The failure of Haemonchus contortus excretory/secretory products to stimulate gastrin secretion in vitro

Excretory/secretory (ES) products collected from exsheathed L3 or parasitic stages of Haemonchus contortus were tested in vitro for gastrin stimulatory properties using an ovine abomasal antral mucosal preparation. In addition, the motility of exsheathed L3 and parasites recovered on weeks 2, 6 and 8 post-infection was studied in water, saline, saline with glucose or ovine blood and in HBSS pH 2.5–7.4. Parasitic stages became immotile rapidly in water and HBSS pH 2.5, more slowly in HBSS pH 3.5, but nearly 100% remained motile for 48 h when blood was included in the medium. Exsheathed L3 motility was reduced only by water and HBSS pH 2.5, and then only in the second week of incubation. Gastrin secretion was not consistently increased by any of the parasite ES products tested in vitro, therefore, they probably do not stimulate the G cell directly to produce the hypergastrinaemia seen in parasitised sheep.     

Aqueous humor dynamics and trabecular meshwork and anterior ciliary muscle morphologic changes with age in rhesus monkeys

PURPOSE: To determine in rhesus monkeys the age-dependence of uveoscleral outflow (Fu) and morphology of the trabecular meshwork (TM) and anterior ciliary muscle (CM). METHODS: Intraocular pressure (IOP) was measured by Goldmann applanation tonometry in monkeys under ketamine anesthesia. After anterior chamber cannulation under pentobarbital anesthesia, aqueous humor formation (AHF), anterior chamber volume, trabecular outflow, and Fu were determined isotopically. The CM and TM were examined by light and electron microscopy. RESULTS: IOP increased significantly with age in monkeys aged 3 to 29 years. AHF and anterior chamber volume were unchanged. Fu was decreased, and trabecular outflow increased in monkeys aged 25 to 29 years compared with the remaining monkeys. Morphologically, there was a significant increase in the thickness of the elastic fibers of the trabeculum ciliare covering the anterior tips of the CM, and an increase in extracellular material between the muscle tips. The number of TM cells decreased with age, whereas the amount of fibrillar material and sheath-derived plaques increased. This increase was less pronounced in the middle filtering portion of the cribriform region than in the anterior and posterior portions. CONCLUSIONS: The decline in Fu in very old rhesus monkeys with normal IOP parallels that seen in normotensive aging humans. This may be correlated with thickening of the elastic fiber sheath in the CM tips in addition to other morphologic changes. The TM findings are analogous to those in the aging human eye and are consistent with the age-related decrease in outflow facility reported in both humans and monkeys.     

Regional cerebral blood flow monitoring in the diagnosis of delayed ischemia following aneurysmal subarachnoid hemorrhage

OBJECT: The goal of this study was to evaluate regional cerebral blood flow (rCBF) monitoring, performed using thermal-diffusion (TD) flowmetry, as a novel means for the bedside diagnosis of symptomatic vasospasm. METHODS: Fourteen patients with high-grade subarachnoid hemorrhage (SAH) who underwent early clip placement for anterior circulation aneurysms were prospectively entered into the study. Thermal-diffusion microprobes were implanted into the white matter of vascular territories that were deemed at risk for developing symptomatic vasospasm. Data on arterial blood pressure, intracranial pressure, cerebral perfusion pressure, rCBF measurement obtained using a TD probe (TD-rCBF), cerebrovascular resistance (CVR), and blood flow velocities were collected at the patient's bedside. The diagnosis of symptomatic vasospasm was based on the manifestation of a delayed ischemic neurological deficit and/or a reduced territorial level of CBF as assessed using stable Xe-enhanced computerized tomography (CT) scanning in combination with vasospasm demonstrated by angiography. Bedside monitoring of TD-rCBF and CVR allowed the detection of symptomatic vasospasm. In the 10 patients with vasospasm the TD-rCBF decreased from 21 +/- 4 to 9 +/- 1 ml/100 g/min (mean +/- standard error of the mean), whereas in the four other patients the TD-rCBF value remained unchanged (mean TD-rCBF = 25 +/- 4 compared with 21 +/- 4 m/100 g/min). A comparison of the results of TD-rCBF and Xe-enhanced CT studies, as well as the calculation of sensitivities, specificities, predictive values, and likelihood ratios, identified a TD-rCBF value of 15 ml/100 g/min as a reliable cutoff for the diagnosis of symptomatic vasospasm. In addition, TD flowmetry was characterized by a more favorable diagnostic reliability than transcranial Doppler ultrasonography. CONCLUSIONS: Thermal-diffusion flowmetry represents a promising method for the bedside monitoring of patients with SAH to detect symptomatic vasospasm. This is of major clinical interest for patients with high-grade SAH, who often cannot be assessed neurologically.     

