as the necessity to improve the diagnosis procedures in children with complex limb anomalies. We analyzed the frequency of variation within hospitals by comparing the frequency during the surveillance period with the frequency of the baseline period within each hospital. For this, we calculated the observed and expected and used the Z test according to the Poisson distribution. The period between the years 1982 and 1999 was established as a baseline period for TEP surveillance since the availability of thalidomide is suspected to have increased after 2000 due to the expansion in clinical indications for its prescription authorized by the Brazilian Health Ministry. Geographical regions were considered too, taking into account the differential prevalence of leprosy in Brazil. The Poisson distribution, with a confidence interval of 95% was used to estimate birth prevalence rate. The CUSUM methodology was used to detect possible increases in TEP frequency after 2000. CUSUM has already been widely used for birth defects surveillance, being able to detect variations of TEP from the BPR of the baseline period by the sum of differences between the number of cases occurring during the surveillance period and a reference value obtained from the baseline period. The false alarm rate was set to one in 500 months =500). Detailed clinical proactive surveillance was conducted from March 2007 to February 2008 with records of newborns from 33 Brazilian hospitals participating in ECLAMC. All newborns with limb reduction defects were assessed and classified according to the type of limb defect and compatibility with TEP. Huwentoxin-I is a neurotoxic peptide isolated from the venom of the Chinese bird spider Ornithoctonus huwena, which is distributed in the hilly areas of the provinces of Yunnan and Guangxi in southern China. The primary structure of HWTX-I was previously determined. It consists of 33 amino acid residues and three pairs of disulfide bonds. Spatial structure analysis demonstrated that HWTX-I adopts a compact structure consisting of a small triple-stranded antiparallel b-sheet stabilized by three disulfide bonds . HWTX-I possesses multiple biological activities. It reversibly blocks neuromuscular transmission in an isolated mouse phrenic nerve-diaphragm preparation. It was demonstrated that HWTX-I is a toxin that blocks N-type voltagegated calcium channels and TTX-S voltage-gated sodium channels in adult rat dorsal root ganglion neurons. It has also been reported that in a rat formalin test model, the Publications Using Abomle CX-4945 intrathecal administration of HWTX-I is effective in antinociception. Therefore, HWTX-I has been considered a model molecule for anti-pain drug development and is currently in phase I clinical trials. Although HWTX-I is the most abundant component in venom, isolating HWTX-I from crude venom using biochemical tools cannot meet the increasing demands of research due to the limited venom supply and purification costs. The ultimate solution to this problem would be the efficient expression of recombinant HWTX-I in prokaryotic organisms, such as E. coli, or eukaryotic systems, such as yeast or cultured cells. In previous attempts, a synthesized nucleotide fragment was used to express rHWTX-I fused with either glutathione S-transferase or ketosteroid isomerase in E. coli cells. The fusion proteins were expressed in the cytoplasm of E. coli. rHWTX-I released from the fusion protein demonstrated extremely low bioactivity before a reduction/renaturation treatment.