Maintaining Internal Validity in Community Partnered Participatory Research: Experience from the Community Partners in Care Study

Objective

With internal validity being a central goal of designed experiments, we seek to elucidate how community partnered participatory research (CPPR) impacts the internal validity of public health comparative-effectiveness research.

Methods

Community Partners in Care (CPIC), a study comparing a community-coalition intervention to direct technical assistance for disseminating depression care to vulnerable populations, is used to illustrate design choices developed with attention to core CPPR principles. The study-design process is reviewed retrospectively and evaluated based on the resulting covariate balance across intervention arms and on broader peer-review assessments. Contributions of the CPIC Council and the study's design committee are highlighted.

Results

CPPR principles contributed to building consensus around the use of randomization, creating a sampling frame, specifying geographic boundaries delimiting the scope of the investigation, grouping similar programs into pairs or other small blocks of units, collaboratively choosing random-number-generator seeds to determine randomized intervention assignments, and addressing logistical constraints in field operations. Study protocols yielded samples that were well-balanced on background characteristics across intervention arms. CPIC has been recognized for scientific merit, has drawn attention from policymakers, and has fueled ongoing research collaborations.

Conclusions

Creative and collaborative fulfillment of CPPR principles reinforced the internal validity of CPIC, strengthening the study's scientific rigor by engaging complementary areas of knowledge and expertise among members of the investigative team.

Chlamydia pneumoniae induces interleukin-12 responses in peripheral blood mononuclear cells in asthma and the role of toll like receptor 2 versus 4: a pilot study

BACKGROUND

Chlamydia pneumoniae causes respiratory infection in adults and children, and has been associated with asthma exacerbations and induction of Immunoglobulin (Ig) E responses. We previously reported that C. pneumoniae enhances T helper (Th) 2 responses of peripheral blood mononuclear cells (PBMC) from asthmatic patients. It is likely that toll like receptor (TLR)-2 and TLR-4 mediate cytokine responses and host defense against C. pneumoniae. Thus, we sought to determine whether engagement of TLR-2 or TLR-4 may induce IL-12 production in our C. pneumoniae model.

METHODS

PBMC (1.5 × 10⁶) from asthmatic patients (N = 10) and non-asthmatic controls (N = 5) were infected or mock-infected for 1 h ± C. pneumoniae TW183 at a multiplicity of infection (MOI) = 1 and MOI = 0.1, and cultured for 48 h ± anti- TLR-2 and TLR-4 antibodies (Abs) (1 mg/mL). Interleukin (IL)-12 (48 h p.i.) and total IgE levels (day 10) were measured in supernatants (ELISA).

RESULTS

High IgE levels were detected in supernatants of C. pneumoniae- infected PBMC from asthmatics on day 10, compared with mock-infected PBMC (p < 0.03). In contrast, IgE was not detected (<0.3 ng/mL) in either C. pneumoniae infected or mock-infected PBMC from non-asthmatics. IL-12 production by C. pneumoniae-infected asthmatic and non-asthmatic PBMC were similar. When anti-TLR4, but not anti-TLR2, was included in culture, IL-12 production by C. pneumoniae- infected asthmatic PBMC decreased.

CONCLUSIONS

C. pneumoniae infection induces IgE production and modulates IL-12 responses in patients with asthma, which may be caused, in part, by differences in TLR-2 and TLR-4 stimulation.

Developing clinical decision support within a commercial electronic health record system to improve antimicrobial prescribing in the neonatal ICU

OBJECTIVE

To develop and implement a clinical decision support (CDS) tool to improve antibiotic prescribing in neonatal intensive care units (NICUs) and to evaluate user acceptance of the CDS tool.

METHODS

Following sociotechnical analysis of NICU prescribing processes, a CDS tool for empiric and targeted antimicrobial therapy for healthcare-associated infections (HAIs) was developed and incorporated into a commercial electronic health record (EHR) in two NICUs. User logs were reviewed and NICU prescribers were surveyed for their perceptions of the CDS tool.

RESULTS

The CDS tool aggregated selected laboratory results, including culture results, to make treatment recommendations for common clinical scenarios. From July 2010 to May 2012, 1,303 CDS activations for 452 patients occurred representing 22% of patients prescribed antibiotics during this period. While NICU clinicians viewed two culture results per tool activation, prescribing recommendations were viewed during only 15% of activations. Most (63%) survey respondents were aware of the CDS tool, but fewer (37%) used it during their most recent NICU rotation. Respondents considered the most useful features to be summarized culture results (43%) and antibiotic recommendations (48%).

