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.

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.

Use of (S)-(trifloxymethyl)oxirane in the synthesis of a chiral beta-adrenoceptor antagonist, (R)- and (S)-9-[[3-(tert-butylamino)-2-hydroxypropyl]oximino]fluorene.

Two synthetic approaches were used to prepare, in chirally pure form, the beta-adrenoceptor antagonist 9-[[3-(tert-butylamino)-2-hydroxypropyl]oximino]fluorene (1a). One of these employed the oxazolidine (S)-6 generated from D-mannitol, while the other utilized (S)-[[(trifluoromethanesulfonyl)oxy]methyl]oxirane (4) as the chiral three-carbon fragment. This latter synthesis was designed to incorporate the amino function in the last step. In vitro, a beta 2 selectivity of only 2.2 was observed for 1a. The example, (S)-9-[[3-(tert-amylamino)-2-hydroxypropyl]oximino]fluorene (1b), was also prepared and found to be selective for the beta 1 receptor by a factor of 2.5. In contrast to other beta-adrenoceptor antagonists, the enantiomers of 1a exhibited no chiral preference; i.e., (S)-1a and (R)-1a possessed a similar order of beta-adrenoceptor antagonistic activity.

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

A series of 2-[4-[3-(substituted-amino)-2-hydroxypropoxy]phenyl]imidazoles is described. The compounds were investigated in vitro for beta-adrenoceptor antagonism, and several examples were found to be selective for the beta 1-adrenoceptor. The structure--activity relationship exhibited by this series of compounds is discussed. (S)-2-[p-[3-[[2-(3,4-dimethoxyphenyl)ethyl]amino]-2-hydroxypropoxy]phenyl]-4-(2 -thienyl)imidazole [(S)-13] was over 100 times more selective than atenolol for the beta 1-adrenergic receptor and has been selected for in-depth studies.

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.

Endocarditis in high-risk neonates.

The clinical spectrum of neonatal endocarditis, including bacterial and nonbacterial types, is examined in five case reports that were drawn from nursery experiences over a recent 2-year period. In contrast to previous reports of 100% mortality from neonatal endocarditis, one patient survived. Changing heart murmur and hematuria were most frequently associated with bacterial and nonbacterial endocarditis in four of the five cases. Pulmonary hypertension, thrombocytopenia, and coagulopathy were also associated with nonbacterial endocarditis. Echocardiograms were performed on four of the patients; only one was suggestive of endocarditis. Staphylococcus aureus was isolated from both cases of bacterial endocarditis, including the single survivor. Thus, it is suggested that the initial antibiotic coverage of any neonate with the clinical syndrome of sepsis, hematuria, and a heart murmur include antistaphylococcal coverage for the possibility of bacterial endocarditis.

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.

Relationship between angiotensin I blockade and antihypertensive properties of single doses of MK-421 and captopril in spontaneous and renal hypertensive rats.

The exact mechanism of action of angiotensin converting enzyme (ACE) inhibitors in reducing blood pressure is not known, although inhibition of angiotensin II formation is the generally accepted mechanism. Experiments were performed in two models of experimental hypertension to determine whether or not inhibition of the pressor response to angiotensin I, 300 ng/kg i.v., would correlate with the antihypertensive response to single oral doses of N-[(S)-1-(ethoxycarbonyl)-3-phenylpropyl]-L-Ala-L-Pro (MK-421), a new ACE inhibitor. Captopril, given as a single oral dose, was studied in spontaneously hypertensive rats (SHR) for comparative purposes. In SHR, MK-421 at 0.1-3 mg/kg p.o. and captopril at 0.1-3 mg/kg p.o. were approximately equipotent with regard to inhibiting the pressor response to angiotensin I (relative potency=1.7; 95% C.I.=0.7-4.5). The magnitude of ACE inhibition and onset of action were similar with both agents, but MK-421 had a longer duration of action. The decrement in systolic pressure following each ACE inhibitor consisted of an initial decrease in blood pressure corresponding to the maximal inhibition of angiotensin I pressor response and a secondary fall in blood pressure which was evident 5-6 h after treatment. At this time, the inhibition of the pressor response to angiotensin I was minimal. Thus, the time course for blockade of angiotensin I and the blood pressure reduction did not correspond. The dose-response regression lines for the antihypertensive effect of each inhibitor, unlike those for ACE inhibition, were flat. The potency ratio computed on the basis of the maximum fall in blood pressure over 6 h revealed that MK-421 was 11.5 times (P less than 0.05) more potent thant captopril. In 2-kidney Grollman renal hypertensive rats (RHR), MK-421 at 0.3-10 mg/kg p.o. inhibited the pressor response to angiotensin I by 65-95%, but produced significant decrements in blood pressure only at 10 mg/kg p.o. The finding that MK-421 was more potent than captopril in lowering blood pressure in SHR, yet equally active in its ability to block angiotensin I pressor responses, suggests that a mechanism(s) other than inhibition of plasma ACE is involved in the decrease in blood pressure was not reduced. However, a higher dose which produced a similar degree of blockade was associated with a significant decrease in blood pressure.

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.

Pediatric aspects of essential hypertension.

Severe hypertension is rarely seen in children, but there is increasing evidence that childhood may be an appropriate time to consider measures for the prevention of hypertension later in life. The normal range for blood pressure in children and the significance of an "elevated" blood pressure are discussed. Evidence is reviewed which indicates that heredity obesity, and sodium intake are important determinants of blood pressure. There is a role for the nutritionist in the management and the possible prevention of essential hypertension.

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.

A simple technique for delivering liquids directly to the mouth of an unrestrained rat.

A simple surgical procedure is described that makes it possible to deliver liquids directly into the mouth of a freely mobile rat. Data presented show that an 8% sucrose solution delivered by this technique is an effective reinforcer in a variety of simple and discriminative schedules of reinforcement.

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.

Erythropoietic effects of PGE2 and 2 endoperoxide analogs.

The erythropoietic effects in exhypoxic polycythemic mice of two endoperoxide and analogs were assessed and compared with PGE2. The 9 alpha, 11 alpha epoxymethano analog (U-44069) was found to be a much more potent erythropoietic stimulus than the 11 alpha, 9 alpha analog (U-46619) or PGE2.

The large-scale isolation of renin-containing granules from rabbit renal cortex by zonal centrifugation.

A new method for the isolation of renin-containing granules from rabbit renal cortex by sequential two-dimensional centrifugation is presented. A mitochondrial fraction produced by preparative differential centrifugation was subjected to isopycnic centrifugation on combined discontinuous and linear density gradients in the same SZ-14 reorienting gradient zonal centrifuge rotor. Renin activity, as assayed by radioimmunoassay for angiotensin I, was localized in a region of the density gradient with a corresponding density of 1.196 Gm. per cubic centimeter or 1.53 M sucrose. The renin-containing granules were enriched 5.0-fold over whole homogenate levels, while peroxisomes were enriched 17.4-fold, lysosomes 23.4-fold, and mitochondria 4.3-fold. Electron microscopic examination of the fraction with highest renin activity showed a granular fraction almost free of contamination from other subcellular material. The data supports the view that renin-containing granules are a distinct subcellular particle. This new method for the large-scale isolation of renin-containing granules makes it possible to obtain the quantity of material necessary to study the release renin at the subcellular level and permit the further biochemical purification and characterization of the enzyme.