Healthy communities: reflections on building alliances in Canada. A view from the middle

The author is currently working in the office of Health Promotion,Ministry of Health in British Columbia. For the past 17 yearsshe has worked in Health and Welfare Canada as an advocate forcitizen participation in developing health programs and policies. This article is based on her experience as an advocate and bureaucratin translating and mediating health promotion rhetoric intoaction. The Canadian Healthy Communities and Strengthening Communitiesprojects are used as examples in analyzing the opportunitiesand contradictions in building alliances.     

Chemical and enzymatic treatment of endothelin

Endothelin-1 (ET), the most potent vasoconstrictor yet discovered, is a peptide containirig 21 amino acids with two intrachain disulfide bridges. With the aim of obtaining two-chain derivatives, Et was submitted to chemical and enzymatic treatments. Reaction of ET with CNBr in 70% HCOOH gave, in addition to the expected [Hse⁷ lactone]-7,8-seco-ET and unreacted material, a by-product whose molecular weight was 25 m.u. greater than that of ET. When the reaction mixture, after lyophilisation, was immediately quenched with NH3-saturated dry MeOH, two products could be recovered in a 5:1 ratio, both obtained by nucleophilic attack of the homoserine lactone: the expected [Hse⁷-NH₂]-7,8-seco-ET and [Hse⁷]ET, resulting from competitive intramolecular reaction of the deprotonated α-amino group of the Asp⁸ residue. The Lys⁹-Glu¹⁰ bond turned out to be very resistant to enzymatic attack both by Lys-C-endopeptidase and trypsin. The 9,10-seco-ET derivative could be obtained by treatment with Lys-C-endopeptidase only by using a high enzyme/ET ratio and after a prolonged incubation time. Cleavage of the Lys⁹-Glu¹⁰ bond could not be achieved by treatment with trypsin, even with a high enzyme/substrate ratio. The main product was 13, 14-seco-ET, deriving from the action of chymotripsin (present as an impurity in the trypsin preparation) on Tyr¹³. The structure of these peptides was confirmed by amino-acid sequence analysis and fast atom bombardment mass spectrometry (FAB-MS). Nicking of the ET structure at different positions had different impact on the biological properties of the resulting derivatives. © Munksgaard 1995.     

p53 OVEREXPRESSION AND HUMAN PAPILLOMAVIRUS INFECTION IN TRANSITIONAL CELL CARCINOMA OF THE URINARY BLADDER: CORRELATION WITH HISTOLOGICAL PARAMETERS

Seventy-nine transitional cell carcinomas (TCCs) of the urinary bladder (25 grade 1, 22 grade 2, and 32 grade 3 tumours) were examined for p53 overexpression by immunohistochemistry with a monoclonal antibody and for human papillomavirus (HPV) infection by the polymerase chain reaction (PCR). Positive immunostaining for p53 was detected in 40·5 per cent of the cases; the percentage of positive cases was significantly lower in low-grade (G1 and G2) TCCs than in high-grade (G3) tumours (10·6 per cent vs. 84·4 per cent; P <0·0001). The overall rate of HPV infection was 32·9 per cent; 20·3 per cent of the cases were positive for HPV 16, 3·8 per cent for HPV 18, and 8·9 per cent for both. Consensus primers as well as type-specific primers for HPV types 6, 11, and 33 failed to detect any additional case with HPV infection. The prevalence of HPV 16 and/or HPV 18 infection was significantly higher in low-grade than in high-grade tumours (44·7 per cent vs. 15·6 per cent; P =0·0061). p53-positive cases were more common among papillary, deeply infiltrating tumours, and HPV-positive cases among papillary, non-infiltrating lesions. According to these data, p53 overexpression and HPV 16/18 infection are common findings in bladder TCC and there appears to be an inverse correlation of p53 overexpression and of HPV infection with tumour aggressiveness. The possibility of different molecular pathways in superficial low-grade and in invasive high-grade tumours is suggested.     

