Correlation between osteochondral changes depicted by magnetic resonance imaging and disease progression

PURPOSE: To determine the consequences of the chronic use of systemic corticosteroids in children with juvenile rheumatoid arthritis by means of evaluating osteochondral effects depicted by magnetic resonance imaging. PATIENTS AND METHODS: We reviewed clinical and magnetic resonance imaging findings in 69 children (72 knees) with juvenile rheumatoid arthritis. Two groups were studied. Group I: 34 (49.3%) children had previous or current use of systemic corticotherapy (22 girls; 12 boys; mean age: 11.3 years; mean disease duration: 5.9 years; mean corticotherapy duration: 2.9 years; mean cumulative dose of previous corticosteroids: 5000 mg); Group II: 35 (50.7%) children had no previous use of corticosteroids (27 girls; 8 boys; mean age: 11.7 years; mean disease duration: 5.3 years). The groups were compared statistically. RESULTS: In the group that had received corticotherapy (Group I), osteochondral abnormalities were significantly correlated to long-standing disease (>3.5 years; p<0.001). This correlation was not found in the group that had no previous history of corticotherapy (Group II). No correlations were established between median dose of corticosteroids and magnetic resonance imaging findings. CONCLUSION: It is important to further investigate the long-term intra-articular effects of systemic corticotherapy to ensure that the side effects of the aggressive therapy will not be more harmful for the joints than the symptoms suffered over the natural course of the disease.

The larval development of palaemonid shrimps from the amazon region reared in the laboratory. V. The abbreviated development of Pseudopalaemon chryseus Kensley & Walker, 1982 (CRUSTACEA : DECAPODA: PALAEMONIDAE)

Larval development of the freshwater palaemonid shrip Pseudopalaemon chryseus Kensley & Walker, 1982 was studied in the laboratory from the offspring oof females collected in a lake of the lower Negro River system. Females carry few (14 to 43), large (1.86 + 0.13 x 1.29 + 0.06 mm), yolk-rich eggs. The species goes throught three larval stages without feeding and the main feature of its larval development is the presence of functional walking legs on hatching. Descriptions and illustrations of the three larval and first juvenile stages are presented.

FOOD CONCENTRATION AND TEMPERATURE EFFECTS ON LIFE CYCLE CHARACTERISTICS OF TROPICAL CLADOCERA (Daphnia gessneri Herbst, Diaphanosoma sarsi Richard, Moina reticulata (Daday)): I. DEVELOPMENT TIME

The effects of food concentration and temperature on embryonic and postem-bryonic duration of three tropical species, Daphnia gessneri(1.5mm), Diaphanosoma sarsi(1.2mm) and Moina reticulata(0.8mm), were investigated as part of life cycle studies which included growth, body size and reproduction. These are the very first experimental studies undertaken on these species. The long-term growth experiments were performed under controlled laboratory conditions at all combinations of temperature (22"C, 27"C and 32"C) and constant food concentration (0.03, 0.05, 0.10, 0.25, 0.50 and 1.00 mgC/L) of the unicellular green alga Scenedesmus acutus.Animals were examined twice daily throughout their life cycle from the neonate to third adult instar. In all three species, temperature exerted the most powerful influence on embryonic duration but there was also a smaller food effect. In D. gessneri,postembry-onic durations remained more or less the same at food levels 0.25 mgC/L but were influenced by temperature. At food concentrations of 0.1 mgC/L or lower, postembryonic durations became increasingly prolonged, particularly at high temperatures. This threshold concentration is affected by temperature: in D. gessneri,it was 0.1 mgC/L at 22oC and 27oC but higher at 32oC (between 0.25 and 0.50 mgC/L). At the same temperature of 27oC, the food threshold level varied between species: it was higher (0.25 mgC/L) for D. sarsiand lower (0.05 mgC/L) for M. reticulatacompared with D. gessneri(0.1 mgC/L). In both embryonic and postembryonic durations there is a body size effect as the absolute durations were longest in the largest species and shortest in the smallest species In all three species, prolongation of postembryonic duration at combinations of high temperature and lowered food levels was accompanied by increased number of juvenile instars.

