[Duplication of the acromioclavicular joint: A case dating from the end of the 19th century]

The duplication of the acromioclavicular joint is a very rare anomaly of shoulder girdle. Here, we present a new case of unilateral duplication of the acromioclavicular joint observed on an individual from the 19th century. In the literature, two hypotheses are proposed to explain the origin of this anomaly. The first is a congenital origin that could be explained by in utero displacement of one of the clavicle's primary ossification centers, or the existence of an additional ossification center. The second is a traumatic origin resulting from an acromioclavicular fracture that occurred during the growth period of the individual. Our macroscopic observations and CT-scan images show no sign of a healed fracture, of complications, or of a bone callus after healing. The hypothesis of a congenital origin for this acromioclavicular duplication is therefore preferred.

Bleeding, thrombosis, and anticoagulation in myeloproliferative neoplasms (MPN): analysis from the German SAL-MPN-registry

BACKGROUND

Patients with Ph-negative myeloproliferative neoplasms (MPN), such as polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are at increased risk for thrombosis/thromboembolism and major bleeding. Due to the morbidity and mortality of these events, antiplatelet and/or anticoagulant agents are commonly employed as primary and/or secondary prophylaxis. On the other hand, disease-related bleeding complications (i.e., from esophageal varices) are common in patients with MPN. This analysis was performed to define the frequency of such events, identify risk factors, and assess antiplatelet/anticoagulant therapy in a cohort of patients with MPN.

METHODS

The MPN registry of the Study Alliance Leukemia is a non-interventional prospective study including adult patients with an MPN according to WHO criteria (2008). For statistical analysis, descriptive methods and tests for significant differences as well as contingency tables were used to identify the odds of potential risk factors for vascular events.

RESULTS

MPN subgroups significantly differed in sex distribution, age at diagnosis, blood counts, LDH levels, JAK2V617F positivity, and spleen size (length). While most thromboembolic events occurred around the time of MPN diagnosis, one third of these events occurred after that date. Splanchnic vein thrombosis was most frequent in post-PV-MF and MPN-U patients. The chance of developing a thromboembolic event was significantly elevated if patients suffered from post-PV-MF (OR 3.43; 95% CI = 1.39-8.48) and splenomegaly (OR 1.76; 95% CI = 1.15-2.71). Significant odds for major bleeding were previous thromboembolic events (OR = 2.71; 95% CI = 1.36-5.40), splenomegaly (OR = 2.22; 95% CI 1.01-4.89), and the administration of heparin (OR = 5.64; 95% CI = 1.84-17.34). Major bleeding episodes were significantly less frequent in ET patients compared to other MPN subgroups.

CONCLUSIONS

Together, this report on an unselected "real-world" cohort of German MPN patients reveals important data on the prevalence, diagnosis, and treatment of thromboembolic and major bleeding complications of MPN.

Application of NAD-dependent polyol dehydrogenases for enzymatic mannitol/sorbitol production with coenzyme regeneration

D-Mannitol and D-sorbitol were produced enzymatically from D-fructose using NAD-dependent polyol dehydrogenases. For the production of D-mannitol the Leuconostoc mesenteroides mannitol dehydrogenase could be used. Gluconobacter oxydans cell extract contained however both mannitol and sorbitol dehydrogenase. When this cell extract was used, the reduction of D-fructose resulted in a mixture of D-sorbitol and D-mannitol. To determine the optimal bioconversion conditions the polyol dehydrogenases were characterized towards pH- and temperature-optimum and -stability. As a compromise between enzyme activity and stability, the bioconversion reactions were performed at pH 6.5 and 25 degrees C. Since the polyol dehydrogenases are NADH-dependent, an efficient coenzyme regeneration was needed. Regeneration of NADH was accomplished by formate dehydrogenase-mediated oxidation of formate into CO2.

Selective inhibition of inducible nitric oxide synthase prevents ischaemic brain injury

1. The aim of this study was to investigate the effect of N-(3-(aminomethyl)benzyl)acetamidine (1400W), a selective inhibitor of inducible calcium-independent nitric oxide synthase (iNOS), on the functional and histopathological outcomes of experimental transient focal cerebral ischaemia in rats. 2. Transient ischaemia was produced by the occlusion for 2 h of both the left middle cerebral artery and common carotid artery. Treatments with 1400W (20 mg kg(-1)) or vehicle were started 18 h after occlusion of the arteries and consisted in seven subcutaneous injections at 8 h interval. Ischaemic outcomes and NOS activities (constitutive and calcium-independent NOS) were evaluated 3 days after ischaemia. 3. 1400W significantly reduced ischaemic lesion volume by 31%, and attenuated weight loss and neurological dysfunction. 4. 1400W attenuated the calcium-independent NOS activity in the infarct by 36% without affecting the constitutive NOS activity. 5. These findings suggest that iNOS activation contributes to tissue damage and that selective inhibitors of this isoform may be of interest for the treatment of stroke.

