POS0485 PLATELET-DERIVED MICROPARTICLES IN SYSTEMIC SCLEROSIS: POTENTIAL NEW PROFIBROTIC BIOMARKER?

Background

Systemic sclerosis (SSc), the most lethal autoimmune rheumatic disorder, is characterized by vascular damage, immune dysregulation and progressive tissue fibrosis [1]. Microparticles (MP) are membrane-derived vesicles released from cells undergoing activation or apoptosis, that participate in regulation of inflammatory responses, homeostasis and vascular function [2]. Prior studies have reported elevated plasma levels of MP in SSc [3,4], but its association with clinical SSc features and its role in the disease pathogenesis has still not been completely elucidated.

Objectives

We aimed to compare serum levels of platelets-derived microparticles (PMP), endothelial cells-derived microparticles (EMP), and monocytes-derived microparticles (MMP) between SSc patients and healthy controls. Also, we aimed to evaluate the association of MP and SSc clinical features.

Methods

In this cross-sectional study, 70 SSc patients and 35 age- and sex-matched healthy controls were recruited. After staining with fluorescent cell-specific monoclonal antibodies (PMP CD42+/31+, EMP CD105+, and MMP CD14+), plasma MP were quantified by flow cytometry. Clinical and nailfold capillaroscopy data from patients were obtained. All of them fulfilled the 2013 ACR/EULAR classification criteria for SSc.

Results

Clinical features of studied population are shown on Table 1. Serum MP levels were significantly increased in SSc patients compared to healthy controls (mean ± SD): 79.2% ± 17.3% vs 71.0% ± 19.8% for PMP (p = 0.033); 43.5% ± 8.7% vs 37.8% ± 10.4% for EMP (p = 0.004); and 3.5% ± 1.3% vs 1.1% ± 0.5% for MMP (p < 0.001) (Figure 1). We observed significantly higher PMP levels in patients with positive anti-topoisomerase-I antibodies compared to those with negative anti-topoisomerase-I antibodies (p = 0.030) and in patients with disease duration > 3 years compared to patients with disease duration ≤ 3 years (p = 0.038).

Table 1.

Demographic and clinical data of studied population

VariableSSc (n=70)Healthy controls (n=35)pFemale/Male63 (90) / 7 (10)31 (88.5) / 4 (11.4)0.68Age, yr.48.9 ± 13.447.6 ± 14.00.63Limited SSc/Diffuse SSc44 (62.9) / 26 (37.1)----Disease duration, yr.6.4 ± 4.0----Modified Rodnan skin score6.5 ± 9.6----Active digital ulcers15 (21.4)----FVC, (n=63)80.9 ± 17.4----ILD38 (54.3)----PAH4 (5.7)----Esophageal dyskinesia42 (60)----Cardiac involvement8 (11.4)----Autoantibodies Anticentromere13 (18.6)---- Anti-topoisomerase-I13 (18.6)----Nailfold capillaroscopy,(n=61) SD Early23 (37.7)---- SD Active15 (24.5)---- SD Late23 (37.7)Calcium channel blockers in use49 (70)----Phosphodiesterase-5 inhibitors in use9 (12.9)----Immunosuppressors in use Glucocorticoids8 (11.4)---- Cyclophosphamide3 (4.3)---- Mycophenolate15 (21.4)---- Azathioprine3 (4.3)---- Rituximab1 (1.4)---- Methotrexate12 (17.1)----

Data are mean ± SD or n (%) unless otherwise stated. FVC: forced vital capacity; ILD: interstitial lung disease; PAH; pulmonary arterial hypertension.

Figure 1.

MP plasma levels in SSc patients vs healthy controls

Conclusion

Serum levels of PMP, EMP and MMP are elevated in scleroderma patients, thus indicating a possible role of these agents in SSc pathogenic mechanisms. The higher plasma titles of PMP observed in patients with longer disease duration and presence of anti-topoisomerase-I, a well-established factor of worse prognosis in SSc, might suggest a profibrotic function for this new potential biomarker.

References

[1]Saketkoo LA et al. Best Pract Res Clin Rheumatol, 2021;35:101707.

[2]Beyer C, Pisetsky DS. Nat Rev Rheumatol, 2010;6:21-9.

[3]Dunne JV et al. Curr Rheumatol Rev, 2013;9:279-300.

[4]Čolić J et al. J Scleroderma Relat Disord, 2019;5:1-15.

Acknowledgements

We appreciate the financial support given by FAPESP (grant 2018/15216-2) and FAPE-SBR.

Disclosure of Interests

None declared.

Arzneimittelnebenwirkungen und Medikationsfehler bei Kindern

Hintergrund

Kinder sind einem höheren Risiko für Nebenwirkungen (NW) und Medikationsfehler (MF) als Erwachsene ausgesetzt, auch weil es häufig an geeigneten Dosierungsempfehlungen, Arzneiformen und adäquaten Applikationsformen mangelt.

Material und Methode

Kurze Literaturübersicht und Auswertung von Spontanberichten aus der Datenbank EudraVigilance bezüglich NW zu Kindern zwischen 2000 und 2019 sowie einer Datensammlung zu MF bei Kindern zwischen 2014 und 2020 in Deutschland.

