Animal models of polycystic kidney disease

Polycystic kidney disease (PKD) is one of the most prevalent causes of heritable renal failure. The disease is characterized by the occurrence of numerous fluid-filled cysts within the parenchyma of kidney. The cysts are epithelial in origin and expand in size, leading to crowding of normal kidney tissue. Ultimately, there is gross enlargement of the kidneys with loss of normal functions, and death usually occurs because of complications related to renal failure. Animal models of polycystic kidney disease are proving to be extremely useful for studying the molecular basis of renal cyst formation and for the isolation of genes carrying the mutations. This article describes the various animal models of polycystic kidney disease, spontaneously and experimentally derived, that have recently been identified.     

Distribution of molluscs in Layari River (Sindh), Pakistan

Between January 1982 and December 1985, 65 species of Mollusca were collected from the Layari River, an ephemeral stream that bisects Karachi. Gastropods were dominant followed by bivalves. The upstream region is hypersaline and devoid of molluscs; the stretch within Karachi is heavily polluted and almost no living molluscs occur here.     

Proteomic profiling of L-cysteine induced selenite resistance in Enterobacter sp. YSU

Background  

Enterobacter sp. YSU is resistant to several different heavy metal salts, including selenite. A previous study using M-9 minimal medium showed that when the selenite concentration was 100,000 times higher than the sulfate concentration, selenite entered Escherichia coli cells using two pathways: a specific and a non-specific pathway. In the specific pathway, selenite entered the cells through a yet to be characterized channel dedicated for selenite. In the non-specific pathway, selenite entered the cells through a sulfate permease channel. Addition of L-cystine, an L-cysteine dimer, appeared to indirectly decrease selenite import into the cell through the non-specific pathway. However, it did not affect the level of selenite transport into the cell through the specific pathway.