Role for mannose-sensitive hemagglutinin in promoting interactions between Vibrio cholerae El Tor and mussel hemolymph

The role of mannose-sensitive hemagglutinin (MSHA) in Vibrio cholerae O1 El Tor interactions with hemolymph of the mussel Mytilus galloprovincialis was studied. Bacterial adherence to and association with hemocytes were evaluated at 4 and 18 degrees C, respectively. In hemolymph serum, the wild-type strain N16961 adhered to and associated with hemocytes about twofold more efficiently than its mutant lacking MSHA. In artificial seawater (ASW), no significant differences between the two strains were observed. N16961 was also more sensitive to hemocyte bactericidal activity than its MSHA mutant; in fact, the percentages of killed bacteria after 120 min of incubation were 60 and 34%, respectively. The addition of D-mannose abolished the serum-mediated increase in adherence, association, and sensitivity to killing of the wild-type strain without affecting the interactions of the mutant. A similar increase in N16961 adherence to hemocytes was observed when serum was adsorbed with MSHA-deficient bacteria. In contrast, serum adsorbed with either wild-type V. cholerae El Tor or wild-type Escherichia coli carrying type 1 fimbriae was no longer able to increase adherence of N16961 to hemocytes. The results indicate that hemolymph-soluble factors are involved in interactions between hemocytes and mannose-sensitive adhesins.     

Self-regulating model for control of replication origin firing in budding yeast

A major research area concentrates on understanding the regulation of replication origin firing. It is now appreciated that checkpoint signaling participates in this controlled process and that defects in such signaling systems affect genome integrity. Inhibition of replication origin firing is most obviously apparent under conditions of replication stress, but origin firing must also be regulated on a minute-by-minute basis as cells progress normally through an unabated S-phase. Here we summarize a straightforward model to account for how origin firing could be controlled by a self-regulating system.     

Supporting persons with developmental disability--a new model

The way we think about and care for people with developmental disability has changed. Twenty-five years ago, society believed that caregivers always knew what was best for their individual and that he or she must be shielded, even shut away from, the harms that could occur in society. Now, people with disability participate in all aspects of community life. They are educated in local schools, live at home or in their own home, and compete with others in the job market. Caregiving for people with developmental disability is no longer modeled on medicine or stigmatizing labels. Instead, caregivers have become support persons who focus on identifying community resources and making the environment friendlier and safer for persons with disability.     

Identification of a new mutation,S305C,in exon 7 of the low-density lipoprotein receptor gene in a Brazilian family with homozygous familial hypercholesterolemia

DNA analysis of the low-density lipoprotein receptor gene of a young Brazilian man, suffering from an extreme form of hypercholesterolemia, revealed the presence of two mutations, thereby confirming the diagnosis of homozygous familial hypercholesterolemia (FH). The first mutation was a mutation frequently found in Brazilian patients with FH, termed C660X or FHLebanese. The second mutation, in which a serine residue was replaced by a cysteine at amino acid position 305 (S305C) was a new mutation never described before. S305C was inherited from the proband's mother, who was of Italian descent. The occurrence of LDL receptor gene mutations of Lebanese and Italian origin in Brazil underlines the genetic heterogeneity of the Brazilian population.