HLA and alveolar echinococcosis

OBJECTIVE: Haemodynamic changes as a consequence of application and release of aortic clamps for surgical repair of aortic coarctation are compensated by cerebrovascular autoregulation. Transcranial Doppler was used to study the effect of these haemodynamic changes upon brain circulation in children during aortic coarctation repair. METHOD: A 2-MHz transcranial Doppler system continuously recorded mean cerebral blood flow velocities from the left middle cerebral artery in 13 children (aged from 5 days to 14 years) during repair of their coarctation. Measurements were performed: prior to aortic clamping (baseline); during the first 5 min after clamp application; 1 min before declamping; at 1, 2, 4 and 6 min after the release of both proximal and distal aortic clamps; and at initial chest closure. A contralateral upper-limb non-invasive blood pressure cuff measured systemic blood pressures. Haemodynamic and anaesthetic parameters were monitored. Patients were stratified by age into two groups: age < 6 months (group A) and age > 6 months (group B). RESULTS: With aortic clamping, systemic blood pressures (range from: -16 to +54%) and cerebral blood flow velocities (range from -40 to +19%) changed slightly (P > 0.05) from initiation to end of aortic clamping. In group A, release of aortic clamps resulted in moderate fluctuations in systemic blood pressures (range from -34 to +15%) (P > 0.05) and a marked reduction in cerebral blood flow velocities (range from -63 to -33%) (P < 0.01). At the time of surgical closure, flow velocities had improved in all infants except one. Group B did not show major reductions in either cerebral blood flow velocity or systemic blood pressures throughout all measurements (P > 0.05). During aortic clamp release, young infants responded with lower brain blood flow velocities as compared to older children (r = 0.68; P < 0.05). CONCLUSION: Transient central nervous system hypotension results as a consequence of flow redistribution during aortic declamping in young infants. Older children usually show a faster autoregulatory compensation to these haemodynamic changes. The observed age-related physiologic differences, suggest that young infants may require higher systemic blood pressures during declamping to prevent the cerebral blood flow reduction. Transcranial Doppler appears to be a valuable monitor of these cerebral haemodynamic changes.     

In vivo treatment with recombinant IL-12 protects C57BL/6J mice against secondary alveolar echinococcosis

A sample of 259 patients with vertical maxillary hyperplasia, mandibular hypoplasia and anterior vertical open bite, collected from three different institutions, was analysed regarding temporomandibular joint (TMJ) sounds, condylar remodelling, and condylar resorption. All patients underwent Le Fort I osteotomies, and bilateral sagittal split advancement osteotomies were performed in 117 patients. Intraosseous wire fixation was used in 149 and rigid internal fixation in 110 patients. Cephalometric and orthopantomographic radiographs were available before surgery, immediately after surgery, one year postoperatively and at the latest follow up. The mean follow up was 69 months (range 20-210 months). The number of patients with TMJ sounds decreased from 38% to 31%. At the latest follow up 23.6% of the patients showed condylar remodelling, 7.7% unilateral condylar resorption and 7.7% bilateral condylar resorption. Condylar contours, as assessed on orthopantomographic radiographs, were classified as five different types. Condyles with preexisting radiological signs of osteoarthrosis or having a posterior inclination were at high risk for progressive resorption. Female patients with severe anterior open bite, high mandibular plane angle and a low posterior-to-anterior facial height ratio, who underwent a bimaxillary osteotomy, were prone to condylar resorption. Bone loss was predominantly found at the anterior site of the condyle. The incidence of condylar resorption was significantly higher after bimaxillary osteotomies (23%) than after only Le Fort I intrusion osteotomies (9%). Avoidance of intermaxillary fixation by using rigid internal fixation tended to reduce condylar changes, in particular in patients who underwent only a Le Fort I osteotomy. Rigid internal fixation in bimaxillary osteotomies resulted in condylar remodelling in 30% and progressive condylar resorption in 19% of the patients. Condylar changes were not significantly different after using either miniplate osteosynthesis or positional screws in bilateral sagittal split osteotomy procedures.     

