Fasting prevents experimental murine colitis produced by dextran sulfate sodium and decreases interleukin-1 beta and insulin-like growth factor I messenger ribonucleic acid

Cytokines and insulin-like growth factors (IGFs) are involved in the induction and/or perpetuation of inflammatory bowel disease. The effect of fasting on inflammatory bowel disease was studied in a mouse experimental model of acute colitis caused by adding dextran sulfate sodium (DSS) to drinking water. Animals were either fed ad libitum or fasted (water only) for 2 days before death. Inflammation and tissue damage, measured as a colitis activity score, were markedly reduced in fasted (2.4 +/- 0.1) compared to fed (5.3 +/- 0.1) DSS animals (P < 0.0001). Colon interleukin-1 beta (IL-1 beta), IGF-I, and tumor necrosis factor-alpha messenger RNAs (mRNAs) were quantified by Northern blot hybridization and expressed as a percentage of mRNA abundance in fed controls. In DSS mice, IL-1 beta mRNA was elevated in the fed group (954 +/- 155%; P < 0.001), but was suppressed in fasted animals (71.1 +/- 11%). IGF-I mRNA also was elevated in fed DSS mice (421 +/- 71%; P < 0.01). This increase was attenuated in fasted DSS mice (202 +/- 17%; P < 0.01 compared to fed DSS mice). Tumor necrosis factor-alpha mRNA was increased in fed DSS mice (162 +/- 15%; P < 0.01), but was not significantly lower in fasted animals. By in situ hybridization, IL-1 beta mRNA was localized to the lamina propria of colonic mucosa in fed DSS animals, but was not detectable in other groups. We conclude that fasting has a protective effect on the progression of acute DSS, induced colitis. This is associated with decreased expression of IL-1 beta and IGF-I mRNAs in the colon.     

Chronic orbital hematic cysts: a case for craniofacial correction

Chronic hematic cysts are rare conditions that usually present to the ophthalmic surgeons with displacement of the globe. There is usually no, or minimal, bone involvement. Two patients with unusual presentations of chronic orbital hematic cysts are reported. These cysts resulted in significant expansion and erosion of the bony orbits. The presentation, operative findings, and reconstruction are reported and discussed.     

Determination of uranium in fertilisers using fission track method

Trace contents of uranium in various commercial fertilizers e.g. ureas, superphosphates, diammonium phosphates have been determined using fission track etch technique. The uranium content in ureas varies from .05 to 1.3 mg kg^–1 whereas in superphosphates it varies linearly with phosphate content.     

Bilateral lower limb oedema due to a distended urinary bladder

A 91-year-old Chinese man developed bilateral lower limb oedema due to venous obstruction resulting from a distended urinary bladder. After the bladder was decompressed by urethral catheterisation, the bilateral lower limb oedema promptly subsided. Although a distended urinary bladder is a rare cause of bilateral lower limb oedema, it can be easily recognised by palpation of the lower abdomen and the relief of symptoms by urethral catheterisation is most rewarding.     

Kinetochores distinguish GTP from GDP forms of the microtubule lattice

During prometaphase in mitotic cell division, chromosomes attach to the walls of microtubules and subsequently move to microtubule ends, where they stay throughout mitosis. This end-attachment seems to be essential for correct chromosome segregating. However, the mechanism by which kinetochores, the multiprotein complexes that link chromosomes to the microtubules of the mitotic spindle, recognize and stay attached to microtubule ends is not understood. One clue comes from the hydrolysis of GTP that occurs during microtubule polymerization. Although tubulin dimers must contain GTP to polymerize, this GTP is rapidly hydrolysed following the addition of dimers to a growing polymer. This creates a microtubule consisting largely of GDP-tubulin, with a small cap of GTP-tubulin at the end. It is possible that kinetochores distinguish the different structural states of a GTP- versus a GDP-microtubule lattice. We have examined this question in vitro using reconstituted kinetochores from the yeast Saccharomyces cerevisiae. We found that kinetochores in vitro bind preferentially to GTP- rather than GDP-microtubules, and to the plus-end preferentially over the lattice. Our results could explain how kinetochores stay at microtubule ends and thus segregate chromosomes correctly during mitosis in vivo. This result demonstrates that proteins exist that can distinguish the GTP conformation of the microtubule lattice.