Antigenic and genomic relation between human influenza A (H3N2) viruses circulating in Argentina during 1998 and the H3N2 vaccine component.

OBJECTIVE: Due to the lack of correlation from 1994 to 1997 between the A H3N2 component of the influenza vaccine recommended for this period and the circulating viruses in Argentina, we decided to study the antigenic and genomic relationships of the 1998 A H3N2 Argentine circulating strains with the corresponding vaccine component for that year as recommended by the World Health Organization (WHO). METHODS: We selected 18 influenza A H3N2 strains isolated in Argentina during 1998 to carry out an antigenic and genomic study of their hemagglutinin (HA) and neuraminidase (NA) proteins. For the genomic study we added 3 isolates from Uruguay. We compared the Argentine and Uruguayan strains with available reference strains. RESULTS: We found that all 18 strains from Argentina were similar to the A/Sydney/5/97 (H3N2) strain, as opposed to the A/Wuhan/359/95 (H3N2) strain, which was the vaccine component. This result was confirmed by the genomic study. CONCLUSIONS: The approach that we applied in Argentina has improved the quality and quantity of information about influenza in the country. This type of work should be encouraged in other countries in order to help choose the most appropriate vaccine components each year and provide individuals with the best possible protection against influenza.

[Dyslipidemia associated with food]. / La dislipidemia asociada con los alimentos.

The increase of the morbi-mortality due to CHD in México, particularly among the Social Security Institute (IMSS) workers led us to do research on the relative risk and the protection provided by foodstuffs usually consumed by these workers. We found significant evidence of low levels of cholesterol associated with dry alcoholic drinks, skimmed milk and yogurt as well as fresh cheeses. C-LDL was low among people that usually consume sweet alcoholic drinks and fresh cheese. High levels of TG were associated with those people consuming food products containing saturated fat (bacon, pork crackling, fatty red meat, fowl with skin) and viscera, more than three standard cups of alcoholic drinks three times a week, soft drinks and salt. Skimmed milk and yogurt and all vegetables were related to low levels of TG. Products related to high levels of C-HDL were all kinds of vegetables and beans. This study of IMSS worker eating habits could be useful to do research on the food intake of other worker populations, and could help us to design Health Education programs based on scientific knowledge.

A recent assessment of cocoa and pesticides in Brazil: an unhealthy blend for plantation workers.

Cocoa is the major source of income for the Brazilian state of Bahia and some 2.3 million people rely on the crop for their livelihood. Most cocoa is grown on large plantations where working conditions are often extremely poor. Few workers using pesticides on plantations, or on small-holdings, have had instruction about safe working practices. Protective clothing is rarely available. The result is frequent complaints about health. None of this likely to improve in the short term given Brazil's perilous economic situation.

Albumin metabolism: effect of the nutritional state and the dietary protein intake

Nine malnourished and nine children who had recovered from malnutrition were given a single injection of albumin-131I and were studied during consecutive periods in which the dietary protein was changed. Malnourished children had significantly lower catabolic rates of albumin than had recovered children on the same protein intake. Both nutritional groups, however, showed a progressive fall in catabolic rate after 3-5 days on a low protein diet (0.7-1.0g/kg per day), and the maximum effect was seen in the 2nd wk of low protein feeding. The catabolic rate could return to normal within 3wk in a malnourished child fed 4g of protein/kg per day. The albumin synthetic rate was measured by a computer technique suitable for nonsteady-state conditions. The synthyetic rate in the malnourished groups (101mg/kg per day) fed on a low protein diet was significantly lower than the rate in the recovered groups (148mg/kg per day). The synthetic rate responded rapidly to a change in diet; when the rate fell, the intavascular albumin mass was maintained by two compensating mechanisms: (1) a net transfer of extravascular albumin into the intravascular pool; and (2) by a delayed fall in the catabolic rate. The net transfer of albumin into the intravascular compartment diminished as the catabolic rate fell. Adaptation to a low protein diet was associated with: (a) low synthetic and catabolic rates of albumin; (b) a reduced extravascular albumin mass; and (c) a capacity for a rapid return to normal in the synthetic rate when the dietary protein was increased (AU)

Observations on the mechanisms of adaptation to the low protein intakes

Experiments are described which attempt to throw light on the mechanism by which animals and man can adapt to low protein intakes. In the rat, studies by constant infusion of labelled amino acid have shown that in the protein depleted animal there is a small reduction in the total protein turnover: this, however, is not enough to account for the great reduction in urinary nitrogen output. Constant infusion and single injection experiments agree in showing that in rats on a low protein diet there is a change in the pattern of protein turnover: synthesis of carcass protein (muscle and skin) is reduced, while that of liver protein is well maintained. The preservation of synthesis in liver seems to depend partly on increased re-utilization of amino acids liberated by the catabolism of tissue protein. This economy may be brought about by adaptive enzyme changes -decreased activity of the urea cycle enzymes and increased activity of amino acid activating enzymes in the liver. These changes, previously described by others in the rat have been shown to occur in the human liver also. Studies in human infant with 75selenium-labelled methionine provide some support for the concept that when the protein intake is limited, turnover is preferentially maintained in the liver. However, not all liver-produced proteins behave in the same way; studies of albumin kinetics in infants show that when the protein intake is altered, there is a rapid change in the rate of albumine synthesis, together with a redistribution of albumin between intra and extravascular spaces. Later and more slowly occurs a change, presumably compensatory, in the rate of albumin catabolism. Hormonal changes may play a part in these adjustments. Increased cortisone and decreased insulin activity would have the effect of promoting amini acid uptake at the expense of muscle. It is concluded that the net nitrogen loss which occurs when the protein intake is reduced results simply from the time-lag before the adaptive mechanisms come into play, and therefore cannot logically be regarded as the loss of reserve protein. The practical implications of this concept are discussed (Summary)