Usefulness and potential pitfalls of sialic acid determination in sera of patients with ovarian tumors

Increasing evidence in the literature indicates that serum sialic acid is increased in cancer patients suggesting a possible usefulness of its determination as a tumor marker. However there are many discrepancies in the data reported, probably due to methodological errors, mainly in lipid bound sialic measurement. In this paper we illustrate the results obtained when we applied a method worked out in our laboratory for the determination of total and fractionated sialic acid (lipid and protein bound) to the analysis of sera from patients with ovarian tumors and the preliminary data on the follow up of selected cases. The potential pitfalls in using this relatively new tumor marker will be critically evaluated.     

zeta PKC induces phosphorylation and inactivation of I kappa B-alpha in vitro.

The zeta isotype of protein kinase C (zeta PKC), a distinct PKC unable to bind phorbol esters, is required during NF-kappa B activation as well as in mitogenic signalling in Xenopus oocytes and mammalian cells. To investigate the mechanism(s) for control of cellular functions by zeta PKC, this enzyme was expressed in Escherichia coli as a fusion protein with maltose binding protein (MBP), to allow immobilization on amylose beads to study signalling proteins in cell extracts that might form complex(es) with zeta PKC. The following evidence for interaction with the NF-kappa B/I kappa B pathway was obtained. MBP-zeta PKC, but not MBP, bound and activated a potentially novel I kappa B kinase of approximately 50 kDa molecular weight able to regulate I kappa B-alpha function. Activation of the I kappa B kinase was dependent on zeta PKC enzymatic activity and ATP, suggesting that zeta PKC controls, directly or indirectly, the activity of a functionally significant I kappa B kinase. Importantly, zeta PKC immunoprecipitates from TNF-alpha-stimulated NIH-3T3 fibroblasts displayed a higher I kappa B phosphorylating activity than untreated controls, indicating the in vivo relevance of these findings. We also show here that zeta PKC associates with and activates MKK-MAPK in vitro, suggesting that one of the mechanisms whereby overexpression of zeta PKC leads to deregulation of cell growth may be accounted for at least in part by activation of the MKK-MAPK complex. However, neither MKK nor MAPK is responsible for the putative I kappa B phosphorylating activity. These data provide a decisive step towards understanding the functions of zeta PKC.     

Salinity and spawning of nurseryfish, <Emphasis Type="Italic">Kurtus gulliveri</Emphasis>, in the Adelaide River of northern Australia with notes on electrofishing and photos of a male carrying eggs

Nurseryfish are unique among fishes in that the males carry the fertilized eggs on a supraoccipital hook on their head. In an attempt to learn where, when, and at what salinities spawning occurs, an ichthyoplankton net was towed at 14 stations in the Adelaide River from the mouth (38 ppt) to the most upstream sections of the river (0.1 ppt). Larval nurseryfish (5–27.5 mm SL) were collected, preserved and measured, and water chemistry parameters were recorded with each sample. Larvae were found in the mid-reaches of the river during July–October, most commonly at salinities between 13.6–0.5 ppt. Salinities increased as the dry season progressed. Larvae were not taken at salinities higher than 19 ppt, nor did they occur in the upper-most reaches of the river system during this time of the dry season. What nurseryfish do and where they occur during the massive influx of freshwater runoff during the wet season (November–April) remains a mystery. Electrofishing for nurseryfish proved to be ineffective in the Adelaide River due to its extraordinary turbidity which made recovery of stunned fish difficult and fresh material of males carrying eggs remains elusive. Two historic photographs showing males carrying eggs are described.     

High performance thin layer chromatography of neutral and acidic glycolipids: application to the chemical diagnosis of lipid storage diseases.

A new technique was utilized for the separation of neutral and acidic glycolipids using an equipment named U-Chamber System. This technique was employed for the chemical diagnosis of inherited inborn errors diseases in which complex glycolipids are involved. Results in the identification of storage products in Tay-Sachs' disease, GM1 gangliosidosis and Fabry's disease are presented.     

The effects of increasing dosages of X-radiation on the chromosomes of the central mudminnow, Umbra limi (Kirtland) (Salmoniformes: Umbridae)

Fish subjected to 350 R, 660 R and 990 R of X-radiation showed chromosomal aberrations such as chromatid breaks and gaps, and chromatid exchanges between several chromosomes. The frequency of aberrations/metaphase increased with radiation dosage. Likewise, the percentage of aberrant cells increased with increased irradiation. The countable metaphases fish was lower for higher doses of radiation. At lower doses single chromatid breaks accounted for most of the aberrations whereas complex aberrations involving the breakage and exchange of fragments between several chromosomes were more frequent in fish subjected to 990 R. Gill tissue yielded three times as many countable metaphases as did spleen tissue.