First Demonstration of an Increased Serum Level of Reactive Oxygen Species During the Peripartal Period in the Ewes

Reactive Oxygen Species (ROS) are produced during oxidative metabolism, and regulate many biological processes. The acute inflammation characterizing parturition induces many physiological changes. Among them, there is evidence that ROS affect the synthesis of many factors involved in parturition. Our study aims to determine serum levels of ROS in periparturient ewes, as well as to establish a value of reference of their physiological concentration.

ROS determination was performed on blood collected every 12 hours in periparturient twin pregnant ewes. Our results will show a significant increase in ROS concentrations from the beginning to the end of the experiment. This increase may be due to the inflammatory process establishing during parturition.     

Prior antiplatelet drug use and short-term mortality in older patients with acute ischemic stroke (AIS)

Some studies suggest that previous treatment with antiplatelet agents (AA) might reduce ischemic stroke severity and improve outcomes in terms of clinical deficits or mortality. We evaluated the effect of the prior chronic use of AA on short-term (30 days) mortality in a sample of consecutive patients with AIS. Four hundred thirty-nine older patients (>65 years) with “major” AIS (modified Rankin scale ≥ 3) consecutively admitted to the University ward of Internal Medicine or Geriatrics were enrolled. Stroke was classified according to Oxfordshire Community Stroke Project (OCSP). Data recorded included: (1) clinical features; (2) medical history including home therapies, and vascular risk factors; (3) routine clinical chemistry analyzes (verb)/analyses (noun). Short-term (30 days) mortality was 27.6%. One hundred fifteen subjects (26.2%) were taking AA before admission. Compared with subjects not treated, subjects taking AA were characterized by higher prevalence of recurrent stroke (35% vs. 22%). In this group, a trend toward a higher prevalence of congestive heart failure (CHF), smoking, and altered levels of consciousness (ALC) was noted. Stroke type and short-term mortality (33% vs. 26.2%; odds ratio = OR = 1.25; 95% confidence interval = CI = 0.75-2.10, age and gender adjusted) were not different between the two groups. Adjustment for glucose, CHF, previous stroke, smoking, and ALC did not change mortality risk (OR = 0.83; 95%CI = 0.40-1.72). We conclude that in older patients hospitalized for “major” AIS, prior use of AA was not associated with any benefit in terms of short-term mortality both in patients with first, as well as in those with recurrent ischemic stroke.     

Studies on hyaluronidase, chondroitin sulphatase, proteinase and phospholipase secreted by Candida species

Summary. We studied the ability of different Candida species to produce, at the same time, hyaluronidase, chondroitin sulphatase, proteinase, and phospholipase to assess whether they could be related to Candida pathogenicity. Only C. albicans was able to produce the four enzymes tested (73%) and was highly virulent to mice. Strains, that lack the capacity to produce one or more of the enzymes assayed, seemed less virulent or avirulent, similarly to the spontaneous hyaluronidase, chondroitin sulphatase, phospholipase and proteinase-deficient C. albicans strain FCF 14,1 which was non-pathogenic to mice. Among the other Candida species tested, none of them produced the four enzymes simultaneously, being less virulent in intravenously inoculated mice.
Zusammenfassung. Es wurde die Fähigkeit mehrerer Candida -Arten, gleichzeitig Hyaluronidase-, Chondroitinsulfatase-, Proteinase- und Phospholipase-Aktivität auszubilden, untersucht und deren Bedeutung als Candida -Pathogenitäts-merkmal bewertet. Nur C. albicans -Stämme waren in der Lage, die vier Enzyme zu bilden und waren für Mäuse hochvirulent. Stämme, welchen die Fähigkeit fehlte, eines oder mehrere dieser Enzyme zu produzieren, schienen weniger virulent oder avirulent zu sein, ähnlich wie der C. albicans -Stamm FCF 14,1, der spontan defizient für alle vier Enzyme war und der sich als nichtpathogen für Mäuse erwies. Von allen übrigen getesteten Candida -Arten produzierte keine gleichzeitig alle vier Enzyme, und diese erwiesen sich bei intravenöser Infektion als weniger virulent für Mäuse.     

Treatment with angiotensin-converting enzyme inhibitors is associated with a reduction in short-term mortality in older patients with acute ischemic stroke

BACKGROUND: Stroke is the third cause of death in older people living in Western countries. We tested the hypothesis that angiotensin-converting enzyme inhibitors (A-I) might affect short-term (30 day) mortality in older persons with severe acute ischemic stroke. METHODS: We analyzed data from a retrospective study including 475 consecutive older patients hospitalized for acute ischemic stroke. Mean age was 78.4 +/- 9.2 years; 58.2% were female. Stroke type was classified according to the Oxford Community Stroke Project (OCSP). RESULTS: Mortality rate was 28%. Thirty-two percent of patients were treated with A-I; mortality was 16.5% in patients treated compared with 33.3% in those not treated (chi(2) p =.001). The odds ratio for mortality in treated patients was: 0.47 (0.25-0.89) after full adjustment (age, sex, mean diastolic and systolic blood pressure, previous stroke and/or transient ischemic attack, congestive heart failure, atrial fibrillation, diabetes, hypertension, coronary heart disease, and previous treatment with A-I); 0.29 (0.09-0.89) in patients with altered level of consciousness after full adjustment; 0.60 (0.33-1.12) after adjustment for OCSP classification, age, and sex; and 0.30 (0.08-0.97) in total anterior circulation infarction stroke type after full adjustment. CONCLUSIONS: Our data suggest that treatment with A-I might reduce short-term mortality in older patients with acute ischemic stroke. Randomized clinical trials should confirm this possible specific effect of A-I.     

