Analytic performance of two automated nonpretreatment digoxin immunoassays

The analytic performance of two automated nonpretreatment digoxin methods, AxSYM Digoxin II and Vitros digoxin immunoassays, was assessed. Both assays had analytic sensitivities of less than 0.2 microg/L, were linear from digoxin concentrations of 0.5 to 4.0 microg/L, and showed acceptable precision, with a maximum total coefficient of variation (CV) of 8.9% and 6.4% for the AxSYM and Vitros, respectively. Comparison of the two methods using samples from patients receiving digoxin gave the following relationship: Vitros = 0.91 x AxSYM + 0.23 (r = 0.97, Sy,x = 0.12). Digoxinlike immunoreactive factor (DLIF) crossreactivity was examined in specimens from patients who had hepatic disease, renal insufficiency, had undergone cardiac surgery, and in neonatal cord blood samples. Minimal crossreactivity was observed for most samples and the average crossreactivity for each group of samples was comparable for the two methods. The recovery of digoxin added to samples from each group of DLIF was similar, except for that from cord blood samples, for which recovery was significantly lower with the AxSYM method. Titration of a digoxin-spiked serum pool with digoxin-immune Fab showed a similar decrease in the measured digoxin concentration for both methods. Overall, the analytic performance characteristics of these two methods were comparable.

From randomized trial to community-focused practice

PURPOSE

To describe the use of findings from a randomized trial--a nursing intervention using telephone contacts to reduce the incidence of low-birth-weight and preterm births--in four community settings in North Carolina, to show that implementing research into practice is important. Low-birth-weight and preterm births are the major cause of high infant mortality in the United States. Rates are highest among African-American women. Telephone intervention as a strategy for preventive health care can be cost effective, reduce low-birth-weight and preterm births in African-American women, and provide a means of health consultation for parents of children age five and under.

ORGANIZING FRAMEWORK

Four community programs are discussed in relation to five phases of implementing and sustaining research in communities: research, transfer, transition, regeneration, and empowerment. Modification from the original research, bonuses, and barriers are described for each program.

METHODS

The randomized trial was conducted from 1990-1995. Randomized trial data and data for subsequent projects were collected from telephone interviews and health care records from 1994-1998. A successful adaptation was made from the original randomized trial to the four programs by (a) educating the staff for each program about the methods and findings in the original research, and (b) working with program staff to make appropriate modifications for each site.

CONCLUSIONS

Findings from a randomized trial can be used in a variety of settings. By working together, researchers and community-health nurses can integrate research findings into community-health nursing practice.

Unloaded heart in vivo replicates fetal gene expression of cardiac hypertrophy

The cardiac response to increased work includes a reactivation of fetal genes. The response to a decrease in cardiac work is not known. Such information is of clinical interest, because mechanical unloading can improve the functional capacity of the failing heart. We compared here the patterns of gene expression in unloaded rat heart with those in hypertrophied rat heart. Both conditions induced a re-expression of growth factors and proto-oncogenes, and a downregulation of the 'adult' isoforms, but not of the 'fetal' isoforms, of proteins regulating myocardial energetics. Therefore, opposite changes in cardiac workload in vivo induce similar patterns of gene response. Reactivation of fetal genes may underlie the functional improvement of an unloaded failing heart.

Reducing preterm and low birthweight births: still a nursing challenge

Preterm birth and low birthweight are correlated with much of the infant death seen in the United States. Despite 15 years of research, both preterm birth rates and low birthweight rates continue to increase. This article describes what is known about the prevention of preterm birth and low birthweight, and offers advice to nurses for nursing interventions that could prove effective in preventing such tragedies in the future.

The prevalence of domestic violence among women seeking abortion

OBJECTIVE

To determine the prevalence of self-reported abuse in a population of women aged 18 years or older seeking elective pregnancy termination, and to compare abused and nonabused women with respect to the primary reasons for pregnancy termination.

METHODS

A self-administered questionnaire was returned by 486 women seeking outpatient abortion. The survey included demographic information, abuse screening, and items regarding partner involvement/awareness of the pregnancy, and abuse as a determinant of the abortion decision. One open-ended item asking the primary reason for pregnancy termination was included.

