A Novel Heterophilic Antibody Interaction Involves IgG4

IgG4 has been implicated in a diverse set of complex pathologies – e.g. autoimmune pancreatitis (AIP), idiopathic membranous nephropathy – and carries unique features including lack of activation of the classical complement pathway and a dynamic Fab‐arm exchange. We recently showed that the rheumatoid factor (RF)‐like activity of IgG4 is achieved through a hitherto unknown, Fc–Fc (and not Fab–Fc as is the case in classical RF; CRF) interaction; hence the name, novel RF (NRF). Here, we further explore the resemblance/difference between CRF and NRF. As heterophilic interactions of human IgM RF (CRF) are well known, we checked whether this is the case for IgG4. Human IgG4 showed variable reactivity to animal IgGs: reacting intensely with rabbit and mouse IgGs, but weakly with others. The binding to rabbit IgG was not through the Fab (as in CRF) but via the Fc piece, as was recently shown for human IgG (NRF). This binding correlates with the IgG4 concentration per se and could therefore be of diagnostic usage and incidentally explain some observed interferences in biological assays. In conclusion, here is defined a novel heterophilic antibody interaction and is established the universality of the unique Fc–Fc binding, both involving IgG4.     

Preconditioning with oxygen attenuates rat renal ischemia-reperfusion injury

BACKGROUND: Short time pretreatment with oxygen is reported to be protective against subsequent ischemia-reperfusion (IR) injury of heart and spinal cord in some animal models. The purpose of this study was to investigate the effects of pre-exposure to hyperoxic environment on rat renal IR injury for the first time. MATERIALS AND METHODS: The effects of 1 h/d pretreatment with oxygen (>or=95%) for 5 days on a right nephrectomized rat model of renal IR injury was investigated by comparing creatinine clearance, fractional excretion of sodium, plasma creatinine, blood urea nitrogen, and histological injury scores among three groups: IR (40 min ischemia-24 h reperfusion), sham (no IR), and hyperoxia (5 days intermittent pretreatment with oxygen + IR). RESULTS: Intermittent pretreatment with oxygen resulted in significant improvement of creatine clearance and fractional excretion of sodium (P 相似文献   

The effects of fructo-oligosaccharides in combination with soy protein on bone in osteopenic ovariectomized rats

OBJECTIVE: The intestinal microflora is important in rendering soy isoflavones bioavailable by facilitating their conversion to equol. Hence, substances that can modulate the intestinal microflora could affect the bioavailability of isoflavones. In this study, we examined the effects of fructo-oligosaccharides (FOS), a prebiotic, on enhancing the effects of soy isoflavones on bone in ovariectomized osteopenic female rats. DESIGN: Sixty-three 9-month-old female Sprague-Dawley rats were either sham-operated (Sham; one group) or ovariectomized (Ovx; four groups) and were fed a control diet for 3 months to induce bone loss. After bone loss was confirmed via dual-energy x-ray absorptiometry, rats were placed on dietary treatment for 4 months. The Sham and one Ovx group received a control diet, and the remaining Ovx groups received either a soy protein-based diet (Soy), a FOS-supplemented diet (FOS), or a soy protein-based and FOS-supplemented diet (Soy+FOS). Before the termination of the study, whole-body bone mineral density (BMD) and bone mineral content (BMC) were assessed under anesthesia. Immediately after euthanasia, bone specimens were collected for the assessments of BMD, BMC, and biomechanical and microarchitectural properties. RESULTS: Whole-body BMD values were significantly higher in FOS and Soy+FOS groups compared with Ovx controls. The tibial BMC increased by 10%, 6%, and 4% in Soy, FOS, and Soy+FOS groups, respectively, compared to the Ovx control group. FOS and FOS+Soy treatments had the most pronounced effects in enhancing lumbar BMC and BMD. The FOS+Soy combination effectively improved tibial microarchitectural properties by enhancing trabecular number and lowering trabecular separation compared with Ovx controls. The effects of dietary treatments on lumbar microarchitectural properties were minimal and biomechanical properties of the femur were not affected by any of the dietary treatments. CONCLUSION: Our findings suggest that, although incorporation of either soy or FOS in the diet of Ovx rats can improve BMD of the whole body, tibiae, and lumbar vertebrae, their combination had no any additive effects. However, in terms of microarchitecture, the combination of soy and FOS had a greater effect in reversing the loss of certain microarchitectural parameters such as tibial trabecular number, separation, and thickness.     

Genetics of type 2 diabetes mellitus and obesity--a review

Type 2 diabetes (T2D) and obesity are recognized as conditions of growing biomedical importance to societies worldwide. Despite this, lack of understanding concerning the processes which normally serve to maintain weight and to regulate glucose concentrations, and ignorance about the mechanisms by which these homeostatic processes fail, remains a significant obstacle to the development of improved tools for management and prevention. There has been a long-standing belief that the identification of the specific genes influencing development of these conditions has the potential to reveal these fundamental processes, thereby providing vital clues to support clinical advances. Furthermore, there has been the hope that this information will translate into the capacity to deliver more 'personalized' medical care, whereby management can be tailored in accordance with an appreciation of individual molecular pathogenesis. As this review indicates, these developments are already a reality for selected monogenic forms of diabetes and obesity. Recent advances in the identification of genes underlying multifactorial forms of these conditions will accelerate efforts to effect similar clinical translation across the full spectrum of disease.     

