Nutritional asse ssme nt and se rum zinc
and coppe r conce ntration in le uke mic childre n
Pediatric Section, Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto,
Ribeirão Preto, Brazil
Ursula Rohr Sgarbieri Mauro Fisberg Luis Gonzaga ToneINTRODUTION
Malnutrition is one of the major problems in cancer patients. Athough not prevalent in all pediatric cancers, malnutritio n in childho o d cancer is a common, serious problem.1 Cancer patients usually have inadequate energ y and pro tein intakes, increased metabolic rate and abnormalities in energy, carbohydrate, lipid and protein metabolism.2 Cancer therapy with chemotherapy and radiation therapy is also potentially damaging to nutritional status.3
The bio lo gical ro le o f trace metals, especially serum zinc (Zn) and serum co pper (Cu), in different physio lo g ic and patho lo g ic co nditio ns has been extensively investig ated in recent years. Zinc, a co nstituent o f mo re than 2 0 0 enzymes, plays an impo rtant ro le in nucleic acid metabo lism, cell replicatio n, tissue repair and g ro wth thro ug h its functio n in nucleic acid po lymerases.4 Co pper is an essential nutrient that is widely distributed in fo o d and water and a co mpo nent o f several metallo enzymes that are required fo r o xidative me ta b o lism, inc luding c yto c hro me o xida se s, fe rro xid a se s, a mino o xid a se s, sup e r o xid o dismutase, asco rbic acid o xidase and tyro sinase.5 Chang es in blo o d zinc and co pper have been fo und in lympho pro liferative diso rders,6 ,7 as well as in breast, lung and g astro intestinal tumo rs.8 ,9
ABSTRACT
Contex t: Malnutritio n in childho o d cancer is co mmo nly a serio us pro blem. Chang es in blo o d z inc and co pper have also been fo und in malig nant diseases.
O bjective: To describe the pro tein-energ y nutritio nal status and serum z inc and co pper o f children with newly
diag no sed leukemia.
Design: Cro ss-sectio nal study. Setting: University referral center.
Pa rticipa nts: 2 3 children with newly diag no sed acute lympho cytic leukemia (ALL) o r acute no n-lympho cytic leukemia (AN LL) between the ag es o f 1 and 1 0 years. The co ntro l subjects were 3 1 healthy scho o l children o f similar ag e fro m lo cal scho o ls.
M a in m ea sures: Anthro po metric measurements o f heig ht/ ag e and weig ht/ heig ht, fo o d intake and serum levels o f z inc and co pper.
Results: Almo st the entire g ro up o f children were eutro phic. Zinc and co pper intake were belo w the reco mmended values. Serum z inc levels were sig nificantly lo wer and serum co pper levels were sig nificantly hig her in the leukemic g ro up when co mpared to no rmal children. Conclusion: At the time o f diag no sis the children suffering fro m leukemia were no t o vertly malno urished but blo o d analysis sho wed alteratio ns in co ncentratio ns o f the trace elements z inc and co pper.
Key w ords: Leukemia. N utritio nal Assessment. Zinc and Co pper.
Original Article
REVISTA PA ULISTA DE M EDIC IN A
In o rde r to de sc rib e the pro te in-e ne rg y nutritio nal status o f o ur patients with leukemia and in an attempt to help in elucidating the ro le o f the tra c e e le me nts z inc a nd c o p p e r in ma lig na nt d ise a se s, the p re se nt stud y investig ated the serum co ncentratio ns o f zinc and co pper, as well as the daily intake o f these two elements and the nutritio nal status in leukemic children.
METHODS
This stud y c o mp rise d 2 3 c hild re n w ith newly diag no sed acute lympho cytic leukemia (ALL) o r acute no n-lympho cytic leukemia (AN LL), between the ag es o f 1 and 1 0 years admitted to the Pediatric Sectio n o f the Ho spital das Clínicas o f Ribeirão Preto , SP, Braz il. All patients entered the study b efo re rec eiving the first c o urse o f chemo therapy. The g ro up co nsisted o f 1 7 bo ys and 6 g irls. So cio eco no mic indicato rs fo r the children’s families, such as o ccupatio n o f the head o f the ho useho ld, educatio n o f the parents a nd fa mily inc o me , de mo nstra te d tha t the se children were mainly fro m lo w-inco me families.1 0 The co ntro l subjects were 3 1 healthy scho o l children o f similar ag e fro m lo cal scho o ls. The co ntro l g ro up was used o nly fo r co mparing serum z inc and co pper levels.