RESULTS

The prevalence of self-reported abuse in this population was 39.5%. White women were significantly more likely to report any history of abuse than nonwhite women. Relationship issues were the only reason for pregnancy termination given more often by women with an abuse history than by nonabused women. Women with abuse histories were significantly less likely than nonabused women to inform the partner of the pregnancy or to have partner support for or involvement in the abortion decision.

CONCLUSION

The prevalence of abuse reported by women in this population suggests that many women seeking abortion services may have abuse histories. Abused women may have different reasons for pregnancy termination than nonabused women and may be more likely to make the abortion decision without partner involvement. When routine screening for abuse is included in abortion counseling, health providers have the opportunity for developing a safety plan and initiating appropriate referral.

Comparison of four commercial urinary albumin (microalbumin) methods: implications for detecting diabetic nephropathy using random urine specimens

The results of four urinary albumin methods used to identify patients with early diabetic renal disease were compared using random urine samples from healthy and diabetic patients. These methods were the Beckman Array and Behring BNAI immunonephelometric methods, the Dade aca particle-enhanced turbidimetric inhibition immunoassay method, and the INCSTAR SPQ immunoturbidimetric method. The albumin/creatinine ratio reference interval was found to be 2-20 mg albumin/g creatinine (mg/g) for the Array and 3.5-27.5 mg/g for the aca method. All four methods were compared using urines from a group of diabetic and nondiabetic patients. The BNAI, SPQ and Array methods compared well with one another while the aca demonstrated a positive bias of almost 60% at the 30 mg/g and 300 mg/g levels with certain lots of reagent and calibrator. Calibrator cross-over experiments demonstrated that some of the positive bias of the aca method could be accounted for by calibrator differences.

A randomized trial of nurse intervention to reduce preterm and low birth weight births

OBJECTIVE

To test the effect of telephone calls from registered nurses to low-income pregnant women on the rates of low birth weight (LBW) and preterm births.

METHODS

A total of 1554 women receiving prenatal care in a public clinic who met study criteria and who consented were assigned randomly to intervention and control groups. Women in the intervention group received telephone calls from a registered nurse, one or two times weekly from 24 weeks' through 37 weeks' gestation. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Low birth weight rates were 10.9% in the intervention group and 14.0% in the control group (RR 0.75; 95% CI 0.55, 1.03; P = .072). For gestational age less than 37 weeks, rates were 9.7 in the intervention group and 11.0 in the control group (RR .87; 95% CI 0.62, 1.22; P = .415). In the subgroup of low-income black women 19 years of age and older, a statistically significant difference was found in preterm birth rates before 37 weeks (8.7% in the intervention group versus 15.4% in the controls [RR 0.56; 95% CI 0.38, 0.84; P = .004]).

CONCLUSION

There was no difference in LBW or preterm births between intervention and control groups in the total sample. In a secondary analysis of black subjects 19 years of age and older, there was a significant difference in preterm birth rates.

Attitudes and practices of registered nurses toward women who have experienced abuse/domestic violence

OBJECTIVE

To compare the education, attitudes, and practices related to domestic violence of perinatal nurses from three types of practice sites.

DESIGN

A descriptive study of responses to a questionnaire administered to a convenience sample and through a mailing.

SETTING

Education conferences and responses to a mailing.

PARTICIPANTS

Two hundred seventy-five nurses in perinatal practice (87 public health, 71 hospital, 117 private office).

MAIN OUTCOME MEASURES

Primary outcomes were attitudes and beliefs about domestic violence and nursing behavior when domestic violence was identified. The effects of education about domestic violence on practice and the effect of a personal/family history of domestic violence on practice were examined.

RESULTS

Some differences were found in the attitudes and beliefs of nurses from different practice sites, but more differences were found in their behaviors. Only 54% of the total sample reported having education about domestic violence, received in formal or continuing education programs. Public health nurses were the most likely to have such education. Education affected both attitudes and behavior. In the total sample, 31% of nurses reported abuse of themselves or family members.

CONCLUSIONS

Nursing care for women who have experienced domestic violence includes assessment and appropriate counseling. Many nurses in this study lacked education about domestic violence. The provision of education about abuse and domestic violence is a first step toward a change in nursing practice.

