41 research outputs found
POEMS syndrome and calciphylaxis: an unrecognized cause of abnormal small vessel calcification
Induction of sister-chromatid exchange in human blood lymphocytes by aqueous extract of palmyrah (Borassus flabellifer) flour
Special Article - HUMAN ANTI-RHINOSPORIDIAL ANTIBODY DOES NOT CAUSE METABOLIC INACTIVATION OR MORPHOLOGICAL DAMAGE IN ENDOSPORES OF RHINOSPORIDIUM SEEBERI, IN VITRO
This report describes the use of the MTT-reduction and Evan′s
blue-staining tests for the assessment of the viability and
morphological integrity, respectively, of rhinosporidial endospores
after exposure to sera from rhinosporidial patients with high titres of
anti-rhinosporidial antibody. Sera from three patients, with nasal,
ocular and disseminated rhinosporidiosis respectively were used, with
human serum without anti-rhinosporidial antibody for comparison, with
or without added fresh guinea pig serum as a source of complement. All
four sera tested, with or without guinea-pig serum, had no effect on
the morphological integrity or the viability of the endospores and it
is suggested that anti-rhinosporidial antibody has no direct protective
role against the endospores, the infective stage, in rhinosporidiosis.
This finding is compatible with the occurrence of chronicity,
recurrence and dissemination that are characteristic of
rhinosporidiosis despite the presence of high titres of
anti-rhinosporidial antibody in patients with these clinical
characteristics. The possible occurrence of humoral mechanisms of
immunity that involve anti-rhinosporidial antibody with cells such as
leucocytes and NK cells, in vivo, cannot yet be discounted, although
the presence of high titres of anti-rhinosporidial antibody in patients
with chronic, recurrent and disseminated lesions might indicate that
such antibody is non-protective in vivo
The use of mtt [3-(4, 5-dimethyl-2-thiazolyl) -2, 5-diphenyl -2h- tetrazolium bromide]-reduction as an indicator of the effects of strain-specific, polyclonal rabbit antisera on Candida albicans and C. krusei
There is only scanty data on the effects of specific antibody, with or
without complement, on Candida albicans or Candida krusei in
cell-free systems in vitro , although previously published work has
shown that specific antibody mediates anti- Candida immunity in vivo
by inhibition of adherence to host cells or surfaces and by the
promotion of phagocytosis and intra-phagocytic killing. The MTT (3-[4,
5-dimethyl-2-thiazolyl] -2, 5-diphenyl -2H- tetrazolium
bromide)-reduction method as a test of the viability of fungi was used
to investigate the effect of complement, normal serum and immune serum
on these two species of Candida that are of increasing importance as
opportunistic pathogens. We report that normal rabbit serum or
strain-specific, polyclonal anti- Candida rabbit antibody, with or
without guinea pig complement, did not cause the reduction of total
cell-mass or of the viability of either C. albicans or C. krusei, in
vitro as determined by the MTT-reduction test. Complement alone without
specific antibody, also, had no such effect on these two Candida
species
Special Article - THE EFFECTS OF BIOCIDES (ANTISEPTICS AND DISINFECTANTS) ON THE ENDOSPORES OF RHINOSPORIDIUM SEEBERI
No data exists on the activity of biocides (antiseptics and
disinfectants) on Rhinosporidium seeberi that causes
rhinosporidiosis in humans and animals. On account of the inability to
culture R. seeberi, in vitro , dyes were used to assess the
morphological integrity and viability of biocide-treated endospores
that are considered to be the infective stage of this pathogen. Evan's
Blue (EvB) identifies the morphological integrity of the endospores
while MTT (3-[4, 5-dimethylthiazol-2yl]-2, 5-diphenyl tetrazolium
bromide) identifies metabolic activity through its reduction by
cellular dehydrogenases to microscopically visible deposits of
insoluble formazan. MTT-negativity has earlier been shown to correlate
with absence of growth of yeast and mycelial fungi in culture and could
thus indicate the loss of viability of MTT-negative rhinosporidial
endospores. Hydrogen peroxide, glutaraldehyde, chloroxylenol,
chlorhexidine, cetrimide, thimerosal, 70% ethanol, iodine in 70%
ethanol, 10% formalin, povidone-iodine, sodium azide and silver nitrate
were tested on freshly-harvested endospores and all biocides caused
metabolic inactivation with or without altered structural integrity as
shown by absence of MTT-staining after 3, 24 or 36 hour after exposure,
while EvB stained only the endospores treated with sodium azide,
ethanol, thimerosal, chloroxylenol, glutaraldehyde and hydrogen
peroxide. With clinically useful biocides - chlorhexidine,
cetrimide-chlorhexidine, 70% ethanol, povidone-iodine and silver
nitrate, a total period of exposure of endospores to the biocide, for
seven minutes, produced metabolic inactivation of the endospores.
Anti-rhinosporidial antiseptics that could be used in surgery on
rhinosporidial patients include povidone-iodine in nasal packs for
nasal and naso-pharyngeal surgery, chlorhexidine and
cetrimide-chlorhexidine on the skin, while povidone-iodine and silver
nitrate could have application in ocular rhinosporidiosis