Nutritional assessment by anthropometric methods
Standardized anthro po metry measurements o f bo dy weight and height were perfo rmed by trained nurses, within the first 24 hours of admission.
W a te rlo w ’ s1 1 c la ssific a tio n syste m o f nutritio nal status, based o n the co ncepts o f heig ht-fo r-a g e a nd w e ig ht-ht-fo r-he ig ht, w a s use d . Percentag e-o f-the-median values fo r each reco rd were calculated fro m the reference median o f the N CHS reference po pulatio n.1 2
Serum zinc and copper determination
Serum z inc and co pper were determined in the pediatric o nco lo g y labo rato ry by ato mic spectro pho to metry. N o rmal levels were defined by z inc > 7 0 ug / dl and co pper > 9 0 ug / dl.1 3
Dietary intake history
Mean daily intakes were assessed thro ug h the 2 4 ho ur dietary recall metho d, fo r o ne day, perfo rmed to g ether with the child’s mo ther. Tallies were translated into estimates o f calo ries, pro tein, z inc a nd c o ppe r a nd c o mpa re d to the RDA nutritio nal standards.1 4
Sta tistic a l Me tho d s. Da ta a na lysis w a s p e rfo rme d using the C hi-sq ua re a nd Ma nn-W hitney tests. Partial co rrelatio n was used to study a relatio nship between two variables. P va lue s ³ 0 . 0 5 w e re c o nsid e re d sta tistic a lly sig nificant. All results are expressed as mean and standard deviatio n (SD).
RESULTS
The characteristics o f patients are sho wn in Table 1 .
So cio eco no mic indicato rs fo r the children’s families demo nstrated that these children were mainly fro m lo w inco me families.
Anthro po metric indices used to assess the nutritio nal status o f the children demo nstrated a malnutritio n prevalence o f 3 0 %. Fo ur children presented weig ht deficits fo r heig ht (wasting ) and three children presented heig ht deficits fo r ag e (stunting ).
The e stima te d a ve ra g e d a ily inta ke o f c a lo rie s, p ro te ins, z inc a nd c o p p e r a re summariz ed in Table 2 . Averag e daily intake o f calo ries o f this po pulatio n was 1 6 8 1 kcal (SD 3 5 7 ), daily intakes rang ed fro m 9 4 9 to 2 2 1 2 Ta ble 1 - Physica l cha ra cteristics of the children.
G irls Bo ys
Ag e ALL AN LL ALL AN LL To tal
1
|
3 years - - 2 1 33
|
6 years 4 - 6 1 1 16
||
1 0 years 1 1 6 1 9Tota l 5 1 1 4 3 2 3
ALL - Acute Lympho cytic Leukemia
Kcal. Fo r pro tein, the estimated averag e daily intake was 6 6 g (SD 1 6 ), daily intakes rang ed fro m 2 9 .3 to 8 7 .9 g . Fo r z inc, the estimated averag e daily intake was 8 .2 mg (SD 2 .9 ), daily intakes rang ed fro m 4 .0 to 1 3 .7 mg and fo r co pper was 0 .4 7 mg (SD 0 .2 6 ), daily intakes rang ed fro m 0 .1 5 to 1 .1 4 mg . N o statistically sig nificant difference in the mean intakes o f these nutrients between sex and ag e g ro ups was fo und. Serum z inc co ncentratio n was sig nificantly decreased in the leukemic g ro up, co mpared to the co ntro l g ro up [1 0 9 (SD 4 5 ) ug / dl vs. 1 2 2 (SD 2 5 ) ug / dl] ( p< 0 .0 5 ), and serum co pper co ncentratio n was sig nificantly increased in the leukemic g ro up, co mpared to the co ntro l g ro up [1 9 5 (SD 9 0 ) ug / dl vs. 1 2 0 (SD 4 2 ) ug / dl] (p< 0 .0 5 ), as demo nstrated in Fig ures 1 and 2 .