Acetabular revision in total hip replacement with a press-fit cup

The need for supplementary screw fixation in acetabular revisions is still widely debated. We carried out 439 acetabular revisions over an eight-year period. In 171 hips with contained or small segmental defects, the Morscher press-fit cup was used. These revisions were followed prospectively. No screws were used for additional fixation. A total of 123 hips with a mean follow-up of 7.4 years (5 to 10.5) were available for clinical and radiological review. There was no further revision of a press-fit cup for aseptic loosening. Radiological assessment revealed osteolysis in three hips. Of the original 171 hips there was cranial and medial migration of up to 6 mm at two years in 44 (26%). No further migration was seen after the second post-operative year. Acetabular revision without screws is possible with excellent medium-term results in well selected patients.     

CD38 low IgG-secreting cells are precursors of various CD38 high-expressing plasma cell populations

Despite the important role immunoglobulin G (IgG)-secreting plasma cells play in memory immune responses, the differentiation and homeostasis of these cells are not completely understood. Here, we studied the differentiation of human IgG-secreting cells ex vivo and in vitro, identifying these cells by the cellular affinity matrix technology. Several subpopulations of IgG-secreting cells were identified among the cells isolated from tonsils and bone marrow, particularly differing in the expression levels of CD9, CD19, and CD38. CD38 low IgG-secreting cells were present exclusively in the tonsils. A major fraction of these cells appeared to be early plasma cell precursors, as upon activation of B cells in vitro, IgG secretion preceded up-regulation of CD38, and on tonsillar sections, IgG-containing, CD38 low cells with a plasmacytoid phenotype were found in follicles, where plasma cell differentiation starts. A unitary phenotype of migratory peripheral blood IgG-secreting cells suggests that all bone marrow plasma cell populations share a common precursor cell. These data are compatible with a multistep model for plasma cell differentiation and imply that a common CD38 low IgG-secreting precursor gives rise to a diverse plasma cell compartment.     

Selective killing of B-cell hybridomas targeting proteinase 3, Wegener's autoantigen

Wegener's granulomatosis (WG) is a rare disease characterized by granulomatous lesions, small vessel vasculitis and the presence of anti-neutrophil cytoplasmic autoantibodies (C-ANCAs) in the sera of affected patients. Their main target antigen is proteinase 3 (PR3), a neutrophil and monocyte-derived neutral serine protease. Since the standard treatment of this severe autoimmune disease, with cyclophosphamide and corticosteroids, is associated with potential side-effects, the development of a more specific immunotherapeutic agent is warranted. The key role of ANCA in the pathogenesis of vasculitis and the effectiveness of anti-CD20 antibodies in patients with refractory WG points towards the importance of B cells in WG. We thus evaluated a new approach to selectively eliminate PR3-specific autoreactive B cells by targeting the B-cell receptor. For this purpose we used a bifunctional recombinant fusion protein consisting of the antigen PR3 and a toxin. The cytotoxic component of this novel fusion protein was the ribonuclease angiogenin, a human toxin with low immunogenicity. The toxin was stabilized by exchanging the catalytically relevant histidine in position 44 with glutamine to eliminate the autoproteolytic activity. PR3H44Q was fused either to the N terminus or to the C terminus of angiogenin. The recombinant proteins were expressed in 293T cells. Binding assays demonstrated the appropriate size and recognition by anti-PR3 antibodies. Using TUNEL technology, we demonstrated that these autoantigen toxins kill proteinase 3-specific B-cell hybridomas selectively by inducing apoptosis. The data indicate that autoantigen-toxins are promising tools in the treatment or co-treatment of autoimmune diseases in which the antigen is known.