Inflammatory islet damage in patients bearing HLA-DR 3 and/or DR 4 haplotypes does not lead to islet autoimmunity

Summary The hypothesis was tested that islet autoimmunity is induced by ongoing islet cell destruction in subjects with susceptibility genes HLA-DR 3 and/or DR 4. Sixty-one patients with confirmed chronic pancreatitis were analysed, 30 of whom expressed HLA-DR 3 and/or DR 4. Electron microscopy studies in 10 patients showed that the inflammatory process also affected islets, as recognisable from islet cell lysis, intrainsular fibrosis and immune cell infiltrates. None of the sera tested contained any of three markers of islet autoimmunity, ICA, IAA or GAD antibodies. A correlation was seen between the loss of exocrine function, as determined by the ALTAB-test, and of beta-cell function, as determined by the C-peptide response to i. v. glucagon. However, there was no preferential loss of beta-cell function in patients with HLA-DR 3 and/or DR 4. We conclude that islet cell destruction occurs during chronic pancreatitis, but does not trigger islet autoimmunity, even in the presence of HLA-DR 3 and/or DR 4. [Diabetologia (1994) 37: 471–475] Received: 18 August 1993 and in revised form: 17 November 1993     

Foscarnet and ganciclovir combination therapy for CMV disease in HIV-infected patients

Summary An open prospective trial of combined ganciclovir and foscarnet therapy for 3 weeks was initiated in 14 episodes of severe CMV-disease in 13 HIV-infected patients (all CDC class IV, age 30–42, median 34 years, CD4+ cell count 0–80, median 10/µl). In seven episodes of gastrointestinal disease (five colitis, two esophagitis) remission of symptoms and mucosal changes was achieved in five. In seven episodes of retinitis, scarring was achieved in six. Renal toxicity was seen in two patients, moderate hematologic toxicity in eight patients. Overall efficacy was comparable to monotherapy; no new toxicities were seen with the combination of these two drugs.

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Kombinationstherapie mit Ganciclovir und Foscarnet bei schwerer CMV-Erkrankung bei HIV-infizierten Patienten

Zusammenfassung In 14 Episoden einer CMV-Erkrankung bei 13 HIV-infizierten Patienten wurde eine Kombinationstherapie mit Ganciclovir und Foscarnet in einer offenen, prospektiven, nicht randomisierten Studie durchgeführt. Alle Patienten (n=13, Alter 30–42, Median 34 Jahre; CD4+Lymphozyten 0–80, Median 10/µl; alle Stadium IV CDC) wurden über 3 Wochen mit 2 × 5 mg/kg/d Ganciclovir und 2 × 90 mg/kg/d Foscarnet behandelt. In sieben Episoden einer gastrointestinalen CMV-Erkrankung (Colitis fünf, Ösophagitis zwei) wurde eine Remission in fünf Episoden erzielt, bei CMV-Retinitis in sechs von sieben Fällen. Nephrotoxizität trat bei zwei Patienten auf, mäßige Hämatotoxizität bei acht Patienten, sämtlich reversibel. Die Wirksamkeit der Therapie ist ähnlich der Monotherapie, die Nebenwirkungen sind additiv.

     

Sera from patients with heparin-induced thrombocytopenia generate platelet-derived microparticles with procoagulant activity: an explanation for the thrombotic complications of heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia is characterized by moderate thrombocytopenia and thrombotic complications, whereas quinine/quinidine-induced thrombocytopenia usually presents with severe thrombocytopenia and bleeding. Using flow cytometry and assays of procoagulant activity, we investigated whether sera from patients with these immune drug reactions could stimulate normal platelets to generate platelet-derived microparticles with procoagulant activity. Sera or purified IgG from patients with heparin-induced thrombocytopenia stimulated the formation of platelet-derived microparticles in a heparin-dependent fashion. Further studies showed that heparin-induced thrombocytopenia sera also produced a marked increase in procoagulant activity. In contrast, sera from patients with quinine- or quinidine-induced thrombocytopenia did not generate platelet-derived microparticles nor generate increased procoagulant activity. However, quinine/quinidine-induced thrombocytopenia sera produced a significant increase in the binding of IgG to platelets in a drug-dependent fashion, whereas sera from patients with heparin-induced thrombocytopenia demonstrated no drug-dependent binding of IgG to platelets. We also observed increased levels of circulating microparticles in patients with acute heparin-induced thrombocytopenia compared with control patients. Our observations indicate that the generation of procoagulant platelet-derived microparticles in vivo is a plausible explanation for the thrombotic complications observed in some patients with heparin-induced thrombocytopenia.     