DISCUSSION
Anthropometric and Biochemical Nutritional Assessment
In o ur study 3 0 % o f the c hildre n we re ma lno urishe d o n a d missio n. This ra te o f malnutritio n was similar to that o bserved in o ther studies.1 5 ,1 6
Fo ur o f o ur children presented weig ht deficit fo r heig ht o n admissio n. It has been sug g ested that the cause o f this weig ht lo ss co uld be due to b o th dec rea sed c a lo ric inta ke a nd inc rea sed e ne rg y re q uire me nt.2 Thre e o f o ur c hild re n p re se nte d he ig ht d e fic it fo r a g e . A simila r
incidence was demo nstrated by Victo ra et al.1 7 in his study o f the nutritio nal status o f children o f urban and rural areas o f so uthern Braz il.
The majority of data presented on malnutrition in children with cancer is derived fro m children who have been under therapy fo r co nsiderable lengths o f time; amo ng these children, malnutritio n is frequent and it is o ften severe. Ho wever, a child with newly diagno sed disease seems to have the same average nutritio nal status as is seen in the po pulatio n fro m which the child co mes.1 8
Altho ug h the majo rity o f the children in o ur study were well-no urished o n admissio n, the start o f chemo therapy o r radio therapy can alter the b a la nc e fro m a d e q ua te no urishme nt to malno urishment. Assessment o f nutritio nal status at the time o f diag no sis and during treatment is the re fo re e sse ntia l fo r p la nning nutritio na l interventio n.
Mean Daily Intakes
C a lo rie s. The e stima te d a ve ra g e d a ily intake o f calo ries in this po pulatio n was clo se to the re c o mme nd e d d ie ta ry a llo w a nc e (RDA) (1 8 0 0 to 2 4 0 0 Kcal). Reduced energ y intake was seen o nly in patients fro m the upper ag e rang e (6 to 1 0 years) (Table 2 ). This lo w calo ric intake may be attributable to the lo ss o f appetite presented by these children prio r to diag no sis.
Pro tein. The averag e daily intake o f pro tein fo r these children exceeded the RDA (1 6 to 2 3 g )
Ta ble 2 - Dieta ry ca lories, protein, zinc a nd copper inta k e by a ge a nd sex (M ea n a nd Sta nda rd Desvia tion).
Years (Ag e) Calo ries (Kcal) Pro tein (g ) Zinc (mg ) Co pper (mg )
G irls
0
|
3 years — — — —3
|
6 years 1 7 2 0 (4 7 7 ) 5 5 .7 (1 5 ) 7 .3 (2 .9 ) 0 .4 9 (0 .1 2 )6
||
1 0 years 1 4 6 3 (3 2 3 ) 5 0 .8 (1 4 ) 6 .8 (3 .0 ) 0 .4 3 (0 .1 1 )Bo ys
0
|
3 years 1 6 2 1 (4 4 3 ) 6 9 .8 (1 8 ) 9 .5 (2 .2 ) 0 .4 3 (0 .2 5 )3
|
6 years 1 6 5 1 (4 3 9 ) 6 6 .7 (2 0 ) 8 .1 (3 .3 ) 0 .5 1 (0 .3 2 )in all ag e g ro ups. Dietary so urces o f pro tein fo r these children were mainly milk, meat, eg g s, pasta and cereals.
Zinc. The present study do cumented a mean daily intake o f z inc which was lo wer than the mean RDA o f 1 0 mg / day fo r these ag e g ro ups. In g eneral, the best so urces o f dietary z inc are the mo st expensive fo o d items, especially meats. As the ma jo rity o f the c hildre n in this study sub siste d o n lo w -inc o me d ie ts, the y a re a t particular risk fo r marg inal o r inadequate z inc nutritio n. Dietary z inc deficiency is no w kno wn to o ccur in children and ado lescents fro m widely diverse areas all o ver the wo rld.1 9
Co pper. This study also demo nstrated that the mean daily co pper intake o f these children was less than the reco mmended dietary allo wance
(RDA) o f 0 .7 to 2 .0 mg / day. The richest so urces o f dietary co pper include shellfish, meats, nuts, seeds and leg umes. Altho ug h the diets o f o ur children co ntained reaso nable amo unts o f fish, meats and leg umes, it seems that the quantity ing ested was insufficient.