Intestinal and systemic humoral immunological events in the susceptible Balb/C mouse strain after oral administration of Echinococcus multilocularis eggs

The aim of the study was to investigate the systemic and, for the first time, the intestinal humoral events in the susceptible Balb/C mouse strain after oral administration of Echinococcus multilocularis eggs. Thirty-one mice were divided into three groups; W-2, W-8 and control group. Each mouse of the W-2 and W-8 groups was orally infected with 1,500 E. multilocularis eggs, two weeks and eight weeks before sacrifice respectively. Control group mice received phosphate buffer saline. Measurement of anti-E. multilocularis and non-specific IgG, IgA and IgM, and of a transudation marker, albumin, were performed in serum and intestinal washings by a time-resolved immunofluorometric assay. These results were complemented by microscopic examination of the intestinal mucosa. This infection model is well-suited to the study of mucosal immunity during alveolar echinococcosis. It showed a major specific intestinal response in the early stage of the disease whereas the systemic response predominated later in the disease. Histopathological studies and calculation of the relative coefficient of excretion of Ig also confirmed that the presence of the parasite, even during a short period, was responsible for a local immunological and inflammatory response and for a change in mucosal permeability. Mucosal immunity could thus play a role in tolerance induction against E. multilocularis that could be a prerequisite for the subsequent development of the larvae in the liver, and for the occurrence of the parasitic disease, alveolar echinococcosis.     

Lack of H-2 gene influence on mouse susceptibility to secondary alveolar echinococcosis

To determine whether the development of hepatic Echinococcus multilocularis infection is influenced by major histocompatibility-linked genes, metacestode growth and host immune responses were compared in 4 C57BL/10 congenic murine strains of H-2b, H-2d, H-2k and H-2q haplotypes. Although the H-2q strain appeared slightly more resistant than the other strains, the 4 strains of mice developed comparable spleen cell proliferative response and Th1/Th2 cytokine production at 13 weeks p.i. A kinetic analysis, performed in 2 of these congenic strains, showed a similar pattern of parasite growth in these mice and failed to detect any significant difference in the production of parasite-specific IgM, IgG1 and IgG2, antibodies. Consequently, this study indicates that the control of secondary alveolar echinococcosis is not H-2 gene-linked.     

The level of the collagen cross-link pyridinoline reflects the improvement of cutaneous lesions in one case of skin alveolar echinococcosis

Cutaneous parasitic lesions, associated with a dense fibrous reaction, markedly improved under albendazole treatment in one case of supraumbilical skin localization of alveolar echinococcosis. Since collagen cross-linking increases during fibrogenesis and contributes to the stability of fibrotic lesions, we monitored the level of the cross-links pyridinoline and pentosidine in skin lesions from this patient to determine if they would reflect the changes occurring during treatment. We looked at the deposition of cross-linked type I collagen by immunohistochemistry and also measured the serum concentrations of pentosidine and of a fragment of type I collagen (ICTP), which contains a site of pyridinoline formation. Albendazole treatment did not affect either the collagen content of skin lesions or the serum concentrations of ICTP and pentosidine, but it led to a pronounced decrease in pyridinoline level concomitant with the disappearance, observed by immunohistochemistry, of extensively cross-linked fibrotic type I collagen. The follow-up of collagen cross-linking by pyridinoline in skin tissue thus appears to be useful in reflecting the improvement of fibrotic skin diseases during therapy.     

Railway wheel profile fine-tuning system for profile recommendation

This paper develops a wheel profile fine-tuning system (WPFTS) that comprehensively considers the influence of wheel profile on wheel damage, vehicle stability, vehicle safety, and passenger comfort. WPFTS can recommend one or more optimized wheel profiles according to train operators’ needs, e.g., reducing wheel wear, mitigating the development of wheel out-of-roundness (OOR), improving the shape stability of the wheel profile. Specifically, WPFTS includes four modules: (I) a wheel profile generation module based on the rotary-scaling fine-tuning (RSFT) method; (II) a multi-objective generation module consisting of a rigid multi-body dynamics simulation (MBS) model, an analytical model, and a rigid–flexible MBS model, for generating 11 objectives related to wheel damage, vehicle stability, vehicle safety, and passenger comfort; (III) a weight assignment module consisting of an adaptive weight assignment strategy and a manual weight assignment strategy; and (IV) an optimization module based on radial basis function (RBF) and particle swarm optimization (PSO). Finally, three cases are introduced to show how WPTFS recommends a wheel profile according to train operators’ needs. Among them, a wheel profile with high shape stability, a wheel profile for mitigating the development of wheel OOR, and a wheel profile considering hunting stability and derailment safety are developed, respectively.