Making the links between community structure and individual well-being: community quality of life in Riverdale, Toronto, Canada.

An inquiry into community quality of life was carried out within a framework that recognizes the complex relationship between community structures and individual well-being. Through use of focus groups and key informant interviews, community members, service providers, and elected representatives in a Toronto community considered aspects of their community that affected quality of life. Community members identified strengths of access to amenities, caring and concerned people, community agencies, low-cost housing, and public transportation. Service providers and elected representatives recognized diversity, community agencies and resources, and presence of culturally relevant food stores and services as strengths. At one level, findings were consistent with emerging concepts of social capital. At another level, threats to the community were considered in relation to the hypothesized role neo-liberalism plays in weakening the welfare state.

Gender differences in changes in subcutaneous and intra-abdominal fat during weight reduction: an ultrasound study.

OBJECTIVE: In weight-reducing programs, men usually display greater improvement in metabolic risk factors than women. This gender difference may be related to enhanced weight and fat loss due to a greater energy deficit in men. To clarify the relationship between changes in metabolic profile, body fat composition, and weight loss, both sexes were studied under a regimen in which similar amounts of weight were lost. RESEARCH METHODS AND PROCEDURES: A cross-sectional study using anthropometric (body mass index and waist-to-hip ratio), impedance (bioelectrical impedance analysis) and ultrasound measurement methods (thickness of subcutaneous fat layers, intra-abdominal sagittal diameter) were conducted. The metabolic risk profile was determined by measuring lipids, lipoproteins, and blood pressure. The weight loss program lasted 15 weeks: 3 weeks under controlled conditions in the hospital and 12 weeks on an ambulatory basis. Patients were instructed to follow a mixed diet. Calorie intake was restricted to 1500 kcal/day for the men and 1200 kcal/day for the women. Thirty-two subjects with obesity (16 men and 16 women), with a mean body mass index of 35 kg/m2--matched with regard to age, height, and body weight--took part in the study. RESULTS: As expected, weight loss was similar for both sexes (-13.4 kg vs. -12.8 kg). Also, body fat mass changed to the same extent in absolute and relative terms. The waist-to-hip ratio was identical before and after treatment in both sexes. The men lost more visceral fat than the women. This result is based on changes in intra-abdominal diameter as well as abdominal subcutaneous fat in relation to waist circumference. Changes in abdominal diameter were paralleled by reductions in triglycerides and increases in high-density lipoprotein-cholesterol. Subcutaneous fat loss was more pronounced in women than in men. DISCUSSION: Where absolute and relative reductions in body weight and body fat are similar, men mobilize more intra-abdominal fat than women, whereas women lose more subcutaneous fat. The greater reduction in intra-abdominal fat seen in men is accompanied by a more pronounced improvement in the metabolic risk profile. Therefore, greater improvement of risk factors in men is not only related to a greater negative energy balance, as shown in most studies, but is also sex-specific.

Recombinant tissue plasminogen activator in cases with fibrin formation after cataract surgery: a prospective randomised multicentre study.

AIMS: This study investigated the effect of tissue plasminogen activator (tPA) in patients with severe intracameral fibrin after extracapsular cataract extraction or phacoemulsification with posterior chamber intraocular lens implantation. METHODS: A randomised prospective multicentre study was carried out in 86 patients with intraocular fibrin formation 2-8 days after cataract surgery. While the first group (n = 41) received only anti-inflammatory drugs, a single anterior chamber injection of tPA (10 micrograms) as an additional treatment to the standard was given in the second group (n = 44). On days 1, 2, 14, and 90 after randomisation, the visual acuities, slit lamp findings, and intraocular pressures were documented in standardised protocols. Efficacy of treatment was judged by the rate of fibrinolysis (primary objective), the frequency of synechiae, and central capsular fibrosis (secondary objectives). RESULTS: The incidence and quantity of intraocular fibrin were significantly lower in the patients treated with tPA than in the control group (p < 0.05). The frequencies of synechiae were reduced by tPA injection. The capsule fibrosis noted after 3 months was significantly lower in the tPA group (p = 0.027). No ocular side effects were noted after the tPA injections. CONCLUSIONS: Lysis of postcataract fibrin formation is accelerated and increased by a single intracameral injection of 10 micrograms tPA in addition to standard anti-inflammatory treatment. The findings suggest that the tPA injection reduces posterior capsule fibrosis, which still has to be addressed in larger study populations and with a long term follow up.

Using a breastfeeding prevalence survey to identify a population for targeted programs.