Ergebnisse

MPH als zentral wirksames Sympathomimetikum wird zur Behandlung der Aufmerksamkeitsdefizit‑/Hyperaktivitätsstörung (ADHS) eingesetzt.

Im Bewertungszeitraum 2014–2020 wurden dem Bundesinstitut für Arzneimittel und Medizinprodukte 151 MF direkt gemeldet. Häufig gemeldet wurden nicht korrekt durchgeführte Zubereitungen von Arzneimitteln, wie z. B. bei antibiotischen Trockensäften, die zu fehlerhaften Dosierungen führten.

Schlussfolgerung

Zudem sollten andere Informationsquellen (z. B. Dosierungsdatenbanken) intensiv genutzt werden, zum einen, um bereits vorhandene Informationen im klinischen und im ambulanten Setting besser umzusetzen, zum anderen, um die Kenntnisse zu Anwendungsrisiken bei Kindern zu verbessern. Diesbezüglich sollte die Meldebereitschaft der Ärzte- und Apothekerschaft zu NW und MF weiter erhöht werden.

Decreased number of T cells bearing TCR rearrangement excision circles (TREC) in active recent onset systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is characterized by several T lymphocyte abnormalities. An indirect assessment of recent thymus emigrants (RTE) has been recently been made available by measuring the number of TCR recombination excision circles (TREC) in peripheral T cells. We studied TREC levels in peripheral blood mononuclear cells (PBMC) of 32 SLE patients with active disease and 32 normal age- and sex-matched controls. Signal-joint TREC concentration was determined by real-time quantitative-PCR as the number of TREC copies/μg PBMC DNA. SLE patients had lower TREC levels (4.1 ±3.9 ×104 TREC/μg DNA) than controls (8.9 ±7.9 ×104/μg DNA) ( P = 0.004). There was an inverse correlation between age and TREC levels in controls ( r = 20.41, P = 0.02) but not in SLE patients. No clinical association was observed between TREC levels and clinical and laboratory SLE manifestations. TREC levels tended to be lower in patients with SLEDAI above 20 than in the rest of the patients ( P = 0.08). The decreased PBMC TREC levels is indicative of a low proportion of RTE in SLE and could be caused by decreased RTE output and/or by increased peripheral T cell proliferation in this disease. The under-representation of RTE in the peripheral T cell pool may play a role in the immune tolerance abnormalities observed in SLE.

Interobserver Variability in the Differential Diagnosis of Benign Bone Tumors and Tumor-like Lesions

PURPOSE

The interobserver-variability of radiological diagnosis of benign bone tumors (BBT) and tumor-like lesions (TLL) was examined in order to identify difficult-to-diagnose entities, to examine the frequency of advanced diagnostics and to describe the number of interdisciplinary tumor center diagnoses (IDT) in comparison with diagnoses upon referral (ED) and radiologists´ diagnoses (RD).

MATERIALS AND METHODS

We retrospectively reviewed 413 patients with 272 BBT and 141 TLL, classified either histologically or through interdisciplinary consultation. Discrepancies between groups were analyzed and rates of additional imaging and biopsy to establish diagnosis were assessed.

RESULTS

In BBT the number of identical radiological diagnoses was 56 (ED) and 81 % (RD) compared to the IDT, while in the latter additional imaging were obtained in 30 % cases. In 21 % (12 % to establish diagnosis) BBT were biopsied, the ED matching the histology 40 %, the RD 60 % and the IDT 76 % of the time. For TLL diagnosed through radiology, ED and RD matched IDT 31 % and 61 % of the time, with additional imaging being obtained in 21 % of cases (IDT). In 36 % (27 % to establish diagnosis) biopsy was performed, with histological diagnosis matching the IDT, RD and ED in 51, 27 and 20 %. Diagnostic challenges were apparent in enchondromas, non-ossifying fibromas (NOF), solitary (SBC) and aneurysmal bone cysts (ABC). Ganglia can be misinterpreted as a tumor.

CONCLUSIONS

Establishing a definitive diagnosis for BBT and TLL can be challenging with the latter posing greater difficulties. An interdisciplinary approach involving radiologists, orthopedics and pathologists was found to improve diagnostic accuracy.

KEY POINTS

• Benign bone tumors (BBT) and tumor-like lesions (TLL) present a diagnostic challenge, while enchondroma, NOF, SBC and ABC were difficult to diagnose, and ganglia can be misinterpreted as a tumor• Additional imaging studies were required for diagnosis in 29 % and 21 % of cases for BBT and TLL, respectively, biopsies in 12 % of cases for BBT and 27 % for TLL• Sound diagnoses can be made through interdisciplinary case discussion, while reducing the risk of overtreatment Citation Format: • Scheitza P, Uhl M, Hauschild O et al. Interobserver Variability in the Differential Diagnosis of Benign Bone Tumors and Tumor-like Lesions. Fortschr Röntgenstr 2016; 188: 479 - 487.

[The abdominal compartment syndrome - relevance and therapeutic consequences]

BACKGROUND

Intra-abdominal hypertension (IAH) has a high prevalence among critically ill patients. It is increasingly recognised as a risk factor for poor outcome. PATIENTS / MATERIAL AND METHODS: A review of the literature including explicit management instructions was performed. We report the standardised techniques for intra-abdominal pressure (IAP) measurement as well as consensus definitions and treatment recommendations ranging from conservative measures to decompression laparotomy.

