The Effects of Systemic Hypoxia on Colon Anastomotic Healing: An Animal Model

PURPOSE Acute postoperative systemic hypoxia occurs frequently in the clinical setting following intestinal resection, as a result of complications such as pneumonia, pulmonary edema, or the acute respiratory distress syndrome. Although it is well established that oxygen is essential for metabolism in general and intestinal anastomotic healing, the mechanisms by which systemic hypoxia affect this process are not clear. The purpose of this study was to establish an animal model to simulate acute systemic hypoxia and to examine the effects on anastomotic healing. We investigated the hypothesis that systemic hypoxia impairs anastomotic healing in the colon by disrupting revascularization via changes in the expression of two putative angiogenic factors: inducible nitric oxide synthase and vascular endothelial growth factor.METHODS Phase I: Juvenile male Sprague–Dawley rats underwent carotid artery cannulation. In a controlled environment the FiO₂ was incrementally decreased from 21 to 9 percent and the resultant PaO₂ measured. Phase II: Animals underwent colonic transection with immediate reanastomosis and were placed in either a normoxic (FiO₂ 21 percent) or hypoxic (FiO₂ 11 percent) environment for seven days. Perianastomotic in vivo tissue oxygen saturation was measured before segmental colon resection in each of the animals and at seven days before measurement of anastomotic bursting pressure. Perianastomotic tissue samples were assessed by Western blot assay for the expression of vascular endothelial growth factor and inducible nitric oxide synthase protein. Sections from each tissue sample were taken and evaluated by a pathologist blinded to treatment group for determination of anastomotic healing score.RESULTS Phase I: Incrementally decreasing the FiO₂ resulted in a progressive decrease in PaO₂ (r ² = 0.77). Phase II: Animals maintained in a hypoxic environment had a significant decrease in tissue oxygen saturation (73 ± 9 percent vs. 94 ± 3 percent; P < 0.0001) and anastomotic bursting pressure (118 ± 18 mmHg vs. 207 ± 30 mmHg; P < 0.0001) compared with normoxic controls. Systemic hypoxia induced a significant increase, when compared with normoxic controls, in vascular endothelial growth factor (247.1 ± 9.5 vs. 142.2 ± 10.6; P < 0.0001) and inducible nitric oxide synthase (259.6 ± 21.1 vs. 120.2 ± 10.9; P < 0.0001) protein expression and led to a significant decrease in the overall wound-healing score.CONCLUSION This study validates a new animal model to study the effects of acute systemic hypoxia on colonic anastomotic healing. In this model, systemic hypoxia directly translated into local tissue hypoxia, and anastomotic healing was impaired. Contrary to our original hypothesis, hypoxia led to a significant increase in vascular endothelial growth factor and inducible nitric oxide synthase protein expression at the colonic anastomotic site. Impairment in anastomotic integrity despite upregulation of these angiogenic factors could be a result of the inability of wounded tissue to respond to vascular endothelial growth factor and inducible nitric oxide synthase or alternatively, hypoxia may adversely affect collagen synthesis and deposition directly.Supported by Alberta Children’s Hospital Research Foundation.Presented in part at the meeting of The American Society of Colon and Rectal Surgeons in New Orleans, Louisiana, June 21 to 26, 2003.Reprint requests to: David L. Sigalet, M.D., Ph.D., FRCSC, Department of Surgery, Room 1746, Health Sciences Centre, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 2T9.     

The potential effectiveness of warning labels on cigarette packages: the perceptions of young adult Canadians

BACKGROUND: Since 1989 when health warning labels appeared on Canadian cigarette packages, the labels have changed from text only covering less than one quarter of the package to text and graphics covering over half the package. This study examines how Canadians in their 20s feel about the current graphic warning labels and their potential to prevent smoking and encourage quitting. METHODS: Participants between 20 and 24 years of age were part of a 10-year cohort study begun when the group was in Grade 6, with the purpose of examining factors that may affect smoking. Five questions about warning labels were added to the 2002 questionnaire requesting information on perceptions of the labels and their potential impact on smoking behaviours of young adults. One item had been included in previous questionnaires. RESULTS: 32.8% (n = 1267) of the respondents were smokers, with males (35.6%) being more likely to smoke than females (30.4%). Current smokers were less likely than experimental/ex-smokers to believe that warning labels with stronger messages would make people their age less likely to smoke. Female current smokers were more likely to think about quitting. CONCLUSION: Despite the efforts taken in developing the labels, some young adults are skeptical about their effects. Warning labels may have to be modified to target issues that are relevant to young adults; gender differences are important in this modification. Warning labels can offer an additional component to a comprehensive tobacco control program, in that they provide health information.     

Viability analysis of alginate encapsulated micro-organisms using fluorescent stains

The encapsulation of micro-organisms such as bacteria and fungi in biopolymers is currently being evaluated as delivery systems in many fields. Information about the viability and morphology of the organisms in the microparticle is often required to ascertain the longevity of the systems. A rapid method using fluorescent stains for microbial viability has been validated for organisms within alginate microparticles. Usually viability is assessed by dissolving the microparticles and cell culturing. This new method is advantageous for slow growing or filamentous organisms because these are not quickly or accurately enumerated by plate counts. In addition, the technique also allows the morphology of the organism to be monitored over time.     

