Pain, Analgesic Use, and Patient Satisfaction With Spinal Versus General Anesthesia for Hip Fracture Surgery : A Randomized Clinical Trial

BACKGROUND

The REGAIN (Regional versus General Anesthesia for Promoting Independence after Hip Fracture) trial found similar ambulation and survival at 60 days with spinal versus general anesthesia for hip fracture surgery. Trial outcomes evaluating pain, prescription analgesic use, and patient satisfaction have not yet been reported.

OBJECTIVE

To compare pain, analgesic use, and satisfaction after hip fracture surgery with spinal versus general anesthesia.

DESIGN

Preplanned secondary analysis of a pragmatic randomized trial. (ClinicalTrials.gov: NCT02507505).

SETTING

46 U.S. and Canadian hospitals.

PARTICIPANTS

Patients aged 50 years or older undergoing hip fracture surgery.

INTERVENTION

Spinal or general anesthesia.

MEASUREMENTS

Pain on postoperative days 1 through 3; 60-, 180-, and 365-day pain and prescription analgesic use; and satisfaction with care.

RESULTS

A total of 1600 patients were enrolled. The average age was 78 years, and 77% were women. A total of 73.5% (1050 of 1428) of patients reported severe pain during the first 24 hours after surgery. Worst pain over the first 24 hours after surgery was greater with spinal anesthesia (rated from 0 [no pain] to 10 [worst pain imaginable]; mean difference, 0.40 [95% CI, 0.12 to 0.68]). Pain did not differ across groups at other time points. Prescription analgesic use at 60 days occurred in 25% (141 of 563) and 18.8% (108 of 574) of patients assigned to spinal and general anesthesia, respectively (relative risk, 1.33 [CI, 1.06 to 1.65]). Satisfaction was similar across groups.

LIMITATION

Missing outcome data and multiple outcomes assessed.

CONCLUSION

Severe pain is common after hip fracture. Spinal anesthesia was associated with more pain in the first 24 hours after surgery and more prescription analgesic use at 60 days compared with general anesthesia.

PRIMARY FUNDING SOURCE

Patient-Centered Outcomes Research Institute.

Intramedullary Nailing of Open Tibial Fractures: Provisional Plate Fixation

Tibia fracture is the most common type of long bone fracture, and intramedullary nailing is the preferred treatment. In open fractures, a provisional plate is often used to maintain reduction. It is unknown whether this practice increases the risk of infection or other complications. This study retrospectively compared patients who were treated at a level 1 trauma center with intramedullary nailing of an open tibia fracture. Patients who were included: (1) were 18 years or older; (2) were treated between January 1, 2005, and June 30, 2013; (3) had an open fracture of the tibia; and (4) were treated operatively with intramedullary nailing, with or without provisional plate fixation. Patient sex, history of diabetes, history of smoking, mechanism of injury, and side of injury were analyzed. Postoperative complications included infection, delayed union or non-union, compartment syndrome, and death. After the authors controlled for age, Gustilo-Anderson type, and AO/Orthopaedic Trauma Association classification, they found that provisional plate use did not significantly increase the risk of infection (adjusted odds ratio, 1.64; 95% confidence interval, 0.51-5.32; P=.41) or any other complications (adjusted odds ratio, 1.24; 95% confidence interval, 0.46-3.35; P=.67). In the subgroup of patients who had a provisional plate (n=35), removal of the plate did not significantly decrease the risk of infection (adjusted odds ratio, 0.43; 95% confidence interval, 0.07-2.69; P=.36) or other complications (adjusted odds ratio, 0.55; 95% confidence interval, 0.12-2.46; P=.44). In open tibia fractures treated with intramedullary nailing, provisional plate stabilization, a valuable reduction aid, did not increase the risk of infection or other complications. Because of the small subgroup size, however, definitive conclusions cannot be drawn about removal of these provisional plates. [Orthopedics. 2016; 39(5):e931-e936.].

[Phantom studies using a high-resolution CT for ex-vivo imaging of degradable magnesium implants and simulated peri-implant bone formation in rabbit tibiae]

PURPOSE

Evaluation of the suitability of the high-resolution CT XtremeCT for ex vivo imaging of degradable magnesium implants with simulated peri-implant bone formation in rabbit tibiae and development of a method for calibrating the mass concentration of a magnesium alloy in an implant volume.

MATERIALS AND METHODS

Using specially designed phantoms, degradable magnesium implants of the alloys LAE442, ZEK100, AX30 and MgCa 0.8 %, without coating and with peri-implant bone formation simulated by a coating, as well as rabbit tibiae were scanned. CT numbers and the contrast-to-noise-ratio (CNR) of the studied materials were determined. The visual distinction between implant and coating was evaluated. To calibrate the implant density, exemplary LAE442 pins with different mass concentrations were scanned using a specially constructed phantom. Subsequently, CT numbers corresponding to the appropriate mass concentration were determined.

RESULTS

The implants, coating and substantia corticalis showed a similar density. Visual distinction between coating and implant was strongly dependent on the respective magnesium alloy and chosen scan parameter. A CNR of at least 0.2 was required for a distinction between implant and coating. For the mass concentration, a high CT number linearity (R2=0.99) throughout the measuring range (1811-1273 mg/cm3 LAE442) was found.

CONCLUSION

As expected, the XtremeCT is primarily suitable for the imaging of bone tissue and implants. Good visual distinction of peri-implant bone formation on magnesium implants in an ex vivo phantom model ranges from possible to difficult depending on the bone density and alloy composition.

Development of a statewide collaborative to decrease NICU central line-associated bloodstream infections

OBJECTIVE

To characterize hospital-acquired bloodstream infection rates among New York State's 19 regional referral NICUs (at regional perinatal centers; RPCs) and develop strategies to promote best practices to reduce central line-associated bloodstream infections (CLABSIs).

STUDY DESIGN

During 2006 and 2007, RPC NICUs reported bloodstream infections, patient-days and central line-days to the Department of Health, and shared their results. Aiming to improve, participants created a central line-care bundle based on visiting a potentially best performing NICU and reviewing the literature.