The Larval Development of Palaemonid Shrimps from the Amazon region reared In the laboratory. VII. Abbreviated development of Pseudopalaemon amazonensis Ramos-Porto, 1979 (Crustacea: Decapoda: Caridea)

Larval development of the freshwater shrimp Pseudopalaemon amazonensis Ramos-Porto was studied in the laboratory based on the offspring of ovigerous females collected in a small “terra-firme” forest stream near Manaus, Brazil. Ovigerous females with a mean total length of 36.5 ± 1.9 mm carried 13-19 eliptical, yolk-rich eggs measuring 2.55 ± 0.16 x 1.64 ± 0.11 mm. The larval period consisted of 3 benthie stages and the larvae accomplished metamorphosis after 7-8 days without feeding. The newly-hatched larva had sessile eyes and all appendages, except for the uropods; chelipeds were present as uniramous buds, but walking legs were fully developed and functional. Descriptions and illustrations of the 3 larval and first juvenile stages are presented.

Larval development of Lepidophthalmus siriboia Felder & Rodrigues, 1993 (Decapoda: Thalassinidea) from the Amazon region, reared in the laboratory

The complete larval development of the ghost shrimp Lepidophthalmus siriboia Felder & Rodrigues, 1993 was described and illustrated in detail from specimens reared in the laboratory. Ovigerous females were collected at Canela Island in the northeastern region of the State of Pará. The larvae hatch as a prezoea, in which they persist for less than 3 hours. The larval development consists of three zoeal stages and a megalopa. The zoeal development averaged from 69 to 111 hours. The period in the megalopa stage was about 185 hours (about 8 days). The percentage of individuals succeeding in molt into juvenile stage was 91,8%. The first juvenile stage was reached 254 hours (about 10 days) after hatching. Morphological comparisons and their relationship with larvae of congeneric species are briefly discussed.

Developmental morphology of mouthparts and foregut of the larvae and postlarvae of Lepidophthalmus siriboia Felder & Rodrigues, 1993 (Decapoda: Callianassidae)

In this study, the gross morphology of the mouthparts and foregut of the ghost shrimp Lepidophthalmus siriboia were investigated from larvae and postlarvae reared in the laboratory. The mouthparts (maxillae and maxillipeds) of the zoeae have a reduced number of setae and spines (or is absent in some individuals), and the foregut, under developed, have few minute setae in the cardiac and pyloric chambers. In contrast, after the metamorphosis into megalopa stage, all feeding appendages have many setae and, the foregut shows a well-developed gastric mill with strong lateral teeth. In the juvenile stage occurs an increase of setae and spines in the mouthparts and the foregut becomes more specialized. These observations strongly suggest that a lecithotrophic development occurs during all zoeal stages but the megalopa and juvenile stages are feeding animals. The functional morphology of the feeding structures of L. siriboia and other decapods will be briefly discussed.

The morphology of the foregut of larvae and postlarva of Sesarma curacaoense De Man, 1892: a species with facultative lecithotrophy during larval development

Previous study on the resistance of larvae of Sesarma curacaoense submitted to starvation has revealed a facultative lecithotrophy during zoeal stages, but megalopa and first juvenile stages are exclusively feeding stages. In the present study, the gross morphology and fine structure of the foregut of S. curacaoense were investigated during larval, megalopa and first juvenile stages. The foregut of the zoea I show specific setae and a filter press apparently functional. The foregut undergoes changes in the zoea II (last larval stage) with increment of setae number, mainly on the cardiopyloric valve and complexity of the filter press. After metamorphosis to megalopa stage the foregut become rather complex, with a gastric mill supporting a medial and two lateral teeth well-developed. The foregut of the first juvenile is more specialized compared to the previous stage, showing similar characteristics of the decapod adults. These results provide further evidence of facultative lecithotrophic development in the larvae of S. curacaoense.

Tambaqui growth and survival when exposed to different photoperiods

The use of different photoperiods (light) were investigated during tambaqui (Colossoma macropomum) juvenile growth under captivity. Light intensity tested was: continuous dark (24hrs without light), natural photoperiod simulation (10hrs of light and 14hrs without light) and continuous light (24 with light). No mortality was recorded among treatments. Significant differences was observed after 50 days of experiment among mean fish weight, fish kept under a continuous darkness showed a better specific growth rate (6.02%) when compared to control fish (natural photo period, 3.67%). Fish exposed to continuous light presented the lowest mean specific growth rate (2.04%). It is possible to improve tambaqui juvenile weight gain performance when kept under continuous darkness.