Because info rmatio n o n the co pper co ntent o f fo o ds is inc o mple te a nd va lue s a re o fte n missing fro m databases, co pper intake is o ften underestimated.2 0
Trace Elements
Se rum Zinc . The de c re a se d se rum z inc c o nc e ntra tio n in the le uke mic g ro up is in ag reement with previo us data.2 1
Mean serum z inc level in o ur children was slig htly lo wer than fo und in o ur co ntro l g ro up and lo wer than fo und by Fisberg et al2 2 in healthy children.
The determinatio n o f circulating levels o f z inc either in plasma o r serum has been the mo st widely used appro ach fo r the assessment o f z inc nutritio n. Metabo lic states o ther than a chang e in Zn nutritio nal status alter the labile Zn po o l. Stress, infectio n, fo o d intake, sho rt-term fasting and ho rmo nal state all appear to influence the amo unt in the plasma.2 4 In this study no significant c o rre la tio n w a s fo und b e tw e e n se rum z inc co ncentratio n and nutritio nal status, infectio n o r fo o d intake.
Se rum C o p p e r. The inc re a se d c o p p e r co ncentratio n o bserved is similar to that o bserved by o ther wo rkers.2 1
Mean serum co pper level in o ur children was sig nificantly hig her than fo und in o ur co ntro l g ro up and hig her than demo nstrated by Brag a
2 3
in healthy children.
Since many conditions can alter blood copper c o nc e ntra tio n, d iffe re nt va ria b le s suc h a s inflammato ry co nditio ns, infectio us diseases and copper intake were studied to determine their relative co ntributio ns. No po sitive co rrelatio n was fo und between these variables and serum copper levels.
Trace Elements vs. Cancer
This stud y d e mo nstra te d a lte re d se rum Figure 2 - Serum Cooper Concentra tions (ug/ dl) in
N orma l a nd Leuk emic Children
109*
122*
100
105
110
115
120
125
Serum Zinc (ug/dl)
* p< 0.05
Leukemic Normal
195*
120*
0 50 100 150 200
Serum Copper (ug/dl)
* p < 0.05
Leukemic Normal
Figure 1 - Serum Zinc Concentra tion (ug/ dl) in N orma l a nd Leuk emic Children
z inc a nd c o p p e r le ve ls in p a tie nts w ith ne w ly d ia g no se d le uke mia .
The blo o d serum levels o f z inc and co pper in malig nant diseases have been the subject o f a multitude o f investig atio ns, and their po ssible invo lvement has been well-reco g niz ed in many cancero us co nditio ns. Altered z inc and co pper co ncentratio ns in the plasma o r serum have been previo usly repo rted in cancer patients.2 1 ,2 4 ,2 5
The g e ne ra l tre nd to w a rd s slig htly d e c re a se d z inc c o nc e ntra tio ns in ma lig na nt d ise a se s sup p o rts the e xp e rime nta l re sults o b ta ine d b y Bro w n e t a l2 6 sug g e sting tha t z inc d e fic ie nc y is a sso c ia te d w ith the e tio lo g y o f c a nc e r.
Severa l studies2 7 ,2 8 sho w tha t serum Cu levels in ma lig na nt disea se inc rea se in rela tio n to d ise a se a c tivity. Re missio n is usua lly asso ciated with the return o f Cu levels to no rmal rang es. Serum Cu is sug g ested as a useful index fo r the e xte nt o f le uke mia a nd ma lig na nt lymp ho ma , a nd ma y p re d ic t re sp o nse to c hemo thera py .
Recent studies sug g est that the use o f blo o d z inc and co pper co ncentratio n and the co pper/ z inc ratio (Cu/ Zn) may be useful parameters fo r estimating the presence and pro g no sis o f malig nant tumo rs.6 ,9 ,2 9
A fa r mo re c o mprehensive study o f the basic mechanism fo r alteratio n o f serum co pper and z inc and its sig nificance in all malig nancies is needed.
CONCLUSIONS
This stud y sho w e d tha t ne ithe r b o d y c o mp o sitio n no r e ne rg y inta ke c ha ng e d sig nificantly at the time o f diag no sis. Lo ng -term fo llo w-up is needed, ho wever, to prevent severe weig ht lo ss.
Energ y and pro tein intakes were adequate in a lmo st a ll c hildren. Fifty-six perc ent o f the subjects co nsumed less than the reco mmended a llo w a nc e fo r z inc a nd nine ty-tw o p e rc e nt c o nsume d le ss tha n the re c o mmme nd e d allo wance fo r co pper.
