Potential involvement of gelatinases and their inhibitors in Mannheimia haemolytica pneumonia in cattle

Mannheimia haemolytica infection of the lower respiratory tract of cattle results in a bronchofibrinous pneumonia characterized by massive cellular influx and lung tissue remodeling and scarring. Since altered levels of gelatinases and their inhibitors have been detected in a variety of inflammatory conditions and are associated with tissue remodeling, we examined the presence of gelatinases in lesional and nonlesional lung tissue obtained from calves experimentally infected with M. haemolytica. Lesional tissue had elevated levels of progelatinase A and B and active gelatinase A and B when compared with nonlesional tissue obtained from the same lung lobe. In vitro, M. haemolytica products stimulated production of gelatinase B, but not its activation, by bovine monocytes. Alveolar macrophages showed constitutive production of gelatinase B but no change in response to M. haemolytica products. Bovine neutrophils exposed to M. haemolytica products also released gelatinase B, and there was a significant increase in the activated form of this enzyme. These effects were virtually identical when recombinant O-sialoglycoprotease was used to stimulate these cells. M. haemolytica products also enhanced the expression by bovine monocytes and alveolar macrophages of the tissue inhibitor of metalloproteinase 1. Our results provide evidence that matrix metalloproteinases are activated in lung lesions from cattle with shipping fever and that M. haemolytica virulence products induce production, release, and especially activation of gelatinase B by bovine inflammatory cells in vitro.     

Her-2 protein expression, cellular localization, and gene amplification in colorectal carcinoma.

This study was sought to evaluate the relationship between Her-2 protein expression, cellular localization, gene amplification, and other clinicopathologic parameters in colorectal carcinomas. Her-2 protein expression and gene amplification were assessed in paraffin sections from 106 primary colorectal adenocarcinoma cases using immunohistochemistry and fluorescence in situ hybridization. Both membranous and cytoplasmic immunostaining was evaluated. The results were correlated with each other and with tumor grade, stage, and overall survival. Membranous and cytoplasmic protein expression was identified in 6 (5.6%) and 13 (12.26%) cases, respectively. Gene amplification was detected in 4 (3.7%) cases. There was a high concordance between membranous protein expression and gene amplification (kappa=0.791). No apparent association with any of the clinicopathologic parameters was identified. Membranous Her-2 protein expression and gene amplification are encountered in a small subset of colorectal carcinomas and are highly concordant events. Cytoplasmic protein expression might be either artifactual or it might represent a cross-reacting protein or a precursor form of the mature protein.     

Cryptococcus neoformans var. gattii in the koala (Phascolarctos cinereus): serological evidence for subclinical cryptococcosis.

Cryptococcus neoformans var. gattii has been shown to have a strong association with eucalypts frequently used by koalas and, not surprisingly, it has been shown to colonize the nasal cavities of koalas. The progression from nasal colonization to tissue invasion is critical to understanding the pathogenesis of cryptococcosis in this species and provides a model for pathogenesis of cryptococcosis in other species. Cryptococcal antigenaemia was detected in twenty-eight healthy koalas from three different regions. This was interpreted as representing limited subclinical disease. One koala developed cryptococcal pneumonia 6 months after leaving the study, whereas another developed cryptococcal meningoencephalitis during the course of the study. Opportunistic necropsies on ten antigen-positive koalas resulted in discovery of small cryptococcal lesions in two (paranasal sinus and lung, respectively). Our data suggest that cryptococcal antigenaemia occurs commonly in koalas, especially in areas with a high environmental presence of C n. var. gattii. Subclinical disease appears most likely to manifest as a small focal lesion in the respiratory tract. Possible outcomes include elimination by an effective immune response, quiescence with possibility of later re-activation or direct progression to overt disease. Symptomatic and subclinical cases showed differences in levels of antigenaemia. The data presented have significant implications for koalas in captivity.     

The role of visual feedback of hand position in the control of manual prehension

 Although it is obvious that vision plays a primary role in reaching and grasping objects, the sources of the visual information used in programming and controlling various aspects of these movements is still being investigated. One source of visual information is feedback relating to the characteristics of the reach itself – for example, the speed and trajectory of the moving limb and the change in the posture of the hand and fingers. The present study selectively eliminated this source of visual information by blocking the subject’s view of the reaching limb with an opaque barrier while still enabling subjects to view the goal object. Thus, a direct comparison was made between standard (closed-loop) and object-only (open-loop) visual-feedback conditions in a situation in which the light levels and contrast between an object and its surroundings were equivalent in both viewing conditions. Reach duration was longer with proportionate increases in both the acceleration and deceleration phases when visual feedback of the reaching limb was prevented. Maximum grip aperture and the proportion of movement time at which it occurred were the same in both conditions. Thus, in contrast to previous studies that did not employ constant light levels across closed- and open-loop reaching conditions, a dissociation was found between the spatial and temporal dimensions of grip formation. It appears that the posture of the hand can be programmed without visual feedback of the hand – presumably via a combination of visual information about the goal object and proprioceptive feedback (and/or efference copy). Nevertheless, maximum grip aperture (like the kinematic markers examined in the transport component) was also delayed when visual feedback of the reaching limb was selectively prevented. In other words, the relative timing of kinematic events was essentially unchanged, reflecting perhaps a tight coupling between the transport and grip components. Received: 3 July 1998 / Accepted: 18 November 1998     