DISCUSSION

During the study period, the CDS tool functionality was hindered by EHR upgrades, implementation of a new laboratory information system, and changes to antimicrobial testing methodologies. Loss of functionality may have reduced viewing antibiotic recommendations. In contrast, viewing culture results was frequently performed, likely because this feature was perceived as useful and functionality was preserved.

CONCLUSION

To improve CDS tool visibility and usefulness, we recommend early user and information technology team involvement which would facilitate use and mitigate implementation challenges.

Enalapril-induced acute kidney injury in neonates

Angiotensin converting enzyme inhibitors have been used in the neonatal population for both cardiac and renal diseases. Past reports have described deleterious renal and neurological consequences as a result of these drugs. This report describes two infants receiving enalapril for different indications who suffered renal impairments, likely a result of concomitant diuretic use. These cases demonstrate the risks associated with ACE inhibitor use and the importance of vigilant monitoring when using these medications.

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.

Co-location of health care for adults with serious mental illness and HIV infection

This study describes persons with serious mental illness and comorbid HIV infection and examines the effect of co-location of mental health and HIV care on satisfaction, service utilization, and appropriateness of care. One hundred and eighteen subjects completed interviews and gave blood samples; medical records were abstracted. Most reported few barriers to care and satisfaction with mental health and HIV treatment. Co-location of mental health and HIV care did not influence satisfaction with care, utilization of services, or appropriateness of care. This report challenges the notion that persons with serious mental illnesses receive inadequate health care and that they have minimal capacity for illness management. These subjects may be benefiting from increased funding for, and attention to, persons with HIV infection.

Prevalence and co-occurrence of violence, substance use and disorder, and HIV risk behavior: a comparison of sheltered and low-income housed women in Los Angeles County

BACKGROUND

Violence against women, substance use and disorder, and HIV represent three significant threats to the health of women, yet little is known about the extent of these epidemics among indigent women. This study investigates and documents differences in the prevalence and co-occurrence of physical and sexual violence, substance use and disorder, and HIV risk behavior in sizable probability samples of sheltered homeless and low-income housed women.

METHODS

Retrospective self-reports were obtained through structured interviews with stratified random samples of women residing in shelters (N = 460) and low-income housing (N = 438) in Los Angeles County, California.

RESULTS

Sheltered women were more likely than housed women to report experiencing physical and sexual violence, substance use and disorder, HIV risk behavior, and co-occurrence of these problems in the past year. Differences remained when propensity weights were used to equate the groups on demographic and background characteristics.

CONCLUSIONS

Findings suggest remarkable need for services among communities of indigent women. Higher rates of problems among women in shelters highlight the importance of differentiating among subgroups of indigent women in community-based prevention and intervention activities and tentatively suggest a protective influence of housing.

Pathophysiology of neonatal resuscitation: application in a global context

Despite the adoption of evidence-based guidelines for neonatal resuscitation, formulated with international consensus, the process of resuscitating a newly born infant remains a uniquely local activity. Variations in the physical environment, cultural and medical beliefs, and available resources mediate significant difference in practices worldwide. Yet, the universal nature of the physiology surrounding birth, and its disturbances, provides a common basis for reference. Recognition of the importance of assistance available at the moment of birth, management of the thermal environment, and establishment of adequate ventilation is nearly universal. Differences in specific practices arise from local differences in the risks and challenges to perinatal health, which, in turn, stem from the environment or the available resources. Valuable information can be learned through comparison and evaluation of different techniques. In such a way, the evidence base for neonatal resuscitation can be strengthened and infants around the world can share in the benefits realized.

Medications during resuscitation -- what is the evidence?

Medication use during neonatal resuscitation is uncommon. The infrequent use of resuscitation medications has impeded rigorous investigations to determine the most effective agents and/or dosing regimens. The medications most commonly used during delivery room resuscitation include epinephrine, sodium bicarbonate, naloxone hydrochloride and volume expanders. The available evidence for each of these medications is reviewed in this article.