Protein kinase C and receptor kinase gene expression in olfactory receptor neurons

Recent biochemical evidence indicates that protein kinase C (PKC) and G-protein-coupled receptor kinases (GRKs) are involved in olfactory signal termination and desensitization. The polymerase chain reaction (PCR) was used to investigate the expression of PKC and GRK genes in olfactory tissue and in isolated olfactory receptor neurons from channel catfish (Ictalurus punctatus). Sequence analysis of cloned PKC PCR products showed that the alpha, beta, delta, epsilon, and theta isotypes were expressed in olfactory tissue. Sequence analysis of PCR products obtained from isolated olfactory receptor neurons showed that PKC beta and PKC delta were expressed in the receptor cells. A 600-bp GRK PCR product was obtained from isolated olfactory neurons that shared 86% and 92% amino acid sequence identity to the mammalian beta-adrenergic receptor kinase gene products beta ARK1 and beta ARK2, respectively. Go6976, a specific inhibitor of calcium-regulated PKC activity, completely inhibited odorant-stimulated PKC activity in isolated olfactory cilia. This result suggested that odorant-stimulated PKC activity is mediated by the calcium-sensitive PKC beta isotype. Taken together, these results are consistent with the conclusion that PKC beta and beta ARK mediate odorant receptor phosphorylation and olfactory signal termination.

Protein kinase C and receptor kinase gene expression in olfactory receptor neurons

Recent biochemical evidence indicates that protein kinase C (PKC) and G-protein-coupled receptor kinases (GRKs) are involved in olfactory signal termination and desensitization. The polymerase chain reaction (PCR) was used to investigate the expression of PKC and GRK genes in olfactory tissue and in isolated olfactory receptor neurons from channel catfish (Ictalurus punctatus). Sequence analysis of cloned PKC PCR products showed that the alpha, beta, delta, epsilon, and theta isotypes were expressed in olfactory tissue. Sequence analysis of PCR products obtained from isolated olfactory receptor neurons showed that PKC beta and PKC delta were expressed in the receptor cells. A 600-bp GRK PCR product was obtained from isolated olfactory neurons that shared 86% and 92% amino acid sequence identity to the mammalian beta-adrenergic receptor kinase gene products beta ARK1 and beta ARK2, respectively. Go6976, a specific inhibitor of calcium-regulated PKC activity, completely inhibited odorant-stimulated PKC activity in isolated olfactory cilia. This result suggested that odorant-stimulated PKC activity is mediated by the calcium-sensitive PKC beta isotype. Taken together, these results are consistent with the conclusion that PKC beta and beta ARK mediate odorant receptor phosphorylation and olfactory signal termination.

Parent Line: nurse telephone intervention for parents and caregivers of children from birth through age 5

PURPOSE

To describe the development and implementation of Parent Line, a program to improve the health and development status of children through periodic telephone contact by nurses.

POPULATION

Low-income parents of children from birth through age 5.

CONCLUSION

Telephone contact with a nurse, combined with peer counselor contact when no telephone is available, is welcomed by parents and can address needs in a timely way that might be unmet otherwise. Telephone intervention can provide social and emotional support, education, and advocacy for families.

PRACTICE IMPLICATIONS

The telephone can be of value to pediatric nurses in providing anticipatory guidance and health teaching, and be a support to parents throughout the preschool years.

Family violence issues in obstetrics and gynecology, primary care, and nursing texts

OBJECTIVE

To evaluate major texts in obstetrics and gynecology, primary care, and nursing for their content in the area of family violence.

METHODS

The study included 48 medical texts and 19 nursing texts published between 1990 and 1996. Key words and phrases were identified and indices searched. Minimum requirements for content on domestic violence included 12 issues identified as important. If the text contained any information on an issue, it received one point. A domestic violence content score was calculated, and a maximum score of 12 was possible. Textbooks were evaluated for content related to domestic violence as well as rape, child sexual abuse, abuse in pregnancy, and elder abuse.