Spindle cell metaplasia of the thyroid arising in association with papillary carcinoma and follicular adenoma

Spindle cell proliferations of the thyroid have been described in association with reactive processes and aggressive malignant neoplasms. We describe spindle cell proliferations in 10 patients arising in association with papillary carcinoma and follicular adenoma. The spindle proliferations were 0.3 to 3.0 cm in size, constituted from 1% to 95% of the primary neoplasm, and were either admixed with the neoplastic elements or peripherally located within the primary tumor Cytologically, these proliferations showed bland-appearing spindle cells with fine chromatin and subtle nucleoli. Mitoses were rare, and inflammation was minimal. Immunostains showed reactivity with thyroglobulin, indicating their follicular origin. We believe it is important to recognize these metaplastic proliferations and distinguish them from aggressive malignant neoplasms.     

Cat-scratch disease relapse in a kidney transplant recipient

Cat-scratch disease, an infectious illness infrequently reported in kidney transplant patients, is caused by the organism Bartonella henselae and is transmitted through contact with cats or kittens. It is a self-limited disorder in the general pediatric population. Here we present a case of unsuspected cat-scratch disease in a pediatric kidney transplant patient who presented with fever and lymphadenopathy. Eight months after treatment with a short course of azithromycin, the patient developed a recurrence of cat-scratch disease. We emphasize that the evaluation of a young immunocompromised kidney transplant patient presenting with fever and lymphadenopathy should include unusual infections such as cat-scratch disease. We review the diagnosis and treatment of this uncommon infection in the organ transplant population.     

An assessment of gait analysis in the rehabilitation of children with walking difficulties

Purpose: To assess the current status of computerized gait analysis techniques in the management of children with cerebral palsy or spina bifida who have significant walking disorders. Method: Synthesis of available data from a review of the literature, drawing on MEDLINE, EMBASE, PRE-MEDLINE, HealthStar and PsychInfo. Other information was obtained from persons with expertise in computerized gait analysis. Cost data were obtained from Canadian rehabilitation centres and the provincial health ministry. Results: This technology seems helpful in detecting gait changes. However, available evidence is insufficient to draw conclusions about the influence of computerized gait analysis on treatment outcomes. Part of the rationale for use of the technology is that costs of gait analysis (of the order of $CAN 2,000 per examination) would be offset by a decrease in followup surgical procedures and associated hospital care. There could also be a major influence on children's independence and quality of life. However, there are as yet no convincing data to support these propositions. Conclusions: Computerized gait analysis is a potentially useful technology in the management of children with walking disabilities, but its efficacy is not established. It should be regarded as a developing technology and its clinical application linked to systematic collection and assessment of outcomes data.     

Replacing Emulsifier in a Prebiotic Ice Cream: Physical and Chemical Evaluation and Acceptance

Consumers are very interested in the development of new food products, which presents sensorial, nutritional, and physicochemical quality. Thus, this study aimed to evaluate the addition of chia seed mucilage as an emulsifier substitute on the physical and chemical characteristics and on acceptance of chocolate-flavored prebiotic ice cream (with inulin). The ice creams had good physicochemical characteristics: The sample with the lowest mucilage content (0.6 g/100 g) showed higher resistance to melting, however, showed less overrun. Ice creams with higher concentrations of mucilage (1.2 or 1.8 g/100 g) had higher overrun. All ice creams had scores between 6 and 7 in the evaluated attributes, indicating that consumers liked slightly to moderately. The fatty acid composition of the mucilage was predominantly polyunsaturated fatty acids. It can be concluded that it is possible to develop prebiotic ice cream with chia seed mucilage as an emulsifier that have appropriate chemical composition and acceptance.     

Care providers’ views and experiences of postnatal care in private hospitals in Victoria,Australia

Objectivein Australia, as in other developed countries, women have consistently reported lower levels of satisfaction with postnatal care compared with antenatal and intrapartum care. However, in Victoria Australia, women who receive private hospital postnatal care have rated their care more favourably than women who received public hospital care. This study aimed to gain a further understanding of this by exploring care providers’ views and experiences of postnatal care in private hospitals.Designqualitative design using semi-structured interviews and thematic analysis.Settingprivate maternity hospitals in Victoria, Australia.Participantseleven health-care providers from three metropolitan and one regional private hospital including eight midwives (two maternity unit managers and six clinical midwives) and three obstetricians.Findingstwo global themes were identified: ‘Constrained Care’ and ‘Consumer Care’. ‘Constrained care’ demonstrates the complexity of the provision of postnatal care and encompasses midwives’ feelings of frustration with the provision of postnatal care in a busy environment complicated by staffing difficulties, a lack of continuity and the impact of key players in postnatal care (including visitors, management and obstetricians). ‘Consumer care’ describes care providers’ views that women often approach private postnatal care as a consumer, which can impact on their expectations and satisfaction with postnatal care. Despite these challenges, care providers, particularly midwives, highly valued (and generally enjoyed working in) postnatal care.Key conclusionsthis study, along with other Australian and international studies, has identified that hospital postnatal care is complex and characterised by multiple barriers which impact on the provision of quality postnatal care. Further research is needed to evaluate routine postnatal practices and continuity of care within the postnatal period. In-depth qualitative studies investigating women's expectations and experiences of postnatal care in both the public and private sector are also needed.