
the aetiology and treatment of
urinary calculus
investigations in this laboratory have been
based on the hypothesis that calculus formation is
primarily a process of crystallization from super-
saturated solutions rather than one of adsorption
on a specific protein matrix, as has been postulated
by boyce and his colleagues (boyce and king,
1963).  that crystallization is the primary factor
is strongly suggested by the recent studies of
vermeulen, lyon and gill (1964).  these authors
produced artificial concretions which closely
resembled urinary calculi by immersing a rotating
wire loop in normal urine for several days and
slowly adding the appropriate stone-forming
elements.
if the above hypothesis is correct then the
factors of primary interest in urinary stone
formation are those responsible for supersaturation,
nucleation and crystal poisoning.  much remains
to be learnt about these various factors, their
inter-relationships, and their relative importance.
the significance of the urinary colloids (proteins,
muco-proteins and polysaccharides) in calculus
formation is still not clear but it is probable that
they play an important secondary role in binding
crystalline precipitates to form a non-friable
calculus.  since time is an important factor in
crystal growth such non-specific binding by
proteins would increase the chances of stone
growth and retention within the upper urinary
tract.