RESULTS

The abdominal compartment syndrome (ACS) is defined as a sustained IAH > 20 mmHg accompanied by new organ dysfunctions. It occurs predominantly in surgical patients and is associated with a poor outcome. Organ dysfunctions related to IAH mainly concern the kidneys and -respiratory system. The mechanism of action essentially is a perfusion deficit. Clinical judgement alone does not allow a valid estimate of intra-abdominal pressure.

CONCLUSION

In patients at risk the IAP should be measured. In case of IAH conservative options for lowering the pressure are mandatory. Decompression laparotomy should be considered if conservative measures fail.

Severe ankylosing spondylitis and diffuse systemic sclerosis: case report of a genetic trap

A rare association of ankylosing spondylitis (AS) and systemic sclerosis (SSc) is reported in a Brazilian Mestizo patient presenting a human leucocyte antigen (HLA) genotype that included HLA SSc-susceptibility genes previously reported in different ethnic groups and HLA-B27 associated with AS. The underlying genetic background supporting the full expression of both SSc- and AS-susceptibility alleles and the pertinent literature are discussed.

Cold stimulus fingertip lacticemy test--an effective method to monitor acute therapeutic intervention on primary Raynaud's phenomenon and systemic sclerosis

OBJECTIVES

The recently developed cold stimulus fingertip lacticemy test (CS-FTL) provides biochemical assessment of peripheral perfusion in patients with Raynaud's phenomenon (RP). We evaluated how the CS-FTL test can assess the acute effect of nifedipine in microvascular dynamics on primary RP and RP secondary to SSc.

METHODS

A double-blinded controlled trial with crossover design was performed in 20 primary RP and 20 SSc patients. Patients received one single sublingual placebo or 10 mg nifedipine capsule, with crossover after a 15-day washout period. FTL was determined in resting conditions (pre-CS-FTL) and 10 min after CS (post-CS-FTL), before and 1 h after drug administration. Percent variation in post- vs pre-CS-FTL was expressed as deltaCS-FTL.

RESULTS

Before intervention, CS induced FTL decrease in primary RP (deltaCS-FTL = -21.3 +/- 13.0%) and FTL increase in SSc patients (deltaCS-FTL = +24.5 +/- 21.2%). Placebo had no effect on pre-CS-FTL, post-CS-FTL and deltaCS-FTL in primary RP and SSc. Nifedipine induced a significant decrease in pre-CS-FTL (1.94 +/- 0.45 vs 1.57 +/- 0.41 mg/dl; P = 0.005) and post-CS-FTL (1.53 +/- 0.35 vs 1.32 +/- 0.37 mg/dl; P = 0.004) in primary RP and a significant decrease in post-CS-FTL (3.18 +/- 1.43 vs 2.56 +/- 1.30 mg/dl; P = 0.028) and deltaCS-FTL (+15.9 +/- 24.7% vs -12.9 +/- 16.6%; P = 0.001) in SSc.

CONCLUSIONS

The CS-FTL test was able to demonstrate and quantify a dual effect of nifedipine on the biochemical dimension of peripheral perfusion in primary RP and in SSc patients in which there was a significant improvement in tissue perfusion in resting conditions and after exposure to a CS. The CS-FTL test will enrich the armamentarium for investigation and clinical evaluation of conditions associated with RP.

Surgery for cystic lymphangioma in Gorlin–Goltz syndrome

INTRODUCTION

We present a case of three major lymphomesenteric cysts in a female patient with known basal cell nevus syndrome (BCNS or Gorlin-Goltz syndrome).

DISCUSSION

Although those cysts have been reported to appear in this syndrome, the exact prevalence is not known. In this case, the patient suffered from severe and recurrent abdominal pain due to bowel obstruction.

CONCLUSION

By causing severe symptoms, cystic lymphangiomas are an important complication of the BCNS despite of their seldom occurrence. Surgeons confronted with intraabdominal masses in a patient with BCNS should always be aware of this manifestation of the disorder and plan interdisciplinary operations.

Minor inflammation after surgical evacuation compared with fibrinolytic therapy of experimental intracerebral hemorrhages

OBJECTIVES

Toxic components released from the intracerebral blood clot, such as thrombin and hemoglobin, potentially trigger brain edema formation and therefore favor an early evacuation of the clot. Despite a significant reduction in hematoma size in our porcine model of hematoma induction by injecting autologous blood ICP-controlled into the right frontal white matter with subsequent fibrinolysis using recombinant tissue-plasminogen activator (rt-PA) and aspiration of the liquefied clot (n = 9), local rt-PA promoted delayed perihematomatous edema formation and invoked a substantial inflammatory reaction compared with controls (n = 11).

METHODS

We therefore modified our formerly developed porcine model of intracerebral hemorrhage in removing the hematoma by open craniotomy and suction of the clot in seven animals. The residual hematoma size and extent of perifocal edema were evaluated over 10 days on planimetry of the MRI data, and correlated to the histopathological changes of edema and inflammation found at autopsy.