The prevalence of distal junctional kyphosis following posterior instrumentation and arthrodesis for adolescent idiopathic scoliosis

Distal junctional kyphosis (DJK) is a radiographic finding in patients that undergo spinal instrumentation and fusion, since there is an abrupt transition between fixed and mobile spinal segments.The true incidence of DJK is variable in literature and seems that has a multifactorial etiology. A consecutive series of 130 patients (mean age 15.6 years) with adolescent idiopathic scoliosis who underwent posterior spinal fusion and instrumentation were evaluated by analyzing coronal and sagittal angulation and balance measurements from standing radiographs obtained pre-operatively, within 6 weeks post-operation, at two years postoperative and at the latest follow-up. There was 35 male and 95 female. The mean time of follow-up was 36 months. The incidence of DJK at latest follow-up was 6.9% (9 patients). In DJK group, distal junctional angle from pre-operative of -12.5° lordosis (-30 to 0) reached to -5.5° (P=0.015) at 6 weeks postoperation and to -1.4° (-20 to 12°) (P=0.000) at 2 years follow-up,with mean of 12.1° kyphotic change (10-20°). In non DJK group, distal junctional angle from pre-operative angle of -7.5° reached -8.1° at 2 years follow-up (P=0.43). The mean age of DJK group at surgery was 17 years and for non-DJK group was 15.4 years (P=0.022). Distal junctional kyphosis was less common in this study than previous reports and stabilized after two years. The magnitude of coronal cobb angles or multiplicity of coronal curves had no effect in developing DJK that may be prevented by incorporation of the first lordotic disc into the fusion construct.     

Gill histopathology of cultured European sea bass, <Emphasis Type="Italic">Dicentrarchus labrax</Emphasis> (L.), infected with <Emphasis Type="Italic">Diplectanum aequans</Emphasis> (Wagener 1857) Diesing 1958 (Diplectanidae: Monogenea)

The mortality of juvenile European sea bass, Dicentrarchus labrax (L.), in the spring of the last 5 years in the northern coast of the Adriatic Sea has been attributed to heavy infections of the gill monogenean Diplectanum aequans (Wagener 1857) Diesing 1858. The histopathological examination of 38 sets of gills from hosts measuring 16.46 ± 0.26 cm in total length (mean±S.E.) and weighing 45.98 ± 2.37 g (mean±S.E.) were conducted using light and transmission electron microscopy. Twenty-eight (73.6%) D. labrax specimens were infected (34.61 ± 4.42, mean intensity±S.E.; 5–100, range) with the majority of D. aequans attaching to the median and apical portions of the primary gill filaments. The sites of attachment were marked by the common presence of haemorrhages and a white mucoid exudate. In histological sections, the opisthaptors of the parasites were observed to penetrate deeply, lying in close proximity to the basal membrane of primary lamella where they induced a hyperplastic response. Disruption and fusion of the secondary lamellae were common in all infected specimens with several individuals also exhibiting a marked erosion and inflammation of the epithelium of the primary and secondary lamellae. In infected fish, cellular changes in the epithelium underlying the bodies of worms were noted typified by an elevation in the number of mucous and rodlet cells and a reduction in the number of chloride cells.     

Algorithms for automated oximetry along the retinal vascular tree from dual-wavelength fundus images

We present an automated method to perform accurate, rapid, and objective measurement of the blood oxygen saturation over each segment of the retinal vascular hierarchy from dual-wavelength fundus images. Its speed and automation (2 s per entire image versus 20 s per segment for manual methods) enables detailed level-by-level measurements over wider areas. An automated tracing algorithm is used to estimate vessel centerlines, thickness, directions, and locations of landmarks such as bifurcations and crossover points. The hierarchical structure of the vascular network is recovered from the trace fragments and landmarks by a novel algorithm. Optical densities (OD) are measured from vascular segments using the minimum reflected intensities inside and outside the vessel. The OD ratio (ODR=OD600/OD570) bears an inverse relationship to systemic HbO2 saturation (SO2). The sensitivity for detecting saturation change when breathing air versus pure oxygen was calculated from the measurements made on six subjects and was found to be 0.0226 ODR units, which is in good agreement with previous manual measurements by the dual-wavelength technique, indicating the validity of the automation. A fully automated system for retinal vessel oximetry would prove useful to achieve early assessments of risk for progression of disease conditions associated with oxygen utilization.     

Study of cement apparatus, cement production and transportation in adult male Neoechinorhynchus rutili (Acanthocephala, Eoacanthocephala)

Investigation with light and electron microscopy has been made of the cement apparatus of the mature male Neoechinorhynchus rutili, a parasite of Gasterosteus aculeatus. N. rutili possesses a single compact mass of glandular tissue (cement gland) with eight giant nuclei. The nucleus is lobe-shaped and has a conspicuous nucleolus with a granular appearance. The cytoplasm of the gland contains prominent rough endoplasmic reticulum, mitochondria and electron dense secretory granules. A short duct connects the gland with a single, separate cement reservoir. The duct appears to lack a lumen and is seen as an electron-dense, compact structure. Many microtubules of approximately 150 nm outer diameter are located throughout the cytoplasm of the duct. It is proposed that the microtubules in N. rutili are responsible for the transport of cement granules from the gland to the reservoir. The cement reservoir appears as a compact organ filled with granules measuring at least 0.5 μm in diameter. Received: 5 January 2000 / Accepted: 15 March 2000