Plasma polyunsaturated fatty acids and the decline of renal function

BACKGROUND: Recent studies suggest an association between polyunsaturated fatty acids (PUFAs) and the development of chronic kidney disease. The aim of this study was to examine the relationship between PUFAs and renal function in older adults. METHODS: We performed a cross-sectional and prospective analysis of 931 adults, > or = 65 years old, enrolled in the InCHIANTI study, a population-based cohort in Tuscany, Italy. Plasma PUFAs were measured at enrollment, and creatinine clearance was estimated by the Cockcroft-Gault equation at baseline and after 3-year follow-up. RESULTS: At enrollment, participants with higher creatinine clearance had higher concentrations of HDL cholesterol, total plasma PUFAs, plasma n-3 fatty acid (FA), and plasma n-6 FA and lower triglycerides. From enrollment to the 3-year follow-up visit, creatinine clearance declined by 7.8 (12.2) mL/min (P <0.0001). Baseline total plasma PUFAs, n-3 FA, n-6 FA, and linoleic, linolenic, and arachidonic acids were strong independent predictors of less steep decline in creatinine clearance from baseline to follow-up (P <0.0001, after adjusting for baseline creatinine clearance). After adjusting for baseline creatinine, baseline total plasma PUFAs, n-3 FA, and linoleic, linolenic, and arachidonic acids were negatively associated with creatinine at 3-year follow-up. Participants with higher plasma PUFAs at enrollment had a lower risk of developing renal insufficiency, defined by a creatinine clearance <60 mL/min, during 3-year follow-up. CONCLUSION: High PUFA concentrations, both n-3 FA and n-6 FA, may attenuate the age-associated decline in renal function among older community-dwelling women and men.     

Autoantibodies in the sera of Trypanosoma cruzi-infected individuals with or without clinical Chagas disease

Variations in the levels and the specificities of autoantibodies directed against a panel of antigens (cytoskeleton proteins, DNA, laminin) were analyzed in the sera from two groups of humans infected with Trypanosoma cruzi. One group was constituted of apparently healthy blood donors (BD) and the other of patients with clinically confirmed Chagas disease (CCH). In both infected groups, a high proportion but not all sera exhibited dramatic enhancement of IgM and IgG autoantibodies directed against all antigens tested. Sera positive for IgG autoantibodies were generally found more frequently in the CCH than in the BD group, except for anti-actin antibodies more often present in BD sera. Anti-laminin IgG antibodies were present in a similar number of individuals in both groups. Although the titers of anti-laminin IgG antibodies were in general higher in CCH, their dissociation constants were in the same range (7 × 10^?8–10^?7M) in both groups. IgG autoantibodies were demonstrated to be polyreactive with laminin and other self antigens as well. Circulating immune complexes were present in sera from both groups and the activity of the antibodies dissociated from these complexes was directed against all the antigens of the panel. Although the IgE concentration was significantly enhanced in several subjects from both groups, the incidence of positive sera was higher in the CCH (60%) than in the BD (39%) group. Our results demonstrate that autoantibodies with the characteristics of natural autoantibodies are found in both T. cruzi-infected apparently healthy individuals and patients. © 1993 Wiley-Liss, Inc.     

Production of Paracoccidioides brasiliensis exoantigens for immunodiffusion tests.

Growth curves of the yeast form of Paracoccidioides brasiliensis B-339 based on total and viable cell counts were determined. Crude culture filtrate antigens were obtained after 7, 10, 15, 20, 25, and 30 days of incubation. Different patterns of proteins were obtained by affinity chromatography on Sepharose 4B-immunoglobulin G complex made with immunoglobulin G from patients with paracoccidioidomycosis, with subsequent analyses by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and scanning densitometry. Three major proteins were excreted during the time course of a 30-day culture: a doublet at 20 to 21 kilodaltons (kDa) and molecules of 43 and 52 kDa. The 43-kDa antigen was present throughout the growth period, and its level reached a peak on days 15 to 20 and then decreased considerably toward day 30. The antigenic preparations collected on days 7, 10, 15, and 20 gave better reactions in immunodiffusion tests than those collected on days 25 and 30. The 7-day exoantigen gave a sensitivity of 97.1% and specificity of 100% on immunodiffusion. The main line of precipitation had a very high intensity, showing a total identity with that of a previously purified glycoprotein of 43 kDa. A 7-day crude exoantigen displayed a high level of sensitivity and specificity, being reproducible from batch to batch and retaining its activity for years when kept lyophilized. A protocol is recommended for the production of a stable diagnostic antigen to be used in immunodiffusion tests for paracoccidioidomycosis.     

The endeavor of high maintenance homeostasis: resting metabolic rate and the legacy of longevity

Metabolism, the continuous conversion between structural molecules and energy, is life in essence. Size, metabolic rate, and maximum life span appear to be inextricably interconnected in all biological organisms and almost follow a "universal" law. The notion of metabolic rate as the natural "rate of living" filled most of the academic discussion on aging in the early 20th century to be later replaced by the free-radical theory of aging. We argue that the rate of living theory was discarded too quickly and that studying factors affecting resting metabolic rate during the aging process may provide great insight into the core mechanisms explaining differential longevity between individuals, and possibly the process leading to frailty. We predict that measures of resting metabolic rate will be introduced in geriatric clinical practice to gather information on the degree of multisystem dysregulation, exhaustion of energy reserve, and risk of irreversible frailty.