Quantitative assessment of respiratory function following contusion injury of the cervical spinal cord

A prerequisite for higher-level visual tasks such as object recognition is a segmentation of the image into distinct two-dimensional regions. While it has long been assumed that the human visual system jointly exploits region and boundary cues for image segmentation, we report the results of psychophysical experiments which suggest that the visual system relies on geometric properties of bounding contours such as closure and not on the texture of the two-dimensional regions they partition. These findings suggest that the visual system may code and links contours into coherent shapes before surface properties are conjoined.     

Malignant mucosal melanoma of the head and neck: review of the literature and report of 14 patients

BACKGROUND: Fortunately, primary malignant mucosal melanoma of the head and neck is a rare entity. A paucity of data elucidating the predictive factors as well as the unpredictable and aggressive biologic behavior of mucosal melanoma compound the vexing clinical situation. This review summarizes what the literature reveals about the epidemiology, patient survival, patterns of local recurrence, and local and distant metastasis of the disease. Over 1000 patients with this disease have been reported. Survivals at 5 and 10 years is 17% and 5%, respectively. Approximately 19% of patients present with lymph node metastasis and another 16% develop lymph node metastases after treatment, whereas 10% present with distant metastasis. Local metastasis does not affect survival; this is in sharp contrast with skin melanoma. Over 50% of patients experience local treatment failure, and salvage treatment is effective in only 25% of these cases. Local failure is the harbinger of distant metastases. Patients with nasal mucosal melanoma have a 31% 5-year survival rate, whereas sinus melanoma patients fare poorly, with a 0% rate of 5-year survival. METHODS: The authors conducted a retrospective review of 14 patients with characteristics similar to those in the literature in terms of outcome. RESULTS: The 5-year survival rate for these patients was 14%. Whole-body positron emission tomography was performed on 3 patients to detect metastatic disease. The patterns of local recurrence, distant metastasis, and survival for these patients were compared with the same data for patients described in the literature. CONCLUSIONS: Surgery appears to have the greatest efficacy in the management of mucosal melanoma, although radiation therapy may play an increasingly important role in the future.     

Estimation of Koc values for deuterated benzene, toluene, and ethylbenzene, and application to ground water contamination studies

Sorption partition coefficients between water and organic carbon (Koc) for deuterated benzene, toluene, and ethylbenzene have been estimated by measuring values of the octanol-water partition coefficient (Kow) and HPLC retention factors (k1), which correlate closely to values of Koc. Measured values of log Kow for non-deuterated and deuterated toluene are 2.77 (+/- 0.02) and 2.78 (+/- 0.04), respectively, indicating that within experimental error, log Koc for deuterated and non-deuterated toluene are the same. The HPLC method provides greater precision, and yields values of delta log Koc (= log Koc [deuterated]-log Koc [non-deuterated]) of -0.021 (+/- 0.001) for benzene, -0.028 (+/- 0.002) for toluene, and -0.035 (+/- 0.003) for ethylbenzene. The small values of delta log Koc demonstrates that deuterated compounds are excellent tracers for the hydrologic behavior of ground water contaminants.     

Capsular polysaccharide synthesis in Streptococcus pneumoniae serotype 14: molecular analysis of the complete cps locus and identification of genes encoding glycosyltransferases required for the biosynthesis of the tetrasaccharide subunit

We suggested that sexual differentiation of the reproductive system in gonochoric species of invertebrates can be characterized by common molecular mechanisms in spite of high morphological divergences of reproductive tract organs in different animal groups. The present study focused on this problem and report our observations on biochemical characteristics of male-associated polypeptide (MAP) identified in the gonad tissue of bivalve molluscs, Mytilus galloprovincialis, in comparison to those of male-specific carboxylesterase (esterase S) of Drosophila virilis ejaculatory bulbs. We provide evidences for the immunochemical similarity of Mytilus MAP and Drosophila esterase S. We also show that MAP is characterized by esterase activity toward both, alpha- and beta-naphthyl acetates. Using immunofluorescence, we found MAP in the gonad (mantle) connective tissue, membranes of follicles and around gonad ducts but not in sperm cells. Nevertheless, the levels of MAP expression depend on presence or absence of ripe spermatozoa in the gonad follicles. In mature gonads before spawning, MAP is expressed at high level, while in the spent gonads only traces of this polypeptide could be detected. Using Western immunoblot, MAP was not observed in spermatozoa obtained by biopsy of gonad follicles. In contrast, we found this protein in spawned sperm cells. Thus, we suggest that spawning may be required to establish the trafficking mechanisms that control whether MAP is retained or excreted by the gonad. Taken together, the results indicate that MAP of M. galloprovincialis is structurally and functionally related to esterase S of D. virilis ejaculatory bulbs.     