RESULT

All 19 RPCs participated in this quality initiative, contributing 218,096 patient-days and 56,911 central line-days of observation. Individual RPC nosocomial sepsis infection (NI) rates ranged from 1.0 to 5.8 NIs per 1000 patient-days (2006), and CLABSI rates ranged from 2.6 to 15.1 CLABSIs per 1000 central line-days (2007). A six-fold rate variation among RPC NICUs was observed. Participants unanimously approved a level-1 evidence-based central line-care bundle.

CONCLUSION

Individual RPC rates and consequent morbidity and resource use attributable to these infections were substantial and varied greatly. No center was without infections. It is hoped that the cooperation and accountability exhibited by the RPCs will result in a major network for characterizing performance and improving outcomes.

Initiating delivery room stabilization/resuscitation in very low birth weight (VLBW) infants with an FiO(2) less than 100% is feasible

BACKGROUND

Oxygen exposure during delivery room (DR) resuscitation, even when brief, is potentially toxic. A practice plan (PP) was introduced for very low birth weight (VLBW) infants < or = 1500 g as follows: initial FiO(2) from 0.21 to 1.0 using blenders, oxygen guided by oximetry to maintain saturation between 85% to 95% from birth.

OBJECTIVE

To determine whether the initiating FiO(2) could be safely lowered, and by doing so whether the number of infants with a PaO(2) >80 mm Hg could be minimized on admission, as well as lowering oxygen requirement at 24 h.

METHODS

In all, 53 infants admitted between June 2006 and June 2007 were evaluated and compared with 47 infants from 2004 managed with 100 % oxygen (historical comparison group (HC)).

RESULT

Stabilization/Resuscitation included intubation (n=28) and continuous positive airway pressure (CPAP) (n=25); no cardiopulmonary resuscitation (CPR). The heart rate increased rapidly in all cases. The initiating FiO(2) decreased from 0.42 to 0.28 over 12 months (P=0.00005); 14 (26%) were resuscitated with room air. Correspondingly, the pH increased from 7.24 to 7.30 (P=0.002) and PCO(2) decreased from 53 to 41 (P=0.001). A comparison of infants during the PP with the HC revealed that 36/53 versus 21/47 had an initial PaO(2) <80 mm Hg (P=0.02); the median PaO(2), that is, 64 versus 86 and saturation, that is, 95% versus 99% on admission were significantly lower. The median FiO(2) at 24 h was 0.25 versus 0.40.

CONCLUSION

DR resuscitation of VLBW infants can be initiated with less oxygen even with room air without concomitant overt morbidity. This change was associated with more infants with an initial PaO(2) <80 mm Hg and lower saturation values on admission as well as a lower FiO(2) requirement at 24 h.

Studying determinants of length of hospital stay

Clinicians are accustomed to focusing on individual patients. However, when studying how long their patients stay in the hospital, the focus must widen. Length of stay summarizes the performance of the entire, exceedingly complex, NICU system. Ordinary statistical methods for modeling patient outcomes assume that what happens to one patient is unrelated to what happens to another. However, patients in the same NICU are exposed to similar hospital practices, so patient outcomes may be correlated. Length of stay data must be analyzed by methods that account for possibly correlated outcomes. In addition, to improve patient care and outcomes, predictive models must include determinants clinicians can influence. Such variables describe care process exposures, available beds, demand for beds, and staffing levels.

Neuropsychiatric thalamocortical dysrhythmia: surgical implications

Clearly, more clinical experience must be amassed to define in detail the possibilities of this surgical approach in disabling neuropsychiatric disorders. We propose, however, that the evidence for benign and efficient surgical intervention against the neuropsychiatric TCD syndrome is already compelling. The potential appearance of strong postoperative reactive manifestations requires a close association between surgery and psychotherapy, with the latter providing support for the integration of the new situation as well as the resolution of old unresolved issues.

State level estimates of the incidence and economic burden of head injuries stemming from non-universal use of bicycle helmets

OBJECTIVE

To develop national and state level estimates for preventable bicycle related head injuries (BRHIs) and associated direct and indirect health costs from the failure to use bicycle helmets.

METHODS

Information on the effectiveness and prevalence of use of bicycle helmets was combined to estimate the avoidable fraction, that is, the proportion of BRHIs that could be prevented through the use of bicycle helmets. The avoidable fraction multiplied by the expected number of BRHIs gives an estimate of the number of preventable cases. Direct and indirect health costs are estimated from a social perspective for the number of preventable BRHIs to assess potential cost savings that would be achieved if all riders wore helmets.

RESULTS

Approximately 107,000 BRHIs could have been prevented in 1997 in the United States. These preventable injuries and deaths represent an estimated $81 million in direct and $2.3 billion in indirect health costs. Estimates range from 200 preventable BRHIs and $3 million in health costs in Wyoming (population 480,000) to 13,700 preventable BRHIs and $320 million in health costs in California (population 32.3 million).

CONCLUSIONS

A number of successful approaches to increasing bicycle helmet use exist, including mandatory use laws and community based programs. The limited use of these strategies may be related to the fact that too little information is available to state agencies about the public health and economic burden of these preventable injuries. In conjunction with information on program costs, our estimates can assist state planners in better quantifying the number of preventable BRHIs and the costs and benefits of helmet promotion programs.

Second-generation microstimulator

The first-generation injectable microstimulator was glass encased with an external tantalum capacitor electrode. This second-generation device uses a hermetically sealed ceramic case with platinum electrodes. Zener diodes protect the electronics from defibrillation shocks and from electrostatic discharge. The capacitor is sealed inside the case so that it cannot be inadvertently damaged by surgical instruments. This microstimulator, referred to as BION, is the main component of a 255-channel wireless stimulating system. BION devices have been implanted in rats for periods of up to 5 months. Results show benign tissue reactions resulting in identical encapsulation around BION and controls. Stimulation threshold levels did not change significantly over time and ranged between 0.81 to 1.35 mA for all the animals at a 60 micros pulse width. All of the tests performed to date indicate that the BION is safe and effective for long-term human implant. We have elected to develop BION applications by seeking collaboration with the research community through our BION Technology Partnership.

