Variability of breath hydrogen excretion in breast-fed infants during the first three months of life

Breath hydrogen excretion was measured serially in breast-fed infants. There was marked variability in H2 excretion, both within and between infants. The findings indicate that unabsorbed food is not the only substrate, and that breath H2 may not be an effective method to assess carbohydrate absorption in young infants.

Double-blind crossover comparison of human and porcine insulins in patients reporting lack of hypoglycaemia awareness

There has been much debate about reports that some insulin-treated diabetic patients lose awareness of hypoglycaemic symptoms on changing from porcine to human insulin. In a double-blind, crossover study, we sought differences between porcine and human insulin in the frequency and characteristics of hypoglycaemic episodes among patients who reported a reduction of awareness of hypoglycaemia after changing treatment. We studied 50 patients referred by their physicians because of complaints of lack of awareness of hypoglycaemia on human insulin. They had had diabetes for a mean of 20 (SD 12) years and 70% had good or acceptable glycaemic control. Each patient was treated in a double-blind manner for four 1-month periods, two with human and two with porcine insulin, in random order. Only 2 patients correctly identified the sequence of insulin treatments used; 8 or 9 would have been expected to do so by chance alone. The mean percentage of hypoglycaemic episodes associated with reduced or absent awareness was 64% (SD 30%) for human insulin and 69% (31%) for porcine insulin. We could find no statistically significant differences between the insulin species with respect to glycaemic control or the frequency, timing, severity, or awareness of hypoglycaemia. Reduced hypoglycaemia awareness is common with both human and porcine insulins.

The fasciitis-morphea complex in children

OBJECTIVE

To describe the clinical presentation and treatment of the combined syndrome of fasciitis and morphea in children.

SETTING

The rheumatic disease clinic of a university children's hospital.

PATIENTS

Six children who were referred for signs or symptoms of fasciitis were observed.

SELECTION PROCEDURES

All children who were referred for fasciitis were included in the study.

INTERVENTIONS

Therapy included prednisone initially and subsequent long-term treatment with penicillamine and alternate-day doses of prednisone.

MEASUREMENTS AND RESULTS

Symptoms of morphea appeared 1 year before to 4 years after the first signs of fasciitis were observed. The fasciitis was characterized by usually symmetrical, centrifugal swelling, pain, and contracture formation. The morphea and fasciitis did not appear in the same areas of the body.

CONCLUSIONS

The fasciitis and morphea are clearly linked manifestations. The fasciitis, but not the morphea, appears to respond to treatment with steroids. Treatment with penicillamine may ameliorate the sclerosis of the morphea but does not stop new lesions from appearing.

Antibodies to lipid A in pauciarticular juvenile arthritis: clinical studies

IgG antibodies to monophosphoryl lipid A (MPL) are more concentrated in synovial fluids than in the blood of children with pauciarticular juvenile arthritis. Correlations between IgG anti-MPL levels and numbers of inflamed joints were highly significant in 2 of 10 patients followed for 8 years and suggestive in 2 patients followed for shorter periods. A fifth patient had a correlation between IgM anti-MPL and joint count.

Adaptation to juvenile rheumatic disease: A controlled evaluation of functional disability with a one-year follow-up

Compared the adaptation of 165 patients with juvenile rheumatic disease (JRD) to that of their healthy siblings. Patients were divided into those with mild functional disability and those with moderate/severe disability. Adaptation in several domains was assessed by parents and children on two occasions 1 year apart. The adjustment difficulties of the JRD children were limited primarily to social functioning but appeared also in the psychological and family problems domains. Compared to "mild" patients, "moderate/severe" patients had more adjustment difficulties; in some areas, mild patients functioned as well as their healthy siblings. Some Time 1 differences were replicated at Time 2. The results help to delineate (a) the specific domains in which children with chronic disease have adjustment difficulties and (b) the factors that put children at risk for developing adjustment problems.

Complement C5a receptor assay for high throughput screening

The complement C5a receptor on U937 cells, a human histiocytic lymphoma cell line, stimulated with dibutyryl-cAMP have been stabilized for at least 3 months at a dilute, ready to use concentration. [125I]-Bolton Hunter labeled C5a, (recombinant, human) has been prepared by reverse phase HPLC to 2200 Ci/mmol. Using a filtration binding assay the Kd from receptor saturation analysis is 10-40 pM and there are 50,000-100,000 receptor sites per cell. These reagents have permitted the development of a reliable, reproducible and convenient drug screening assay, in kit format, for compounds acting at the C5a receptor.

