Prediction of indications for valve replacement among asymptomatic or minimally symptomatic patients with chronic aortic regurgitation and normal left ventricular performance

BACKGROUND: Optimal criteria for valve replacement are unclear in asymptomatic/minimally symptomatic patients with aortic regurgitation (AR) and normal left ventricular (LV) performance at rest. Moreover, previous studies have not assessed the prognostic capacity of load-adjusted LV performance ("contractility") variables, which may be fundamentally related to clinical state. Therefore, 18 years ago, we set out to test prospectively the hypothesis that objective noninvasive measures of LV size and performance and, specifically, of load-adjusted variables, assessed at rest and during exercise (ex), could predict the development of currently accepted indications for operation for AR. METHODS AND RESULTS: Clinical variables and measures of LV size, performance, and end-systolic wall stress (ESS) were assessed annually in 104 patients by radionuclide cineangiography at rest and maximal ex and by echocardiography at rest; ESS was derived during ex. During an average 7.3-year follow-up among patients who had not been operated on, 39 of 104 patients either died suddenly (n = 4) or developed operable symptoms only (n = 22) or subnormal LV performance with or without symptoms (n = 13) (progression rate=6.2%/y). By multivariate Cox model analysis, change (delta) in LV ejection fraction (EF) from rest to ex, normalized for deltaESS from rest to ex (deltaLVEF-deltaESS index), was the strongest predictor of progression to any end point or to sudden cardiac death alone. Unadjusted deltaLVEF was almost as efficient. Symptom status modified prediction on the basis of the deltaLVEF-deltaESS index. The population tercile at highest risk by deltaLVEF-deltaESS progressed to end points at a rate of 13.3%/y, and the lowest-risk tercile progressed at 1.8%/y. CONCLUSIONS: Currently accepted symptom and LV performance indications for valve replacement, as well as sudden cardiac death, can be predicted in asymptomatic/minimally symptomatic patients with AR by load-adjusted deltaLVEF-deltaESS index, which includes data obtained during exercise.     

Plasma-derived proteins in airway defence, disease and repair of epithelial injury

One significant characteristic of the airway mucosa in vivo, that cannot easily be mimicked in vitro, is its microcirculation, which generates a highly dynamic, biologically active milieu of plasma-derived molecules that may pass to the airway lumen in vivo. New data on the mechanisms of airway mucosal exudation indicate that the protein systems of circulating plasma may contribute significantly to the biology and immunology of the lamina propria, its surface epithelium and the luminal surface, not only in injured airways, but also in airways that are activated but display no sign of oedema, epithelial disruption, or increased absorption capacity. We suggest that present knowledge of the mechanisms of plasma exudation, together with rapidly emerging information (not detailed herein) on receptors, target cells and cellular responses to the plasma-derived molecules, must be considered in any realistic model that investigates "immuno-inflammatory" mechanisms of the airway mucosa.     

Isotype-specific antibody responses to foot-and-mouth disease virus in sera and secretions of "carrier' and "non-carrier' cattle

Isotype-specific antibody responses to foot-and-mouth disease virus (FMDV) were measured in the sera and upper respiratory tract secretions of vaccinated and susceptible cattle challenged with FMDV by direct contact or by intranasal inoculation. A comparison was made between cattle that eliminated FMDV and those that developed and maintained a persistent infection. Serological and mucosal antibody responses were detected in all animals after challenge. IgA and IgM were detected before the development of IgG1 and IgG2 responses. IgM was not detected in vaccinated cattle. Challenge with FMDV elicited a prolonged biphasic secretory antibody response in FMDV "carrier' animals only. The response was detected as FMDV-specific IgA in both mucosal secretions and serum samples, which gained statistical significance (P < 0.05) by 5 weeks after challenge. This observation could represent the basis of a test to differentiate vaccinated and/or recovered convalescent cattle from FMDV "carriers'.     

Transient temperature responses of hydronic radiant floor heating system by different pipe embedding depth and water supply condition

"Ondol" is a Korean unique heating system. It is a specific radiant floor heating system using combustion heat of briquette or timber in Korea. Such traditional "Ondol" is changed to radiant heating system with pipe-coil embedded in the floor or slab. This study has contributed to the understandings of the transient behaviours of Ondol-heated floor panels and enclosure exposed to this type of heating system. The result is that the water supply temperature had a large effect on the rate of increase in floor surface and room air temperature. But, in spite of a higher water supply temperature, the heat flow rate was not increased considerably. The shallow pipe embedding depths, of course, result in a low heat flow rate.     