Early-stage breast cancer treatment among medically underserved women diagnosed in a national screening program, 1992-1995

BACKGROUND

Little research has been conducted on the breast cancer treatment of low income, underserved women. This study was designed to describe initial treatment of breast cancer among low-income women diagnosed through federally funded screening programs in Detroit, Michigan, and the states of New Mexico and California; and to compare the treatment received by program women with early-stage breast cancer with that of all women diagnosed in those regions.

METHODS

Data from the three screening programs were linked with cancer registry data from the corresponding geographic areas. All women diagnosed between 1992 and 1995 through the state-based screening programs and all women contemporaneously diagnosed with breast cancer in the three regions were studied. Descriptive analyses were done of the proportion of women with breast cancer receiving treatment; the proportion of early-stage breast cancer (stage I or II) cases treated with breast-conserving surgery, and the proportion treated with mastectomy; and among women with breast-conserving surgery, the proportion receiving radiation therapy. Logistic regression models controlled for age and stage at diagnosis, race or ethnicity and geographic region.

RESULTS

Less than 2% of program women diagnosed with breast cancer received no treatment. More than two of five women with early-stage breast cancer underwent breast-conserving surgery, with 72% of these women receiving radiation therapy. Multivariate regression analysis revealed that women with stage IIA or IIB breast cancer had lower odds of undergoing breast-conserving surgery than women with stage I (0.51 [95% CI = 0.30-0.87] and 0.36 [95% CI = 0.19-0.70], respectively). Women over age 65 and those with incompletely staged cancer had the lowest odds for receiving radiation therapy after breast-conserving surgery (0.29 [95% CI = 0.09-0.99] and 0.14 [95% CI = 0.03-0.72], respectively). Women diagnosed through the screening programs had odds of undergoing breast-conserving surgery similar to those of all women in the regions (1.11 [95% CI= 0.89-1.39]).

CONCLUSIONS

Treatment patterns for women diagnosed with early-stage breast cancer through three state-based screening programs appear to have been similar to those reported in the literature. In addition, their treatment appears to have been similar to that of other women during the same time period.

"Thinking upstream" to evaluate and to improve the daily work of the newborn intensive care unit

One may divide patient care problem-solving approaches into two categories: (1) "Ready, aim, fire" and (2) "Ready, fire, aim." The present paper invites the reader to think about these distinctions and to identify which of these categories might apply to the reader's daily work experience. Espousing the first of these categories, and anchored in the notions of systems thinking, this paper offers the reader a framework to better understand and implement the daily work of the newborn intensive care unit. This knowledge and competence may be achieved by "thinking upstream," connecting "downstream" outcomes with "upstream" work process steps. The central elements that govern and inform the process of "thinking upstream" are articulated here in actionable terms.

Methodological issues in estimating smoking-attributable mortality in the United States

The authors explored two methodological issues in the estimation of smoking-attributable mortality for the United States. First, age-specific and age-adjusted relative risk, attributable fraction, and smoking-attributable mortality estimates obtained using data from the American Cancer Society's second Cancer Prevention Study (CPS II), a cohort study of 1.2 million participants (1982-1988), were compared with those obtained using a combination of data from the National Mortality Follow-back Survey (NMFS), a representative sample of US decedents in which information was collected from informants (1986), and the National Health Interview Survey (NHIS), a nationally representative household survey (1987). Second, the potential for residual confounding of the disease-specific age-adjusted smoking-attributable mortality estimates was addressed with a model-based approach. The estimated smoking-attributable mortality based on the CPS II for the four most common smoking-related diseases-lung cancer, chronic obstructive pulmonary disease, coronary heart disease, and cerebrovascular disease-was 19% larger than the estimated smoking-attributable mortality based on the NMFS/NHIS, yet the two data sources yielded essentially the same smoking-attributable mortality estimate for lung cancer alone. Further adjustment of smoking-attributable mortality for disease-appropriate confounding factors (education, alcohol intake, hypertension status, and diabetes status) indicated little residual confounding once age was taken into account.

U.S. Air force recruit injury and health study

OBJECTIVES

To assess the types, rates, and risks of injury for male and female USAF recruits.

DESIGN

Outpatient visits for female (5250) and male recruits (8656) were collected and analyzed for rate of injury, types of injuries, and risk of injury throughout a 6-week training period.

RESULTS

One third of female recruits and one sixth of male recruits were injured at least once during recruit training. The overall rate for injuries in women and men was 63.0 and 27.8 per 1000 person-weeks, respectively. The adjusted relative risk for women versus men for all injuries was 2.22, and was consistent (1.67 to 3.27) across injury sites. Despite declining absolute rates of injury by week (106.1-13.4 for women and 53.7-13.2 for men), relative risk of injury for women versus men remained fairly constant throughout each training week. The relative risk for injury serious enough to result in medical hold was 1.69 for women vis-a-vis men. Approximately half of all medical discharges for women and men were for injuries.

CONCLUSIONS

Female recruits were injured twice as often as male recruits, and were 1.5 times more likely to be removed from their training cohort for injury. Relative risk for injuries to specific body areas remained fairly consistent, indicating that no gender-specific injuries were occurring. Further efforts to determine the cause of injuries should be undertaken, and interventions aimed at reducing the disparate risk of injuries in women should be developed and evaluated.

Preimplantation genetic diagnosis for spinal muscular atrophy type I

OBJECTIVE

Couples with children who have spinal muscular atrophy type I (SMA) face a 25% risk of having affected offspring with spontaneous conception. Preimplantation genetic testing (PGT) is possible for the deletions in the survival motor neuron (SMN) gene that have been identified in 98% of SMA type I cases. PGT would provide new reproductive options for families at risk for SMA.

