Water Birth and Perinatal Outcomes in British Columbia: A Retrospective Cohort Study.

OBJECTIVE: This study aimed to quantify adverse neonatal outcomes in a cohort of registered midwife (RM)-attended conventional and water births in British Columbia. METHODS: The study included all term singleton births in British Columbia between January 1, 2005 and March 31, 2016 attended by RMs. Births were allocated to a conventional birth cohort or a water birth cohort according to where the actual birth of the neonate took place. The primary outcome was a composite adverse neonatal outcome (Apgar <7 at 5 minutes, resuscitation need, neonatal intensive care unit admission). Secondary outcomes included individual components of the primary outcome, maternal length of labour, and degree of perineal laceration (Canadian Task Force Classification Level II-2). RESULTS: The population included 25 798 births. Of these, 23 201 were conventional, and 2567 were water births. The rate of the composite adverse neonatal outcome was not higher in water births compared with conventional births (hospital conventional, 5.0%; hospital water, 4.2%; home conventional, 3.4%; and home water, 2.9%). Rates of individual components of the composite adverse neonatal score were not greater in the water birth cohort. Maternal outcomes included statistically shorter labours in the water birth cohort and no difference between the cohorts in incidence of third- and fourth-degree lacerations. CONCLUSION: Water births attended by RMs in British Columbia are not associated with higher rates of adverse neonatal outcomes than conventional births attended by midwives.

Epidemiologic assessment of mortality, building collapse pattern, and medical response after the 1992 earthquake in Turkey. Disaster Reanimatology Study Group (DRSG).

BACKGROUND: Post-earthquake engineering and epidemiologic assessments are important for the development of injury prevention strategies. This paper describes mortality and its relationship to building collapse patterns and initial medical responses following the 1992 earthquake in Erzincan, Turkey. METHODS: The study consisted of: 1) background data collection and review; 2) design and implementation of a field survey; and 3) site inspection of building collapse patterns. The survey included: 1) national (n = 11) and local (n = 17) officials; 2) medical and search and rescue (SAR) workers (n = 38); and 3) a geographically stratified random sample of lay survivors (n = 105). The survey instruments were designed to gather information regarding location, injuries, initial actions and prior training of survivors and responders, and the location, injuries, and management of dead and dying victims. A case-control design was constructed to assess the relationship between mortality, location, and building collapse pattern. RESULTS: There was extensive structural damage throughout the region, especially in the city where mid-rise, unreinforced masonry buildings (MUMBs) incorporating a "soft" first floor design (large store windows for commercial use) and one story adobe structures were most vulnerable to collapse. Of 526 people who died in the city, 87% (n = 456) were indoors at the time of the earthquake. Of these, 92% (n = 418) died in MUMBs. Of 54 witnessed deaths, 55% (n = 28) of victims died slowly, the majority of whom (n = 26) were pinned or trapped (p < 0.05). Of 42 MUMB occupants identified through the survey, those who died (n = 25) were more likely to have been occupying the ground floor when compared with survivors (n = 28) (p < 0.01). Official medical and search and rescue responders arrived after most deaths had occurred. Prior first-aid or rescue training of lay, uninjured survivors was associated with a higher likelihood of rescuing and resuscitating others (p < 0.001). CONCLUSIONS: During an earthquake, MUMBs with soft ground floor construction are highly lethal, especially for occupants on the the ground floor, suggesting that this building type is inappropriate for areas of seismic risk. The vulnerability of MUMBs appears due to a lack of lateral force resistance as a result of the use of glass store front windows and the absence of shear walls. The prevalence of this building type in earthquake-prone regions needs to be investigated further. A large portion of victims dying in an earthquake die slowly at the scene of injury. Prior public first-aid and rescue training programs increase participation in rescue efforts in major earthquakes and may improve survival.

The BALB/c mouse B-cell response to pigeon cytochrome c initiates as a heteroclitic response specific for the self antigen mouse cytochrome c.

Direct evidence is presented in support of the longstanding but unproven hypothesis that B lymphocytes specific for self antigens (Ags) can be used in the immune response to foreign Ags. We show that the B cells in BALB/c mic responding early to pigeon cytochrome c (CYT) produce antibodies that recognize and bind the major antigenic site on mouse CYT with greater affinity than they bind pigeon CYT i.e., they are heteroclitic for the self Ag. Furthermore, these B cells express the same combination of immunoglobulin variable region (V) genes that are known to be used in B-cell recognition of mouse CYT. Over time, the response to pigeon CYT becomes more specific for the foreign Ag through the recruitment of B cells expressing different combinations of V genes and, possibly, somatic mutation of the mouse CYT specific B cells from early in the response. Cross-recognition of pigeon CYT by mouse CYT-specific B cells results from the sharing of critical amino acid residues by the two Ags. Although B-cell recognition of the self Ag, mouse CYT, is very specific, which limits the extent to which foreign Ags can cross-activate the autoreactive B cells, it is possible that polyreactive B cells to other self Ags may be used more frequently in response to foreign Ags.