Aortic valve stenosis

There is a long latent period in the clinical course of aortic valve stenosis in adults. Symptoms usually occur in the case of critical stenosis, when aortic orifice area is under 0.7 cm2 (0.4 cm2/m2). In this study 78 patients with critical aortic valve stenosis were investigated. The first manifestation of the disease was dyspnea (78.2%), angina (52.5%), less often a syncope (34.6%), while 17.9% of patients were asymptomatic. Left ventricular systolic function was preserved in 77% of patients, while left ventricular dyastolic dysfunction occurred in almost all the patients. In 42 patients (53.4%) aortic valve replacement was performed. Left ventricular systolic function improved in 88.1% of patients postoperativelly, as well as in patients with preoperatively preserved or poor systolic function. Recovery was fast particularly during the first 6 postoperative months. After the surgery the improvement of the left ventricular dyastolic function was slower then systolic, particularly in patients with extreme hypertrophy of myocardium in whom the process of recovery might last several years.     

The effect of anesthesia on the photoresponses of four sympatric species ofDrosophila

Five isofemale strains from each of four sympatric species,Drosophila immigrans, D. repleta, D. melanogaster, andD. affinis, were lightly anesthetized with ether, CO₂, Flynap, or cold temperature. The photoresponse of each treatment group was measured in an open field and a Y-tube apparatus. Relative light values were compared with those of the unanesthetized control groups of each species, as well as among the different treatments themselves and among species. Significant differences between species were apparent for all treatments in the Y-tube and for all treatments except ether and CO₂ in the open field. Response to anesthesia may differ between species due, in part, to their differing genotypes. Comparing treatment groups within species in the Y-tube design, all species exceptD. melanogaster showed significant differences between treatments. In the open field, onlyD. affinis was significantly affected. Particularly in the Y-tube, anesthetized flies generally differed significantly from the controls, indicating that the use of anesthesia during a behavioral study could cause deviations in behavior from that of normal unanesthetized flies.     

DNA adduct formation of the food carcinogen 2-amino-3-methylimidazo[4, 5-f]quinoline (IQ) in liver, kidney and colo-rectum of rats

DNA adducts of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)have been measured in the liver, kidney, and colorectum of maleFischer-344 rats given a single oral dose of IQ (20 mg/kg).The pattern and distribution of DNA adducts examined by ³²P-postlabelingwas similar in all tissues. N-(Deoxyguanosin-8-yl)-2-amino-3-methylimidazo-[4,5-f]quinoline(dG-C8-IQ) was the principal adduct identified and it accountedfor     

Probiotics or pro‐healers: the role of beneficial bacteria in tissue repair

Probiotics are beneficial microorganisms, known to exert numerous positive effects on human health, primarily in the battle against pathogens. Probiotics have been associated with improved healing of intestinal ulcers, and healing of infected cutaneous wounds. This article reviews the latest findings on probiotics related to their pro‐healing properties on gut epithelium and skin. Proven mechanisms by which probiotic bacteria exert their beneficial effects include direct killing of pathogens, competitive displacement of pathogenic bacteria, reinforcement of epithelial barrier, induction of fibroblasts, and epithelial cells' migration and function. Beneficial immunomodulatory effects of probiotics relate to modulation and activation of intraepithelial lymphocytes, natural killer cells, and macrophages through induced production of cytokines. Systemic effects of beneficial bacteria and link between gut microbiota, immune system, and cutaneous health through gut–brain–skin axes are discussed as well. In light of growing antibiotic resistance of pathogens, antibiotic use is becoming less effective in treating cutaneous and systemic infections. This review points to a new perspective and therapeutic potential of beneficial probiotic species as a safe alternative approach for treatment of patients affected by wound healing disorders and cutaneous infections.     

No evidence of linkage to chromosome 9q21-22 in a Swedish family with frontotemporal dementia and amyotrophic lateral sclerosis

Frontotemporal dementia (FTD) is a neurodegenerative disorder, sometimes occurring together with amyotrophic lateral sclerosis (ALS) within the same family. Recently, a region on chromosome 9q21–22 was reported to harbour a locus that may participate in both disorders [Hosler, B.A., et al., JAMA., 284 (2000) 1664-1669]. In the present study, a Swedish pedigree with both ALS and FTD segregating in the family was investigated by linkage analysis with five markers on chromosome 9q21–22. The pedigree included 17 individuals in two generations, with five affected cases available for analysis. As two-point logarithm of odds scores close to zero were obtained for all markers tested, the region on chromosome 9q21–22 is suggested to be excluded as candidate region in this Swedish FTD/ALS family. Our conclusion is therefore that additional loci involved in these two disorders must be operating.     

Opsonophagocytosis-inhibiting mac protein of group a streptococcus: identification and characteristics of two genetic complexes

Recently, it was reported that a streptococcal Mac protein (designated Mac(5005)) made by serotype M1 group A Streptococcus (GAS) is a homologue of human CD11b that inhibits opsonophagocytosis and killing of GAS by human polymorphonuclear leukocytes (PMNs) (B. Lei, F. R. DeLeo, N. P. Hoe, M. R. Graham, S. M. Mackie, R. L. Cole, M. Liu, H. R. Hill, D. E. Low, M. J. Federle, J. R. Scott, and J. M. Musser, Nat. Med. 7:1298-1305, 2001). To study mac variation and expression of the Mac protein, the gene in 67 GAS strains representing 36 distinct M protein serotypes was sequenced. Two distinct genetic complexes were identified, and they were designated complex I and complex II. Mac variants in each of the two complexes were closely related, but complex I and complex II variants differed on average at 50.66 +/- 5.8 amino acid residues, most of which were located in the middle one-third of the protein. Complex I Mac variants have greater homology with CD11b than complex II variants. GAS strains belonging to serotypes M1 and M3, the most abundant M protein serotypes responsible for human infections in many case series, have complex I Mac variants. The mac gene was cloned from representative strains assigned to complexes I and II, and the Mac proteins were purified to apparent homogeneity. Both Mac variants had immunoglobulin G (IgG)-endopeptidase activity. In contrast to Mac(5005) (complex I), Mac(8345) (complex II) underwent autooxidation of its cysteine residues, resulting in the loss of IgG-endopeptidase activity. A Mac(5005) Cys94Ala site-specific mutant protein was unable to cleave IgG but retained the ability to inhibit IgG-mediated phagocytosis by human PMNs. Thus, the IgG-endopeptidase activity was not essential for the key biological function of Mac(5005). Although Mac(5005) and Mac(8345) each have an Arg-Gly-Asp (RGD) motif, the proteins differed in their interactions with human integrins alpha(v)beta(3) and alpha(IIb)beta(3). Binding of Mac(5005) to integrins alpha(v)beta(3) and alpha(IIb)beta(3) was mediated primarily by the RGD motif in Mac(5005), whereas binding of Mac(8345) involved the RGD motif and a region in the middle one-third of the molecule whose sequence is different in Mac(8345) and Mac(5005). Taken together, the data add to the emerging theme in GAS pathogenesis that allelic variation in virulence genes contributes to fundamental differences in host-pathogen interactions among strains.