Angiotensin carboxypeptidase activity in urine from normal subjects and patients with kidney damage

Angiotensin carboxypeptidase (ACP) activity has been detected in urine samples from normal subjects and patients with hypertension and diabetes by determining the enzyme's ability to convert angiotensin I to des-Leu angiotensin I. Gel filtration chromatography of a concentrated urine sample indicated that about equal amounts of the enzyme exist as 100 kDa and 500 kDa molecular weight forms, respectively. This ACP activity co-eluted with activity that cleaved histidine from des-Leu angiotensin I to form angiotensin II and activity that cleaved tyrosine from benzyloxycarbonyl-glutamyl-tyrosine (ZGT). These results suggest that the urinary ACP activity is due to cathepsin A as we have reported previously for the porcine kidney enzyme. Analysis of sequential urine samples from a single individual over a 6-day period revealed as much as a 6-fold fluctuation in creatinine-normalized ACP activity. Of five male healthy adult subjects, the creatinine-normalized urinary ACP activity ranged from 1.7 to 3.7 mU/mL with a mean of 2.8 mU/mL. However, five male patients with renovascular hypertension had elevated levels of ACP activity with a mean of 11.6 mU/mL. Of five male patients with diabetic nephropathy, all had elevated ACP activity levels with a mean of 21.0 mU/mL. It is concluded that ACP activity in the urine is due to cathepsin A probably derived from kidney tissue, and that the release is increased in patients with kidney damage. We suggest that urinary ACP activity should be evaluated further for a possible relationship to renal hypertension and as a potentially early marker for diabetic nephropathy.

Immunologic abnormalities of juvenile arthritis

Many immunologic abnormalities have been found in children with all forms of chronic arthritis, but few are clinically useful or well understood. However, in children with arthritis it is important to distinguish among those with rheumatoid factor, antinuclear antibodies, or hypogammaglobulinemia. Rheumatoid factor is specific for adult-type rheumatoid arthritis; the presence of antinuclear antibodies increases the likelihood that the child may develop uveitis; and hypogammaglobulinemia may be associated with complicating infections. Other unusual antibodies, autoantibodies, antigen-antibody complexes, and complement activation products are found in children with arthritis, but none of these define a diagnostic or consistent group of diseases. Similarly, changes in the numbers of immunologically active cells and regulating mechanisms occur but not in specific patterns. As yet, none of the known immunologic abnormalities explain the pathogenesis of these diseases and only a few appear disease specific.

C3 activation products correlate with antibodies to lipid A in pauciarticular juvenile arthritis

IgM antibodies to monophosphoryl-lipid A were found to be elevated in sera from children with all forms of juvenile arthritis (JA) and systemic lupus erythematosus. Of more interest, in patients with pauciarticular JA, IgG antibody titers to monophosphoryl-lipid A were found to be correlated with the C3a concentration and the C3d:C3 ratio. Although the full specificity of these antibodies is unknown, they are the first that have been found to be correlated with complement activation products in any form of JA.

Characteristics of a thrombin inhibitor secreted by activated platelets

A 77-kDa complex of thrombin and a protein secreted by activated platelets had little if any thrombin amidolytic activity, indicating that the secreted protein is an inhibitor. The molecular weight of the inhibitor before reaction with thrombin was approximately 50,000. The apparent second-order rate constant for complex formation was estimated to be 1.3 x 10(6) M-1 s-1 (mean of four measurements); it was not affected by heparin or heparinase. These properties distinguish this inhibitor from other protease inhibitors secreted by platelets. The inhibitor reacted with trypsin and possibly with urokinase but not with factor Xa.