RESULTS

The edema volume on day 4 was significantly less in the surgical group compared with the lysis group (p < 0.03). On day 10, however, the difference in edema size was not statistically significant compared with the lysis group (p < 0.07) and the control group (p < 0.09). The inflammatory response was minor compared with the lysis and control group.

DISCUSSION

In conclusion, despite a significant reduction in hematoma size by surgical removal of the clot, only the inflammatory response, but not the extent of delayed edema can be positively influenced.

Expression of annexin-1 in multiple sclerosis plaques

This study describes the distribution and identity of annexin-1 positive cells in the central nervous system in patients with multiple sclerosis (MS). Glucocorticoid-inducible, anti-inflammatory properties have been ascribed to annexin-1, a member of a family of calcium-binding proteins that are referred to collectively as annexins. We have found annexin-1 to be spatially associated with active MS lesions and demonstrated a stage-dependent expression of annexin-1 in MS plaques. All of the most important pathogenetically involved cells of MS lesions showed a strong annexin-1 reactivity. Both correlation analysis and double staining procedures suggested annexin-1 expression in macrophages and perivascular lymphocytes, where a cytoplasmic reactivity was displayed, whereas in activated, gemistocytic astrocytes it was also concentrated close to the plasma membrane. Although the exact roles of annexin-1 in this setting are still to be determined, a possible contribution to anti-inflammatory processes might be suggested.

Efficient evaluation of serial sections by iterative Gabor matching

Evaluation of electron microscopic images of serial sections is a time-consuming process requiring a high level of expertise. Here we present an algorithm to ease and accelerate this process. It is a modification of an algorithm successfully used in computer vision for object recognition. However, rather than recognising individual structures, we estimate the spatial mapping of a whole section onto the consecutive one. This mapping is used to transfer labelled information of the very first section, e.g. a classification by a human expert of different visible structures, onto structures visible in the next section. We investigate its performance on an artificially constructed benchmark as well as on real electron microscopic samples taken in primary visual cortex and demonstrate its potential for dramatically facilitating the evaluation process of serial sections.

Non-contact eye-tracking on cats

The objective of visual systems neuroscience has shifted over the past few years from determining the receptive fields of cells towards the understanding of higher level cognition in awake animals viewing natural stimuli. In experiments with awake animals it is important to control the relevant aspects of behavior. Most important for vision science is the control of the direction of gaze. Here we present Dual Purkinje eye-tracking on cats, which--as a non-contact method--brings a number of advantages. Along with the presented methods for calibration and for synchronization to off-the-shelf video presentation hardware, this method allows high precision experiments to be performed on cats freely viewing videos of natural scenes.

Growth hormone (GH) induces the formation of protein complexes involving Stat5, Erk2, Shc and serine phosphorylated proteins

The aim of this study was to investigate the interaction of Stat5 with key effector proteins Erk2 and Shc after activation by growth hormone (GH), using Chinese Hamster Ovary (CHO) cells stably expressing the wild type rabbit growth hormone receptor (GHR). In coimmunoprecipitation experiments, we show GH-induced formation of complexes consisting of Stat5a and Erk2, and Stat5a and Stat5b association with the protein adaptor Shc. In CHO cells treated with GH, a rapid association of tyrosine and serine phosphorylated Stat5a with activated Erk2 is observed. In contrast, Shc proteins interact with non-phosphorylated forms of Stat5. Using truncated and tyrosine mutants of the GHR, we identify a carboxy-terminal domain of the receptor, which is critical for serine phosphorylation of Stat5a and Stat5a/Erk2 complex formation. In addition, tyrosine residues of this region of the GHR are not required for Stat5a/Erk2 interaction but are essential for Stat5a serine phosphorylation. Moreover, we detect serine phosphorylated proteins associated with Erk2, Shc and Stat5: both Stat5 isoforms interact with a serine phosphorylated protein of 63 kDa, which is shown to be related to the serine-threonine kinase Akt-1. Our results support the importance of serine phosphorylation cascades in GH signaling and open another pathway of GH signal transduction.

Cell death in vasculitic neuropathy

Vasculitic neuropathy shows cluster of differentiation (CD)4+ and CD8+ perivascular infiltrates. CD8+ cells kill the target by different ways. Some mechanisms require the release of granzymes and T-cell restricted intracellular antigen (TIA-1) which induce cell death by apoptosis. A nonsecretory ligand-mediated mechanism has been proposed for apoptosis and requires the interaction of Fas and Fas-ligand. We studied apoptosis by immunohistochemistry and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) in nerve biopsy specimens in 19 cases of vasculitic neuropathy and 8 controls. In vasculitic neuropathy, perivascular mononuclear cells expressed TIA-1, granzyme A, and granzyme B. Regarding the ligand-mediated mechanism, we observed Fas+ and Fas-ligand+ mononuclear cells in an epineurial-perivascular distribution. Cells undergoing apoptosis, as demonstrated by TUNEL, represented mononuclear cells. In vasculitic neuropathy, apoptosis by both a secretory and a nonsecretory mechanism is suspected. However, apoptosis seems to be restricted to inflammatory mononuclear cells, suggesting that it may play a critical role in recovery from vasculitic neuropathy.