RESULTS

Thirty-seven percent of physician texts and 63% of nursing texts included some content on domestic violence. On our domestic violence content scale, 16% of medicine texts and 10% of nursing texts scored 9-12.

CONCLUSION

The availability of information on family violence is limited in both medical and nursing texts.

A new tool to measure pressure under burn garments

This article introduces a new tool to measure the pressure that is under pressure garments. The Iscan (Tekscan, Inc.) system uses a patented ultra-thin (0.007 inch) sensor with multiple sensing locations that sample continuously at 100 times per second. It is noninvasive, convenient, and quick. The study had two parts. First, we established the validity and reliability of the device. Next, garment/scar interface pressures were measured on new garments with use of the Iscan system. Four garment types were studied, with 10 measurements made in each group: Isotoner gloves (Smith & Nephew Roylan, Inc.); custom-fit pressure gloves; Tubigrip forearm sleeves (Seton Health Care Group); and custom-fit pressure forearm sleeves. Mean garment/scar interface pressures were 18 +/- 2 mm Hg for the Isotoner glove, 34 +/- 5 mm Hg for the custom-fit pressure glove, 20 +/- 7 mm Hg for the Tubigrip sleeve, and 35 +/- 6 mm Hg for the custom-fit sleeve. We concluded that the Iscan system can be used to measure pressure under pressure garments accurately and reliably, and that custom-fit hand and forearm garments provide more pressure than Isotoner gloves or Tubigrip sleeves.

A check on rational drug design: crystal structure of a complex of human immunodeficiency virus type 1 protease with a novel gamma-turn mimetic inhibitor

We have previously reported (Newlander et al., J. Med. Chem. 1993, 36, 2321-2331) the design of human immunodeficiency virus type 1 (HIV-1) protease inhibitors incorporating C7 mimetics that lock three amino acid residues of a peptide sequence into a gamma-turn. The design of one such compound, SB203238, was based on X-ray structures of reduced amide aspartyl protease inhibitors. It incorporates a gamma-turn mimetic in the P2-P1' position, where the carbonyl of the C7 ring is replaced with an sp3 methylene group yielding a constrained reduced amide. It shows competitive inhibition with Ki = 430 nM at pH 6.0. The three-dimensional structure of SB203238 bound to the active site of HIV-1 protease has been determined at 2.3 A resolution by X-ray diffraction and refined to a crystallographic R-factor (R = sigma magnitude of Fo magnitude of - magnitude of Fc magnitude of /sigma magnitude of Fo magnitude of, where Fo and Fc are the observed and calculated structure factor amplitudes, respectively) of 0.177. The inhibitor lies in an extended conformation in the active site; however, because of the constrained geometry of the C7 ring, it maintains fewer hydrogen bonds with the protein than in most other HIV-1 protease-inhibitor complexes. More importantly, the inhibitor binds to the enzyme differently than predicted in its design, by binding with the P2-P1' alpha-carbon atoms shifted by approximately one-half a residue toward the N-terminus from their presumed positions. This study illustrates the importance of structural information in an approach to rational drug design.

Anion dependence of bumetanide binding and ion transport by the rabbit parotid Na(+)-K(+)-2Cl- co-transporter: evidence for an intracellular anion modifier site

The anion dependence of [3H]bumetanide binding and 22Na+ transport by the rabbit parotid Na(+)-K(+)-2Cl- co-transporter was studied in acinar basolateral membrane vesicles (BLMVs). Cl-, Br- and NO3- have a biphasic effect on binding consistent with the presence of two anion sites associated with the bumetanide binding event, a high-affinity stimulatory site and a lower-affinity inhibitory site. We show that formate shares only the stimulatory site and SO4(2-) only the inhibitory site. The initial rate of [3H]bumetanide binding was stimulated by formate or low [Cl-] and inhibited by SO4(2-) or high [Cl-], but the rate of [3H]bumetanide dissociation was not affected by the presence of these anions in the dissociation medium. However, when [3H]bumetanide was bound to BLMVs in the presence of formate its rate of dissociation was more than four times faster than when binding took place in the presence of Cl-. These observations indicate that the binding of bumetanide and the stimulatory anion are ordered such that the anion must necessarily bind first and subsequently cannot dissociate until after bumetanide dissociates. In zero-trans-flux experiments, extravesicular SO4(2-) and formate had no effect on 22Na+ transport via the co-transporter [Turner and George (1988) J. Membr. Biol. 102, 71-77]. Thus neither of the anion sites associated with bumetanide binding is a Cl- transport site. However, we show here that SO4(2-) inhibits transport when present in the intravesicular space. Since the BLMV preparation is predominantly oriented cytosolic-side-in, this observation indicates the existence of an inhibitory cytosolic anion modifier site. Our data suggest that this site is identical to the inhibitory anion site associated with bumetanide binding.