International Guidelines for Neonatal Resuscitation: An excerpt from the Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care: International Consensus on Science. Contributors and Reviewers for the Neonatal Resuscitation Guidelines

The International Guidelines 2000 Conference on Cardiopulmonary Resuscitation (CPR) and Emergency Cardiac Care (ECC) formulated new evidenced-based recommendations for neonatal resuscitation. These guidelines comprehensively update the last recommendations, published in 1992 after the Fifth National Conference on CPR and ECC. As a result of the evidence evaluation process, significant changes occurred in the recommended management routines for: * Meconium-stained amniotic fluid: If the newly born infant has absent or depressed respirations, heart rate <100 beats per minute (bpm), or poor muscle tone, direct tracheal suctioning should be performed to remove meconium from the airway. * Preventing heat loss: Hyperthermia should be avoided. * Oxygenation and ventilation: 100% oxygen is recommended for assisted ventilation; however, if supplemental oxygen is unavailable, positive-pressure ventilation should be initiated with room air. The laryngeal mask airway may serve as an effective alternative for establishing an airway if bag-mask ventilation is ineffective or attempts at intubation have failed. Exhaled CO(2) detection can be useful in the secondary confirmation of endotracheal intubation. * Chest compressions: Compressions should be administered if the heart rate is absent or remains <60 bpm despite adequate assisted ventilation for 30 seconds. The 2-thumb, encircling-hands method of chest compression is preferred, with a depth of compression one third the anterior-posterior diameter of the chest and sufficient to generate a palpable pulse. * Medications, volume expansion, and vascular access: Epinephrine in a dose of 0.01-0.03 mg/kg (0.1-0.3 mL/kg of 1:10,000 solution) should be administered if the heart rate remains <60 bpm after a minimum of 30 seconds of adequate ventilation and chest compressions. Emergency volume expansion may be accomplished with an isotonic crystalloid solution or O-negative red blood cells; albumin-containing solutions are no longer the fluid of choice for initial volume expansion. Intraosseous access can serve as an alternative route for medications/volume expansion if umbilical or other direct venous access is not readily available. * Noninitiation and discontinuation of resuscitation: There are circumstances (relating to gestational age, birth weight, known underlying condition, lack of response to interventions) in which noninitiation or discontinuation of resuscitation in the delivery room may be appropriate.

Coexistent holoprosencephaly and Chiari II malformation

Chiari II malformations and holoprosencephaly have been considered to be brain malformations that differ with respect to teratogenic insult, embryologic mechanism, and morphology. We herein describe coexistent Chiari II malformation and holoprosencephaly that occurred in a viable infant. A review of the literature regarding Chiari II malformations and holoprosencephaly suggests that a disturbance to the mesenchyme in early embryologic life may be the cause of both malformations.

Recommendations for follow-up care of individuals with an inherited predisposition to cancer. II. BRCA1 and BRCA2. Cancer Genetics Studies Consortium

OBJECTIVE

To provide recommendations for cancer surveillance and risk reduction for individuals carrying mutations in the BRCA1 or BRCA2 genes.

PARTICIPANTS

A task force with expertise in medical genetics, oncology, primary care, gastroenterology, and epidemiology convened by the Cancer Genetics Studies Consortium (CGSC), organized by National Human Genome Research Institute (previously the National Center for Human Genome Research).

EVIDENCE

Studies evaluating cancer risk, surveillance, and risk reduction in individuals genetically susceptible to breast and ovarian cancer were identified using MEDLINE (National Library of Medicine) and from bibliographies of articles thus identified. Indexing terms used were "genetics" in combination with "breast cancer," "ovarian cancer," and "screening," or "surveillance" in combination with "cancer family" and "BRCA1" and "BRCA2." For studies evaluating specific interventions, quality of evidence was assessed using criteria of the US Preventive Services Task Force.

CONSENSUS PROCESS

The task force developed recommendations through discussions over a 14-month period.

CONCLUSIONS

Efficacy of cancer surveillance or other measures to reduce risk in individuals who carry cancer-predisposing mutations is unknown. Based on expert opinion concerning presumptive benefit, early breast cancer and ovarian cancer screening are recommended for individuals with BRCA1 mutations and early breast cancer screening for those with BRCA2 mutations. No recommendation is made for or against prophylactic surgery (eg, mastectomy, oophorectomy); these surgeries are an option for mutation carriers, but evidence of benefit is lacking, and case reports have documented the occurrence of cancer following prophylactic surgery. It is recommended that individuals considering genetic testing be counseled regarding the unknown efficacy of measures to reduce risk and that care for individuals with cancer-predisposing mutations be provided whenever possible within the context of research protocols designed to evaluate clinical outcomes.

