Workshop the role of electron microscopy in environmental conservation

Abstracts of The X1V Congress of the Italian Society of lz'lectron Microscopy

164

p a r t i c l e s w e r e l o c a t e d m a i n l y in a r e a s c e n t r a l to m y o f i b r i l s a n d r i c h in g l y c o gen and m i t o c h o n d r i a . Within nerves containing both microfibers, giant and medium axons, dense o s m o p h i l i c m a t e r i a l a p p e a r e d to o c c u p y the w h o l e s p a c e of s o m e f i b e r s at the p e r i p h e r y of n e r v e s , in c o n t a c t w i t h neuroglial cells containing hexagonal p a r t i c l e s , b o t h i s o l a t e d or c l o g g e d in f o r m s of p s e u d o c r y s t a l s . V a r i o u s s t a g e s of m a t u r a t i o n of caps i d e s a n d c h r o m a t i c m a t e r i a l w e r e obs e r v e d in a p p a r e n t l y e x t r a c e l l u l a r s i t e s e i t h e r d e g e n e r a t i v e in n a t u r e o r in s p a c e s f i l l e d f r o m c o l l a g e n f i b r i l s . Tunnel forms of polycapsides were o b s e r v e d as f r e q u e n t l y in i r i d o v i r u s e s of a m p h y b i a . T h e s e o b s e r v a t i o n s s u g g e s t t h a t in R u n g g e r ' s d i s e a s e of O c t u p u s the s i t e of f i r s t i n f e c t i o n is the i n n e r m a n t l e in the v i c i n i t y of the s t e l l a t e g a n g l i o n f r o m w h e r e the i n f e c t i o n p r o b a b l y e x p a n d s t h r o u g h o u t the n e r v e s - - v i a n e u r o g l i a - - t o the t e n t a c l e s a n d t h a t t u m o r s a n d s e l f - m u t i l a t i o n m a y be t e r m inal p h e n o m e n a . The p a r a l i z i n g n a t u r e of the m o r b a p p e a r s s u b s t a n t i a t e d b y the s e l e c t i v e l o c a l i z a t i o n of the v i r u s es w i t h i n m y o c y t e s , n e u r o g l i a a n d by the d a m a g e to n e u r o p i l e . No epidemiological conclusions can b e d r a w n f r o m the p r e s e n t s t u d y b e c a u s e of the l i m i t e d n u m b e r of c a s e s . 1.

D. Rungger, M. Rastelli, E. Brandle and R. G. Malsberger, Journal of Invertebrate Pathology 17 (1971) 72-80.

WORKSHOP T H E R O L E OF E L E C T R O N M I C R O S C O P Y IN E N V I R O N M E N T A L C O N S E R V A T I O N

E V I D E N C E OF T H E E F F E C T S OF W E A T H E R I N G ON L I T H O I D M A T E R I A L S E M P L O Y E D IN ARCHITECTURE L.

Lombardini

a n d S. V a n n u c c i

Istituto di M i n e r a l o g i a e Petrografia dell'Universita di U r b i n o , Via M. O d d i 14, 60129 Urbino; CNR Centro di S t u d i o per la Mineralogia e la Geochimica dei Sedimenti, V i a G. La Pira 4, 5 0 1 0 0 Firenze

The s t u d y of the c a u s e s a n d m e c h a n isms of the d e g r a d a t i o n o f l i t h o i d m a t e r i a l s (stone, b r i c k s , m o r t a r s , p l a s ters) e m b r a c e s m o s t s c i e n t i f i c d i s c i -