Muscle hypertrophy due to scarring of the S1 nerve root

Segmental muscle enlargement occurs in a variety of neurogenic conditions. We present a patient with calf hypertrophy, likely produced by continuous neuromuscular irritability and compensatory type 1 and type 2 muscle fiber hypertrophy. The underlying lesion of the S1 nerve root was caused by scarring, which could be demonstrated by Gadolinum enhanced, fat saturated magnetic resonance imaging. Thus, the application of this technique is recommended in otherwise etiologically unclear cases of neurogenic muscular lesions in order to detect chronic nerve root pathology.

[30 years multiple system atrophy concept: retrospect and overview of multiple system atrophy]

Multiple system atrophy represents an enigmatic, clinico-pathologically defined neurodegenerative disease. According to findings of the last three decades, the historically derived, previously used terms olivopontocerebellar atrophy, striatonigral degeneration, and Shy-Drager-syndrome should be avoided in clinical use because of both the clinical and morphological overlap between these syndromes. Complex neurodegenerative syndromes other than multiple system atrophy according to recently developed criteria, should rather be referred to as multiple system degenerations.

Growth hormone (GH) and prolactin receptors in human peripheral blood mononuclear cells: relation with age and GH-binding protein

GH receptors (GHRs) and PRL receptors (PRLRs) were studied in human peripheral blood mononuclear cells (PBMC) using flow cytometry, biotinylated anti-GH receptor monoclonal antibody 10B8, and biotinylated human PRL. Variations of GHR and PRLR expression and the relationship of plasma GHBP and GH receptor in PBMC subsets were examined as a function of age and sex. By double immunofluorescence staining, we show that about 30% of total cells express GH receptors, with a low expression in T cells, whereas almost all B cells and monocytes are GH receptor positive. Four age groups were defined among the 64 normal volunteers, aged 12 to 85 yr, who were included in the study. The percentage of PBMC expressing GH receptors is significantly lower in group 2 (20-40 yr) than in group 1 (12-20 yr) and group 4 (>60 yr). In T cells, monocytes and B cells, no significant changes are detected in either the percentage of GH receptor positive cells or in the GH receptor level per cell. The level of PRLRs expressed in PBMC is significantly higher in age group 2 than in age group 4. A negative correlation is observed between plasma GHBP and the percentage of PBMC expressing GH receptors. These results suggest that regulation of GH receptors in lymphocytes and in other target cells could be different.

Neurological manifestations of chronic hepatitis C

Hepatitis C virus (HCV) infection is often associated with abnormal immunological responses. We describe four patients with vasculitic neurological signs and symptoms following HCV infection. A 56-year-old woman with HCV infection developed peripheral neuropathy characterized by asymmetric distal painful hypesthesia, dysesthesia and moderate motor weakness of the lower limbs. Serological examinations revealed cryoglobulinemia and low levels of complement C4. A biopsy of the sural nerve revealed vasculitic neuropathy. HCV infection associated immunomediated vasculitis was diagnosed. While steroid therapy was ineffective, treatment with interferon-alpha improved the neuropathy considerably without, however, eliminating HCV infection. A 62-year-old man with HCV infection developed peripheral sensory neuropathy. Complement C3 was slightly diminished. Nerve biopsy revealed vasculitic neuropathy. A 71-year-old woman developed chronic symmetric sensomotor polyneuropathy. HCV hepatitis followed blood transfusions. Cryoglobulins tested positive, consistent with type II cryoglobulinemia. Complements C3 and C4 were diminished. Inflammatory infiltrates in the sural nerve biopsy specimen led to the diagnosis of chronic vasculitic disorder. A 55-year-old woman with HCV infection developed vasculitis of the skin, connective tissue, visceral organs, and kidney, leading to hemodialysis. Neurologically she developed severe apathy and drowsiness, myoclonic jerks, exaggerated deep tendon reflexes, and positive pyramidal signs. Magnetic resonance imaging of the brain showed diffuse increased signal abnormalities involving supra- and infratentorial white matter suggesting cerebral vasculitis. Cryoglobulins were positive, complements C3 and C4 slightly diminished (54 mg/dl, 4.3 mg/dl). Supportive therapy resulted in neurological improvement. Treatment with interferon-alpha was discontinued because of agranulocytosis. In patients with peripheral neuropathy or signs of leucencephalopathy, a hepatitis C associated vasculitis should be considered in the differential diagnosis.

Aldosterone metabolism in cultures of rat renal cortical and medullary cells

The metabolism of 4-(14)C-d-aldosterone (at 3 nM) was studied in the primary target organ of the hormone, in renal cortical and medullary cell cultures obtained from Wistar rats. Larger amounts of aldosterone were metabolized in medullary cells than in cortical cells, as measured by a decreased 4-(14)C-d-aldosterone radioactivity concentration (26+/-9% and 12+/-7% of the initial aldosterone added, respectively (n=5, p<0.05)). The 14C radiometabolites of aldosterone in both cultures co-chromatographed with 5alpha dihydro- (DHA) and 3alpha,3beta tetrahydroaldosterone (THA). Aldosterone metabolism was totally inhibited by a mineralocorticoid receptor antagonist canrenoat (Soldactone) (at 10(-5) to 10(-3) M), while the glucocorticoid receptor antagonist RU 38486 (Roussel UCLAF) (at 10(-5) to 10(-4) M) had no effect. Thus, the study confirmed that, in rat kidney, aldosterone can be converted to its reduced metabolites by a metabolism which is inhibited by a mineralocorticoid receptor antagonist. This indicated that the metabolism might play some role in modulation of the intracellular response to aldosterone in the kidney.