Often, efforts to improve overall population health require identifying and targeting programs to specific high-risk populations. Breastfeeding is an example. In order to determine initiation and duration rates among various groups in the City of Toronto, a random sample of 434 mothers with infants at four months of age was surveyed to determine the prevalence of breastfeeding and major impacts on its duration. The study found that, overall, 83% of mothers initiated breastfeeding at birth. The greatest rate of decline occurred during the first month. At four months postpartum, 57% of mothers continued to breastfeed, including 35% who were exclusively breastfeeding and 22% who were supplementing breast milk with formula. Breastfeeding duration was related to a number of factors, including information and support, parity, education, use of formula supplements and country of birth. Specific groups are identified for targeted programs, and a number of strategies are proposed.

Type-1 insulin-like growth factor receptor overexpression produces dual effects on myoblast proliferation and differentiation.

Using a retroviral vector, we developed a line of C2 mouse skeletal myoblasts, C2-LISN, which expressed high levels of the human type-1 insulin-like growth factor (IGF) receptor. When switched to low serum medium, C2-LISN myoblasts underwent terminal differentiation extremely rapidly compared to control C2 myoblasts. In high serum conditions which were not permissive for differentiation, C2-LISN myoblasts expressed ten-fold higher levels of the myogenic transcription factor myogenin than did control C2 myoblasts. When cultured in low serum medium with both transforming growth factor-beta (TGF-beta) and high concentrations of IGF-I, C2-LISN myoblasts failed to differentiate and grew to very high saturation densities, forming multilayers. Upon removal of TGF-beta, multilayered C2-LISN myoblasts differentiated within 2 days. These results demonstrate that overexpression of the type-1 IGF receptor can amplify signals which stimulate myogenic differentiation. Overexpressed type-1 IGF receptors can also mediate strong mitogenic signals if differentiation is inhibited by TGF-beta. The C2-LISN myoblast cell line may be a useful model to investigate the intracellular pathways which stimulate myogenic differentiation. Additionally, overexpression of the type-1 IGF receptor could provide a strategy to expand populations of differentiation-competent myoblasts for experimental or clinical applications.

Ligand-dependent inhibition of myoblast differentiation by overexpression of the type-1 insulin-like growth factor receptor.

The insulin-like growth factors (IGFs) have paradoxical effects on skeletal myoblast differentiation. While low concentrations of IGF stimulate myoblast differentiation, high concentrations of IGF induce a progressive decrease in myoblast differentiation. The mechanism of this inhibition is unknown. Using a retroviral expression vector, we developed a subline of mouse P2 mouse myoblasts (P2-LISN) which expressed 7.5 times higher levels of type-1 IGF receptors than control (P2-LNL6) myoblasts, which were infected with a virus lacking the type-1 IGF receptor sequence. Overexpression of the type-1 IGF receptor caused the IGF dose-response curves of stimulation and progressive inhibition of differentiation to shift to the left. Additionally, at high insulin and IGF-I concentrations, complete inhibition of P2-LISN myoblast differentiation occurred. These results suggest that inhibition of differentiation at high ligand concentrations was not due to the primary involvement of other species of receptors for IGF. Type-1 IGF receptor downregulation as a mechanism for inhibition of differentiation was also ruled out since P2-LISN myoblasts constitutively expressed high levels of type-1 IGF receptors. Additionally, inhibition of differentiation at high concentrations of IGF-I was not correlated with overt stimulation of proliferation or with IGF binding protein (IGF-BP) release into the culture medium. These results indicate that the type-1 IGF receptor mediates two conflicting signal pathways in myogenic cells, differentiation-inducing and differentiation-inhibitory, which predominate at different ligand concentrations.

Emergency thoracotomy: survival correlates with physiologic status.

Emergency thoracotomy is a standard procedure in the management of cardiac arrest in patients sustaining severe trauma. We examined the records of 463 moribund trauma patients treated at our institution from 1980 to 1990 to refine indications for emergency thoracotomy. Patients underwent thoracotomy either in the emergency department (ED) (n = 424) or in the operating room (OR) (n = 39) as a component of continuing resuscitation after hospital arrival. The survival rate was 13% (61 of 463) overall, 2% (3 of 193) for blunt, 22% (58 of 269) for all penetrating, 8% (10 of 131) for gunshot, 34% (48 of 141) for stab-wound patients, and 54% (21 of 39) for patients who underwent emergency thoracotomy in the OR. Survival correlated with the physiologic status of patients both on initial evaluation in the field by paramedics and on arrival at the ED. Patients with penetrating trauma and in profound shock (BP less than 60 mm Hg) or mild shock (BP 60-90 mm Hg) with subsequent cardiac arrest had survival rates of 64% (27 of 42) and 56% (30 of 54), respectively. None of the patients with absent signs of life, defined as full cardiopulmonary arrest with absent reflexes (n = 215), on initial assessment by paramedics in the field, survived. We conclude that (1) no emergency thoracotomy should be performed if no signs of life are present on the initial prehospital field assessment; (2) emergency thoracotomy is an indicated procedure in most patients sustaining penetrating trauma; (3) blunt traumatic cardiac arrest is a relative contraindication to emergency thoracotomy.