Metabolic effects of adding sucrose and aspartame to the diet of subjects with noninsulin-dependent diabetes mellitus

This study compared the effects of adding sucrose and aspartame to the usual diet of individuals with well-controlled noninsulin-dependent diabetes mellitus (NIDDM). A double-blind, cross-over design was used with each 6-wk study period. During the sucrose period, 45 g sucrose (9% of total daily energy) was added, 10 g with each main meal and 5 g with each between-meal beverage. An equivalent sweetening quantity of aspartame (162 mg) was ingested during the aspartame period. The addition of sucrose did not have a deleterious effect on glycemic control, lipids, glucose tolerance, or insulin action. No differences were observed between sucrose and aspartame. Sucrose added as an integral part of the diabetic diet does not adversely affect metabolic control in well-controlled NIDDM subjects. Aspartame is an acceptable sugar substitute for diabetic individuals but no specific advantage over sucrose was demonstrated.

Impact of juvenile arthritis on families. An educational assessment

State of the art patient education programs have as their goals changes in behaviors, coping styles, health status, and/or costs. The accomplishment of these goals often involves not only the patient but also his or her whole family. This is especially true if the patient is a child. Based on this premise, we undertook an educational needs assessment of 50 children with juvenile arthritis (JA) and their families. Through utilization of a grounded theory methodology, open-ended questionnaires were completed by JA children, their parents, and their siblings. The resulting analysis suggests (1) the need for family-based education, (2) differing needs of various family members, and (3) several hypotheses for further study.

Breath hydrogen excretion in infants with colic

Breath hydrogen excretion as an index of incomplete lactose absorption was measured in 118 healthy infants who were either breast fed or given a formula feed containing lactose, some of whom had colic. Infants with colic (n = 65) were selected on the basis of the mother's report of a history of inconsolable crying lasting several hours each day. Infants in the control group (n = 53) were not reported to cry excessively by their mothers. Breath samples were collected using a face mask sampling device preprandially, and 90 and 150 minutes after the start of a feed. Normalised breath hydrogen concentrations were higher in the group with colic than in the control group at each time point. The median maximum breath hydrogen concentration in the colic group was 29 ppm, and in the control group 11 ppm. The percentage of infants with incomplete lactose absorption (breath hydrogen concentration more than 20 ppm) in the colic group was 62% compared with 32% in the control group. The clinical importance of the observed association between increased breath hydrogen excretion and infantile colic remains to be determined. Increased breath hydrogen excretion indicative of incomplete lactose absorption may be either a cause or an effect of colic in infants.

Photoaffinity labeling of dopamine D1 receptors

A high-affinity radioiodinated D1 receptor photoaffinity probe, (+/-)-7-[125I]iodo-8-hydroxy-3-methyl-1-(4-azidophenyl)-2,3,4,5-tetra hyd ro- 1H-3-benzazepine ([125I]IMAB), has been synthesized and characterized. In the absence of light, [125I]IMAB bound in a saturable and reversible manner to sites in canine brain striatal membranes with high affinity (KD approximately equal to 220 pM). The binding of [125I]IMAB was stereoselectively and competitively inhibited by dopaminergic agonists and antagonists with an appropriate pharmacological specificity for D1 receptors. The ligand binding subunit of the dopamine D1 receptor was visualized by autoradiography following photoaffinity labeling with [125I]IMAB and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Upon photolysis, [125I]IMAB incorporated into a protein of apparent agents in a stereoselective manner with a potency order typical of dopamine D1 receptors. In addition, smaller subunits of apparent Mr 62,000 and 51,000 were also specifically labeled by [125I]IMAB in these species. Photoaffinity labeling in the absence or presence of multiple protease inhibitors did not alter the migration pattern of [125I]IMAB-labeled subunits upon denaturing electrophoresis in both the absence or presence of urea or thiol reducing/oxidizing reagents. [125I]IMAB should prove to be a useful tool for the subsequent molecular characterization of the D1 receptor from various sources and under differing pathophysiological states.