用正糖钳夹试验评估基础胰岛素类似物作用特点的研究

健康人通过体内胰岛素的分泌调节，可以保持正常的血糖水平。各种外源性胰岛素制剂在代谢过程上总是尽可能地模拟内源性胰岛素的分泌动力学。理想的外源性基础胰岛素制剂可以模拟健康人的基础胰岛素分泌，以致使用者可以恢复两餐之间和夜间正常生理情况下的血浆胰岛素水平。     

A cross-over evaluation of different methods and devices to measure blood pressure in type 1 diabetic patients with nephropathy

BACKGROUND: In type 1 diabetic patients with nephropathy, tight blood pressure control has been shown to prevent the progression of the disease. Up until now, self-monitoring, ambulatory and office blood pressure values have not been compared in these patients. Thus, we have evaluated blood pressure values obtained in the office by a physician and at home by self-monitoring with those measured under ambulatory conditions in these patients. Additionally, for blood pressure self-monitoring, three different devices (the sphygmomanometer, upper-arm oscillometer and wrist oscillometer) were compared. METHODS: Twenty-one treated hypertensive type 1 diabetic patients [age 45+/-9 years, duration of diabetes 33+/-12 years (mean+/-SD)] with overt diabetic nephropathy participated in this study. At both baseline and the end of the study, daytime ambulatory blood pressure measurement was performed. Office blood pressure was measured at baseline. Additionally, all the patients measured their blood pressure over a 3-week period using each of the three different devices, in random order, for 1 week. RESULTS: The mean office blood pressure values (135+/-21/85+/-12mmHg) were higher than both the ambulatory (131+/-23/80+/-12, P<0.05) and self-monitoring values (130+/-14/78+/-10; P<0.05 for systolic and P<0.02 for diastolic values). The difference between the ambulatory and self-monitoring values were not statistically significant. Diastolic blood pressure values measured with the oscillometric wrist device showed a trend towards higher values when compared to those measured with the sphygmomanometer and with the oscillometric upper-arm device (P=0.065 for diastolic values). CONCLUSION: Office blood pressure measurements may over-estimate blood pressure in patients with type 1 diabetes and diabetic nephropathy. Because the oscillometric wrist device tends to over-estimate diastolic values, upper-arm devices should be preferred for blood pressure self-monitoring in these patients.     

Motor unit number index (MUNIX) in children and adults with 5q-spinal muscular atrophy: Variability and clinical correlations

Spinal muscular atrophy (SMA) is a motor neuron disease associated with progressive muscle weakness and motor disability. The motor unit number index (MUNIX) is a biomarker used to assess loss of motor units in later-onset SMA patients. Twenty SMA patients (SMA types 3 and 4), aged between 7 and 41 years, were clinically evaluated through the Hammersmith Motor Functional Scale Expanded and the Spinal Muscular Atrophy-Functional Rating Scale. The patients underwent compound motor action potential (CMAP) and MUNIX studies of the right abductor pollicis brevis, abductor digiti minimi and tibialis anterior (TA) muscles. Age-matched healthy controls (n = 20) were enrolled to obtain normative CMAP and MUNIX values from the same muscles. Compared to healthy controls, SMA patients showed significant reductions in MUNIX values among all muscles studied, whereas CMAP showed reductions only in the weaker muscles (abductor digiti minimi and TA). MUNIX variability was significantly higher in the SMA group than in the control group. MUNIX variability in TA correlated with CMAP variability. Motor functional scores correlated with TA MUNIX. The MUNIX study is feasible in later-onset SMA patients, and TA MUNIX values correlate with disease severity in patients with mild motor impairment.     