METHODS

Three couples with previously affected children confirmed by DNA testing each underwent in vitro fertilization (IVF) and PGT of the resulting embryos. One or two blastomeres were biopsied from each embryo and analyzed for deletions in exons 7 and 8 of the SMN gene.

RESULTS

Nine embryos were predicted to be unaffected, three to be affected, and one embryo could not be interpreted. One of three patients receiving transfer of unaffected embryos became pregnant with twins.

CONCLUSIONS

Preimplantation genetic testing provides a means for couples at risk for spinal muscular atrophy type I to reduce their chance of initiating an affected pregnancy.

Identification of WASP mutations, mutation hotspots and genotype-phenotype disparities in 24 patients with the Wiskott-Aldrich syndrome

The Wiskott-Aldrich syndrome (WAS), an X-linked immunodeficiency disease caused by mutation in the recently isolated gene encoding WAS protein (WASP), is known to be associated with extensive clinical heterogeneity. Cumulative mutation data have revealed that WASP genotypes are also highly variable among WAS patients, but the relationship of phenotype with genotype in this disease remains unclear. To address this issue we characterized WASP mutations in 24 unrelated WAS patients, including 18 boys with severe classical WAS and 6 boys expressing mild forms of the disease, and then examined the degree of correlation of these as well as all previously published WASP mutations with disease severity. By analysis of these compiled mutation data, we demonstrated clustering of WASP mutations within the four most N-terminal exons of the gene and also identified several sites within this region as hotspots for WASP mutation. These characteristics were observed, however, in both severe and mild cases of the disease. Similarly, while the cumulative data revealed a predominance of missense mutations among the WASP gene lesions observed in boys with isolated thrombocytopenia, missense mutations were not exclusively associated with milder WAS phenotypes, but also comprised a substantial portion (38%) of the WASP gene defects found in patients with severe disease. These findings, as well as the detection of identical WASP mutations in patients with disparate phenotypes, reveal a lack of phenotype concordance with genotype in WAS and thus imply that phenotypic outcome in this disease cannot be reliably predicted solely on the basis of WASP genotypes.

Cellular mechanisms involved in protection and recovery from influenza virus infection in immunodeficient mice

We investigated the role of different lymphocyte subpopulations in the host defense reaction against influenza virus infection, taking advantage of various immunodeficient mouse strains. Whereas, following immunization, wild-type animals showed complete protection against challenge with a lethal dose of A/PR8/34 (PR8) virus, mice that lack both B and T cells but not NK cells (namely, scid and RAG2(-/-) mice) did not display any protective effect in similar conditions. By contrast, J(H)D(-/-) mice devoid of B cells and immunized with virus showed a protective response after challenge with a lethal dose. The immunized J(H)D(-/-) mice that survived completely recovered from the influenza virus infection. Immunized J(H)D(-/+) mice exhibited a more complete protection, suggesting the role of specific antibodies in resistance to infection. To assess the role of natural immunity in the host defense against influenza virus, we carried out experiments with scid mice challenged with lower but still lethal doses of PR8 virus. While an increased NK activity and an increased number of NK1.1+ cells in lungs of scid mice infected with PR8 virus were noted, in vivo depletion of the NK1.1+ cells did not affect the overall survival of the mice. Our results show that specific T cells mediate protection and recovery of J(H)D(-/-) mice immunized with live virus and challenged with lethal doses of influenza virus.

Cigarette smoking and self-reported health problems among U.S. high school seniors, 1982-1989

PURPOSE

To estimate the independent effect of cigarette smoking on respiratory tract symptoms and health status indicators among high school seniors.

DESIGN

Consolidated data sets from one-time cross-sectional survey designs.

SETTING

High schools in the United States, 1982-1989.

SAMPLE

A total of 26,504 high school seniors, with an 83% response rate.

MEASURES

Odds ratios for respiratory tract symptoms and health status indicators for cigarette smokers compared with nonsmokers, while controlling for sex, socioeconomic status, and use of other drugs.

RESULTS

High school seniors who were regular cigarette smokers and who began smoking by grade nine were significantly more likely than never smokers to report shortness of breath when not exercising (adjusted odds ratio [OR] = 2.7), coughing spells (OR = 2.1), productive cough (OR = 2.4), and wheezing or gasping (OR = 2.6). These smokers were also more likely to have seen a doctor or other health professional for an emotional or psychologic complaint (OR = 3.0) and to rate their overall health as poorer than average (OR = 2.4). We found strong dose-response relationships for most outcome measures.

CONCLUSIONS

Cigarette smoking among high school seniors is associated with respiratory tract symptoms and poorer overall physical health and may be a marker for underlying mental health problems. Smoking prevention activities directed at adolescents should include information on the early adverse health consequences of cigarette smoking.

Blood cardioplegia in the senescent heart

As an increasingly aged population undergoes cardiac surgery, myocardial protective strategies must address the fundamental differences between adult and senescent myocardium. In a test of the hypothesis that senescent myocardium is less tolerant of cardioplegic arrest, adult (0.5 to 1.0 years) and senescent (6 to 9 years) sheep underwent 55 minutes of hypothermic blood cardioplegic arrest. A 5-minute dose of terminal warm blood cardioplegic solution was administered followed by 30 minutes of vented reperfusion. Left ventricular volume was monitored by means of sonomicrometric crystals in three orthogonal planes. Myocardial function was assessed with the preload recruitable stroke work relationship. Diastolic function was assessed with two techniques: the "stiffness" coefficient (beta), derived from the exponential end-diastolic pressure-volume relationship, and the time constant of isovolumic left ventricular pressure decay (tau). Data were acquired before arrest and after the reperfusion period. Contractility in the adult hearts was well preserved (preload recruitable stroke work: 63.7 +/- 6.1 versus 56.8 +/- 4.1 mJ/beat per milliliter per 100 gm, prearrest versus postarrest, p = not significant). In contrast, senescent heart contractility was poorly preserved (56.8 +/- 4.1 versus 35.4 +/- 4.2 mJ/beat per milliliter per 100 gm, p < 0.025). Early diastolic relaxation (tau) was prolonged in the adult hearts (42.5 +/- 3.3 versus 48.8 +/- 3.5 msec prearrest versus postarrest, p < 0.05), whereas the senescent hearts were essentially unchanged (49.3 +/- 3.1 versus 52.3 +/- 4.5 msec. p = 0.35). Myocardial stiffness (beta) was unchanged in both groups. When compared with adult hearts, contractility in senescent hearts is poorly preserved after cold blood cardioplegic arrest. Active diastolic relaxation, however, is more prolonged in adult hearts. Passive diastolic properties are unchanged in both groups. Because there are specific age-related differences in tolerance to cardioplegic arrest, extrapolation of myocardial protective strategies from studies in adult hearts to elderly patients may not be appropriate.

