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Biomedical subjects

N Todd

Publications and source records attributed to N Todd.

29 records · Page 2Linked to original sources

Presence of neuropeptide Y in human circle of Willis and its possible role in cerebral vasospasm.

Neuropeptide Y (NPY) has been demonstrated in the human circle of Willis by specific radioimmunoassay. Concentrations were similar in cadaver and peroperative specimens. NPY concentrations were highest around the basilar bifurcation (2.9 +/- 1.0 pmol/g), anterior cerebral artery (2.7 +/- 0.5 pmol/g), and carotid trifurcation (2.4 +/- 0.6 pmol/g). Concentrations were lowest in the basilar artery (1.0 +/- 0.4 pmol/g). Intracarotid administration of NPY (50 pmol to 2 nmol) to rats reduced mean cerebral cortical blood flow by 40-98%. This vasoconstriction lasted for at least 2 h. These findings suggest that NPY may be involved in the cerebral vasospasm which follows subarachnoid haemorrhage and in the maintenance of normal vascular tone.

Animals↗

Fatal fat embolism during ritual initiation.

A young Coast Salish Indian woman became fatally ill during ritual Initiation into the Native Winter Spirit Dancing Society. She died from massive fat emboli associated with subcutaneous bruises that appeared clinically unimportant and were not associated with fractures or other underlying injury. The liver showed extreme fatty metamorphosis.

Adult↗

Toxicity and mutagenicity of 6 anti-cancer drugs in Chinese hamster V79 cells co-cultured with rat hepatocytes.

Toxicity and induction of 6-thioguanine-resistant mutants in Chinese hamster V79 cells, co-cultured with or without isolated rate hepatocytes, by 6 anti-cancer drugs (cyclophosphamide, adriamycin, methotrexate, cytosine arabinoside, 6-mercaptopurine and vincristine) were studied. The effect of hepatocyte density on the cloning efficiency and recovery of mutants was found using dimethylnitrosamine as a positive control. In the absence of hepatocytes, this compound was neither toxic nor mutagenic to V79 cells, but in their presence it was highly mutagenic and extremely toxic. The cloning efficiency and mutation frequency of control (untreated) cells was unaffected by hepatocyte density. All the drugs were toxic to V79 cells, although different responses were found for certain of them depending upon whether hepatocytes were present or not. Cyclophosphamide and adriamycin were clearly mutagenic, and 6-mercaptopurine only weakly so. A slight mutagenic effect was seen for cytosine arabinoside, but both methotrexate and vincristine were negative. Here also, the presence or absence of hepatocytes was important.

Animals↗

Bacteriology and treatment of purulent nasopharyngitis: a double blind, placebo-controlled evaluation.

One hundred forty-two children with purulent nasopharyngitis were randomized to four treatment groups with an antibiotic (cephalexin) alone or combined with a decongestant/antihistamine (pseudoephedrine/triprolidine) or their corresponding placebo equivalents. Follow-up evaluations by parents and physicians and bacteriologic evaluations were performed after 5 to 6 days of therapy. Groups were comparable with regard to age, sex, race, number of patients withdrawn from the study, fever greater than 38.0 degrees C, appearance of nasal discharge, nasal crusting and number of days until follow-up. Initial cultures from patients grew: Streptococcus pneumoniae, 46%; Haemophilus influenzae type b, 21%; and Streptococcus pyogenes, 8%. Nasal crusting was significantly associated with the growth of S. pneumoniae or H. influenzae type b. There were no significant differences between active drug and placebo treatment groups for change in nasal discharge, complications or apparent drug benefit. Cephalexin therapy did not result in a decrease in cultivation of pathogenic organisms from the nasopharynx. Significantly more side effects were attributed to pseudoephedrine/triprolidine treatment than to placebo. Routine culture or treatment of purulent nasopharyngitis should not be considered unless future controlled clinical trials demonstrate some therapeutic benefit.

Bacterial Infections↗

The physiological knowledge required by nurses caring for patients with unstable angina.

Physiological knowledge necessary to critically analyse nursing management of patients with unstable angina is reviewed. The role of endothelium derived relaxing factor, nitrous oxide and atherosclerosis is summarised. The effects of circadian rhythms or clinical signs and symptoms in patients with unstable angina is particularly highlighted. Pharmacological interventions are considered from the perspective of implications for nursing care and other important nursing interventions identified for coronary care nurses.

Angina, Unstable↗