plines, particularly mineralogy, petrography and geochemistry. This type of a n a l y s i s (and in p a r t i c u l a r m e a s u r e m e n t s of v a r i a t i o n s in the m i n e r a l o g i c al, t e x t u r a l a n d p h y s i c a l c h a r a c t e r i s tics) r e s u l t s in the a c c u m u l a t i o n of d a t a w h i c h p e r m i t the r e c o g n i t i o n of the m a i n d e g r a d a t i o n p r o c e s s e s and the s t a t e of c o n s e r v a t i o n of the m a t e r i a l s c o n c e r n e d , b u t c a n n o t d e m o n s t r a t e the real effects produced hy such processes E l e c t r o n m i c r o s c o p y , in c o n j u n c t i o n with microanalysis using X-ray spectrom e t r y , is the o n l y m e a n s o f v i s u a l i z i n g and distinguishing the v a r i o u s e f f e c t s produced by weathering (physical, physico-chemical, chemical, and biologi c a l p h e n o m e n a ) , thus a l l o w i n g us to i n t e r p r e t c o r r e c t l y the v a r i a t i o n s in p a r a m e t e r s m e a s u r e d by o t h e r m e a n s . O v e r a n d a b o v e , s c a n s of a l t e r e d surf a c e s a l s o r e v e a l the p r e l i m i n a r y s t a g e s of w e a t h e r i n g a n d e f f e c t s o v e r shadowed by more intense phenomena. B e s i d e s the e l e c t r o n m i c r o s c o p e a l l o w s us to e v a l u a t e the size, s h a p e a n d n a t u r e of any d i s c o n t i n u i t i e s (cavities and m i c r o c r a c k s ) w h i c h l e a d to a g r e a t i n c r e a s e in the t o t a l p o r o s i t y of the material. Thus, the S E M is n o w a d a y s w i d e l y u s e d in s t u d i e s in a r c h i t e c t u r al c o n s e r v a t i o n ; h o w e v e r , p u b l i c a t i o n s to d a t e h a v e b e e n l i m i t e d to i n v e s t i g a t i o n s of a p a r t i c u l a r type of e f f e c t a n d are o f t e n c o n d i t i o n e d by the f i e l d of s p e c i a l i s a t i o n of the a u t h o r concerned. T h e X I V C o n g r e s s of the S I M E has p r o v i d e d us w i t h the o p p o r t u n i t y to i l l u s t r a t e a c o m p l e t e S E M s t u d y of the weathering processes presently affecting the c o n s t r u c t i o n m a t e r i a l s of the R u s s i a n O r t h o d o x C h u r c h in F l o r e n c e ( P i e t r a f o r t e a n d P i e t r a S e r e n a , two commonly used Florentine sandstones). P a r t i c u l a r l y i n t e r e s t i n g is the f a c t t h a t the w e a t h e r i n g of t h e s e two t y p e s of s t o n e u s e d in a r e l a t i v e l y r e c e n t construction (early 1900's) is c l e a r l y q u i t e d i f f e r e n t f r o m t h a t a c t i n g o n the same t y p e s of b u i l d i n g s t o n e u s e d duri n g the R e n a i s s a n c e a n d B a r o q u e . T h i s is due to the p o o r q u a l i t y of the m a t e r i a l s u s e d (as is a l s o d e m o n s t r a t e d by mineralogical and petrographical analysis) a n d to the m i c r o c l i m a t e in w h i c h the C h u r c h is to b e f o u n d (high h u m i d ity a n d a v e r y p o l l u t e d a t m o s p h e r e ) . This detailed SEM study, supported by o v e r 300 p h o t o g r a p h s some of w h i c h are i l l u s t r a t e d h e r e , r e s u l t e d n o t o n l y in the r e c o g n i t i o n of the a c t u a l w e a t h e r i n g e f f e c t s , b u t a l s o e n a b l e d us to r e l a t e t h e m to the c a u s e s a n d m e c h a -

Abstracts of The XIV Congress of the Italian Society of Electron Microscopy

nisms. Some of the most e v i d e n t e f f e c t s o b s e r v e d i n c l u d e d p h y s i c a l changes occ u r r i n g also on a p p a r e n t l y u n a l t e r e d surfaces. These i n c l u d e d loss of interg r a n u l a r cohesion, f r a c t u r i n g of indi v i d u a l c o m p o n e n t s and in the case of P i e t r a Serena, r e m o v a l of the matrix. E f f e c t s due to c h e m i c a l and p h y s i c o c h e m i c a l p r o c e s s e s w e r e also noted: d i s s o l u t i o n and s e c o n d a r y p r e c i p i t a t i o n of the c a l c i t e cement in P i e t r a f o r t e , m o b i l i s a t i o n and m i g r a t i o n of p a r t i c u l ar e l e m e n t s (Fe and Mg). As a r e s u l t of the t r a n s f o r m a t i o n of c a r b o n a t e s into s u l p h a t e s (due to SO 2 c o n t a i n e d in p o l l u t e d a t m o s p h e r e s ) the n e o f o r m e d g y p s u m was o b s e r v e d to assume various c r y s t a l l i n e h a b i t s (lenticular and tabular p s e u d o h e x a g o n g r a d i n g into prisms) a c c o r d i n g to w h e r e the p r e c i p i t a t i o n o c c u r r e d (exposed surfaces, cavities under the "crusts" etc.), and this is in d i r e c t r e l a t i o n s h i p w i t h the rate of e v a p o r a t i o n of a b s o r b e d water. U l t i m a t e l y , this study has i l l u s t r a ted the q u a n t i t y and v a r i e t y of m i c r o o r g a n i s m s that w e a t h e r e d s u r f a c e s and their m i c r o c l i m a t e s can sustain.