Magnitude of the inflammatory response to cardiopulmonary bypass and its relation to adverse clinical outcomes

INTRODUCTION: Cardiopulmonary bypass (CPB) induces an inflammatory response believed to contribute to postoperative morbidity. We hypothesized that the magnitude of the inflammatory response following CPB would be associated with adverse clinical outcomes. METHODS: Twenty-nine patients had plasma TNF, IL-6, IL-8, elastase, histamine, complement C5a, and complement C3a measured by ELISA before, during, and after cardiac operations employing CPB. Inflammatory mediator levels were analyzed with respect to outcomes. RESULTS: Mediator levels peaked at 4 h post-CPB and either returned to baseline or substantially decreased by 24 h. Patients with peak mediator levels above the median for the group as a whole were classified as 'hyper-responders'; those with levels below the median were classified as 'normal responders'. While IL-8, C3a, and IL-6 levels were independently associated with adverse outcomes, TNF, histamine, and C5a levels were not. Elastase levels trended towards adverse outcomes. IL-8 'hyper-responders' experienced significantly greater postoperative weight gain and had higher IL-8 levels at 24 h (p<0.05), with trends towards renal impairment and protracted supplemental oxygen requirements. C3a 'hyper-responders' strongly trended towards increased bleeding, delayed extubation, greater postoperative weight gain, and decreased levels of independent functioning at discharge (p < or = 0.10). IL-6 'hyper-responders' experienced significantly more postoperative bleeding, delayed extubation, and higher IL-6 levels at 24 h compared to 'normal responders' (p < 0.05). They strongly trended towards greater postoperative weight gain and decreased levels of independent functioning at discharge (p < or = 0.10). CONCLUSIONS: Patients who have an exaggerated inflammatory response to CPB tend to bleed more, require more respiratory support, demonstrate greater capillary leak via weight gain, and display a decline in independent functioning relative to normal responders. Thus, it appears that the magnitude of the inflammatory response to CPB adversely influences clinical outcomes.     

fMRI activation in the human frontal eye field is correlated with saccadic reaction time

Variation in response latency to identical sensory stimuli has been attributed to variation in neural activity mediating preparatory set. Here we report evidence for a relationship between saccadic reaction time (SRT) and set-related brain activity measured with event-related functional magnetic resonance imaging. We measured hemodynamic activation time-courses during a preparatory "gap" period, during which no visual stimulus was present and no saccades were made. The subjects merely anticipated appearance of the target. Saccade direction and latency were recorded during scanning, and trials were sorted according to SRT. Both the frontal (FEF) and supplementary eye fields showed pre-target preparatory activity, but only in the FEF was this activity correlated with SRT. Activation in the intraparietal sulcus did not show any preparatory activity. These data provide evidence that the human FEF plays a central role in saccade initiation; pre-target activity in this region predicts both the type of eye movement (whether the subject will look toward or away from the target) and when a future saccade will occur.     

Glomerular Hypertrophy in Offspring of Subtotally Nephrectomized Ewes

We have shown that fetuses whose mothers underwent subtotal nephrectomy (STNx) before pregnancy had high urine flow rates and sodium excretions, but lower hematocrits, plasma chloride, and plasma renin levels compared with controls. To see if these functional differences in utero persist after birth and are the result of altered renal development, we studied 8 lambs born to STNx mothers (STNxL) and 10 controls (ConL) in the second week of life. These lambs were of similar body weights, nose–rump lengths and abdominal girths. Their kidney weights were not different (ConL 36.1 ± 1.9 vs. STNxL 39.8 ± 3.3 g), nor were kidney dimensions or glomerular number (ConL 423,520 ± 22,194 vs. STNxL 429,530 ± 27,471 glomeruli). However, STNxL had 30% larger glomerular volumes (both mean and total, P < 0.01) and there was a positive relationship between total glomerular volume and urinary protein excretion (P < 0.05) in STNxL. Despite this change in glomerular morphology, glomerular filtration rate, tubular function, urine flow, and sodium excretion rates were not different between STNxL and ConL, nor were plasma electrolytes, osmolality, and plasma renin levels. Thus while many of the functional differences seen in late gestation were not present at 1–2 weeks after birth, the alteration in glomerular size and its relationship to protein excretion suggests that exposure to this altered intrauterine environment may predispose offspring of mothers with renal dysfunction to renal disease in adult life. Anat Rec, 291:318–324, 2008. © 2008 Wiley‐Liss, Inc.     

