Mosquito collections were conducted during a dengue outbreak in Reynosa, Tamaulipas, Mexico, July-December 1995. A total of 6694 adult mosquitoes (four genera and nine species) were captured, of which 2986 (78.3% females and 21.7% males) were Aedes albopictus and 2339 (39.7% females and 60.3% males) were Ae.aegypti. These two species comprised 84.2% of the total collection. Specimens were grouped into pools, nearly 50% of them processed for detection of virus by cythopathic effect in C6-36 and VERO cell cultures and by haemagglutination test. Five pools gave positive haemagglutination reactions and were examined by immunofluorescence using monoclonal antibodies to flavivirus and to dengue virus. One pool of ten Ae.albopictus males was positive for dengue virus: serotypes 2 and 3 were identified by serotype-specific monoclonal antibodies and confirmed by RT-PCR. This is the first report of Ae.albopictus naturally infected with dengue virus in America. Also, it is the very first time Ae.albopictus males have been found infected with dengue virus in the wild.

ONE aspect of the inflammatory reaction about which little is known is the way in which the initial accumulation in the injured tissues of polymorphonuclear leucocytes becomes replaced by a similar collection of mononuclear leucocytes, i.e., lymphocytes, monocytes, macrophages and their derivatives.This transition occura whatever the cause of tissue damage, but exhibits wide differences in the rapidity of its onset, in the time taken for its completion, in the number of cells involved, both polymorph and mononuclear, and in the characteristics of the mononuclear cells. These differences are illustrated by the existence of certain infhmma tory reactions that are commonly designated "mononuclear ", because polymorph infiltration is slight and transient whereas the local accumulation of mononuclear leucocytes is maesive and persistent. In this category are the tuberculin reaction and the local leaione of typhoid fever and tuberculosis. Wide differences are known to exist also in the subsequent characteristics of the mononuclear cells. In some types of inflammation they remain lymphocybs and monocytes, in others they become transformed to macrophages, epithelioid cells, giant cells or plasma, cells. Further variation occurs in the ultimate fate of the mononuclear exudate which may disappear or be aasociatod with collagen formation or undergo the full process of organisation.The purpose of the present investigation was to investigate these problems, especially the primary one of the transformation of cellular exudates from a predominantly polymorph to a predominantly mononuclear character. To do so it was necessary to provide an effective but simple stimulus, and also in some way to label the mononuclear cells participating in the reaction so that their fate could be followed. Both these conditions were met by the use of intradermal injection of macromolecular substances. ~T H O D SIntradermal injections were made into the abdominal wall of albino rats of the Wistar strain. The solutions used were made up in sterile vessels in sterile water or isotonic saline according to the nature and concentration of the solute.The abdominal skin was sterilised with ethanol and the injection performed with a 1 ml. tuberculin syringe and no. 20 needle sterilised by boiling. The volume injected was 0.15 ml.

Oliguric acute renal failure was induced in dehydrated rats by an intravenous injection of human methemoglobin. Oliguria was associated with a markedly reduced pressure in the proximal tubules and efferent glomerular vessels. Neither intratubular obstruction nor massive backdffusion of filtrate were considered to play a decisive role in the establishment of anuria. Tubular compressing interstitial edema was not histologically evident. The major factor leading to anuria was thought to be a reduction of glomerular filtration rate consecutive to an increased preglomerular resistance.

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