Reproductive biology of Macrobrachium surinamicum (Decapoda: Palaemonidae) in the Amazon River mouth

Macrobrachium surinamicum is an indigenous prawn distributed from the lower Amazon and Tocantins river basins to Venezuela in the Orinoco Delta region. It is common bycatch fauna of Macrobrachium amazonicum artisan fishing in the states of Pará and Amapá. The aim of this study was to investigate aspects on reproductive biology (reproductive period, size of sexual maturity population, fecundity, reproductive output and recruitment) of M. surinamicum from four important areas to artisanal prawn fishing located at the Amazon River mouth (Amapá and Pará). The specimens were captured using 20 handcrafted traps called "matapi". A number of 675 prawns were captured, 258 males, 409 females and eight juveniles, resulting in 1:1.6 (Male: Female) sex ratio. The reproductive peak period occurred from March to July, coinciding with the higher rainfall period. The juvenile prawn occurred only in May and July. Total length of egg-bearing females ranged from 12.12 to 38.30 mm, with mean female length at first maturity (L50) of 23.7 mm. Fecundity increased with prawn size and varied between 174 and 1780 eggs per female. Mean egg volume increased gradually from 0.031 (Stage I) to 0.060 mm³ (Stage III) during embryogenesis. Macrobrachium surinamicum depends on brackish water to complete the larval development. Irrespective of female size, reproductive output of M. surinamicum varied between 4.3 % and 35.5 % of their body weight for egg production. The knowledge of the reproductive biology reported in the present study is an important tool to define strategies to preserve M. surinamicum in Amazon River mouth.

Ritmo de alimentação de juvenis de Loricariichthys anus (Siluriformes, Loricariidae) da Lagoa dos Quadros, RS, Brasil

The rhythm of movements and feeding activity of juveniles of Loricariichthys anus (Valenciennes, 1840) in the Quadros lake, South Brazil, are investigated. Between October 1997 and August 1998, 236 specimens were captured during six bimonthly 24 hour gillnet surveys. Significantly elevated levels of movement and feeding activity during the day are registered. The patterns of movement and feeding activity displayed no significant difference, suggesting that high movement activity levels can be attributed to feeding activity. The mean of the intestinal quotient was 1,89, indicating omnivorous feeding habits.

Comportamento alimentar e dieta de serpentes, gêneros Boiruna e Clelia (Serpentes, Colubridae)

Boiruna maculata Boulenger, 1896 and Clelia rustica (Cope, 1878) were observed in captivity feeding snakes and rodents, respectively. Both species have shown a similar procedure in relation to the prey. Major behavior differences among the two species were: rodents killed before being swallowed, and snakes were mostly swallowed alive; both species are able to find the rodents head faster than the snake one; the coils formed during constriction were also used to hold the prey, specially the last coil, while swallowing rodents. Informations on stomach contents was gathered by dissection of preserved specimens of Clelia clelia (Daudin, 1803) and C. plumbea (Wied, 1820) were also included in the dietary study. The majority of preys consisted on snakes and lizards. Other prey items were mammals and birds. Adult snakes prey relatively smaller animals than the juvenile snakes do.

Mudanças temporais na abundância e diversidade da fauna de peixes do infralitoral raso de uma praia, sul do Brasil

Abundance and diversity of the fish fauna in the shallow infralittoral region of Atami Beach, Paraná, Brazil, were studied through monthly collections between July 1998 and June 1999. A total of 7553 fishes from 70 species and 26 families, mainly juvenile forms, was captured in the area. The mean captures in number of species, number of fish and biomass were larger from the end of spring to the middle of autumn; seasonal tendency in richness, diversity (number) and equitability indices were not observed. The largest mean dissimilarity in the composition of the ichthyofauna occurred between June and May in comparison to the period between July and October. The species that contributed most to this dissimilarity were Selene setapinnis (Mitchill, 1815), Conodon nobilis (Linnaeus, 1758) and Stellifer rastrifer (Jordan, 1889). Three great groups reflecting patterns of temporal occurrence of the most abundant species were identified.