Role of kidney in the catabolic clearance of human platelet antiheparin proteins from rat circulation

Stimulated platelets release at least two antiheparin proteins: platelet factor 4 (PF4) and low affinity platelet factor 4 (LA-PF4) from which beta-thromboglobulin (beta TG) is derived. We have found previously marked elevation of LA-PF4/beta TG antigen in platelet poor plasma of patients with chronic renal failure, whereas levels of PF4 remained normal. Therefore, we examined the role of the kidneys in the metabolic clearance of LA-PF4/beta TG and PF4. The supernates of aggregates of thrombin-stimulated human platelets were injected into sham operated control rats, nephrectomized rats, and into rats with acute ureteral ligation. The disappearance of human LA-PF4/beta TG antigen and PF4 in rat plasma determined by specific radioimmunoassays followed biphasic exponential curves. The half-lives (t1/2) for the fast and slow components of LA-PF4 in control rats were 6.4 and 68.4 min. Nephrectomy significantly increased these times to 9.7 and 144 min, while ureteral ligation resulted in no significant change. Comparison of the level of LA-PF4/beta TG antigen and of creatinine in aorta and in renal vein showed 25%-30% extraction of these compounds by the kidney. Less than 0.1% of the total LA-PF4 antigen injected was recovered in the urine of control rats. In contrast to these results, the clearance of PF4 was not affected by nephrectomy. In conclusion: (1) functional renal tissue is necessary for normal clearance of LA- PF4/beta TG, but renal excretion does not play a major role in its elimination suggesting that the protein is catabolized by the kidney; and (2) catabolic clearance of PF4 does not depend on functioning kidney tissue.     

Immunoglobulin G from patients with heparin-induced thrombocytopenia binds to a complex of heparin and platelet factor 4

Heparin-induced thrombocytopenia (HIT) is an important complication of heparin therapy. Although there is general agreement that platelet activation in vitro by the HIT IgG is mediated by the platelet Fc receptor, the interaction among the antibody, heparin, and platelet membrane components is uncertain and debated. In this report, we describe studies designed to address these interactions. We found, as others have noted, that a variety of other sulfated polysaccharides could substitute for heparin in the reaction. Using polysaccharides selected for both size and charge, we found that reactivity depended on two independent factors: a certain minimum degree of sulfation per saccharide unit and a certain minimum size. Hence, highly sulfated but small (< 1,000 daltons) polysaccharides were not reactive nor were large but poorly sulfated polysaccharides. The ability of HIT IgG to recognize heparin by itself was tested by Ouchterlony gel diffusion, ammonium sulfate and polyethylene glycol precipitation, and equilibrium dialysis. No technique demonstrated reactivity. However, when platelet releasate was added to heparin and HIT IgG, a 50-fold increase in binding of radio-labeled heparin to HIT IgG was observed. The releasate was then depleted of proteins capable of binding to heparin by immunoaffinity chromatography. Only platelet factor 4-immunodepleted releasate lost its reactivity with HIT IgG and heparin. Finally, to determine whether the reaction occurred on the surface of platelets or in the fluid phase, washed platelets were incubated with HIT IgG or heparin and after a wash step, heparin or HIT IgG was added, respectively. Reactivity was only noted when platelets were preincubated with heparin. Consistent with these observations was the demonstration of the presence of PF4 on platelets using flow cytometry. These studies indicate that heparin and other large, highly sulfated polysaccharides bind to PF4 to form a reactive antigen on the platelet surface. HIT IgG then binds to this complex with activation of platelets through the platelet Fc receptors.     

Inferior Vena Caval and Right Atrial Thrombosis Complicating an Amebic Hepatic Abscess

We describe a 50-yr-old black laborer who presented with right lower chest pain, weight loss, and pedal edema. Ultrasonography and computed tomograms showed a large abscess cavity in the right lobe of the liver which extended very close to the inferior vena cava. The lumen of the adjacent inferior vena cava was partially occluded by thrombus, which could be traced up into the cavity of the right atrium. The hepatic veins were normally patent. Sterile blood-stained pus was aspirated from the abscess. Antibodies against Entamoeba histolytica were present in high titer in the patient's serum. Although propagation of hepatocellular carcinoma into the inferior vena cava and even up into the right atrium is well recognized, inferior vena caval thrombosis extending up into the right atrium has not hitherto been reported as a complication of amebic hepatic abscess.