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Biomedical subjects

A Crisanti

Publications and source records attributed to A Crisanti.

At least 55 records · Page 3Linked to original sources
PubMed1996

Conserved function of anopheles gambiae midgut-specific promoters in the fruitfly.

Control of malaria by a methodology that would permit the effective blockage of the Anopheles gambiae midgut wall penetration by Plasmodium parasites requires a detailed understanding of both the physiology of the mosquito's digestion, and of the interactions between the parasite and its host. We have transformed Drosophila melanogaster with several constructs that allow the study of the promoter region of two of the major late trypsin genes of A. gambiae. Using several deletions, we have identified, for both genes, small genomic segments that are sufficient to confer tissue specificity to the promoter in a species that is far away in evolution from the mosquito. This will allow further studies that will enable both the understanding of the blood meal digestion, and may potentially be useful for the design of anti-plasmodial constructs at a later stage.

Animals↗
PubMed1995

Constitutive and blood meal-induced trypsin genes in Anopheles gambiae.

Trypsin genes in Anopheles gambiae are arranged as a tightly clustered gene family consisting of seven related coding sequences, devoid of introns. The two blood meal-inducible members of this family, Antryp1 and Antryp2, were shown to play a crucial role in the breakdown of the blood meal constituents. The role of Antryp3,4,5,6, and Antryp7 in the process of blood meal digestion remains to be elucidated. We have examined the localization and the expression patterns of these trypsins as well as the functional interactions in blood meal digestion between trypsins and other gut-specific proteases. Northern blot and RT-PCR analysis indicated that the genes Antryp3,4,5,6, and Antryp7 are all constitutively expressed in unfed female mosquitoes. Soon after blood feeding the mRNA of these trypsin genes became undetectable and appeared again at the end of the gonotrophic cycle. The blood meal-inducible trypsin Antryp1 was also constitutively expressed at low level in the gut of adult female mosquitoes. This trypsin was the only member of this gene family to be expressed in the gut of male and female pupae. By using antisera that specifically recognized recombinant Antryp4 we were able to show that the corresponding protein in Anopheles is synthesized and stored in the gut epithelium of unfed females as zymogen. Secretion and activation of this trypsin was shown to occur in the midgut lumen immediately after fluid ingestion and independently of the protein content of the meal. Recombinant trypsins expressed in Escherichia coli, with the exception of Antryp5 and Antryp6, were able to activate in vitro recombinant A. gambiae chymotrypsinogen, thus suggesting that blood meal ingestion is able to trigger a cascade of events leading to the activation of several proteases.

Amino Acid Sequence↗
PubMed1995

Molecular cloning and expression of a 70-kilodalton heat shock protein of Candida albicans.

By screening an expression library of the yeast form of Candida albicans with a serum directed against whole fungal cells, a cDNA (2,325 bp) encoding a stress protein of C. albicans was cloned and sequenced. The cloned sequence (CaRLV130) identified a single open reading frame with a length of 1,968 bp coding for a protein containing 656 amino acid residues (70 kDa). The deduced amino acid sequence was 84% similar to the sequence of the Saccharomyces cerevisiae SSA1 gene, which encodes one member of the 70-kDa heat shock protein (Hsp70) family. The relevant gene (C. albicans HSP70 gene [CaHSP70]) was localized on the highest-M(r) (R1; approximately 3.8 Mb) chromosome of C. albicans as determined by pulse-field electrophoresis. CaHSP70 was expressed after heat shock, as demonstrated by Northern (RNA) blotting and reverse transcriptase-PCR with specific pairs of oligonucleotide sequences and gene probes. A recombinant protein was obtained in Escherichia coli after cloning of the full coding sequence into the BamHI site of the pDS56/RBSII6xhisE- plasmid and purification by nickel chelate affinity chromatography. The recombinant protein (6xhis-CaHsp70) was efficiently recognized in immunoblots by a monoclonal antibody directed against a common epitope of eukaryotic Hsp70 proteins, as well as by sera from normal human subjects. Moreover, immune mouse sera against the purified recombinant protein recognized native, heat-inducible constituents with sizes of around 70 kDa in whole-cell protein extracts of C. albicans. Overall, our data demonstrate that CaHSP70 encodes one member of a family of proteins (Hsp70) which usually represent highly conserved immunodominant antigens of infectious agents.

