Comparison of amplitude of human soleus H-reflex during sitting and standing.

The modulation of the H-reflex in the human soleus muscle under conditions of different length or of background EMG activity was compared in 7 healthy subjects under three conditions: sitting, standing with support, and standing without support. The amplitude of the H-reflex increased when the muscle was shortened in both the sitting and standing conditions. The degree of increase in H-reflex was smaller during standing than sitting for the same change in muscle length. The H-reflex was augmented according to the increase of the background EMG. The "reflex gain", the ratio of the increase in amplitude of the H-reflex to soleus muscle EMG activity, decreased on sitting, standing with support and standing without support, ranked in that order. From these observations, it is concluded that the H-reflex is modulated by both muscle length and the degree of postural stability. The modulation of the reflex could be interpreted in terms of gain compensation and would serve to stabilize posture. A decrease in reflex gain may be appropriate in stabilizing the spinal reflex feedback loop during standing, especially without support.     

Detection of extended-spectrum-beta-lactamase-producing members of the family Enterobacteriaceae with Vitek ESBL test.

A three-phase analysis of the Vitek ESBL test and a double-disk (2 disk) test was performed to assess their ability to detect extended-spectrum beta-lactamases (ESBLs) in members of the family Enterobacteriaceae. In the first two phases involving detection of ESBLs in 157 stains processing well-characterized beta-lactamases, sensitivity and specificity were found to be 99.5 and 100%, respectively, for the Vitek ESBl test and 98.1 and 99.4%, respectively, for the 2-disk test. In the third phase, in which the ability of each test to detect ESBLs in 295 clinical isolates was assessed, there was only one false positive (Vitek ESBL test). Across all three phases, the Vitek ESBL test was found to be much easier to perform than the 2-disk test. The latter also involved subjective interpretation of results. There were a total of 176 Escherichia coli and 157 Klebsiella pneumoniae isolates and less than 40 isolates of each of 14 other species evaluated. In a supplemental study of Klebsiella oxytoca, an organism possessing a chromosomal beta-lactamase similar to an ESBL, the Vitek ESBL test was found to be capable of detecting hyperproduction of this enzyme in strains of this species as well. These data indicate that the Vitek ESBL test is reliable for the detection of ESBLs in E. coli and K. pneumoniae, the two species in which ESBLs are most common, and of hyperproduction of the K. oxytoca beta-lactamase, a situation which engenders a level of resistance to this species similar to that seen with ESBLs.     

DGGE-based whole-gene mutation scanning of the dystrophin gene in Duchenne and Becker muscular dystrophy patients

Duchenne and Becker muscular dystrophy (DMD and BMD) are caused by mutations in the dystrophin gene. Large rearrangements in the gene are found in about two-thirds of DMD patients, with approximately 60% carrying deletions and 5-10% carrying duplications. Most of the remaining 30-35% of patients are expected to have small nucleotide substitutions, insertions, or deletions. To detect these subtle changes within the coding and splice site determining sequences of the dystrophin gene, we established a semiautomated denaturing gradient gel electrophoresis (DGGE) mutation scanning system. The DGGE scan covers the dystrophin gene with 95 amplicons, PCRed either individually or in a multiplex setup. PCR and pooling were performed semiautomatically, using a pipetting robot and 384-well plates, enabling concurrent amplification of DNA of four patients in one run. Amplification of individual fragments was performed using one PCR program. The products were pooled just before gel loading; DGGE requires only a single gel condition. Validation was performed using DNA samples harboring 39 known DMD variants, all of which could be readily detected. DGGE mutation scanning was applied to analyze 135 DMD/BMD patients and potential DMD carriers without large deletions or duplications. In DNA from 25 out of 44 DMD patients (57%) and from 5 out of 39 BMD patients (13%), we identified clear pathogenic changes. All mutations were different, with the exception of one DMD mutation, which occurred twice. In DNA from 10 out of 44 potential DMD carriers, including four obligate carriers, we detected causative changes, including one pathogenic change in every obligate carrier. In addition to these pathogenic changes, we detected 15 unique unclassified variants, i.e., changes for which a pathogenic nature is uncertain.     

Carbon-11 labelled tyrosine to study tumor metabolism by positron emission tomography (PET)

To measure the rate of protein synthesis in human neoplasms by positron emission tomography, we prepared no carrier added DL-(1-¹¹C)-tyrosine by ¹¹C-carboxylation of the appropriate -lithioisocyanide followed by hydrolysis of the isocyanide function and removal of the protecting methoxy group. The purification, resolution and solvent switch to saline was performed by high performance liquid chromatography (HPLC). DL-(1-¹¹C)-Tyrosine in 0.1 N NaH₂PO₄ buffer was prepared with a radiochemical yield of 8%–16% (EOS, 35 min). The enantiomeric separation and solvent switch to saline were achieved in 5 min and 10 min respectively. Consequently L-(1-¹¹C)-tyrosine in physiological saline was obtained in 2%–4% radiochemical yield. Tumor accumulation in rats with the experimental WALKER 256 carcinosarcoma was observed for both the L- and D-isomer. Using positron emission tomography a tumor/muscle ratio of two was observed for the L-isomer 15 min after injection. The corresponding figure for the D-isomer was 2.5. The first clinical results with DL-(1-¹¹C)-tyrosine show accumulation of radioactivity in meningioma, a primary breast carcinoma and in liver metastases of a colonic carcinoma.     