Intact antiinfluenza virus immune response in targeted kappa-deficient mice

Immunoglobulins are encoded by genes located in three different loci, the heavy chain (IgH), kappa light chain (Ig kappa), and lambda light chain (Ig lambda) loci. In mice, the kappa/lambda ratio of B cells is 95:5. In a previous study, we reported that kappa gene deletion causes the alternative usage of lambda 1 (93%) and lambda 2 (7%) light chains, and that the kappa anti-TNP repertoire is compensated for by the lambda repertoire even though the latter is clonally restricted in K-/- mice. To investigate the contribution of lambda antibodies to protection against virus, we compared K-/- mice with 129/Sv wild-type mice with respect to immune responses to influenza virus. PR8 virus immunized K-/- and 129/Sv mice showed no difference in the titer of anti-HA antibodies. Furthermore, the same immunized mice had sufficiently high neutralizing antibody titer to prevent infection when challenged with 7.5 x 10(4) TCID50 of PR8 virus. In addition, immunized K-/- mice were resistant to infection with 7.5 x 10(4) TCID50 and 7.5 x 10(5) TCID50 (10 and 100 LD50, respectively) of PR8 virus. Finally, K-/- mice are also capable of inducing cytotoxic T cells. These results suggest that the lambda repertoire can compensate for the kappa repertoire by generating a fully protective neutralizing antibody response.

Glycosylation of neuraminidase determines the neurovirulence of influenza A/WSN/33 virus

The neuraminidase (NA) gene of influenza A/WSN/33 (WSN) virus has previously been shown to be associated with neurovirulence in mice and growth in Madin-Darby bovine kidney (MDBK) cells. Nucleotide sequence analysis has indicated that the NA of WSN virus lacks a conserved glycosylation site at position 130 (corresponding to position 146 in the N2 subtype). To investigate the role of this carbohydrate in viral pathogenicity, we used reverse genetics methods to generate a Glyc+ mutant virus, in which the glycosylation site Asn-130 was introduced into the WSN virus NA. Unlike the wild-type WSN virus, the Glyc+ mutant virus did not undergo multicycle replication in MDBK cells in the absence of trypsin, presumably because of lack of cleavage activation of infectivity. In contrast, revertant viruses derived from the Glyc+ mutant were able to replicate in MDBK cells without exogenous protease. Nucleotide sequence analysis revealed that the NAs of the revertant viruses had lost the introduced glycosylation site. In contrast to wild-type and revertant viruses, the Glyc+ mutant virus was not able to multiply in mouse brain. These results suggest that the absence of a glycosylation site at position 130 of the NA plays a key role in the neurovirulence of WSN virus in mice.

Interpoint squared distance as a measure of spatial clustering

The expectation and variance for the mean interpoint squared distance are presented. In order to evaluate these expressions it is necessary to calculate the moments of a bivariate uniform distribution defined over an arbitrary polygon. Expressions for these moments are presented, allowing the mean interpoint squared distance to be used as a measure of spatial clustering. The distribution and power of this test statistic is explored on the unit square, and the spatial distribution of 11 cases of non-Hodgkin's lymphoma is investigated to illustrate an application of the approach.

Surveillance for and comparison of birth defect prevalences in two geographic areas--United States, 1983-88

PROBLEM/CONDITION

CDC and a number of states have developed surveillance systems to monitor the birth prevalence of major defects.

REPORTING PERIOD COVERED

This report covers birth defects surveillance in Metropolitan Atlanta, Georgia and selected jurisdictions in California for the years 1983-1988.

DESCRIPTION OF SYSTEM

The California Birth Defects Monitoring Program and the Metropolitan Atlanta Congenital Defects Program are two population based surveillance systems that employ similar data collection methods. The prevalence estimates for 44 diagnostic categories are based on data from 1983 to 1988 for 639,837 births in California and 152,970 births in metropolitan Atlanta. The prevalences in the two areas are compared adjusting for race, sex and maternal age using Poisson regression.

RESULTS

Regional differences in the prevalence of aortic stenosis, fetal alcohol syndrome, hip dislocation/dysplasia, microcephalus, obstruction of the kidney/ureter, and scoliosis/lordosis may be attributable to general diagnostic variability. However, differences in the prevalences of arm/hand limb reduction, encephalocele, spina bifida, or trisomy 21 (Down Syndrome) are probably not attributable to differences in ascertainment because these defects are relatively easy to diagnose.

INTERPRETATION

Regional differences in prenatal diagnosis and pregnancy termination may affect prevalences of trisomy 21 and spina bifida. However, the reason for differences in arm/hand limb reduction is unknown, but may be related to variability in environmental exposure, heterogeneity in gene pool, or random variation.

ACTIONS TAKEN

Because of the similarities of these data bases, several collaborative studies are being implemented. In particular, the differences in the birth prevalence of spina bifida and Down Syndrome will focus attention on the impact of prenatal diagnosis.