Cysteine protease CPP32, but not Ich1-L, is expressed in germinal center B cells and their neoplastic counterparts

Ich-1/Nedd2 and CPP32/YAMA are cysteine proteases related to interleukin 1-beta-converting enzyme (ICE), which act as apoptosis effectors. Both molecules are expressed in T- and B-cell lines. The authors investigated their in vivo cellular distribution in normal and neoplastic human lymphoid tissues. Sixty-eight representative non-Hodgkin's lymphomas (NHL) and Hodgkin's disease (HD) samples, normal lymphoid organs, and nonlymphoid tumors were analyzed by immunohistochemistry (IHC). CPP32 expression in benign tissues was restricted to germinal center B cells, plasma cells, and a few interfollicular immunoblasts. All follicular NHLs and most diffuse large cell NHLs were CPP32 positive. Among T-cell NHLs, CPP32 expression was mainly observed in anaplastic large cell NHLs, whereas the other subtypes were less frequently positive. In contrast, lymphoid organs displayed only weak Ich1-L expression, located in sinusal histiocytes and thymic epithelial cells. Lymphomas were Ich1-L negative, except for T-cell-rich B-cell NHLs, and about half of the HD samples, in which Reed-Sternberg cells (RSC) were usually Ich1-L positive/CPP32 negative. Extralymphoid Ich1-L reactivity was found in particular organs like the kidney and various tumors. Western blot analysis confirmed the specificity of immunostaining. Neither CPP32 nor Ich1-L expression were correlated with intratumoral DNA fragmentation, as determined by the TUNEL assay. Altogether, these results indicate that CPP32 is preferentially expressed in germinal centers and thus could be involved in B-cell maturation. The differential expression of CPP32 and Ich1-L suggests that cysteine proteases differ in substrate specificities and carry out functions unrelated to apoptosis.

Neuroprotective effects of riluzole on a model of Parkinson's disease in the rat

The aim of the present study was to analyse whether riluzole, a compound that interacts with the voltage-dependent sodium channel and impairs glutamatergic transmission, would exhibit a neuroprotective activity in a model of Parkinson's disease in the rat. Impaired skilled forelimb use, circling behavior, and altered dopaminergic metabolism of the mesotelencephalic system were evaluated in unilaterally 6-hydroxydopamine-lesioned rats. Riluzole was administered twice 15 min before, and 24 h after, the lesion. Riluzole reduced both the contralateral rotations induced by apomorphine and the ipsilateral ones elicited by amphetamine. Moreover, the decreased dopaminergic metabolism seen after 6-hydroxydopamine injection was attenuated in the riluzole-treated animals, at both the striatal and nigral levels. These biochemical and behavioral results demonstrate the ability of riluzole partially to protect the degeneration of the nigrostriatal dopaminergic neurons induced by the toxin 6-hydroxydopamine. Perhaps, the most striking evidence for the protective effect of riluzole was that this compound improved the skilled paw use, a complex sensorimotor behavior which is not easily ameliorated by palliative therapies such as dopaminergic grafts. These results extend previous data showing that riluzole counteracts the toxicity induced by 1-methyl-4-1,2,3,6-tetrahydropyridine and 1-methyl-4-phenylpyridinium in rodent dopaminergic neurons. The use of riluzole may be considered of potential interest for the neuroprotective therapy of Parkinson's disease.

