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Biomedical subjects

M Hackett

Publications and source records attributed to M Hackett.

47 records · Page 3Linked to original sources

Isolation and identification of a cardioactive peptide from Tenebrio molitor and Spodoptera eridania.

We isolated several cardioactive peptides from extracts of whole heads of the mealworm, Tenebrio molitor, and the southern armyworm, Spodoptera eridania, using a semi-isolated heart of Manduca sexta for bioassay. We have now isolated from each species the peptide with the strongest effect on rate of contraction of the heart. The peptides were identified using micro Edman sequencing and mass spectrometric methods. This cardioactive peptide has the same primary structure from both species: Pro-Phe-Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2, a cyclic nonapeptide which is identical to crustacean cardioactive peptide (CCAP) originally isolated from the shore crab, Carcinus maenas, and subsequently isolated from Locusta migratoria and Manduca sexta. This is additional evidence that CCAP has widespread occurrence in arthropoda.

Amino Acid Sequence↗

Dioxin intoxication from chronic exposure of horses to pentachlorophenol-contaminated wood shavings.

Investigations into the cause of health problems on a horse-breeding farm led to the discovery of high concentrations (630 to 9,810 mg/kg of bedding) of pentachlorophenol in wood shavings used as bedding for horses over a period of 2 to 4 years. Toxicologic signs in the horses were characteristic of toxic effects associated with exposure of polychlorinated dibenzo-p-dioxins and dibenzofurans. Tissue residue analysis confirmed presence of toxic polychlorinated dibenzo-p-dioxin and dibenzofuran isomers known to be in pentachlorophenol, substantiating the bioavailability of polychlorinated dibenzo-p-dioxins and dibenzofurans in the wood shavings. The findings provide evidence that residue concentrations in the range of 2 ng/g of toxic polychlorinated dibenzo-p-dioxin isomers in liver or fat correlate with toxicologic effects in horses.

Animals↗

Survival of cultured allogeneic keratinocytes transplanted to deep dermal bed assessed with probe specific for Y chromosome.

To determine the survival of cultured allogeneic keratinocytes transplanted to a deep dermal bed 24 tattoos that had been removed by deep shave excision in 19 patients were grafted with sheets of cultured allogeneic keratinocytes from donors of the opposite sex. Cells carrying the Y chromosome were identified in biopsy specimens taken from the graft site by in situ DNA hybridisation with a biotinylated Y probe (pHY 2.1) and visualised with a technique using immunoperoxidase. The cultured allograft sites were biopsied one, two, and three weeks after transplantation. No male cells were identified in any biopsy specimen from female patients who were given transplants of male cultured keratinocytes, and all biopsy specimens from male patients, who received female cultured keratinocytes, showed percentages of male cells within the normal range for male skin. The beneficial effects of cultivated allogeneic keratinocytes result from effects on wound healing other than forming a successful graft that "takes."

Bandages↗

The effects of deliberate hypotension and foot down tilt on the incidence of deep vein thrombosis during plastic surgical operations: a pilot survey.

The incidence of postoperative deep vein thrombosis (DVT) has been investigated in a group of 88 patients undergoing plastic surgical operations on the head and neck, and upper limb. Fifty-two cases were operated upon in the foot-down tilt position and 36 were horizontal. With the effects of blood pressure ignored as a possible contributory factor, the incidence of thrombosis in the latter group was 8-3% and was slightly higher in the tilted group (11-5%). Of those who were hypotensive, 3 developed DVT out of 41 (7-3%) who were tilted; whilst in the 11 who were normotensive and tilted 3 developed DVT, an incidence of 27-3%. Of those who were normotensive and operated flat the incidence of deep vein thrombosis was 8-0%, while in those subjected to a foot-down tilt it was 27-3%. The hypothesis has been advanced that frequent inflation and deflation of the cuff used for monitoring blood pressure in the hypotensive patients may release fibrinolytic activity and explain these differences. Age, sex and operative duration were not found to have an effect. It is concluded that the incidence of postoperative deep vein thrombosis in patients undergoing plastic surgical operations is lower than that found in general surgery, and is not worsened by deliberate hypotension.

Humans↗