Exposure misclassification due to residential mobility during pregnancy in epidemiologic investigations of congenital malformations

This study addressed the question of how maternal migration between conception and birth affects estimates of risk in studies of congenital malformations when movement is related to the exposure. For example, in studying the potential association between proximity to a chemical waste site and the occurrence of birth defects, incorrect inferences might be drawn if maternal residence at birth was used as a surrogate for exposure at conception in the case when a significant amount of media attention influenced some women to move away from the site after becoming pregnant. A simple statistical model is proposed that defines the distance to a fixed exposure point measured at birth as a function of the distance to the point measured at conception, the probability of movement, the direction of movement, and the distance moved. Bias is the difference between the expected results when distance is measured at birth versus conception. The amount of bias can be substantial for movement patterns that may be likely to occur. This simplified model was used in an effort to explore and better understand the relationships between maternal migration and risk.

Induction of antihemagglutinin antibodies by polyclonal antiidiotype antibodies

Antiidiotypic antibodies can be envisioned as an alternative approach in the development of vaccines against influenza virus, which exhibits natural antigenic variations. In our work, we obtained two polyclonal cross-reactive anti-Id antibodies against PY102, VM113, and VM202 mAbs, which in turn are specific respectively for PR8 virus and laboratory-induced virus variants (PY102-V1 and VM113-V1). With these cross-reactive anti-Id antibodies, we were able to elicit anti-HA antibodies in mice. In comparing the anti-HA antibody response in animals injected with anti-Id antibodies to those immunized with PR8 influenza virus, we demonstrated that the HI titer was higher after virus immunization and that the PR8 virus boost was more efficient in this group. Our results showed that the polyclonal cross-reactive anti-Id antibodies were more efficient than the individual anti-Ids at eliciting responses. At the same time, we demonstrated that PR8-primed T cells, cultured with B cells from animals immunized with anti-Id antibodies, were able to produce anti-PR8 antibodies subsequent to stimulation with influenza virus.

Quality control of birth defect registry data: a case study

The California Birth Defects Monitoring Program maintains a population-based registry of children born with congenital malformations. Trained data collectors routinely visit hospitals and genetics centers to identify cases and abstract information. These data are provided to the public health, medical, and lay communities and are used for conducting prevalence and case-control studies. A stratified sample of each data collector's work for one data year was reevaluated to assess the quality of case ascertainment and record abstraction. The sample included data from 109 facilities (37 percent) and 729 abstracts (5 percent). There are three steps in data collection: case-finding, the process of identifying potential cases; culling, the process of reviewing the charts of potential cases to determine which are reportable; and abstracting, the process of recording information from the charts of reportable cases. The probability that a potential case is missed during casefinding is 7 percent for small facilities, 4 percent for medium facilities, and 1 percent for large facilities. The probability that a reportable case is mistakenly classified as not reportable during culling is 3 percent for small and medium facilities and 1 percent for large facilities. The probabilities of incorrectly abstracting selected diagnoses and demographic items are slightly higher (8 percent for small and medium facilities and 6 percent for large facilities) because these are more complex processes than are casefinding and culling. Finally, the overall probability of missing a case from the registry is 3 percent. Therefore, these data indicate that the information collected by this registry are both reliable and complete.

Cost efficient sampling design for quality control of a birth defects registry

Quality control studies of registries are frequently conducted. We employed a cost effective sampling scheme for assessing the quality of case identification and abstracting in one birth defects registry. The general sampling method was a stratified two-stage design, and the optimal sample size for each stratum was chosen to minimize cost, which was defined as time for data collection. The resulting sample sizes depended on the variability in the number of abstracts between and within data collection facilities, and the amount of time needed to complete each data collection step. The most time effective scheme was to visit several facilities each for a short period of time rather than fewer facilities for a longer period of time. Cost efficient sampling strategies, such as the method used here, can be applied to ensure precision in registry quality control analyses and other public health studies.

Reporting and selection bias in case-control studies of congenital malformations

Retrospective studies of congenital malformations frequently rely on exposures reported by study subjects. Differential error in exposure reporting by cases and controls, which has alternatively been referred to as "recall bias" and "reporting bias," may result in a biased effect measure. Some authors have attempted to avoid reporting bias by comparing exposures between two malformed groups, rather than between cases and nonmalformed controls. This approach, however, may introduce its own bias, which we call selection bias. Both reporting bias and selection bias are shown to be algebraically equivalent to bias arising from exposure misclassification. The magnitudes of these biases are compared for a range of plausible parametric values. The case-control design is sensitive to both differential reporting and selection bias, and the choice of study design involves balancing these two sources of bias.

Cells expressing an H chain Ig gene carrying a viral T cell epitope are lysed by specific cytolytic T cells

The epitope corresponding to amino acid residues 147-161 of the nucleoprotein (NP) of influenza A virus is recognized by CTL in association with H-2Kd class I Ag. Herein, we engineered an Ig molecule carrying this CTL epitope by replacing the diversity gene segment of the H chain V region of an anti-arsonate antibody with an oligonucleotide that encodes the CTL epitope. The chimeric H chain gene was expressed either alone or together with the parental L chain in the nonsecreting BALB/c myeloma B cell line, SP2/0. The Ig produced by cells transfected with both the chimeric H chain and parental L chains genes expressed the NP epitope but lost the original arsonate binding activity. In addition, SP2/0 cells expressing the chimeric H chain either alone or together with the parental L chain were lysed by class I restricted NP-epitope specific CTL. By contrast, SP2/0 cells pulsed with soluble chimeric Ig molecules were not lysed by the specific CTL. These observations indicate that: 1) this particular CTL epitope can be expressed on Ig molecules without altering the H and L chain pairing; 2) this CTL epitope can be generated from this chimeric Ig in which it is surrounded by flanking regions distinct from those of the viral NP; and 3) the generation of this CTL epitope from the Ig molecule requires the endogenous pathway as do viral proteins.