Adaptation of thermafil components to canal walls

In summer 1991 an outbreak of a Salmonella enteritidis epidemic involving about 600 cases of gastroenteritis occurred at one of the leading pharmaceutical companies in southwestern Germany. The main source was a cold fruit soup, in addition Salmonella were isolated from meat strips and a curd cheese which were used for a salad dressing. A total of 2300 contaminated food portions were served resulting in an attack rate of about 25%. The possible origin could have been an asymptomatic Salmonella-positive member of the kitchen personnel who was the only one who was involved with the preparation of all the incriminated foods. A further spread of the epidemic and especially the possible contamination of pharmaceuticals was avoided by the timely and adequate reaction of the company's occupational medical service. This case exemplifies how classical crisis management, "increased initiative on one's own for prevention of infections in all areas of food processing" (Steuer) and finally the cooperation of the company with different institutions of the public health authorities contribute to the control of such a catastrophic scenario.     

S-phase fractions of breast carcinomas. Relationships to morphology, estrogen and progesterone receptors, and early recurrence

Analysis of the S-phase fractions (SPF) measured by in vitro thymidine labeling, morphological appearances, and estrogen receptor (ER) assays of primary invasive breast carcinomas demonstrated several interrelationships. Lobular, mucinous, tubular, and adenocystic carcinomas consistently had low SPF and were usually positive for ER. The same was true for the carcinomas of no special histologic type [the not otherwise specified (NOS) group of E. R. Fisher including "infiltrating ductal" and undifferentiated carcinomas] with minimal anaplasia. Medullary, atypical medullary, and morphologically unclassifiable carcinomas with marked nuclear anaplasia nearly always had high SPF and were usually negative for ER. High SPF was associated with advanced stages of carcinoma initially or with early recurrence following mastectomy.     

Autoantibodies to the insulin receptor. Effect on the insulin-receptor interaction in IM-9 lymphocytes

The serum of some patients with insulin-resistant "diabetes" contains antibodies that bind to and block the cell membrane receptors for insulin. In this report, we have characterized the effects of the antireceptor antibodies on the interaction of (125)I-insulin with its receptor on the human lymphoblastoid cell line IM-9. Up to 95% of specific insulin binding can be inhibited by pretreatment of the cells with these immunoglobulins. The onset of the inhibitory effect is time- and temperature-dependent, and the effect is reversed extremely slowly if the cells are suspended in a large excess of antibody-free buffer. These features of antibody binding can be easily distinguished from those for insulin binding to its receptor. The inhibitory effect of the antibodies can be reversed by exposure of the cells to conditions known to elute surface immunoglobulins. The three antireceptor sera studied appear to alter the insulin-receptor interaction in different ways. Two antisera markedly reduce receptor affinity through combined effects on the insulin association and dissociation rates, and, additionally, have smaller effects on available receptor number. A third antiserum primarily affects available receptor number and has little effect on receptor affinity. All three antisera inhibit the capacity of insulin to promote negatively cooperative site-site interactions among insulin receptors. The data suggest that these autoantibodies to the insulin receptor bind to different determinants on the receptor and may therefore be useful as unique probes of insulin receptor structure and function.     

Alcohol's Effect on Triggered Displaced Aggression.

The authors examined alcohol's effect on triggered displaced aggression, the hostile reaction to a second provoking person after provocation from a first. Participants consumed an alcoholic or a nonalcoholic beverage. Subsequently, one individual provoked all of them with moderate intensity. Then, 2 groups were studied: those who received or who failed to receive a second provocation of minimal intensity. Consistent with prior research, participants who received a second, minimal provocation displayed more aggression than those who did not. After participants drank alcohol, the magnitude of this difference was significantly greater, indicating that alcohol increases triggered displaced aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure Refinement by a Liquid Metal Cooling Solidification Process for Single-Crystal Nickel-Base Superalloys

Single crystals of a nickel-base superalloy were directionally solidified (DS) over a range of cooling rates to evaluate the benefits of a new high thermal gradient solidification process. Solidification experiments were conducted on cylindrical bars with a liquid-metal-enhanced cooling process. This higher gradient casting process was evaluated for the degree of structure refinement, microstructural variability, and porosity distributions. Cylindrical bars of 1.6-cm diameter were solidified at rates between 8.4 and 21.2 mm/min using a tin-based, liquid metal cooling (LMC) technique and at a rate of 3.4 mm/min with a conventional Bridgman process. The LMC process produced a refined microstructure with average primary dendrite arm spacing (PDAS) and secondary dendrite arm spacing (SDAS) values as low as 164 and 25 μm, respectively, for the bar geometry evaluated. An optimum intermediate withdrawal velocity of 12.7 mm/min produced up to a 50 and 60 pct refinement in PDAS and SDAS, respectively. Further increases in withdrawal velocity produced smaller SDAS and pore sizes, but undesirable grain boundaries and excessive secondary dendrite arm growth. Voronoi tessellation methods were used to examine the extremes of the dendrite arm spacings in comparison to the average measurements, the packing of dendrites, and the correlation of porosity size and location with the dendrite structure. A simple expression for prediction of the maximum pore size is developed.