Short therapeutic window for MK-801 in transient focal cerebral ischemia in normotensive rats

The present study investigates the role of N-methyl-D-aspartate (NMDA) receptors in a model of transient focal cerebral ischemia in normotensive rats. The left middle cerebral artery and both common carotid arteries were occluded for 60 min. Preliminary studies indicated that this gave reproducible infarctions of the cortex and striatum. These infarctions were the result of severe ischemia followed by complete reperfusion after clamp removal, as showed by striatal tissue Po2 monitoring. Microdialysis indicated that glutamate concentration increased immediately after occlusion and returned to the baseline value 40 min after clamp removal. MK-801 (1 mg kg-1 i.v.), an antagonist of the NMDA glutamatergic receptor, reduced the cortical infarct volume by 29% (p < 0.001) and the striatal infarct volume by 14% (p < 0.05) when given just prior to ischemia, but had no neuroprotective activity when given 30 min after the onset of ischemia. This short therapeutic window for MK-801 suggests that NMDA receptors play only a transient role in reversible focal ischemia in rats.

Effects of complete and partial lesions of the dopaminergic mesotelencephalic system on skilled forelimb use in the rat

This study compares certain behavioural consequences of partial and complete unilateral lesions of the dopaminergic mesotelencephalic system. We investigated skilled forelimb use, rotations induced by apomorphine and amphetamine, and dopaminergic metabolism of the nigrostriatal system of rats that had received a unilateral injection of 6-hydroxydopamine into the medial forebrain bundle. The rats classified Apo(+), that rotated after the administration of apomorphine, had a complete lesion of the nigrostriatal system, whereas those classified Apo(-), that did not rotate after the administration of apomorphine, had a partial lesion of the nigrostriatal system. In the Apo(+) rats, 99.8% of the dopamine in the striatum was depleted, as was 85% of that in the substantia nigra. For the Apo(-) rats, 72% of the dopamine in the striatum was depleted as was 56% of that in the substantia nigra. When investigated with the staircase test, the animals with the most severe dopamine depletions were those most impaired in the paw reaching task. Complete and partial unilateral depletions of the dopaminergic mesotelencephalic system impaired the hierarchic phases of paw reaching differently. A complete dopamine depletion, but not a partial one, decreased the number of attempts made with the contralateral paw, and induced a bias towards the ipsilateral paw. A partial dopamine lesion impaired the sensorimotor co-ordination of both paws, whereas the complete dopamine lesion had a greater effect on the contralateral paw than on the ipsilateral paw. The mild paw reaching impairments observed in animals with moderate depletions of dopamine are proposed as a model of the early symptoms of Parkinson's disease that may be useful for the development of protective or restorative therapies.

A member of the selectin family (GMP-140/PADGEM) is expressed on thrombin-stimulated rat platelets in vitro

1. Granule membrane protein (GMP-140) is an integral alpha-granule membrane glycoprotein, expressed on the surface of human platelets following degranulation, and is part of a new family of adhesion molecules (selectins) related to the endothelial leukocyte adhesion molecule (ELAM-1) and to the lymphocyte homing receptors in man (Leu-8/TQ1) and in mouse (gp90MEL-14). 2. The cross-reactivity with rat platelets of the monoclonal antibodies (MAb), LYP20 and S12, directed against human GMP-140 was examined, with the purpose of assessing the homology of GMP-140 between human and rat platelets and of using positive MAbs to detect platelet activation in vivo in response to vascular disease in rats. 3. By ELISA technique, LYP20 gave a greater OD reading with thrombin-stimulated rat platelets than with resting platelets. 4. 125I-LYP20 bound significantly more to thrombin-stimulated rat platelets (3875 +/- 750 molecules/platelet) than to resting platelets (645 +/- 240 molecules/platelet, P less than 0.01) with 50% maximum binding at 0.13 +/- 0.02 microgram/ml; 125I-S12 did not bind to rat platelets. 5. By fluorescence-activated flow cytometry there were significantly more fluorescent thrombin-stimulated platelets (56 +/- 7% of total), compared with resting platelets (8 +/- 1% of total, P less than 0.001). 6. Western blots of rat platelet lysates showed that LYP20 bound to a single band identified, under non-reducing conditions, as having the same apparent M(r) as GMP-140. 7. LYP20 immunoprecipitated a protein which became radiolabelled on the surface of thrombin-activated rat platelets; S12 did not recognize any protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of glycoprotein IIa (beta 1 subunit of very late activation antigens) in platelet functions