Cells expressing an H chain Ig gene carrying a viral T cell epitope are lysed by specific cytolytic T cells

The epitope corresponding to amino acid residues 147-161 of the nucleoprotein (NP) of influenza A virus is recognized by CTL in association with H-2Kd class I Ag. Herein, we engineered an Ig molecule carrying this CTL epitope by replacing the diversity gene segment of the H chain V region of an anti-arsonate antibody with an oligonucleotide that encodes the CTL epitope. The chimeric H chain gene was expressed either alone or together with the parental L chain in the nonsecreting BALB/c myeloma B cell line, SP2/0. The Ig produced by cells transfected with both the chimeric H chain and parental L chains genes expressed the NP epitope but lost the original arsonate binding activity. In addition, SP2/0 cells expressing the chimeric H chain either alone or together with the parental L chain were lysed by class I restricted NP-epitope specific CTL. By contrast, SP2/0 cells pulsed with soluble chimeric Ig molecules were not lysed by the specific CTL. These observations indicate that: 1) this particular CTL epitope can be expressed on Ig molecules without altering the H and L chain pairing; 2) this CTL epitope can be generated from this chimeric Ig in which it is surrounded by flanking regions distinct from those of the viral NP; and 3) the generation of this CTL epitope from the Ig molecule requires the endogenous pathway as do viral proteins.

Cytogenetic results from the U.S. Collaborative Study on CVS

Cytogenetic data are presented for 11,473 chorionic villus sampling (CVS) procedures from nine centres in the U.S. NICHD collaborative study. A successful cytogenetic diagnosis was obtained in 99.7 per cent of cases, with data obtained from the direct method only (26 per cent), culture method only (42 per cent), or a combination of both (32 per cent). A total of 1.1 per cent of patients had a second CVS or amniocentesis procedure for reasons related to the cytogenetic diagnostic procedure, including laboratory failures (27 cases), maternal cell contamination (4 cases), or mosaic or ambiguous cytogenetic results (98 cases). There were no diagnostic errors involving trisomies for chromosomes 21, 18, and 13. For sex chromosome aneuploidies, one patient terminated her pregnancy on the basis of non-mosaic 47,XXX in the direct method prior to the availability of results from cultured cells. Subsequent analysis of the CVS cultures and fetal tissues showed only normal female cells. Other false-positive predictions involving non-mosaic aneuploidies (n = 13) were observed in the direct or culture method, but these cases involved rare aneuploidies: four cases of tetraploidy, two cases of trisomy 7, and one case each of trisomies 3, 8, 11, 15, 16, 20, and 22. This indicates that rare aneuploidies observed in the direct or culture method should be subjected to follow-up by amniocentesis. Two cases of unbalanced structural abnormalities detected in the direct method were not confirmed in cultured CVS or amniotic fluid. In addition, one structural rearrangement was misinterpreted as unbalanced from the direct method, leading to pregnancy termination prior to results from cultured cells showing a balanced, inherited translocation. False-negative results (n = 8) were observed only in the direct method, including one non-mosaic fetal abnormality (trisomy 18) detected by the culture method and seven cases of fetal mosaicism (all detected by the culture method). Mosaicism was observed in 0.8 per cent of all cases, while pseudomosaicism (including single trisomic cells) was observed in 1.6 per cent of cases. Mosaicism was observed with equal frequency in the direct and culture methods, but was confirmed as fetal mosaicism more often in cases from the culture method (24 per cent) than in cases from the direct method (10 per cent). The overall rate of maternal cell contamination was 1.8 per cent for the culture method, but there was only one case of incorrect sex prediction due to complete maternal cell contamination which resulted in the birth of a normal male.(ABSTRACT TRUNCATED AT 400 WORDS)

Distance and risk measures for the analysis of spatial data: a study of childhood cancers

Three statistical approaches, used to detect spatial clusters of disease associated with a point source exposure, are applied to childhood cancer data for the city of San Francisco (1973-88). The distributions of incident cases of leukemia (51 cases), brain cancer (35 cases), and lymphatic cancer (37 cases) among individuals less than 21 years of age are described using three measures of clustering: distance on a geopolitical map, distance on a density equalized transformed map, and relative risk. The point source of exposure investigated is a large microwave tower located southwest of the center of the city (Sutro Tower). The three analytic approaches indicate that the patterns of the major childhood cancers are essentially random with respect to the point source. These results and a statistical model for spatial clustering are used to explore distance and risk measures in the analysis of spatial data. Both types of measures of spatial clustering are shown to perform similarly when a specific area of exposure can be defined.

Congenital malformations and birthweight in areas with potential environmental contamination

Public concern exists about the potential for reproductive damage that may result from exposures to environmental contaminants. Therefore, the authors sought to determine if there was an association between a child's congenital malformation or a child's lowered weight at birth and his or her mother's residence in a census tract where a site of environmental contamination had been documented. Exposure designations were derived from existing sources of information. Except for an elevated risk (odds ratio = 1.5) for infants with malformations of the heart and circulatory system, this investigation did not reveal increased risks for most malformations or for lowered birthweight among babies born to women who lived in these census tracts. Methodologic issues inherent to investigations that rely on existing data sources are discussed.

Inhibition of multicycle influenza virus replication by hybrid antibody-directed cytotoxic T lymphocyte lysis

Bifunctional antibodies with specificity for the TCR/CD3 complex as well as to a target cell-surface Ag can redirect CTL to lyse the target cell. We have produced a hybrid hybridoma, HHA6, which secretes bifunctional antibodies capable of redirecting CTL to lyse influenza virus-infected target cells. When added along with CTL to virus-infected cells, these antibodies very efficiently inhibit multicycle virus replication. Because hybrid hybridomas reassort H and L chains randomly we attempted to purify bifunctional antibody by using HPLC. The purification increased the potency of HHA6. This increase probably reflects an enrichment of the active species and the removal of inhibiting antibody species.

Inhibition of multicycle influenza virus replication by hybrid antibody-directed cytotoxic T lymphocyte lysis

Bifunctional antibodies with specificity for the TCR/CD3 complex as well as to a target cell-surface Ag can redirect CTL to lyse the target cell. We have produced a hybrid hybridoma, HHA6, which secretes bifunctional antibodies capable of redirecting CTL to lyse influenza virus-infected target cells. When added along with CTL to virus-infected cells, these antibodies very efficiently inhibit multicycle virus replication. Because hybrid hybridomas reassort H and L chains randomly we attempted to purify bifunctional antibody by using HPLC. The purification increased the potency of HHA6. This increase probably reflects an enrichment of the active species and the removal of inhibiting antibody species.