Thrombin cleavage-independent deposition of fibrinogen in extracellular matrices

Lung epithelial cells (A549) synthesize and secrete fibrinogen (FBG) in vitro when stimulated with interleukin-6 and dexamethasone. This FBG secretion is polarized in the basolateral direction, suggesting that FBG is a component of the extracellular matrix (ECM). Immunofluorescent staining of A549 cells showed a fibrillar pattern of FBG, similar to the staining detected using antibodies against the matrix constituents, collagen type IV and fibronectin (FN). The same pattern of staining was detected using antibodies against fibrinopeptides A and B, as well as with the T2G1 monoclonal antibody against the fibrin-specific epitope, beta15-21. Matrix staining was unaltered in the presence of the thrombin inhibitor, hirudin, or the plasmin inhibitor, aprotinin, consistent with the interpretation that matrix deposition of FBG does not require such enzymatic action. Metabolic labeling studies confirmed that FBG secreted from A549 cells or deposited into the ECM showed no evidence of thrombin or plasmin proteolytic processing or of transglutaminase-mediated covalent cross-linking (gamma-gamma dimers or alpha-polymers). Incubation of either A549 cell-derived or purified plasma FBG with cultures of human foreskin fibroblasts resulted in FBG deposition in the ECM that colocalized with matrix fibrils containing endogenously produced FN and laminin (LN). Binding of FBG to this exogenously produced matrix was unaltered by inhibition of thrombin and plasmin action, yet also exhibited exposure of the fibrin-specific epitope, beta15-21. The majority (approximately 70%) of newly synthesized and secreted FBG is bound to the cell surface as determined by its trypsin-sensitivity. Cell surface-bound FBG is initially deoxycholate-soluble, which, over time, becomes incorporated in the deoxycholate-insoluble ECM in a similar fashion to FN. These data suggest that matrix incorporation requires the binding of secreted FBG to cell-associated matrix assembly sites. However, unlike FN, FBG in the ECM is composed of the dimeric protamer (A alpha/B beta/gamma gamma) and not high molecular weight polymers indicative of fibrin. This study provides evidence that deposition of FBG in both endogenous and exogenously produced matrices results in conformational changes that occur independently of thrombin cleavage. This matrix-bound FBG, on which unique cell-reactive domains are likely exposed, could augment cellular response mechanisms evoked during injury and inflammation.     

Taxanes propagate apoptosis via two cell populations with distinctive cytological and molecular traits

Gross observation at the slaughterhouse determines the primary selection of porcine aortic valves for the manufacture of bioprostheses. This step is critical because only valves with significant abnormalities are rejected. The present study validated this selection process by investigating the pathological characteristics of one series of accepted valves and one series of rejected valves. Macroscopy, x-ray examination, light microscopy, and scanning electron microscopy (SEM) were performed on 5 initially rejected valves, 3 leaflets from 3 other initially rejected valves, and 6 valves that successfully passed this first step in the selection process. Abnormalities were macroscopically visible only on the rejected valves and were described as thick white areas, heavy white striations, thin spots, white plaques, and nodules. Individual variability in the structure of each leaflet was more significant in the rejected valves than in the valves that had passed the first inspection. The leaflets of the rejected valves were also irregularly thick with a lack of consistency in the position and prominence of the different layers. The formation of nodules and the presence of white plaques in the inner fibrosa layer were among the pathological features. The initially accepted valves considered defect free under gross observation continued to display some weaknesses, and not all of the valves selected during the first step of the process were suitable to become bioprostheses. Because the manufacturer carries out further quality control inspections at every step of preparation resulting in additional rejections, it is therefore anticipated that all valves with defects will be rejected. None of the rejected valves were defect free, and rejection was fully justified.     

Increased urinary excretion of 3-hydroxyisovaleric acid and decreased urinary excretion of biotin are sensitive early indicators of decreased biotin status in experimental biotin deficiency

To assess the utility of various indicators of biotin status, marginal biotin deficiency was induced experimentally in normal adults. Ten subjects consumed a diet that contained enough avidin to bind seven times more biotin than that in the diet. Blood and 24-h urine samples were collected before the diet began and twice weekly thereafter for 20 d. The urinary excretion and serum concentration of biotin and its two principal inactive metabolites bisnorbiotin and biotin sulfoxide were determined after HPLC separation with an avidin-binding assay. The urinary concentration of 3-hydroxyisovaleric acid, an indicator of reduced activity of a biotin-dependent enzyme, was quantitated by gas chromatography-mass spectrometry. The urinary excretion of 3-hydroxyisovaleric acid increased significantly (P < 0.0001). For all subjects, the urinary excretion of both biotin and bisnorbiotin decreased significantly (P < 0.0001 for each). In contrast, the mean serum concentration of biotin did not decrease significantly (P = 0.06). These data provide evidence that the urinary excretion of 3-hydroxyisovaleric acid and the urinary excretion of biotin are early and sensitive indicators of biotin deficiency and that the serum concentration of biotin is not.     

Risedronate in the treatment of Paget's disease of bone: an open label, multicenter study

An open-label, multicenter study was conducted to determine the efficacy and safety of oral risedronate (a pyridinyl bisphosphonate) in 162 patients (102 men, 60 postmenopausal women; mean age, 68 years) with moderate to severe Paget's disease of bone (mean serum alkaline phosphatase [ALP] approximately seven times the upper limit of normal). Patients were treated with oral risedronate, 30 mg/day for 84 days, followed by 112 days without treatment. This 196-day cycle was repeated once if serum ALP did not normalize or increased from the nadir value by > or = 25%. At the end of the first and second cycles, the mean percentage decreases for serum ALP were 65.7% and 69.1%, and for urinary hydroxyproline/creatinine 50.4% and 66.9%, respectively. The decreases from baseline in ALP and urinary hydroxyproline/creatinine were significant (p < 0.001). Normalization of serum ALP was observed in 86 patients (53.8%): 53 during the first treatment cycle and 33 during the second. There was a significant proportion of patients reporting a decrease in the pagetic bone pain at days 84 and 196 (p < 0.001). Overall, risedronate was well tolerated. Five patients withdrew due to adverse events, none of which were considered to be drug related. In conclusion, 30 mg of oral risedronate administered daily for 84 days significantly reduced the biochemical indices of disease activity and was associated with pain reduction in patients with moderate to severe Paget's disease of bone. Normalization of ALP was observed in the majority of patients. Repeated administration of risedronate was shown to be beneficial. In general, risedronate was well tolerated and demonstrated a good safety profile.