Kinetics of the formation of thrombin-thrombospondin complexes: involvement of a 77-kDa intermediate

Thrombin forms sodium dodecyl sulfate stable complexes of 77 and greater than 450 kDa with proteins secreted by activated platelets. The kinetics of formation of these complexes were investigated by addition of 125I-thrombin to the supernatant solution of A23187-activated platelets. Complexes were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis either with or without reduction of disulfide bonds. When analyzed on nonreduced gels, the 77-kDa complex reached a maximum at about 3 min and then declined as the greater than 450-kDa complex increased. On reduced gels (on which there was no greater than 450-kDa complex) the 77-kDa complex approached the level of the greater than 450-kDa complex on nonreduced gels. The half-time of formation was less than 1 min for the 77-kDa complex and about 15 min for the greater than 450-kDa complex. These time courses suggested that the 77-kDa complex was incorporated into the greater than 450-kDa complex as an essential precursor. Formation of complexes was inhibited by a competitive inhibitor or a noncompetitive inhibitor of thrombin, and the pH dependence of formation of both complexes was similar to the pH dependence for catalytic activity of thrombin. Ca2+ inhibited formation of the greater than 450-kDa complex but not of the 77-kDa complex. A model is presented in which thrombin and a secreted protein form a 77-kDa complex by a process that involves the active site of thrombin. The 77-kDa complex is then incorporated into a greater than 450-kDa complex by thiol-disulfide exchange with thrombospondin, a process that is inhibited by Ca2+. Thrombin in the greater than 450-kDa complex had no catalytic activity.

Conversion of angiotensin I to angiotensin II by cathepsin A isoenzymes of porcine kidney

We have reported the existence of a carboxypeptidase in a human renal extract that converts Angiotensin I (AI) to Angiotensin II (AII) in two steps with des-leu-AI (dl-AI) being formed as an intermediate. Since this carboxypeptidase had properties similar to cathepsin A, the ability of cathepsin A to metabolize AI was studied. Cathepsin A was purified from hog kidney with enzyme activity being monitored using both benzyloxycarbonyl-glutamyl-tyrosine (ZGT) and AI as substrates. The procedure separated the expected large and small molecular weight forms of cathepsin A as well as two additional isoenzymes. All of the isoenzymes had carboxypeptidase activity with ZGT, AI, and dl-AI. No detectable cleavage of AII was observed. Cathepsin A,S (small) activity with ZGT or AI as substrate was inhibited to a similar extent by diisopropylfluorophosphate, mersalyl acid, and a decapeptide renin inhibitor. It is concluded that the renal angiotensin carboxypeptidase activity is catalyzed by cathepsin A. By its ability to convert AI to AII, cathepsin A may be a component of the intrarenal renin-angiotensin system.

Dual role of norepinephrine in the hippocampal CA1 region of the rat: inhibition and disinhibition

Norepinephrine (NE) has been shown to produce either an inhibitory or an excitatory influence on CA1 pyramidal neurons of the hippocampus depending on the dosage. It was suggested that NE, in addition to exerting a direct inhibitory effect on pyramidal cells, may also act upon recurrent inhibitory interneurons to produce a disinhibition of the pyramidal cells. The present study was undertaken to examine the effect of NE on alveus-evoked inhibition, presumably mediated by the basket cell interneurons innervating the pyramidal cells. Experiments were carried out on the in vitro hippocampal slice preparation and inhibition was assessed by the percent reduction of the stratum radiatum evoked population spike response when preceded by a conditioning pulse delivered to the alveus to activate the inhibitory interneurons via the recurrent collaterals of the pyramidal cells. Paired pulse stimulation resulted in inhibition of the stratum radiatum evoked test response with conditioning-test intervals up to 60 ms. NE (50 microM) perfusion resulted in a significant and reversible reduction of the alveus-evoked recurrent inhibition. Intracellular recordings using a similar paired pulse paradigm corroborated the extracellular data well. The possible roles of NE in the physiological functioning and pathophysiology of epileptiform activity of the hippocampus are discussed.

Insulin-like growth factors I and II in children with systemic onset juvenile arthritis

Systemic onset juvenile arthritis (JA) has been associated with growth failure in children whether or not treated with adrenocorticosteroids. Growth hormone secretion has been reported to be normal, but production of insulin-like growth factors has not been studied. We measured serum concentrations of insulin-like growth factor I and II in a group of children with systemic JA at different times, and during treatment with only nonsteroidal antiinflammatory therapy or while receiving prednisone. Mean concentrations of insulin-like growth factor I and II were below normal for age whether or not prednisone was being given. Growth failure during periods of active disease was observed in both groups. Only 4 of 11 prepubertal children in whom growth rates were measured grew 4.5 cm or more/year. However, longitudinal studies of individual children showed that lowest growth rates occurred while taking prednisone and that growth rates were not correlated to insulin-like growth factor levels.