Improvement of intraoperative somatosensory evoked potentials by ketamine

Many anaesthetics effect the latency and amplitude of somatosensory evoked potentials (SSEP). We present a patient who underwent two anterior/posterior spine fusions (A/PSF) at age 11 and 12 years old after resection of a spinal astrocytoma. She did have residual neurologic deficits of her lower extremities. SSEPs were unobtainable during the first surgery using an opioid-based anaesthetic. A ketamine-based anaesthetic was used for the second surgery and SSEPs were easily monitored. No other factors seem to have changed between the two surgeries. The anaesthetic management during each procedure is reviewed and the contributions of other factors to SSEP monitoring discussed.     

Blastomere Analysis: Issues for Discussion

There has been little professional discussion about the implications of blastomere analysis for genetic screening. In this article, some of the legal, ethical, and practical issues associated with the technology are identified. Issues are categorized as those involving availability and payment, phenotype selection, and imperfect genes. Nurses need to be knowledgeable about these issues to participate in the formation of policies governing the use of blastomere analysis and other genetic screening procedures.     

AV Pacing and LV Performance

Five patients with impaired left ventricular function (LV) and implanted AV sequential pacemakers underwent serial radionuclide angiograms. The goal was a non-invasive evaluation of the rapid changes in left ventricular performance elicited by rate, pacing mode and AV interval manipulation. End diastolic volume, end systolic volume, stroke volume and cardiac output were increased by AV sequential pacing in comparison with ventricular pacing at 70 beats per minute. No significant change in ejection fraction and blood pressure were noted with changing AV sequential pacing rates at usual pacing rates. Our data suggest that a short A V interval (150 ms) improved LV performance more than a long AV interval (250 ms). A non-invasive technique to optimize left ventricular performance on an acute basis by varying heart rate, AV interval and pacing mode with the implanted AV sequential pacemaker is feasible and may be useful in selective clinical situations.     

Clonal expansion of Vγ3/Vδ3-expressing γδ T cells in an HIV-1/2-negative patient with CD4 T-cell deficiency

Immunological investigations were carried out in an HIV-1/2//HTLV-1-negative patient with CD4 T-cell deficiency (0.357–0.6 × 10⁹/l) and expansion of γδ T cells which accounted for 26–42% of peripheral blood lymphocytes during an observation period of 3 years. Flow cytometry analyses with a panel of available Vγ/Vδ-specific monoclonal antibodies indicated that the pathologically expanded γδ population expressed Vγ2 or Vγ3 paired with Vδ3 on the surface but lacked the expression of activation antigens such as CD38 or CD71. Cloning and sequencing of RT-PCR products obtained after amplification of cDNA with Vγ-Cγ and Vδ-Cδ specific primers confirmed the presence of a clonally expanded Vγ3/Vδ3 population in the peripheral blood of this patient. Cytotoxicity assays performed with purified γδ T cells as effectors and resting or preactivated autologous CD4 T cells as targets failed to reveal evidence for autoreactive cytotoxicity of Vγ3/Vδ3 cells as a possible mechanism of CD4 T-cell deficiency in this patient.     

Use of Food Quotients in Human Doubly Labeled Water Studies: Comparable Results Obtained with 4 Widely Used Food Intake Methods

Information on the macronutrient composition of the diet is needed in doubly labeled water studies to convert measured rates of carbon dioxide production into values for total energy expenditure. There is no general consensus, however, about the best method to determine food intake for this purpose. Four common methods of measuring food intake (7-day weighed food intake, 24-hour recall, and Fred Hutchinson Cancer Research Center/Block and Willett food frequency questionnaires) were tested for their ability to provide comparable food quotient and total energy expenditure data in doubly labeled water studies in 10 young and 10 older women. All methods gave mean values for total energy expenditure that were within 1% of each other. Individual values obtained using the 24-hour recall and food frequency questionnaires were within ±3% (standard deviation) of values determined using data from the 7-day weighed food record. These results suggest that it is not necessary to use time-consuming and expensive 7-day food records in doubly labeled water studies; instead, food intake data obtained more easily by 24-hour recall or food frequency questionnaire can provide comparable data. J Am Diet Assoc. 1998;98:1015-1020.