Five cases of thrombocytopenia induced by primary human herpesvirus 6 infection.

Five patients suffering from exanthem subitum with thrombocytopenia were confirmed as primary human herpesvirus 6 (HHV-6) infection by serological test. All cases had thrombocytopenia during the acute phase of exanthem subitum. The clinical features of these cases were benign, and all recovered without any specific treatment. Moreover, 4 of the 5 cases showed a mild elevation of hepatic transaminase during the same period, and other viral infections including cytomegalovirus, Epstein-Barr virus, and human herpesvirus 7 were ruled out in these patients. It was speculated that direct inhibition of platelet production by the virus or cytokine induced by the virus-infected cells was the mechanism of the thrombocytopenia induced by primary HHV-6 infection.

Heterogeneity of drug susceptibility of mouse active anaphylactic shock.

To determine the main mediators for mouse anaphylactic shock, the suppression of active anaphylactic shock by cyproheptadine, an antagonist of histamine/serotonin, and CV-6209, an antagonist of platelet-activating factor (PAF), was systematically evaluated using various mouse strains. The suppression was quite heterogeneic depending on the mouse strain and method for sensitization. When sensitization was done with bovine serum albumin (BSA) plus Bordetella pertussis organisms, anaphylactic shock in C57BL/6N mice was suppressed by cyproheptadine but not by CV-6209. In contrast, shock in C3H/HeN and WBB6F1-W/Wv mice was suppressed by CV-6209 but not by cyproheptadine. Shock in BALB/c mice was suppressed by both agents but that in WBB6F1-(+)/+ mice was not at all by either one. DS and BDF1 mice showed differences due to the length of the sensitization period; shock was not suppressed by cyproheptadine with a shorter sensitization (9 to 11 days) but clearly suppressed with prolonged sensitization of 14 to 15 days. Shock in DS, WBB6F1-(+)/+ and BDF1 mice, which was not suppressed by either agent alone, was strongly suppressed by the combination of the two agents. In animals which had been sensitized with BSA emulsified with Freund's complete adjuvant (FCA) and given DL-propranolol as a shock potentiator, a similar pattern of drug susceptibility as that in the pertussis-vaccinated animals was obtained in general, although a discrepancy was seen with regard to the suppression of CV-6209 in C3H/HeN and BDF1 mice. Synergistic suppression by CV-6209 and cyproheptadine was also very clear with the WBB6F1-(+)/+ mice sensitized using FCA. In addition, results quite similar to those with cyproheptadine were obtained with the other two antihistamines, triprolidine almost devoid of antiserotonin activity and oxatomide, in testing with BDF1 mice sensitized using Bordetella pertussis organisms. From these findings, the conclusion is that histamine and PAF play major roles solely or in combination in mouse active anaphylactic shock.

Urine kallikrein excretion in relation to renal sodium handling in minimal change nephrotic syndrome.

Twenty-four-hour urine kallikrein excretion (Uka), urine protein excretion, renal sodium handling, and the activity of the renin-angiotensin-aldosterone system were serially studied in 11 children at three different stages of the minimal change nephrotic syndrome (MCNS)-edema forming state, proteinuric steady state in which a relapse of the disease was just starting but no edema as yet and remission. The value for Uka was significantly increased in the edema forming state in contrast to the normal values of proteinuric steady state and remission. Serum sodium concentration was only decreased in the edema forming state and the degree of hypoalbuminemia and proteinuria did not differ between the edema forming and proteinuric steady states. Urine volume, absolute and fractional sodium excretion were significantly decreased in the edema forming and proteinuric steady states as compared with those in remission, suggesting that sodium retention was present in both states of the disease although the change in these parameters was more profound in the edema forming state than in the proteinuric steady state. Creatinine clearance did not differ among each stage of the disease. Plasma renin activity and plasma aldosterone concentration were significantly increased in the edema forming state as compared with those in the proteinuric steady state and remission. Plasma renin activity and plasma aldosterone concentration were significantly correlated directly with Uka and plasma aldosterone concentration was correlated inversely with urine sodium excretion. No relation was noted between Uka and other variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Intermittent versus long-term tapering prednisolone for initial therapy in children with idiopathic nephrotic syndrome.