Homing in on the homeless: assessing the physical health of homeless adults in Los Angeles County using an original method to obtain physical examination data in a survey

OBJECTIVE

Public policy that decreases the finding for social services may combine with the ascendancy of corporate managed care to increase the health care deficit. Assessing the health impact of these policy changes on various populations is a fundamental challenge for health services research. Disadvantaged populations, such as the homeless, are likely to be affected disproportionately. Research quality data on the physical health of such populations are difficult and expensive to obtain. In particular, physical examination data have not been available and self-reports are insufficient. Our objective: to develop and utilize a structured physical exam system enabling lay survey researchers to report reliably physical findings related to six tracer conditions in a disadvantaged population.

STUDY SETTING

A field survey of homeless adults in Los Angeles County, California. Respondents were 363 homeless adults representing a subsample of a probability sample of the county's homeless adult population.

STUDY DESIGN

We integrated existing measures with expert clinical opinion and original means of data collection into a structured physical exam enabling lay interviewers to identify the prevalence of vision problems, significant skin disorders, peripheral vascular disease of the lower extremities, selected podiatric disorders, hypertension, and tuberculosis in a sample of homeless adults.

PRINCIPAL MEASURES

We describe lay interviewer performance in terms of mastery of the necessary material based on written and practical exams and in terms of the number of respondents successfully followed. We base our description of the instrument on the time necessary to complete it, and on the proportion of each component successfully completed during the field survey, as well as on interrater reliability. We report the prevalence of the various clinical conditions according to self-report and according to the structured limited physical exam, as well as the marginal proportion of respondents who were identified by the physical exam and not by self-report.

PRINCIPAL FINDINGS

Interviewers performed the exam successfully under field conditions. Respondent acceptance of the instrument was high. Interrater agreement was 100 percent regarding the need for referral on the basis of blood pressure and vision. Kappa statistics for skin, foot, and edema findings were .67,.71, and .81, respectively. Adjusted for sampling weights, 60 percent of this population required referral for at least one of the specified conditions. For those portions of the survey for which both self-report and physical exam data were available, lay interviewers made significant percentages of referrals on the basis of physical findings alone.

CONCLUSIONS

High blood pressure, poor vision, peripheral vascular diseases of the feet and legs, and significant skin conditions are prevalent among the homeless in Los Angeles County. Without physical exam data, estimates of the prevalence of these conditions will be incorrect. Researchers can use laypersons to collect reliable and valid physical exam data on disadvantaged populations. This represents a new tool for assessing and monitoring the health of these populations.

Congenital cytomegalovirus infection presenting as cerebral ventriculomegaly on antenatal sonography

Antenatal sonography in two cases demonstrated cerebral ventriculomegaly and decreased head circumference, subsequently found to be secondary to cytomegalovirus (CMV) infection. In both cases, the lateral ventricles were enlarged and lissencephaly was diagnosed in the neonatal period. The findings of ventriculomegaly and decreased head circumference on antenatal sonography warrant further investigation for CMV via amniotic fluid cultures or fetal blood, given the poor prognosis in infants with symptomatic infection.

Vasectomy and prostate cancer risk: methodological review of the evidence

Two recent studies have reported a significantly elevated risk of prostate cancer among vasectomized men. To assess whether the new results conflict with earlier studies that found no significant overall association, and, if so, whether such a conflict could have a methodological basis, we reviewed the six major epidemiological studies of this topic. Statistical analysis revealed significant (p < 0.01) heterogeneity among the associations in the six studies, attributable to one of the recent studies. Scrutiny of the studies for fulfillment of eight methodological standards for scientific validity revealed that no study completely fulfilled more than four standards, and that all studies were deficient in avoiding detection bias and obtaining accurate vasectomy histories. Our review indicates that the evidence on this topic is indeed conflicting, that the quality of the evidence does not resolve the conflict, and that future studies of this topic, designed to ensure scientific credibility of results, are needed.