Smectic ordering in solutions and films of a rod-like polymer owing to monodispersity of chain length

Solutions and melts of stiff ('rod-like') macromolecules often exhibit nematic liquid crystalline phases characterized by orientational, but not positional, molecular order. Smectic phases, in which macromolecular rods are organized into layers roughly perpendicular to the direction of molecular orientation, are rare, owing at least in part to the polydisperse nature (distribution of chain lengths) of polymers prepared by conventional polymerization processes. Bacterial methods for polypeptide synthesis, in which artificial genes encoding the polymer are expressed in bacterial vectors, offer the opportunity to make macromolecules with very well defined chain lengths. Here we show that a monodisperse derivative of poly(gamma-benzyl alpha,L-glutamate) prepared in this way shows smectic ordering in solution and in films. This result suggests that methods for preparing monodisperse polymers might provide access to new smectic phases with layer spacings that are susceptible to precise control on the scale of tens of nanometres.

Growth hormone-binding protein in the goat: characterization, evolution under exogenous growth hormone treatment, and correlation with liver growth hormone receptor levels

This report describes the identification and characterization of a specific, high-affinity growth hormone-binding protein (GHBP) in lactating goat serum. Serum samples were incubated with [125I]human GH as ligand and in the absence or in the presence of bovine GH as competitor. GH-GHBP complex formation was performed by high-performance liquid chromatography, and the radioactivity was recorded on-line with a Berthold LB detector connected to a computer. The results showed that a serum protein was able to bind specifically to human GH and bovine GH but not to ovine prolactin. Scatchard plots indicated an affinity constant of 4.5 x 10(8) M-1 and a maximum binding capacity of 4.8 x 10(-10) mol/l. In addition, we conducted a 4-wk study to determine the effects of recombinant bovine GH administration on milk production in lactating goats. The effects of recombinant bovine GH treatment on milk production and on the regulation of GHBP and hepatic GH receptor levels were studied. As expected, recombinant bovine GH injected daily increased yields of milk, fat, protein (40, 61, and 40%, respectively), and circulating insulin-like growth factor 1 concentrations compared with controls. During the pretreatment and treatment periods, the control goats exhibited a constant amount of GHBP in serum. No consistent effect of GH treatment on GHBP level was observed. The binding of [125I]bovine GH to hepatic microsomal membranes of GH-treated goats was significantly decreased compared with that of control goats. After MgCl2 desaturation of membranes, the results demonstrated that the down-regulation of GH hepatic receptors, observed for the treated goat group, was induced by receptor occupancy without modification of binding affinity. The GH receptor gene expression, analyzed by slot blot and hybridization with an [alpha-32P]GH receptor cDNA probe, was not modified by the GH treatment. In lactating goats, the galactopoietic effect of exogenous GH involved a hepatic receptor occupancy. The individual concentration of GHBP in serum cannot explain the individual variations of responses to GH treatment in goats.

Carcinoid tumors of the lung: immuno- and ligandohistochemistry, analysis of integrated optical density, syntactic structure analysis, clinical data, and prognosis of patients treated surgically

BACKGROUND

Analysis of potentially prognostic relevant factors of carcinoid tumors of the lung.

METHODS

Clinical features, tumor size, and features derived from immuno- and ligandohistochemistry, cytometry and histometry, and survival have been analyzed in 82 potentially curatively resected carcinoid tumors of the lung.

RESULTS

Patients with typical carcinoid tumors had a longer history of symptoms (13 vs. 8 months), fewer smoked (30% vs. 80%), and developed less frequently lymph node metastases (20% vs. 65%) compared to patients with atypical carcinoids. Statistically significant differences between both cell types have been observed in cytometric and histometric features, and binding of Lewis A trisaccharide (Lea). Prognosis is associated with the cell type, presence of lymph node metastases and heparin-binding lectin (HBL), certain cytometric and structural features, and binding of macrophage migration inhibitory factor (MIF) and beta-N-acetyl-D-galactosamine (beta-GalNAc).

CONCLUSIONS

Complete lymph node dissection is necessary, data of cytometry, histometry, and ligandohistochemistry might eventually predict the course of the disease.

Differential activation of Stat3 and Stat5 by distinct regions of the growth hormone receptor

The GH receptor (GHR) is a member of the cytokine receptor superfamily; its signaling involves the activation of Janus tyrosine kinases (JAK2) and Stat (signal transducers and activators of transcription) transcription factors. Using truncated and tyrosine mutants of the receptor, we show that different receptor domains are essential for the activation of Stat3 and Stat5. GH-dependent phosphorylation of JAK2, Stat3, and Stat5, as well as transactivation studies with reporter genes containing Stat3 and Stat5 DNA-binding elements, was performed in cells expressing the various GHR mutants. The membrane-proximal region of the receptor necessary for JAK2 activation is sufficient for Stat3 activation. In contrast, C-terminal tyrosine residues of GHR are absolutely required for Stat5 activation. The same residues are also involved in the regulation of JAK2 dephosphorylation, possibly through the activation of a phosphatase. Using in vitro experiments with glutathione-S-transferase fusion proteins, we demonstrate that the SH2 domain of Stat5 binds to the carboxy-terminal tyrosine-phosphorylated residues of GHR. Our results show that a cytokine receptor can mediate differently the activation of distinct Stat proteins that could be involved in cytokine-specific effects.