Very late activation antigens (VLAs) are glycoproteins (GPs) that play a major role in platelet adhesion to extracellular matrix. These GPs, members of the integrin family, are heterodimer complexes with different alpha subunits noncovalently associated with a common beta 1 subunit known as GPIIa. GPIa-IIa (also known as VLA2), GPIc-IIa (VLA5), and GPIc*-IIa (VLA6) are involved, respectively, in platelet adhesion to collagen, fibronectin, and laminin. At this stage, very little is known about the role of GPIIa in platelet adhesive functions. In this study, we have generated a monoclonal antibody (MoAb) (LYP22) directed against GPIIa. Immunoaffinity chromatography using LYP22 combined with two-dimensional nonreduced-reduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows that the antibody brings down all VLA subunits. Western blots indicate that the binding site of LYP22 on GPIIa is disulfide bridge-dependent. The number of LYP22 binding sites is not increased on stimulation with thrombin and is in the range of what is observed with another anti-GPIIa MoAb (A-1A5). LYP22 is the first anti-GPIIa MoAb to inhibit aggregation and secretion of washed platelets stimulated with collagen, thrombin, or arachidonic acid. Moreover, the lag-phase usually observed on collagen stimulation is significantly prolonged (by 60 seconds) in the presence of LYP22. This lag-phase, mediated by LYP22, is also observed in the presence of plasma proteins and is coupled with a reduced effect on collagen-induced platelet aggregation. In addition, LYP22 affects the adhesion of resting platelets to type III collagen, but not to fibronectin, laminin, or type I collagen. These results strongly indicate that the site on GPIIa, bearing the LYP22 epitope, is an active participant in signal transduction controlling platelet functions.

Separation of important new platelet glycoproteins (GPIa, GPIc, GPIc*, GPIIa and GMP-140) by f.p.l.c. Characterization by monoclonal antibodies and gas-phase sequencing

A large number of membrane glycoproteins (around 40) are present on the surface of human blood platelets. Some of these glycoproteins are expressed in relatively small amounts, and their functions, as well as their structure, remain to be elucidated. The aim of the present study was to separate rapidly, under non-denaturing conditions, and characterize minor glycoproteins such as Very Late Antigens (VLA) (GPIa, GPIc, GPIc* and GPIIa) and GMP-140 (also known as PADGEM). VLAs and GMP-140 are respectively members of the integrin and selectin families. Platelet membrane glycoproteins were separated by wheat-germ agglutinin lectin affinity and Mono Q anion-exchange f.p.l.c. Peaks bearing isolated glycoproteins were electrophoresed on one- or two-dimensional SDS/polyacrylamide gels, Western blotted on to Immobilon poly(vinylidene difluoride) membranes and gas-phase-sequenced. The identity of isolated glycoproteins was also obtained by the use of monoclonal or polyclonal antibodies and tryptic peptide maps. Five minor [GPIa, GPIc, GPIc*, GPIIa and GMP 140 (PADGEM)], as well as a major (GPIIIb) glycoprotein, were eluted at low salt concentrations. GPIIb-IIIa and GPIb were eluted at high salt concentrations. The N-terminal sequence of platelet GPIa was identical with that obtained by Takada & Hemler [(1989) J. Cell Biol. 109, 397-407]. However, the N-terminal sequence of platelet GPIc + Ic* and GPIIa were found to differ from those deduced from cDNA sequences isolated from human placenta or umbilical-vein endothelial-cell cDNA libraries. The combined use of f.p.l.c. and gas-phase sequencing techniques provides a very powerful tool to separate and characterize rapidly platelet or other cellular proteins for structural, immunological and functional studies.

Inhibition of platelet functions by a monoclonal antibody (LYP20) directed against a granule membrane glycoprotein (GMP-140/PADGEM)

Granule membrane protein (GMP-140), also known as platelet activation-dependent granule-external membrane (PAD-GEM) is an integral membrane glycoprotein that is expressed on the platelet surface following degranulation. GMP-140, also expressed by endothelial cells, is part of a new family of cell adhesion molecules (selectins) related to the endothelial leukocyte adhesion molecule (ELAM-1) and to the lymphocyte homing receptors in humans (Leu-8/TQ1) and in mouse (gp90MEL-14). The role of GMP-140 in platelet functions remains to be elucidated. In this study, a monoclonal antibody, LYP20, was raised against GMP-140. LYP20, directed against a disulphide bridge-dependent epitope, significantly binds to thrombin-stimulated platelets (12,200 +/- 1,184 bound molecules/platelet, kd = 5.0 +/- 0.61 nmol/L) compared with controls (2,400 +/- 266 molecules/platelet, kd = 2.3 +/- 0.54 nmol/L) and inhibits collagen or thrombin-induced aggregation of washed platelets or platelets in platelet-rich plasma. In addition, LYP20 inhibits rosetting of thrombin-activated platelets to U937 cells. These results strongly suggest that GMP-140 plays an important role in platelet aggregation and platelet interaction with other blood cells.