Status report on maternal and child health indicators

The health of pregnant women and children has improved substantially since the 1960s. In the past decade, however, progress in preventing infant deaths, reducing the incidence of low-birth-weight infants, and ensuring first trimester prenatal care has slowed. African-American infants suffer a significantly higher risk of poor pregnancy outcome. Immunization rates for preschoolers remain low. Changing social conditions including a rising child poverty rate, a high teenage birth rate, an increased rate of births to unmarried women, and higher levels of unintended pregnancy may be contributing to stalled progress.

Voices from different places: but why a medical school faculty?

Interdisciplinary collaboration between nursing and medicine is a valued goal, but one which is difficult to achieve. Two nurses who are faculty members in medical schools reflect on their unique roles and how these encompass interdisciplinary research, teaching, and practice.

Etiology of low-birthweight birth: a population-based study

BACKGROUND

Preterm and low-birthweight births remain the major correlates of infant mortality in the United States. The recognition that these births result from varying proximal etiologies is essential to the development of preventive strategies specific to each etiologic group.

METHODS

Using vital statistics data tapes provided by the North Carolina Center for Health and Environmental Statistics, mothers in 20 counties who delivered infants with birthweights between 1 pound and 5 pounds, 8 ounces were identified. Maternal hospital records of 4,754 women were reviewed for data about prenatal and intrapartal events. Two perinatologists classified births into four proximal etiology groups: term-lowbirthweight, medically indicated preterm birth, preterm premature rupture of membranes, and idiopathic preterm birth. Information from birth certificate and hospital records was merged to provide an expanded data set.

RESULTS

Race, age, education, and marital status are associated with different patterns of proximal etiology. Rates were higher for all etiologies in black women and in young women; however, the absolute number of LBW births was highest among white women. Idiopathic preterm birth was highest in black women and decreased as age increased; medical indications for preterm birth increased with increasing age.

CONCLUSIONS

Classification of LBW births by etiologic group provides insights of value to both clinicians and researchers. Studies in which LBW and/or preterm birth are the outcome variables will be enhanced by identifying etiology. Multiple preventive strategies should address varying etiologic groups.

Analogues of the thrombin receptor tethered-ligand enhance mesangial cell proliferation

Thrombin stimulates cytosolic calcium mobilization and tritiated thymidine incorporation in rat glomerular mesangial cells. This effect may be mediated by a thrombin receptor similar to the receptor found in human platelets. In order to test this possibility, a series of analogues of the thrombin receptor peptide, SFLL-RNPNDKYEPF, was evaluated for their effects on mesangial cells. Analogues of the thrombin receptor peptide containing five, six, seven and 14 amino acids were as efficacious as thrombin with respect to calcium mobilization and thymidine incorporation, although they were significantly less potent. The dissimilarity in potency between thrombin and the thrombin receptor peptides is consistent with the kinetics of the proposed mechanism of action of the enzyme, since the cleavage by thrombin of its receptor results in a tethered ligand which is at a relatively high concentration compared to the free peptides in solution. Those thrombin receptor peptide analogues which showed decreased activity in platelets were tested in mesangial cells. Removal of serine at position one, N-acetylation, or replacement of the phenylalanine at position two with alanine resulted in analogues which were inactive in stimulating mesangial cell proliferation or calcium mobilization. In addition, those analogues which had no stimulatory effects in mesangial cells were not antagonists of SFLLRN-mediated calcium mobilization and thymidine incorporation in mesangial cells.