Distortion-product otoacoustic emissions in human newborns and adults

Cubic distortion-product otoacoustic emissions (DPEs) may have clinical and research applications. We reliably recorded DPEs at some frequencies in all of the normal-hearing human adults and newborns tested. Adult and newborn DPEs were of comparable amplitude, with the exception that a prominent dip between 1 and 3 kHz in the adult data was less evident in the newborn data. DPE amplitude was a linear function of the intensity of the eliciting primary stimuli. The slopes of the linear input-output functions increased with increasing frequency. Except at the highest frequencies assessed, adult input-output functions were steeper than newborn input-output functions.

Maximum length sequence auditory evoked brainstem responses in human newborns and adults

Experiment 1 investigated developmental differences at high stimulus rates by using maximum length sequences (MLSs) and cross-correlation techniques to recover auditory evoked brainstem responses (ABRs). Reliable MLS ABRs were recorded in all of the newborns tested at the highest rate presented (minimum interpulse interval = 1.1 msec). Interpreting developmental rate effects from latency and amplitude shifts is problematic. Identification of higher order kernals offers new information concerning developmental rate effects. Kernel slices were measured at lower rates in more adults than newborns, suggesting that the newborn auditory system is less sensitive to temporal nonlinearities than the mature auditory system. This runs counter to developmental rate studies using conventional stimuli. Experiment 2 investigated developmental differences at high rates due to varying stimulus intensities. MLS wave V intensity functions were less steep than conventional wave V intensity functions. MLS thresholds were also higher than conventional thresholds (primarily due to the newborn data). Without equating for signal-to-noise ratio, it is difficult to make unambiguous conclusions concerning the observed developmental differences.

Neisseria sicca endocarditis with embolic phenomena

Two patients with poor oral hygiene developed Neisseria sicca endocarditis, one after probable intravenous drug abuse and Staphylococcus aureus endocarditis and the other after a periodontal surgical procedure. Both experienced significant embolic phenomena and both required 6 or more weeks of intravenous antibiotic therapy. The diagnosis of N. sicca endocarditis must be considered when this organism is isolated from blood cultures in patients with emboli.

Oral contraceptive use and the risk of chlamydial and gonococcal infections

Oral contraceptive users were compared with nonusers with respect to the rate of cervical infections by Chlamydia trachomatis and Neisseria gonorrhoeae. The comparison was adjusted for differences in demographic and behavioral characteristics between the two groups. The rates of infection among oral contraceptive users were increased by approximately 70% (statistically significant) for both pathogens. Cervical ectopy was implicated in the increased rate of chlamydia but not gonorrhea. Rates of gonorrheal infection differed significantly among oral contraceptive formulations; rates were higher for formulations containing more androgenic progestins.

Respiratory origin of fluctuations in arterial blood pressure in premature infants with respiratory distress syndrome

A variable fluctuating pattern of arterial BP often precedes intraventricular hemorrhage in mechanically ventilated preterm infants. To learn more about the origin of this pattern, arterial BP and respiratory muscle activity were studied in five intubated premature infants who were at high risk for intraventricular hemorrhage. We monitored esophageal pressure, gastric pressure, and arterial BP. Consistent findings were: (1) arterial BP fluctuations have the same frequency and direction of change as esophageal and gastric pressure changes associated with spontaneous breathing (R ranged from .93 to .98, P less than .001); (2) spontaneous apneic pauses were accompanied by sudden and complete cessation of arterial BP fluctuations; (3) large "cough-like" fluctuations in esophageal and gastric pressures, seen in all infants, were associated with the largest fluctuations in arterial BP; (4) cutaneous stimulation had negligible effect on fluctuation in arterial BP provided no change in esophageal and gastric pressures occurred; (5) the effects of change in esophageal and gastric pressures on arterial BP were nearly simultaneous (0.05 to 0.25 second latency); (6) respirator pressure fluctuations had negligible effects on the fluctuations in arterial BP. These data suggest that the fluctuations in arterial BP are directly related to respiratory muscle activity and are most consistent with the familiar pulsus paradoxus that occurs in various other cardiorespiratory diseases.

Tracheal stenosis. Lethal malformation in two infants of diabetic mothers

In two infants of diabetic mothers, severe respiratory distress developed at birth and the infants died shortly thereafter. Autopsy revealed tracheal stenosis and significant cardiac abnormalities.