Forty-six children with steroid-responsive nephrotic syndrome were randomly allocated to receive two different prednisolone regimens for initial therapy. Twenty-nine children (group 1) received an intermittent regimen (60 mg/m2/day for 4 weeks, followed by 40/mg/m2/day on 3 days a week for 4 weeks); 17 children (group 2) had a long-term regimen (60 mg/m2/day for 4 weeks, followed by the same dose on alternate days for 4 weeks and the doses tapered by 10 mg/m2, given on alternate days every 4 weeks for 5 months). There was no difference between the two groups in the regimen used to treat relapses, steroid responsiveness, number of patients with relapses, and frequency of toxic reactions to steroids. However, the number of patients with a relapse within 6 months after initial therapy and the number of those with frequent relapses or steroid dependence were significantly higher in group 1 than in group 2 (P less than 0.05 for both). The data indicate that the long-term tapering regimen appears to be both safe and preferable to the intermittent regimen for initial therapy in children with idiopathic nephrotic syndrome.

Atrial fibrillation following methylprednisolone pulse therapy.

Two children, one with renal manifestations of systemic lupus erythematosus and the other with idiopathic nephrotic syndrome, were treated with methylprednisolone pulses. Neither had previous evidence of underlying cardiac disease. Within 24 h of pulse therapy, they complained of palpitations and developed atrial fibrillation which reversed spontaneously or after anti-arrhythmic therapy. Subsequent serial electro- and echocardiograms were normal. We propose that the arrhythmias were a complication of steroid pulse therapy.

Effect of corticosteroids on coagulation factors in children with nephrotic syndrome.

Prothrombin time (PT), activated partial thromboplastin time (APTT) and plasma procoagulant activities were studied in 38 children with nephrotic syndrome in the presence or absence of prednisolone therapy. PT was normal but APTT was prolonged during relapse in untreated patients. Increased factors V, VII, VIII, XI and XIII in both treated and untreated and factor IX in treated patients, as well as decreased factors X and XII in untreated patients, were observed during relapse. These coagulation factor changes were unrelated either to the dose of prednisolone or underlying renal histology and normalized with clinical remission. However, plasma levels of factors II, V, VIII, IX, X and XI were still increased in treated patients. The data suggest that corticosteroids shorten APTT, raise both intrinsic and extrinsic factors, and therefore have favorable and unfavorable effects on the coagulation system in children with nephrotic syndrome.

Mouse anti-benzylpenicilloyl IgE monoclonal antibody: preparation, characterization and cross-reactivity.

Anti-benzylpenicilloyl (BPO-) monoclonal antibody of the IgE class was prepared from spleens of immune C57BL/6 mice whose sera reacted with BPO-hapten, penicillin G(PCG) polymer, cephalothin (CET)-hapten and CET polymer. Affinity chromatography experiments showed that the haptenic specificity of the IgE monoclonal antibody (designated BIE-13CE) was directed mainly to phenylacetyl portion of BPO group. BIE-13CE antibody reacted on passive cutaneous anaphylaxis (PCA) assay with BPO-hapten, CET-hapten, cephaloridine-hapten and CET polymer, but did not react with PCG polymer, ampicillin-hapten, or cefazolin-hapten. These results indicated that the sera of the immune C57BL/6 mice contained IgE antibodies capable of cross-reacting at the monoclonal antibody level with various forms of eliciting antigens and that the cross-reactivity of the antibody could be ascribed essentially to the structural similarity of acyl side chains of the antibiotics. The structure of the CET polymer is also discussed in terms of its PCA reactivity with the monoclonal antibody and analytical and spectral data of the polymer.

Effect of dipyridamole treatment on proteinuria in pediatric renal disease.

The effect of dipyridamole on proteinuria was studied in 60 children with various renal diseases. A significant decrease in 24-hour urine protein excretion was observed within a few months after treatment in 32 (53%) of the patients with minimal or moderate mesangial proliferation. The effect was reproducible and parallelled by a reduction in plasma levels of beta-thromboglobulin. Renal function in patients significantly improved with the therapeutical effect. The appropriate dosage was 4-10 mg/kg daily and no serious toxicity was seen despite large dosage and even in long-term application. The data suggest that dipyridamole treatment appears safe and has a beneficial effect on proteinuria dependent on its effect on platelets in renal disease.

Cephalothin and penicillin G polymers as elicitors of rat PCA mediated by mouse IgE antibodies.

PCA-eliciting activities of cephalothin- and penicillin G-polymers were examined in rats sensitized with homologous IgE antibodies of mouse origin. Cephalothin-polymers elicited PCA regardless of the source of antibodies and the methods to raise them, the minimal effective dose being 2 to 20 micrograms/animal. Penicillin G-polymers provoked PCA only when anti-benzylpenicilloyl IgE antibody of C57BL/6J mouse raised early after immunization was used. The minimal effective dose in this case was 5 micrograms/animal, being comparable to that of cephalothin polymers.