Multicentric angiofollicular lymph node hyperplasia with peripheral neuropathy, pseudotumor cerebri, IgA dysproteinemia, and thrombocytosis in women. A distinct syndrome

Four women with multicentric angiofollicular lymph node hyperplasia had a distinct clinical syndrome characterized by peripheral neuropathy, pseudotumor cerebri, IgA dysproteinemia, and thrombocytosis. The nodes displayed typical morphologic changes of the plasma cell variant of multicentric angiofollicular lymph node hyperplasia. The pathologic changes are morphologically distinct from angioimmunoblastic lymphadenopathy with dysproteinemia although clinical similarities do exist. In these four cases, the lymphadenopathy was usually bulky and multicentric. There was frequent splenic involvement. The neuropathies were severe and disabling. Clinical courses have been variable with some responses to therapy with steroids and alkylating agents. No neoplastic transformations have occurred. Multicentric angiofollicular lymph node hyperplasia may represent a reactive lesion in which the antigenic stimulus is unknown but results in follicular hyperplasia, angiogenesis, and the systemic manifestations of hyperimmune stimulation. We believe this clinical syndrome may represent a distinct variant of multicentric angiofollicular lymph node hyperplasia, and it requires close observation for neoplastic transformation and other complications of its multisystem nature.

Detection of excess disease near an exposure point: a case study

Many studies have evaluated the likelihood of adverse health effects associated with environmental contamination from point source exposures. Two statistical measures used in these studies are the ratio, R, of the observed to the expected number of cases occurring in the area containing the point and the average distance, D, between the cases and the point. This paper estimates the probability of detecting an association between disease and exposure when one actually exists (power) for R and D for several specific and plausible statistical models. Results are presented in the context of rare diseases such as congenital malformations. The practical implications of using these measures for the evaluation of risk of disease in environmental epidemiologic investigations are discussed.

Sudden infant death syndrome among Asians in California

We analyzed California linked birth and infant death records for 1978 to 1985 to determine the ethnic-specific incidence of sudden infant death syndrome in five Asian-American subgroups, and to assess the association of sudden infant death syndrome with cultural assimilation. The overall incidence of sudden infant death syndrome for these groups was 1.1/1000 live births (194 cases). The ethnic-specific incidence was statistically associated with the immigration status of each ethnic group, as measured by the proportion of all live births for which the mother was born in the United States, with a higher incidence for groups that have been in the United States for the longest period. A logistic model was used to examine simultaneously the association of sudden infant death syndrome with maternal ethnicity, ethnic homogeneity or heterogeneity of the parents, and maternal birthplace (United States, or elsewhere). The logistic analysis did not yield statistically significant evidence to support cultural assimilation as a factor in the incidence of sudden infant death syndrome for these groups. This finding may be due to small sample size and inadequate indicators of assimilation. It may also be that other factors relating to immigration and selective migration affect the incidence of sudden infant death syndrome among Asian-Americans.

Nucleotide changes in sequential variants of influenza virus hemagglutinin genes and molecular structures of corresponding monoclonal antibodies specific for each variant

We have generated four monoclonal antibodies specific for one or more members of a series of two sequentially derived PR8 influenza virus variants. Three of these antibodies share cross-reactive idiotypes. The amino acid sequences of these antibodies were determined, and it was found that two of these antibodies use genes from the VH7183 family, whereas the third uses a gene from the VHJ558 family. All four monoclonal antibodies derive from different families of genes encoding the variable region of the kappa chain. The RNA sequence of the parent PR8 virus as well as the RNA sequences of the sequential variants were also determined, and it was demonstrated that the variant hemagglutinin molecules differed from the parent molecule by only a single amino acid interchange. Despite these subtle differences in antigenic structures of hemagglutinin, and the cross-reactive idiotype of the antibodies, their primary structures were very different. These data reinforce the idea that a wide variety of antibody structures exist which are directed against subtly different structures in biologically important antigens.

Sudden infant death syndrome and birth weight

We studied 2962 cases of sudden infant death syndrome (SIDS), derived from linked birth and death records, to specify further the descriptive epidemiologic data on recognized SIDS risk factors and to examine interrelationships among multiple risk factors and SIDS while controlling for the influence of birth weight (using logistic regression). The results generally confirmed those of other studies, with the exception of a higher incidence of SIDS among Chinese and Japanese babies and a lower incidence among Hispanic babies, all in comparison with white, non-Spanish (Anglo) infants. Median age at death was found to vary by birth weight, with very low birth weight babies being about 6 weeks older (postnatal age) than normal birth weight babies at time of death. The association of the risk factors with SIDS remained when birth weight data were statistically controlled; the association of these risk factors with SIDS cannot be explained by their relationship to birth weight. An interaction was found between race and maternal age and between multiparity and type of hospital of birth. There was no interaction between birth weight and the other risk factors.

Pyometra involving uterus masculinus in a cat

A neutered male cat with a history of intermittent antibiotic-responsive fever and strangury had pyometra involving uterus masculinus. The infected structure was removed, and episodes of infection and strangury ceased.

An examination of three spatial disease clustering methodologies

Patterns of disease in space are often analysed to determine whether a relationship exists between a disease outcome and environmental exposures. This report examines the performance of three cluster analytical methods when applied to a single data set. These methods, designed to assess the purely spatial variation of events, have been examined to assess their ability to detect clustering in an area where disease rates have previously been shown to be significantly elevated. The ability of these methods to detect spatial clustering was also examined using simulation techniques. All three methods were found to be poor at detecting spatially localized disease rates which were approximately three time the expected rate, as measured by the relative risk.

"Rates" of birth defects

The proportion of children born with a particular defect is not a "birth defect rate" but, rather, a prevalence proportion. The implications of confusing a rate and a proportion are discussed in terms of the interpretation of birth defect data. It is recommended that "prevalence proportion" or "prevalence" be used to report the frequency of various defects rather than the often-used "prevalence rate."