Application of attributed graphs in diagnostic pathology

OBJECTIVE

To compute attributed graphs based upon calculation of the minimum spanning tree (MST) for various applications in diagnostic lung pathology.

STUDY DESIGN

The study design included assistance in histologic diagnosis, confirmation of the diagnosis in single cases, measurement of texture alterations after induction chemotherapy, estimation of prognosis of operated-on lung cancer patients and analysis of lung cancer cells in association with differentiation markers. The histologic slides were Feulgen stained, and features of the integrated optical density (IOD) were associated with the nodes of the MST. The same procedure was applied to immunohistochemically and ligand histochemically stained slides by calculation of the mean staining intensity of the cytoplasm of tumor cells. A measure for structural entropy was introduced by computing the relative differences in distance and IOD between neighboring tumor cells in a 1/r2 field of force. In addition, the current of entropy was computed.

RESULTS

Structural entropy reflects alterations in regular textures; the current of entropy is an especially good prognostic parameter in lung cancer. In immunochemistry and ligand histochemistry, construction of the attributed MST permits detailed insight into locally different staining behavior of tumor cells and immunocompetent cells.

CONCLUSION

Attributed graphs contain important information that can be used for the estimation of survival or for confirmation of diagnostic entities, such as tumor cell types.

Oligoclonal T cell proliferation in patients with rheumatoid arthritis and their unaffected siblings

OBJECTIVE

To analyze whether patients with rheumatoid arthritis (RA) have an intrinsic defect in T cell proliferation and survival, possibly contributing to the infiltration of the synovial membrane with CD4+ T cells.

METHODS

Fifteen patients with seropositive RA, 11 patients with psoriatic arthritis, 20 normal controls, and 9 affected and 13 unaffected siblings from 7 multiplex families with RA were analyzed for clonal proliferation. To investigate this clonal T cell proliferation, CD4+ T cells were purified from peripheral blood and synovial fluid by magnetic bead separation. T cell receptor (TCR) beta-chain sequences were amplified by reverse transcriptase-polymerase chain reaction, using TCR BV and BJ gene segment-specific primer sets. Clonally expanded T cell specificities were identified by size fractionation and sequencing of the amplified product.

RESULTS

All RA patients carried clonally expanded CD4+ T cells in the peripheral blood compartment. Such expanded CD4+ T cell clonotypes were only infrequently observed both in normal individuals (P < 0.0001) and in patients with psoriatic arthritis (P = 0.004). Lymphoproliferation of selected CD4+ T cells was shared by affected and unaffected siblings from RA multiplex families (P = 0.005 and P = 0.0003, respectively, compared with normal controls). Expanded clonotypes persisted for several years and contributed to the T cell infiltrate in the joint. Clonal T cell proliferation involved a diverse spectrum of TCR molecules.

CONCLUSION

RA patients have an abnormality in the homeostasis of CD4+ T cells, characterized by the emergence of clonally proliferating populations. The presence of clonal outgrowth of selected CD4+ T cells specificities in unaffected siblings of RA patients suggests that oligoclonality of CD4+ T cells is inherited and is a risk factor for, rather than a result of, synovial inflammation.

T cell receptor germline gene segments and HLA haplotypes control the length of the CDR3 of human T cell receptor beta chains

The third complementarity determining region (CDR3) is the most variable part of alpha beta T cell receptors (TCR) and represents the putative antigen contacting site. To identify parameters determining the structural diversity of the CDR3 region, the CDR3 length distributions of 66 BV-J combinations in peripheral CD4+ T cells (6 BV and ll BJ gene segments) of 12 unrelated individuals were analyzed. The median CDR3 length ranged from 8 to 12.5 amino acids and was partially determined by the usage of the BV and BJ gene segment. Beyond the influence of germline-encoded TCR gene segments, donors expressed an individual pattern of preferred CDR3 size classes. To identify mechanisms determining this individual pattern, 17 first-degree relatives from five families were studied. CDR3 length profiles were shared by some but not all relatives. Sharing of CDR3 length profiles correlated with the inheritance of both HLA-DR haplotypes. These data suggest that the length of the TCR beta chain is selected and that restrictions on the diversity of the CDR3 length are imposed by germline-encoded TCR gene segments as well as by major histocompatibility complex-dependent mechanisms.