Se rum z inc le ve ls we re de c re a se d a nd
serum co pper levels increased in ALL o r AN LL c hildren when c o mpa red to hea lthy c o ntro ls. Further studies are necessary, ho wever, to better interpret these finding s.
REFERENCES
1. Van-Eys J. Nutritio n o f children with cancer. Fro nt Radiat Ther Onco l 1982;16:177-83.
2. Wesdo rp RIC, Krause R, Meyenfeldt MF. Cancer cachexia and its nutri-tio nal implicanutri-tio ns. Br J Surg 1983;70:352-5.
3. Go ttlieb JA, Drewinko B. Review o f the current clinical status o f plati-num c o o rd inatio n c o m p le xe s in c anc e r c he m o the rap y. Canc e r 1975;59:621-8.
4. Halstead JA, Smith JC. Plasma zinc in health and disease. Lancet 1970;1:322-5.
5. Cartwright GE, Wintro be MM. Co pper metabo lism in no rmal sub-jects Am J Clin Nutr 1964;14:224-32.
6. Gupta SK, Shukla V, Gupta V, et al. Serum trace elements and Cu/Zn ratio in malignant lympho mas in children. J Tro pical Pediatrics 1994;40:185-7.
7. Co hen Y, Epelbaum E, Haim N, et al. The value o f serum co pper levels in no n-Ho dgkin’s lympho ma. Cancer 1984;53:296-300. 8. Andrews GS. Studies o f plasma zinc, co pper, cerulo plasmin and
gro wth ho rmo ne. With special reference to carcino ma o f the bro n-chus. J Clin Patho l 1979;32:325-33.
9. Gupta SK, Shukla V, Vaidya MP, et al. Serum trace elements and Cu/Zn ratio in breast cancer patients. J Surgical Onco lo gy 1991;46:178-81. 10. Grunberg J, Equivel N, Sitkewicj A, Farias Y. Méto do de classificacio n
so cial de Graffar: instructivo co n mo dificacio nes y definicio nes. Co urrier 1981;31(5):492-4.
11. Waterlo w JC. Classificatio n and definitio n o f pro tein: calo rie malnu-tritio n. Br Med J 1972;3:566-9.
12. NCHS. Gro wth charts. US Department o f Health, Educatio n and Wel-fare . Pub lic He alth se rvic e , He alth Re so urc e s Ad m inistratio n, Ro ckville, MD, 1976.
13. Sprague S, Slavin W. Determinatio n o f iro n, co pper and zinc in blo o d serum by an ato mic abso rptio n metho d requiring o nly dilutio n. Abso rp Newslett 1965;4:228-33.
14. Reco mmended daily allo wances (RDA) subco mmittee. On the tenth editio n o f the RDAs. Euro pean J Clin Nutr 1990;44(2):13-21. 15. Carter P, Can D, Van-Eys J, et al. Nutritional parameters in children with
can-cer. J Am Diet Assoc 1983;82(6):616-22.
16. To ne LG, Sgarbieri UR, Vieira MNCM. Avaliação do estado nutricio nal de crianças po rtado ras de neo plasias malignas. Jo rnal de Pediatria 1991;67(3/4):101-11.
17. Victo ra CG, Vaughan PJ, Kikwo o d BR. Risk facto rs fo r malnutritio n in Brazilian children: the ro le o f so cial and enviro nmental variables. Bull Wo rld Health Org 1986;64(2):299-309.
18. Van-Eys J. Malnutritio n in children with cancer: incidence and co nse-quence. Cancer 1979;43:2030-5.
19. Sanstead HH. Zinc deficiency: a public health pro blem? Am J Dis Child 1991;145:853-9.
20. Turlund JR. Co pper. In: Shils M, Olso n JA, Shike M, edito rs. Mo dern nutritio n in health and disease. 8th ed. Philadelphia: Lea & Febiger 1994;231-40.
21. Delves HT, Alexander FE, Lay H. Co pper and zinc co ncentratio n in the plasma o f leukemic children. Br J Haemato l 1973;24:525-33. 22. Fisberg M, Amancio OS, No brega FJ. Plasma zinc and co pper
23. Braga JAP. Avaliaç ão d o e stad o nutric io nal e im p o rtânc ia d o s o ligo elemento s zinco , co bre e ferro na do ença falcifo rme. São Paulo : 1994 (MSc Thesis).