Evaluation of the in vitro Cytotoxicity of some Sesquiterpene Lactones on a Human Lung Carcinoma Cell Line Using the Fast Green Dye Exclusion Assay.

Amongst the properties associated with the sesquiterpene lactones, their cytotoxicity is probably the most valuable. In this IN VITRO study cytotoxicity of some sesquiterpene lactones from EUPATORIUM CANNABINUM L. and related compounds have been tested on a human small cell lung carcinoma cell line, using the Fast Green dye exclusion assay (FGA). From the results certain conclusions could be drawn about structure activity relationship. Eupatoriopicrin, eupatoriopicrin acetonide, "substance 1" and hiyodorilactone E showed highest cytotoxicity (ID50 1-2 microg/ml) following 1 h incubation. Moieties of the sesquiterpene lactones (alpha-methylene gamma-butyrolactone, eupatolide, angelic and tiglic acid) and related compounds (alantolactone and isoalantolactone) were less or not active at these concentrations. From the results of the experiments it can be concluded that the entire molecule (germacranolide ester) is necessary for optimal cytotoxicity IN VITRO and that cytotoxicity increases with decreasing hydrophilicity.     

Effects of Anthocyanin on Intestinal Health: A Systematic Review

Intestinal health relies on the association between the mucosal immune system, intestinal barrier and gut microbiota. Bioactive components that affect the gut microbiota composition, epithelial physical barrier and intestinal morphology were previously studied. The current systematic review evaluated evidence of anthocyanin effects and the ability to improve gut microbiota composition, their metabolites and parameters of the physical barrier; this was conducted in order to answer the question: “Does food source or extract of anthocyanin promote changes on intestinal parameters?”. The data analysis was conducted following the PRISMA guidelines with the search performed at PubMed, Cochrane and Scopus databases for experimental studies, and the risk of bias was assessed by the SYRCLE tool. Twenty-seven studies performed in animal models were included, and evaluated for limitations in heterogeneity, methodologies, absence of information regarding allocation process and investigators’ blinding. The data were analyzed, and the anthocyanin supplementation demonstrated positive effects on intestinal health. The main results identified were an increase of Bacteroidetes and a decrease of Firmicutes, an increase of short chain fatty acids production, a decrease of intestinal pH and intestinal permeability, an increase of the number of goblet cells and tight junction proteins and villi improvement in length or height. Thus, the anthocyanin supplementation has a potential effect to improve the intestinal health. PROSPERO (CRD42020204835).     

Immunologic and clinical stages in HIV-1-infected Ugandan adults are comparable and provide no evidence of rapid progression but poor survival with advanced disease

Clear understanding of the natural history of HIV-1 disease is critical for planning and developing appropriate therapeutic strategies for HIV-1-infected populations in the developing world. Present knowledge about Africa is based on very limited data that largely use clinical staging as the prognostic marker; this approach has not been prospectively validated. Our objectives were to compare clinical staging and CD4+ T-cell counts as prognostic tools and to describe survival and cause of death in seroprevalent HIV-1-infected Ugandan adults by means of a prospective cohort study. Consecutive HIV-1-infected adults registering with a community HIV/AIDS clinic in Entebbe, Uganda were enrolled between October 1994 to January 1995 and observed during follow-up until the end of December 1997. Baseline CD4+ T-cell count distribution showed clear and appropriate associations with clinical stage in the 201 participants. Both provided equivalent prognostic information: median survival with CD4+ T-cell count <200 cells/microl was 9 months (95% confidence interval [CI], 7-15 months) compared with 19 and 7 months (95% CI, 10-28 and 0-8 months, respectively) in clinical stages 3 and 4, respectively; survival at 3 years with CD4+ T-cell count > or =200 cells/microl was 68% and for clinical stage 1 and 2, 80% and 60%, respectively. Clinical stage 3 and 4 were 76% sensitive and 65% specific for predicting a CD4+ T-cell count <200 cells/microl, positive predictive value of 56%, negative predictive value 78%. In all, 82 participants died (41%; mortality rate 216 of 1000 person-years) and was strongly associated with low CD4+ T-cell counts. In conclusion, clinical staging is valid and comparable with staging by CD4 T-cell counts for epidemiologic measurements. Mortality with early disease in Entebbe appears equivalent to that found in the developed world but there is poor survival with advanced disease.