Clinical course of hypophosphatemic rickets in 23 adults

Twenty-three adult patients (19 females, 4 males) with x-linked hypophosphatemic rickets (HPR) underwent a retrospective evaluation of the clinical course and a clinical examination by a nephrologist, orthopedic surgeon and dentist. Blood and urine analysis, bone density measurements with QCT and DEXA, ultrasonic examination of the kidneys were performed and the patients were asked to fill in a standardized questionnaire on pain and psychosocial rehabilitation. Mean final height was 152.4 cm +/- 8.5 SD in females and 157.3 cm +/- 8.9 SD in males. Decreased joint mobility was seen in all patients, deviations of the normal leg axis in 18/23 patients in spite of 69 correcting osteotomies in the past. Dental (n = 14) and psychosocial problems were associated with inability to work (n = 8). There was a trend that patients with a very low Tp/GFR had a more severe course of the disease. Early therapy with vitamin D metabolites and phosphate had a beneficial effect on growth, bone density and deformations. Eight patients had nephrocalcinosis due to vitamin D and phosphate therapy and had normal kidney function. Four patients had urinary tract abnormalities. We conclude that patients with HPR should receive continuous interdisciplinary care given by nephrologists, orthopedic surgeons, physiotherapists and dentists not only during childhood but also as adults.

Pulse amplitude and frequency modulation of parathyroid hormone in primary hyperparathyroidism

Pulsatile secretion of PTH in human subjects has been described recently. However, the pattern of PTH secretion in primary hyperparathyroidism (pHPT) remains to be characterized. In this study intact PTH was measured in 9 female patients with pHPT. As a control group we present data from 10 postmenopausal women. In addition to parameters of calcium metabolism and bone mass, PTH was measured in samples drawn over 4 or 6 h every 2 min by central venous blood sampling. The mean intact PTH concentration was 39.0 +/- 20.3 ng/L in healthy women and 193.2 +/- 127.9 ng/L in female patients with pHPT (P < 0.01). Pulse rhythm analysis showed significant differences between both groups for total PTH secretion per h (patients, 1196.4 +/- 485.3 ng/L; control group, 271.7 +/- 132.2 ng/L), basal PTH secretion per h (patients, 852.4 +/- 459.1 ng/L; control group, 185.6 +/- 126.1 ng/L), and average PTH secretion per pulse (patients, 112.6 +/- 54.8 ng/L; control group, 23.2 +/- 7.1 ng/L). Both patients and control subjects had, on an average, five pulses per h, and the pulsatile secretion accounted for about 50% of the total secretion. Differences in power spectrum analysis were consistent with these findings. The cross-correlation of PTH and calcium indicates an impaired feedback regulation in pHPT. PTH secretion in female patients with pHPT results from both an increased basal secretion and an increased amplitude of PTH pulses. Other features of secretion are the same as those in normal women. Feedback regulation of PTH and calcium is impaired in pHPT.

Pulse amplitude and frequency modulation of parathyroid hormone in early postmenopausal women before and on hormone replacement therapy

Although the pathophysiology of postmenopausal osteoporosis has been investigated extensively, it is still not established in what respect PTH is related to the events. Recently, consistent data on the pulsatile secretion of PTH in man have been published. In this study intact PTH was measured in six early postmenopausal women before and after 6 months of hormone replacement therapy (HRT; 0.6 mg conjugated estrogens and 5 mg medrogestone). In addition to parameters of calcium metabolism and bone mass and to control HRT, intact PTH was measured in blood drawn over 6 h every 2 min. With HRT there was a 30% reduction in PTH secretion. Both the amount secreted per pulse (baseline, 26.8 +/- 6.9 ng/L; HRT, 21.4 +/- 7.6 ng/L; P < 0.05) as well as the basal secretion (baseline, 232.6 +/- 117.6 ng/L.h; HRT, 145.5 +/- 80.0 ng/L.h; P < 0.01) were reduced, whereas the pulse count per h remained constant (baseline, 5.1 +/- 2.2; HRT, 5.1 +/- 1.3). Power spectrum analysis showed a shift in spectral maxima consistent with these findings. Ionized and total calcium were slightly, but nonsignificantly, reduced with treatment. In summary we conclude that in early postmenopausal women, HRT reduces the secretion of PTH by reducing both the basal secretion and the amount secreted per pulse. It is conceivable that some of the known effects of HRT on bone metabolism might be mediated by the modulation of PTH secretion.

Alteration of human lung parenchyma associated with primary biliary cirrhosis

The clinical history, radiological and histomorphological alterations of the lung parenchyma in a patient suffering from primary biliary cirrhosis are described. The 70-year-old woman had developed a primary biliary cirrhosis, verified by serological abnormalities (AMA positivity, elevated IgM levels) and by liver biopsy. The lung parenchyma displayed immature epithelioid granulomas and characteristics of a chronic organizing pneumonia. Lung function revealed moderate restrictive changes; chest radiographs revealed bilateral, diffuse, patchy infiltrates in the basal lobes. Application of immunohistology detected antigens in liver cells reactive with anti-IgD and anti-IgG, in pneumocytes those reactive with anti-IgD. Presence of macrophage migration inhibitory factor (MIF) by application of its antibody and of the ligand sarcolectin as well as expression of binding capacities to MIF could not be demonstrated in the liver and lung parenchyma. Neoglycoproteins exposing fucose, N-acetyl-D-glucosamine, lactose and mannose residues did not bind to both the liver and lung tissue. The data indicate that at least some patients with primary biliary cirrhosis may develop or suffer from immunological abnormalities, affecting the lung.