New families of adhesion molecules play a vital role in platelet functions

Adhesion molecules play a crucial part in cell-matrix and in cell-cell interactions. These interactions, which are essential to the body's defense processes, involve adhesion molecules belonging to different families: integrins, immunoglobulins and selectins. Integrins are expressed by a large number of tissues, whereas other adhesion molecule families are restricted to a small number of cell types. A recent symposium dealt with the recruitment of circulating platelets at specific sites, their adhesion to extracellular matrix components and their activation by agonists leading to aggregation or attachment to other cells. These events, supporting hemostasis and thrombosis, involve integrins, selectins and other adhesion molecules. This report focuses on newly reported integrins (GPIa, GPIc, GPIIa), selectins (GMP-140) and GPIIIb, previously known as 'minor' surface oriented platelet glycoproteins. Major membrane glycoproteins such as GPIIb-IIIa (an integrin) and GPIb, which also play a vital role in platelet functions, have been extensively reviewed elsewhere.

Rapid purification and partial characterization of human platelet glycoprotein IIIb. Interaction with thrombospondin and its role in platelet aggregation

Glycoprotein IIIb (also known as glycoprotein IV) is a major glycoprotein present on the surface of human platelets. Recent studies suggest that glycoprotein IIIb may be a receptor site for thrombospondin. Thrombospondin, a multifunctional adhesive glycoprotein released from stimulated platelets, plays an important role in the stabilization of platelet aggregates. In this study, a new method for the purification of glycoprotein IIIb is described. Glycoprotein IIIb was isolated from Triton X-114 platelet membrane extracts, under nondenaturing conditions, by tandem anion-exchange and size exclusion fast protein liquid chromatography. The purified glycoprotein had the same apparent molecular mass (88 kDa) under nonreducing or reducing conditions. The tryptic peptide map of the purified protein was identical to that of bona fide glycoprotein IIIb as isolated from two-dimensional polyacrylamide gels of platelet membrane proteins. In addition, the purified glycoprotein was recognized by an anti-GPIIIb monoclonal antibody (OKM5). The purified glycoprotein specifically bound to thrombospondin in the presence of calcium. Monospecific anti-GPIIIb antibodies interfered with the expression of endogenous thrombospondin on thrombin-activated platelets and partially inhibited collagen- and thrombin-induced platelet aggregation without a significant effect on platelet secretion. Glycoprotein IIIb, by interacting with thrombospondin on the activated platelet surface, may play an important role in the platelet aggregation process.

Residual amounts of glycoprotein Ib concomitant with near-absence of glycoprotein IX in platelets of Bernard-Soulier patients

A study of the Bernard-Soulier syndrome in two unrelated families using different polyclonal antibodies in a sensitive immunoblot assay showed residual amounts of platelet membrane glycoprotein (GP) lb in the eight homozygotes, as well as the near-absence of GPlb beta and GPIX. The eight heterozygotes studied showed a double band pattern for GPlb and about half the normal level of GPlb beta and GPIX. Therefore, we conclude that the Bernard-Soulier syndrome is heterogeneous and is probably not due to gene deletions.

Assessment of left ventricular diastolic function in patients receiving anthracycline therapy

Abnormalities in left ventricular filling have been described as an early finding in coronary artery disease and in cardiomyopathy. The present study was undertaken to determine whether impaired diastolic function may be an early sign of anthracycline cardiotoxicity. Radionuclide left ventricular curves of 30 treated patients were compared with the curves of 17 normal, agematched, volunteers. The curves were analyzed for ejection fraction, peak filling rate (normalized for end diastolic counts and for stroke counts), time to peak filling rate and filling fraction in the first third of diastole normalized for cycle length. In 20 patients (Groups A and B), we analyzed the radionuclide ventriculography preceding the decrease of systolic function or a clinical congestive heart failure. In ten patients (Group C) who ended a treatment regimen without systolic dysfunction or clinically evident cardiotoxicity, we analyzed the ventriculography at the end of the therapy. Among the diastolic indexes, only the first third filling fraction was abnormal in a minority of the patients (6/20 in Groups A and B). Our findings suggest that diastolic dysfunction is uncommon in anthracycline treated patients prior to systolic dysfunction.