Race differences in infant mortality from endogenous causes: a population-based study in North Carolina

This study examines the associations between race, birth weight, and mortality from endogenous causes for all singleton births born in 1984-1987 in a 20-county region of North Carolina. A more detailed analysis of preterm low birth weight infants examines these associations according to the proximate medical causes (medical etiology) of the preterm birth. Overall, black infants were found to have approximately twice the mortality risk of white infants. Most of the excess black mortality risk is explained by the larger proportion of black infants born at lower birth weights. The pattern of race differences in infant mortality by birth weight generally replicates the results of earlier studies, but the relative risk ratios within specific birth weight categories are smaller than previously reported. Among preterm low birth weight infants, the association between race and endogenous mortality differs within categories of medical etiology. The mortality risk is the same for black and white infants born preterm due to premature rupture of the membranes (PROM), lower for black infants born preterm due to medical problems, and higher for black infants born preterm due to idiopathic premature labor (IPL).

A novel constrained reduced-amide inhibitor of HIV-1 protease derived from the sequential incorporation of gamma-turn mimetics into a model substrate

C7 mimetics, designed to lock three amino acid residues of a peptide chain into a gamma-turn conformation, were introduced sequentially between the P3 to P2' positions of a model HIV-1 protease substrate I (resulting in compounds II-IV) to probe its conformational requirements in binding to HIV-1 protease. Of these, compound IIIa with the C7 mimetic replacing Asn-Tyr-Pro, corresponding to the P2 through P1' positions of substrate, was found to be an inhibitor with a Ki of 147 microM. Reduction of the amide bond in the C7 mimetic of IIIa resulted in a novel constrained reduced-amide mimetic VIa with a Ki of 430 nM. This corresponds to over a 300-fold improvement in inhibitory activity over the original C7 mimetic. The inhibitory activity of mimetic VIa was in addition found to be 44-fold better than a similar linear reduced-amide containing inhibitor V. The synthesis of these mimetics are described.

Long-chain fatty acids and ethanol affect the properties of membranes in Drosophila melanogaster larvae

The larval fatty acid composition of neutral lipids and membrane lipids was determined in three ethanol-tolerant strains of Drosophila melanogaster. Dietary ethanol promoted a decrease in long-chain fatty acids in neutral lipids along with enhanced alcohol dehydrogenase (EC 1.1.1.1) activity in all of the strains. Dietary ethanol also increased the incorporation of 14C-ethanol into fatty acid ethyl esters (FAEE) by two- to threefold and decreased the incorporation of 14C-ethanol into free fatty acids (FFA). When cultured on sterile, defined media with stearic acid at 0 to 5 mM, stearic acid decreased ADH activity up to 33%. In strains not selected for superior tolerance to ethanol, dietary ethanol promoted a loss of long-chain fatty acids in membrane lipids. The loss of long-chain fatty acids in membranes was strongly correlated with increased fluidity in hydrophobic domains of mitochondrial membranes as determined by electron spin resonance and correlated with a loss of ethanol tolerance. In the ethanol-tolerant E2 strain, which had been exposed to ethanol for many generations, dietary ethanol failed to promote a loss of long-chain fatty acids in membrane lipids.

Reconstruction of foot burn contractures in children

Burn scar contractures of the foot cause significant morbidity. We reviewed 68 children in regard to number and rates of burn scar contracture recurrence, surgical techniques, and functional and aesthetic results. Two surgical techniques of foot burn scar contracture release have been used. Originally, an incision over the metatarsal heads perpendicular to the line of the metatarsals, which releases the longitudinal arch of the foot was used. More recently, additional releasing incisions parallel to the plane of the metatarsals to release the transverse metatarsal arch have been used. The time between burn injury and primary burn scar contracture release was 4.18 +/- 0.76 years, and the time until the first recurrence was 3.44 +/- 0.46 years. With release of only the longitudinal arch, recurrence of burn scar contractures occurred in 3.5 +/- 0.41 years and in 4.29 +/- 1.27 years in six patients who also received release of the transverse arch. Wound closure at the time of acute burn with split-thickness skin graft expansion ratios of 1:2 and 1:4 had burn scar contractures that required release in 4.21 +/- 0.70 and 2.29 +/- 0.52 years, respectively.