Amino Acid Sequence↗
PubMed1995

The effects of changes in the law concerning mentally disordered offenders: the Alberta experience with Bill C-30.

OBJECTIVE: Until recently, the Criminal Code of Canada, enacted in 1892, stood stalwart to social, political and technological changes, particularly with respect to the regulations pertaining to the management of the mentally ill offender. This became more definitely so with the enactment of the Canadian Charter of Rights and Freedoms (1984) as many regulations in the Code about mentally ill offenders contravened the mandates contained in the Charter. The Supreme Court of Canada's decision on Regina v. Swain spurred the Federal Government to bring the regulations on the mentally ill offender into line with the Charter. The result was the enactment of Bill C-30 which was intended to dramatically change the way in which forensic psychiatry was practised in Canada. This paper presents the Alberta findings from a multi-site evaluation commissioned by the Federal Department of Justice to judge the effects of Bill C-30 on forensic health care practices. METHODS: Health records data were used to compare utilization patterns from the year prior to the enactment of Bill C-30 with the year following. In addition, qualitative data were obtained from key clinical and legal informants outlining implementation difficulties that they had experienced. RESULTS: Results support the judgement that Bill C-30 has not achieved its desired effects with respect to the length of the remand, and has resulted in an increased burden on hospitals and health care providers. In addition, an unanticipated finding was the increased use of the Mental Health Act which was considered to place forensic patients in a position of double jeopardy.

Adult↗
PubMed1994

An evaluation of legal outcome following pretrial forensic assessment.

This paper constitutes the first stage of data analysis in a larger controlled study designed to assess the effect of a forensic psychiatric assessment on legal disposition defined in three ways: 1. the number of days spent in custody prior to trial; 2. the number of sentenced days of incarceration; and 3. the conviction rate. A historical cohort design was used to follow two cohorts of individuals remanded, pretrial, to Southern Alberta Provincial Correctional Centres between 1988 and 1989. The study cohort consisted of all offenders detained who received a forensic psychiatric assessment. The comparison cohort consisted of a random sample of persons detained who did not undergo a forensic assessment. Because of small numbers, individuals below the age of 18 and women were excluded from study. This paper compares socio-legal characteristics of study and comparison subjects in order to better understand forensic psychiatric referral patterns and identify potentially confounding factors that would need to be controlled in subsequent analyses of legal outcomes. No differences were noted with respect to educational level but forensic subjects were found to be slightly older (average of 31 years compared to 29 years). Aboriginal peoples (Native Indian, Inuit and Metis) were three times more common among non-forensic offenders. Forensic patients were more likely to have had a prior forensic assessment but less likely to have a prior criminal detention. In addition, forensic patients were three times more likely to be charged with a crime against a person and counted more offenses in the target episode than comparison subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Thrombospondin related anonymous protein (TRAP) of Plasmodium falciparum binds specifically to sulfated glycoconjugates and to HepG2 hepatoma cells suggesting a role for this molecule in sporozoite invasion of hepatocytes.

Thrombospondin related anonymous protein (TRAP) of Plasmodium falciparum contains an amino acid motif based around the sequence WSPCSVTCG which is also found in region II of the circumsporozoite (CS) proteins of different species of Plasmodium. This amino acid motif confers on the CS protein the ability to bind specifically to sulfated glycoconjugates and to hepatocytes. This suggests that the interaction of CS protein with sulfated glycoconjugates on the surface of the hepatocytes may represent the first molecular event of sporozoite invasion of liver cells. Experimental evidence indicates that TRAP is localized both on the micronemes and on the surface of P. falciparum sporozoites implying that TRAP with its putative sulfated glycoconjugate binding motif may also be involved in recognition and/or entry of hepatocytes by the sporozoite. We show here that different TRAP constructs expressed in Escherichia coli bind to sulfogalactosyl-cerebrosides (sulfatides) and to the surface of HepG2 cells. These interactions are dependent on the presence of the conserved amino acid motif WSPCSVTCG within the sequences of the constructs and are completely inhibited by several sulfated glycoconjugates as well as by suramin, a polysulfonated drug with anti-protozoan activity. Moreover, sporozoite invasion of HepG2 cells is inhibited by antisera raised against these different TRAP constructs and by the presence of low concentrations of suramin. We concluded that TRAP may be one of the parasite encoded molecules in the host-parasite interaction that results in sporozoite invasion of hepatocytes.

Amino Acid Sequence↗