24. Hrgo vic M, Tessner CF, Tho mas FB, et al. Significance o f serum co ppe r le ve ls in adult patie nts with Ho dgkin’s dise ase . Cance r 1973;31:1337-45.
25. Be guin Y, Brasse r F, We b e r G, e t al. O b se rvatio ns o f se rum trac e e l e m e n t s i n c h ro n i c l ym p h o c yt i c l e u ke m i a . C a n c e r 1987;60:1842- 6.
26. Bro wn DA, Chate l KW, Chan AY, e t al. Dis trib utio n o f c ad m ium , c o p p e r and zinc in p re tum o ro us d ie thylnitro s am ine e xp o s e d m ic e a n d in n o n - c a n c e ro u s p a tie n ts . Ch e m Bio l In te ra c t 1980;32:13- 27.
27. Shah I, Lewko w LM, Khila-Nnana U. Co rrelatio ns o f hypercupremia with o ther acute phase reactants in malignant lympho ma. Cancer 1983;51:851-4.
28. Tessner CF, Hrgo vic M, Bro wn BW, et al. Serum co pper co rrelatio ns with bo ne marro w. Cancer 1972;29:173-9.
2 9 . O ya m a T, M a ts u n o K, Ka wa m o to T, e t a l . Effi c i e n c y o f s e -ru m c o p p e r/ zin c ra tio fo r d iffe re n tia l d ia g n o s is o f p a tie n ts w i t h a n d w i t h o u t l u n g c a n c e r. B i o l Tra c e E l e m R e s 1 9 9 4 ; 4 2 : 1 1 5 - 2 7 .
RESUMO
Introduçã o: Crianças po rtado ras de do enças malig nas tendem a ter seu estado nutricio nal co mpro metido , po dendo apresentar também alteraçõ es nas co ncentraçõ es sang uineas de z inco e co bre.
O bjetivo: Investig ar o s parâmetro s antro po métrico s e o s o lig o elemento s z inco e co bre em uma amo stra de crianças po rtado ras de leucemia.
Loca l: Centro de Referência Universitário
Pa rticipa ntes: 2 3 crianças co m diag nó stico recente de leucemia linfo ide ag uda (LLA) o u leucemia não linfo ide ag uda (LN LA), co m idade entre um e 1 0 ano s. O G rupo Co ntro le fo i fo rmado po r 3 1 crianças saudáveis da mesma faixa etária. Va riá veis estuda da s: Fo i feito um estudo transversal, o nde fo ram avaliado s o s dado s antro po métrico s de peso e estatura, a ing estão de calo rias, pro teínas, z inco e co bre e o s níveis sérico s de z inco e co bre assim co mo a ing estão destes minerais. Tipo de Estudo: Estudo Transversal
Resulta dos: A maio ria das crianças não apresento u co mpro metimento do estado nutricio nal e a análise da ing estão alimentar demo nstro u que a ing estão de z inco e co bre estava abaixo das reco mendaçõ es do RDA. O s níveis sérico s de z inco fo ram sig nificantemente meno res e o s níveis sérico s de co bre sig nificantemente maio res nas crianças co m leucemia quando co mparadas às crianças co ntro le.
Conclusã o: O estudo demo nstro u que a maio ria das crianças eram eutró ficas ao diag nó stico , po rém apresentavam níveis sérico s alterado s de z inco e co bre.
Fro m Pediatric Sectio n, Ho spital das Clínicas, Faculdade de Medicina de Ribeirão Preto
Authors
Ursula Rohr Sga rbieri - Dietician, po stg raduate student o f the N utritio n and Metabo lism Divisio n, Department o f Pediatrics, Federal University o f São Paulo .
M a uro Fisberg - Pro fesso r and Head o f the N utritio n and Metabo lism Divisio n, Department o f Pediatrics, Federal University o f São Paulo .
Luis Gonza ga Tone - Assistant Pro fesso r o f the Department o f Pediatrics, Ribeirão Preto Scho o l o f Medicine, University o f São Paulo .
Sources of Funding: N o t declared. Conflict of interest: N o t declared. La st received: 7 April 1 9 9 8 Accepted: 2 6 N o vember 1 9 9 8 Address for correspondence: Ursula Ro hr Sg arbieri
Rua Sete de Setembro , 7 9 9 / 7 0