1例罕见桡侧腕伸肌变异与文献复习

作者于2004年在指导学生对一具90岁男性尸体标本进行解剖时,见其左前臂桡侧腕伸肌区存在有桡侧腕伸副肌(extensor carpi radialis accessorius,ECRA)合并桡侧腕长、短伸肌之间出现两条副肌腱并相互交叉连接的一种罕见的复合变异。     

Molecular genetics of pseudoxanthoma elasticum: type and frequency of mutations in ABCC6

Pseudoxanthoma elasticum (PXE) is a systemic heritable disorder that affects the elastic tissue in the skin, eye, and cardiovascular system. Mutations in the ABCC6 gene cause PXE. We performed a mutation screen in ABCC6 using haplotype analysis in conjunction with direct sequencing to achieve a mutation detection rate of 97%. This screen consisted of 170 PXE chromosomes in 81 families, and detected 59 distinct mutations (32 missense, eight nonsense, and six likely splice-site point mutations; one small insertion; and seven small and five large deletions). Forty-three of these mutations are novel variants, which increases the total number of PXE mutations to 121. While most mutations are rare, three nonsense mutations, a splice donor site mutation, and the large deletion comprising exons 23-29 (c.2996_4208del) were identified as relatively frequent PXE mutations at 26%, 5%, 3.5%, 3%, and 11%, respectively. Chromosomal haplotyping with two proximal and two distal polymorphic markers flanking ABCC6 demonstrated that most chromosomes that carry these relatively frequent PXE mutations have related haplotypes specific for these mutations, which suggests that these chromosomes originate from single founder mutations. The types of mutations found support loss-of-function as the molecular mechanism for the PXE phenotype. In 76 of the 81 families, the affected individuals were either homozygous for the same mutation or compound heterozygous for two mutations. In the remaining five families with one uncovered mutation, affected showed allelic compound heterozygosity for the cosegregating PXE haplotype. This demonstrates pseudo-dominance as the relevant inheritance mechanism, since disease transmission to the next generation always requires one mutant allelic variant from each parent. In contrast to other previous clinical and molecular claims, our results show evidence only for recessive PXE. This has profound consequences for the genetic counseling of families with PXE.     

Utilization of cartilage graft technology for the testing of novel chondro-therapeutic agents

Introduction The aims of the current study were to (i) tissue engineer a cartilage graft with structural and biochemical properties of native articular cartilage in vivo, with potential for use in cartilage repair technologies and (ii) utilize this model as a test system to evaluate the efficiency of novel therapeutics for future research into cartilage metabolism in health and disease. Materials and methods Articular cartilage was harvested from hock joints of (young) 7‐day and (old) 18‐month bovine sources. Cells were isolated by enzymatic digestion and seeded at a range of cell densities (2, 4, 6, 8, 10 and 12 × 10⁶ cells/insert) into type II collagen‐coated Millipore filter inserts and cultured as described previously ( Kandel et al. 1995 ). In order to mimic a catabolic effect on cartilage, some samples were treated with IL‐1α (10 ng/ml) for 24 h in the absence or presence of experimental drugs. Proteoglycan (PG) release, detectable in the medium, was analysed by colorimetric assay ( Farndale et al. 1986 ). At the end of the culture period, cartilage grafts were fixed, sectioned and stained with Alcian Blue or immuno‐fluorescently labelled with a panel of monoclonal antibodies recognizing several components of the graft extracellular matrix. Results Full‐depth chondrocytes from both young and old bovine sources produced a stratified hyaline tissue with distinct zones after 2 weeks in culture. These zones approximated to the surface, middle and deep zones that characterize native articular cartilage in vivo. Increased culture time and seeding density produced cartilage of an increased thickness and cellularity, respectively. Grafts produced from young cartilage contained approximately 3 times more sulfated PG than grafts produced from an old cartilage, indicating an increased matrix secretion in these cultures. Histologically, the old grafts were also thinner and more weakly stained with Alcian Blue, indicating a lower sulfated PG content. Addition of IL‐1α to the cultures resulted in a dramatic PG release from the cartilage grafts, manifest histologically as a loss of Alcian Blue staining in the upper third of the cartilage tissue. Immunofluorescent staining identified subtle changes in matrix composition and in the structure and catabolism of matrix proteoglycans in response to both IL‐1a and the experimental drugs tested. Discussion The grafts produced had many structural and biochemical similarities to articular cartilage in vivo. These grafts may better integrate with the host cartilage in cartilage repair procedure. This culture system also provides ideal conditions to analyse the response of engineered grafts to catabolic factors that occur in the arthritic joint, along with ideal conditions for research into drug therapies. Advantages of this culture system, in comparison with an explant system, are that effects can be analysed within a 24‐h period. Future work will include applying fatty acids, modified glucosamine and some Asian herbal remedies to this culture system and analysing their potential chondroprotective effects.