W h e n one feature only is d e t e c t a b l e , electron m i c r o s c o p y may be used, in add i t i o n to light m i c r o s c o p y and h i s t o chemistry, in o r d e r to d i f f e r e n t i a t e m a l i g n a n t m e s o t h e l i o m a s from c a r c i n o m a s and sarcomas. In our e x p e r i e n c e , the t r a n s m i s s i o n u l t r a s t r u c t u r a l study of tissue specimens is more r e l i a b l e than that of isolated cells f r o m serous fluids. The most d i a g n o s t i c o r g a n e l l e s are junctional s t r u c t u r e s and m i c r o v i l l i . A c h a r a c t e r i s t i c feature of m e s o t h e l i o m a s is the p r e s e n c e of d e s m o s o m e s a n d / o r tight j u n c t i o n s b e t w e e n m e s e n c h i m a l like cells, or b e t w e e n e p i t h e l i c a l - l i k e and m e s e n c h i m a l - l i k e cells. In addition, a d i a g n o s i s of m e s o t h e l i o m a may be made w h e n the t u m o u r a l cells show abundant, long and s l e n d e r m i c r o v i l l i , e s p e c i a l l y a r o u n d their w h o l e outline, a n d / o r in d i r e c t c o n t a c t w i t h the stroma. Since m a l i g n a n t m e s o t h e l i o m a is reg a r d e d as the m o s t s p e c i f i c a s b e s t o s r e l a t e d tumour, the aid of e l e c t r o n m i c r o s c o p y for the i d e n t i f i c a t i o n of this n e o p l a s i a has a role in both occup a t i o n a l and e n v i r o n m e n t a l p a t h o l o g y .

E L E C T R O N M I C R O S C O P Y IN E N V I R O N M E N T A L P A T H O L O G Y : D E T E C T I O N OF M A L I G N A N T MESOTHELIOMA

E N V I R O N M E N T A L N E U R O P A T H I E S OF TOXIC ORIGIN WITH NEUROFILAMENT ACCUMULATION

F. M o l l o

N. R i z z u t o

Istituto di A n a t o m i a e Istologia Patologica, C e n t r o di M i c r o s c o p i a Elettronica della Facolt~ di M e d i cina, Via Santena 7, 1 0 1 2 6 T o r i n o ; Universita di T o r i n o

R e l a t i o n s h i p s b e t w e e n asbestos and tumours of serous m e m b r a n e s are still not c o m p l e t e l y e l u c i d a t e d , m a i n l y in subjects without definite occupational exposure. B e s i d e s its u s e f u l n e s s for the d e m o n s t r a t i o n of m i n e r a l fibres in tissues, e l e c t r o n m i c r o s c o p y may contribute to s o l v i n g some p r o b l e m s by r e c o g n i z i n g (or excluding) the mesot h e l i a l nature of o t h e r w i s e u n c l a s s i fied tumours. Indeed, light m i c r o s c o p ic d i a g n o s i s of m a l i g n a n t m e s o t h e l i o m a is r a t h e r d i f f i c u l t and in s e v e r a l countries, i n c l u d i n g Italy, " m e s o t h e l i o m a panels" are active in r e v i e w i n g h i s t o logical s p e c i m e n s and s t a n d a r d i z i n g d i a g n o s t i c criteria. In light m i c r o s c o p y , e p i t h e l i a l - l i k e and m e s e n c h i m a l - l i k e features can be o b s e r v e d in these tumours, and their s i m u l t a n e o u s p r e s e n c e is an i m p o r t a n t c r i t e r i o n for the p a t h o l o g i c a l diagnosis.

165

Cattedra di N e u r o p a t o l o g i a , Istituto di C l i n i c a N a u r o l o g i c a , Universita Verona, Verona, Italy

A n u m b e r of e n v i r o n m e n t a l toxic agents such as the n e u r o t o x i c h e x a c a r b o n compounds, CS2, a c r y l a m i d e and IDPN, may p r o d u c e damage to the nervous s y s t e m both in man and e x p e r i m e n t a l animals. The p r i m a r y t a r g e t of these toxic agents is the axon, w h i c h b e c o m e s greatly e n l a r g e d e i t h e r in the p r o x i m a l (proximal a x o n o p a t h i e s ) or in the distal segments (distal a x o n o p a t h i e s ) . U l t r a s t r u c t u r a l e x a m i n a t i o n of the axonal s w e l l i n g shows a c c u m u l a t i o n of m o r p h o logically normal neurofilaments with c l u s t e r i n g of the m i c r o t u b u l e s . In the 2 , 5 - H e x a n e d i o n e (2,5-HD, the m a j o r m e t a b o l i t e of n-hexane) i n t o x i c a t i o n , a c c u m u l a t i o n of f i l a m e n t s occurs in the distal s e g m e n t s of the c e n t r a l and peri p h e r a l axons. N e u r o f i l a m e n t s are the main c o m p o n e n t of the c y t o s k e l e t o n , w h i c h are t r a n s p o r t e d from the cell b o d y along the e n t i r e length of the axon at a rate of 0.3 - 1 m m / d a y . Recently, M o n a c o and G a m b e t t i (1983) have