Use of low intensity roentgen ray imaging for determination of tube and catheter placement in the young primate: implication for use of the Lixiscope in the surgical neonate

The new technology of low intensity roentgen ray imaging offers promise in rapid bedside location of tube and catheter placement in the surgical neonate. Using the Lixiscope we have been able to accurately detect in an animal model the exact location of various tubes and catheters used routinely in pre and postoperative neonatal care. Minimal training is required to be able to use the device. We think the Lixiscope offers detection of the positions of standard tubes and catheters with increased speed, as well as a reduction in the radiation exposure for patients and staff in the neonatal unit.

Molecular characterization of the purity of seven human chromosome-specific DNA libraries

We have characterized at the molecular level seven chromosome-specific libraries constructed in phage lambda Charon 21A from flow-sorted human chromosomes. The purity of libraries prepared from chromosomes sorted from hamster X human cells was estimated by species-specific hybridization and ranged from 48% to 83% of clones containing human inserts. Among libraries of chromosomes from human cells, mass screenings were made for repetitive sequences and 20 clones from the #18 and #20 libraries were analyzed in detail. Ten to fifteen percent of all clones contain sequences which can be mapped; 80-100% of these derive from the intended chromosome of origin, demonstrating very high purity and a 35 X enrichment of chromosome-specific sequences over a total genomic library. The two libraries contain a high, though dissimilar, percent of repeat-containing clones; the #18 library has 55% repetitive clones and the #20 library 85%. This dissimilarity may be due to a difference in insert size distribution, since the #18 library has smaller inserts than the #20. This could be caused by variation in extent of digestion of insert DNA and/or differences in sequence organization between the two chromosomes. A method more sensitive than conventional plaque-lift screening was used to detect repetitive inserts; in this way nearly all repetitive clones could be eliminated before purification of their DNAs.

Prevalence and trends in oral contraceptive use in premenopausal females ages 12-54 years, United States, 1971-80

Data from the second National Health and Nutrition Examination Survey (NHANES II) were analyzed to estimate the prevalence of oral contraceptive use in the United States, 1976-80. The overall unadjusted prevalence of oral contraceptive use was 16.7 per cent for premenopausal females ages 12-54 years (19.2 per cent for ages 15-44 years). Approximately 8.7 million females (95 per cent confidence interval, 6.9-10.5 million) were oral contraceptive users at the midpoint of NHANES II (March 1978). Comparison to the NHANES I, conducted in 1971-74, indicated a stable number of overall oral contraceptive users in the US population during the 1970s, with shifts in certain age groups: oral contraceptive use increased for females ages 12-19 years and decreased for females ages 20-49 years. The overall age-adjusted prevalences indicated a 2 per cent (95 per cent CI, 0.2-3.8 per cent) decline in oral contraceptive use from the early to the late 1970s. The NHANES provides comparative data and supports findings from another national survey showing a decrease in the per cent of females using oral contraceptives during 1973-82. Trends in oral contraceptive use are also presented by race, poverty level, rural-urban residence, marital status, and education level.

Everyday forgetting experiences: real-time investigations with implications for the study of memory management in brain-damaged patients

In order to attempt to measure everyday forgetting experiences outside the laboratory, groups of undergraduates, healthy old people, and neuropathological patients with memory complaints were asked to use portable memory diaries. For a period of 7 days, they were immediately to write down every instance of noticing that they had forgotten anything. Types of forgetting, their frequency, and types of cues in the world that served as reminders that forgetting had occurred are discussed.

One side of a deletion breakpoint from the Drosophila melanogaster genome contains a transposable element

The deletion-fusion fragment of the Drosophila melanogaster X-chromosome deficiency Df(1)N5419 was cloned in a lambda phage vector. DNA on the genetic left side of the fusion contains sequences homologous to the roo family of transposable repetitive elements. Restriction mapping data are consistent with the right end of the roo element being situated near the breakpoint. The deficiency is of spontaneous origin, and it is possible that transposition of the roo element was involved in the deletion event.

