Phenylalanine Absorption and Metabolism in Parkinsonian Patients

Oral and intravenous L-phenylalanine loading tests were performed in 13 Parkinsonian patients and in 12 control subjects matched for age and weight. The results showed a normal intestinal absorption and a normal elimination from plasma of phenylalanine in the Parkinsonian patients.     

Fur color gene profiles and length of hair of several cat populations in Cuba, Costa Rica, Colombia, Paraguay, Chile and Argentina, and possible genetic origins of these cat populations

Until the present moment, only a scarce number of Latin American domestic cat populations have been studied from a population genetic standpoint. For this reason, the cat populations of La Havana (Cuba), San José (Costa Rica), Bogota and Ibagué (Colombia), Asuncion (Paraguay), Santiago (Chile) and Buenos Aires (Argentina) were sampled for several coat genes. The results obtained were as follows: (1) there was a strong genetic resemblance between several Hispanic American cat populations (especially, those of Buenos Aires, San José and the two Colombian populations studied) and those from South Western United States (California, Texas and Colorado), which adds support to the suspicion that these populations probably have a common origin; (2) The cat population of Santiago (Chile), contrarily to the other Hispanic American populations studied, showed a strong genetic resemblance with some Anglo North American populations; and (3) The l (long hair) and d (dilution) alleles showed systematic higher frequencies in the Hispanic American populations than those observed in Spain. Although the Hispanic American populations were not identical to the current Spanish populations (with the exception of Asuncion), this historic genetic experiment was very different to that found for the British populations and their overseas colonies.     

Ginseng: America’s botanical drug connection to the orient

Ginseng has long been one of this country’s major botanical drugs in foreign trade. Once harvested only in the forests of the Eastern frontiers, it became a domesticated crop in the late 1800s and now is raised largely in northcentral Wisconsin. Growers there produce an estimated 90% of the cultivated ginseng in the United States. Most American ginseng has been consumed in the Orient, as is reflected in export records dating back to 1821. Over 95% of the nearly 21,000 metric tons (T) shipped in the period 1821–1983 went to the Far East. Hong Kong has served as the center for re-exporting ginseng to China and Southeast Asia. Ginseng has been used in Asia for many purposes, mostly as a curative agent. It has also gained increasing acceptance elsewhere in the world for its alleged value.     

Observations on the invading gastropod <Emphasis Type=Italic>Rapana venosa</Emphasis> in Punta del Este,Maldonado Bay,Uruguay

We report on the first sightings of the invasive Rapa Whelk Rapana venosa in Maldonado Bay (Punta del Este Harbor and Gorriti Island) using in vivo, underwater observations and video surveys. The species was first detected in the Río de la Plata (Uruguay and Argentina) in 1999, and by 2004 it had extended its local distribution to Punta del Este at the eastern boundary of the estuary. Observations performed by SCUBA diving showed that R. venosa is preying on native mussels Mytilus edulis and Brachidontes spp., and that formerly abundant mussel beds are being seriously depleted due to a combination of human extraction, habitat deterioration and predation by the Rapa Whelk.     

Antioxidants protect keratinocytes against M. ulcerans mycolactone cytotoxicity

Background

Mycobacterium ulcerans is the causative agent of necrotizing skin ulcerations in distinctive geographical areas. M. ulcerans produces a macrolide toxin, mycolactone, which has been identified as an important virulence factor in ulcer formation. Mycolactone is cytotoxic to fibroblasts and adipocytes in vitro and has modulating activity on immune cell functions. The effect of mycolactone on keratinocytes has not been reported previously and the mechanism of mycolactone toxicity is presently unknown. Many other macrolide substances have cytotoxic and immunosuppressive activities and mediate some of their effects via production of reactive oxygen species (ROS). We have studied the effect of mycolactone in vitro on human keratinocytes—key cells in wound healing—and tested the hypothesis that the cytotoxic effect of mycolactone is mediated by ROS.

Methodology/Principal Findings

The effect of mycolactone on primary skin keratinocyte growth and cell numbers was investigated in serum free growth medium in the presence of different antioxidants. A concentration and time dependent reduction in keratinocyte cell numbers was observed after exposure to mycolactone. Several different antioxidants inhibited this effect partly. The ROS inhibiting substance deferoxamine, which acts via chelation of Fe²⁺, completely prevented mycolactone mediated cytotoxicity.

Conclusions/Significance

This study demonstrates that mycolactone mediated cytotoxicity can be inhibited by deferoxamine, suggesting a role of iron and ROS in mycolactone induced cytotoxicity of keratinocytes. The data provide a basis for the understanding of Buruli ulcer pathology and the development of improved therapies for this disease.     

Use of green fluorescent protein in visualisation of pneumococcal invasion of broncho-epithelial cells in vivo

The pneumococcus is the principle cause of bacterial pneumonia and also a major cause of bacterial meningitis. The mechanisms and sites of pneumococcal adherence and invasion of the respiratory tract in vivo are not clear however. We have made pneumococci expressing green fluorescent protein (GFP) and used it to trace pneumococcal adherence and invasion in vivo. By using GFP pneumococci we have shown bacterial adherence and invasion of broncho-epithelial cells in vivo by 4 h post-infection, with increases in pneumococcal invasiveness by 24 h. Using confocal image analysis we have shown varying levels of pneumococcal penetration and internalisation into host cells, as well as translocation through epithelial layers. To our knowledge this is the first report of pneumococcal invasion and cellular translocation in vivo.     

Absence of prostaglandins in semen of men with cystic fibrosis is an indication of the contribution of the seminal vesicles

Five men with cystic fibrosis delivered semen samples which were analysed for the content of the four main groups of prostaglandins (PGs). No PGs could be found in any of the specimens. The results of the present study provide further evidence that the seminal vesicles constitute the dominant site of production of PGs in human semen.