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Biomedical subjects

J Gilroy

Publications and source records attributed to J Gilroy.

58 records · Page 4Linked to original sources

Purification and amino acid sequence of a highly insecticidal toxin from the venom of the brazilian spider Phoneutria nigriventer which inhibits NMDA-evoked currents in rat hippocampal neurones.

A new insecticidal toxin Tx4(5-5) was isolated from the fraction PhTx4 of the venom of the spider Phoneutria nigriventer by reverse phase high performance liquid chromatography (HPLC) and anion exchange HPLC. The complete amino acid sequence determined by automated Edman degradation showed that Tx4(5-5) is a single chain polypeptide composed of 47 amino acid residues, including 10 cysteines, with a calculated molecular mass of 5175 Da. Tx4(5-5) shows 64% of sequence identity with Tx4(6-1), another insecticidal toxin from the same venom. Tx4(5-5) was highly toxic to house fly (Musca domestica), cockroach (Periplaneta americana) and cricket (Acheta domesticus ), producing neurotoxic effects (knock-down, trembling with uncoordinated movements) at doses as low as 50 ng/g (house fly), 250 ng/g (cockroach) and 150 ng/g (cricket). In contrast, intracerebroventricular injections (30 microg) into mice induced no behavioural effects. Preliminary electrophysiological studies carried out on whole-cell voltage-clamped rat hippocampal neurones indicated that Tx4(5-5) (at 1 microM) reversibly inhibited the N-methyl-D-aspartate-subtype of ionotropic glutamate receptor, while having little or no effect on kainate-, alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid- or gamma-aminobutyric acid-activated currents.

Amino Acid Sequence↗

Role of bacterial infection in exacerbation of multiple sclerosis.

One hundred consecutive patients admitted to the hospital with a diagnosis of exacerbation of multiple sclerosis were evaluated for an infectious process. All patients received a complete blood count, urinalysis, urine culture with susceptibility studies, blood cultures, and a chest x-ray at the time of admission. A control group of 55 patients carrying the diagnosis of multiple sclerosis but without symptoms of neurologic decline were also studied. Thirty-five percent of patients experiencing exacerbation of their disease were identified as having a significant bacterial infection compared with 11% in the control group with quiescent disease. These results were significant with a P value of < 0.001. When presumptive viral and bacterial infections diagnosed before admission were included, almost 50% of patients could have had an exacerbation of their disease in response to an infectious process. Bacterial infection might well play a role in precipitating relapse in multiple sclerosis as well as influencing treatment.

Adrenal Cortex Hormones↗

The development of formocresol as a medicament for primary molar pulpotomy procedures.

The development of formocresol as a pulpotomy medicament is charted from the 19th Century to the present day. While the solution has come in and out of vogue, few agents can seriously challenge its efficacy. Doubts about its toxicity, mutagenicity, and carcinogenicity have led, however, to a call for a more dilute formulation as well as a review of alternative medicaments. Problems arise in deriving an appropriate formula for a dilute version from existing formulations, which appear to have misinterpreted the concentration of constituents in the original solution.

Europe↗