Protein content and electrophoretic profile of fat body and ovary extracts from workers of Melipona quadrifasciata anthidioides (Hymenoptera, Meliponini)

Workers of Melipona quadrifasciata anthidioides (Lepeletier, 1836) develop their ovaries and lay eggs, therefore the production of vitellogenin is expected. In electrophoretic profiles only fat body extracts from nurse workers and ovary extracts from newly-emerged workers show protein with molecular mass similar to vitellogenin. However, an increase in the protein content was detected in forager fat body. This increase was attributed to storage of vitellogenin or other proteins in the previous phase and not discharged into the hemolymph or to an effect of the increased titre of juvenile hormone in this phase of worker life over the fat body functioning.

Population dynamic of Sesarma rectum (Crustacea, Brachyura, Sesarmidae) from a muddy flat under human impact, Paraty, Rio de Janeiro, Brazil

A population of Sesarma rectum Randall, 1840 under the influence of human impact was studied. Monthly sampling (CPUE, two people during 30 min) took place from August/2001 to July/2002 at an impacted muddy flat in Paraty city, State of Rio de Janeiro (23º13'S, 44º42'W). At the laboratory, specimens were classified by sex and measured with a vernier caliper (0.01 mm). The size at the beginning of the sexual maturity was obtained by means of different techniques: in the case of males it was used the allometric procedure and the macroscopic analysis of gonads wile for females, the size of the smallest ovigerous female was also considered. The population structure was evaluated by means the analysis of the variations in the modes of the size frequency distribution. The fecundity was assessed using sub samples of the egg mass. For males, the macroscopic analyses of gonads revealed larger values of carapace width than those obtained with morphometric analysis. Males larger than 18.5 mm of carapace width can be considered as mature. For females, such size was 17.4 mm CW. Despite of the human impact in the habitat, the population presented to be stable, as indicated by a single mode on the size frequency distribution. The second mode that appeared in some months is probably related to the entrance of juveniles in the population. The sex ratio of this population is closely approximating to 1:1 until crabs reach a carapace width of about 28 mm; after that, males outnumbered females. Comparing the fecundity of the present population with a previous study from Ubatuba, it can be verified a difference in the number of eggs. The fecundity of Paraty's population is significantly lower than the Ubatuba's population. This is probably related to the scarcity of food resource in Paraty, once no vascular plant can be found in that place. The continuity of reproductive processes and the juvenile recruitment suggest this species is able to live in the area with human impact. The ability to obtaining nutrients from different source of food is probably a feature that allows S. rectum to occupy such impacted ecosystem.

Relative growth and morphological sexual maturity of Chasmagnathus granulatus (Crustacea, Varunidae) from a mangrove area in southeastern Brazilian coast

The relative growth and morphological sexual maturity of Chasmagnathus granulatus Dana, 1851 are presented for the first time to a mangrove population. The crabs were obtained during low tide periods, in the mangrove of Jabaquara Beach, Paraty, Rio de Janeiro, Brazil. All crabs in intermolt stage were sexed and had their body parts measured as follows: body height (BH), carapace length (CL) and width (CW), major cheliped propodus height (PH) and length (PL) for each sex, gonopod length (GL) and abdomen width (AW) for males and females, respectively. The relative growth was described using the allometric equation y=ax b and the size at onset sexual maturity was achieved using the software Mature I. The size of specimens ranged from 4.1 mm to 39.5 mm CW. The growth pattern was different between sexes in the cheliped relationships; the relationships BH vs. CW evidenced positive allometry for juveniles; PL vs. CW and PH vs. CW positive allometry for most crabs except juvenile females; AW vs. CW and GL vs. CW evidenced positive allometry for juveniles and isometry for adults. The relationships that best indicated the change from the juvenile to the adult phase were PH vs. CW for males and AW vs. CW for females. The size in which 50% of males from this population are mature is at 19.7 mm of CW (F=144.14; p<0.05) and for females it is at 19.2 mm of CW (F=166.54; p<0.05). The sizes obtained in this mangrove population are larger than those from previous studies, that could be attributed to a species plasticity concerning the habitat structure.