Cycloheximide and heat shock induce new polypeptide synthesis in Neurospora crassa

Treatment of Neurospora crassa with 0.1 microgram of cycloheximide per ml, a concentration which inhibited protein synthesis by about 70%, resulted in the greatly enhanced synthesis of at least three polypeptide bands with estimated molecular weights of 88,000, 30,000, and 28,000. A temperature shift from 25 to 37 degrees C resulted in the appearance of a single new polypeptide band of 70,000 daltons, the same size as the major heat shock-induced proteins observed in species of Drosophila and Dictyostelium. Synthesis of the cycloheximide-stimulated polypeptide bands was on cytoplasmic ribosomes rather than on mitochondrial ribosomes, as incorporation of isotope into the polypeptide bands was inhibited by 1.0 microgram of cycloheximide per ml but not by 1 mg of chloramphenicol per ml. In a mutant with cycloheximide-resistant ribosomes, 0.1 microgram of cycloheximide per ml failed to alter the pattern of protein synthesis from that of the controls. It is suggested that the new synthesis of the polypeptide bands reflects specific mechanisms of adaptation to different kinds of environmental stress, including inhibition of protein synthesis and temperature increases.

Cycloheximide-induced phase shifting of circadian clock of Neurospora

Cycloheximide (CHX), an inhibitor of cytosolic (80S) protein synthesis in eucaryotes, causes phase shifts of the circadian clock of Neurospora crassa when administered as 4-h pulses to cultures in liquid medium. Differential effects of the pulses at different phases of the circadian cycle were observed and plotted as a phase-response curve (PRC). Nearly all phase shifts observed were phase advances, with maximum sensitivity in the middle of the subjective day. Inhibition of protein synthesis by CHX was the same at both phases of the cycle. The PRC was the same at 20 and 25 degrees C. Dose-response curves for the effects of CHX on phase shifting and inhibition of protein synthesis were determined and showed a striking parallel in the responses of these two phenomena to CHX. These results support the view that synthesis of one or more proteins at specific phases of the circadian cycle is necessary for the normal operation of the circadian clock of Neurospora.

Genetic Evidence That Protein Synthesis Is Required for the Circadia Clock of Neurospora

Small doses of cycloheximide given at intervals (pulses) cause phase shifts of the circadian clock of Neurospora. The effects of this drug on the clock are mediated through its inhibition of protein synthesis, since two cycloheximide-resistant mutants whose 80S ribosomes are resistant to cycloheximide showed no phase shift after exposure to the durg.

Assay and Characteristics of Circadian Rhythmicity in Liquid Cultures of Neurospora crassa

Previous work on circadian rhythms of Neurospora crassa has been done almost exclusively with cultures expressing rhythmic conidiation and growing on solid agar medium. Such conditions severely restrict the kinds of biochemical experiments that can be carried out. We have now developed systems which allow indirect assay of circadian rhythmicity in liquid culture. Neurospora was grown in glucose and acetate liquid media under conditions which result in a range of growth rates and morphologies. Liquid media were inoculated with conidia and the cultures were grown in constant light for 33 or 48 hours, by which time floating mycelial pads had formed. Experimental pieces of mycelium then were cut and placed in fresh new liquid medium. As controls, other pieces of mycelium were cut and put directly on solid agar medium in race tubes. All cultures were transferred to constant darkness at this time. This light-to-dark transition set the phase of the circadian clock of both the liquid and solid cultures. At various times after the light-to-dark transition, the mycelial pieces in the liquid were transferred in the dark to solid medium in race tubes, where they grew normally and conidiated rhythmically. Comparison of the phase of the rhythm in these race tubes to the controls demonstrated that, under appropriate conditions, the circadian clock of the liquid cultures functions normally for at least two cycles in constant conditions. Using these culture systems, a significantly greater variety of biochemical studies of circadian rhythmicity in Neurospora is now possible.

Comparison of antibody responses in normal and alloxan diabetic mice

The reason for the increased incidence and severity of infections in diabetic patients has never been satisfactorily explained. This investigation was designed to study the circulating antibody response in alloxan diabetic, insulin treated diabetic and normal CF-1 mice injected with bovine serum albumin. Only those animals treated with alloxan who had elevated serum glucose levels (250 mg./100 ml. or higher) were included in the study, together with a group of normal animals. Animals were bled from the orbital sinus and the serum analyzed for antigen binding capacity of BSA, glucose concentration and serum proteins. BSA was iodinated with I-131 and the antigen binding capacity of each serum sample was determined as micrograms of BSA nitrogen bound by 1 ml. of undiluted serum. Our studies demonstrate that there is no significant difference in antibody response of alloxan treated mice, alloxan treated mice given insulin and normal mice when immunized with BSA under the conditions of the experiments. If the alloxan treated mouse may be considered a laboratory model of diabetes mellitus in man, the results described herein would be consistent with those studies of diabetics which have shown no primary defect in their immune systems.