. Our data demonstrate that an increase of heart rate is associated with an increase of left ventricular contractile function in conscious neonatal and adult sheep. Investigations of the effects of potential inotropic agents on left ventricular contractile performance in newborns and adults must evaluate the independent effect of any simultaneously occurring increase in heart rate.