Systematic reanalysis of genomic data improves quality of variant interpretation.

As genomic sequencing expands, so does our knowledge of the link between genetic variation and disease. Deeper catalogs of variant frequencies improve identification of benign variants, while sequencing affected individuals reveals disease-associated variation. Accumulation of human genetic data thus makes reanalysis a means to maximize the benefits of clinical sequencing. We implemented pipelines to systematically reassess sequencing data from 494 individuals with developmental disability. Reanalysis yielded pathogenic or likely pathogenic (P/LP) variants that were not initially reported in 23 individuals, 6 described here, comprising a 16% increase in P/LP yield. We also downgraded 3 LP and 6 variants of uncertain significance (VUS) due to updated population frequency data. The likelihood of identifying a new P/LP variant increased over time, as ~22% of individuals who did not receive a P/LP variant at their original analysis subsequently did after 3 years. We show here that reanalysis and data sharing increase the diagnostic yield and accuracy of clinical sequencing.

Burden of cardiovascular risk factors and cardiovascular disease in childhood cancer survivors: data from the German CVSS-study.

Aims: The cardiac and vascular late sequelae in long-term survivors of childhood cancer (CVSS)-study aimed to quantify the prevalence of cardiovascular risk factors (CVRF) and cardiovascular disease (CVD) in German childhood cancer survivors (CCS). Methods and results: In the CVSS-study (NCT02181049), 1002 CCS (age range 23-48 years) diagnosed with neoplasia prior to 15 years of age between 1980 and 1990 prospectively underwent a systematic, standardized clinical and laboratory cardiovascular screening, identical to the population-based Gutenberg Health Study (GHS) cohort. For 951 individuals, prevalences of CVRF and CVD were primarily compared to the GHS sample and to two further German population-based cohorts. Using log-binomial regression models, an increased risk for occurrence of arterial hypertension [relative risk (RR) 1.38, 95% confidence interval (95% CI 1.21-1.57)] and dyslipidaemia [RR 1.26 (95% CI 1.12-1.42)] was found. This indicates a premature occurrence compared to the general population of approximately 6 and 8 years, respectively [rate advancement period estimator, RAPhypertension 5.75 (95% CI 3.5-8.0) and RAPdyslipidaemia 8.16 (95% CI 4.4-11.9)]. Overall, no differences were observed for obesity and diabetes. Overt CVD was present in 4.5% (95% CI 3.0-6.6%) of CCS [RR 1.89 (95% CI 1.34-2.66), RAPCVD 7.9 (95% CI 4.1-11.7)], of which the most frequent entities were congestive heart failure and venous thromboembolism. Prevalences of CVRF and CVD increased with age without reaching a plateau over time. Conclusion: This large CCS screening examination revealed consistently in comparison to three population samples a considerably increased risk for premature CVD. The findings in these young adult CCS indicate a high burden of cardiovascular morbidity and mortality in the long term. Clinicaltrials. gov-Nr: NCT02181049.

Breast implant-associated anaplastic large cell lymphoma: two distinct clinicopathological variants with different outcomes.

BACKGROUND: ALK-negative anaplastic large cell lymphoma associated with breast implant (i-ALCL) has been recently recognized as a distinct entity. Among 43 830 lymphomas registered in the French Lymphopath network since 2010, 300 breast lymphomas comprising 25 peripheral T-cell lymphomas (PTCL) were reviewed. Among PTCL, ALK-negative ALCL was the most frequent and all of them were associated with breast implants. PATIENTS AND METHODS: Since 2010, all i-ALCL cases were collected from different institutions through Lymphopath. Immuno-morphologic features, molecular data and clinical outcome of 19 i-ALCLs have been retrospectively analyzed. RESULTS: The median age of the patients was 61 years and the median length between breast implant and i-ALCL was 9 years. Most implants were silicone-filled and textured. Implant removal was performed in 17 out of 19 patients with additional treatment based on mostly CHOP or CHOP-like chemotherapy regimens (n = 10/19) or irradiation (n = 1/19). CHOP alone or ABVD following radiation without implant removal have been given in two patients. The two clinical presentations, i.e. effusion and less frequently tumor mass correlated with distinct histopathologic features: in situ i-ALCL (anaplastic cell proliferation confined to the fibrous capsule) and infiltrative i-ALCL (pleomorphic cells massively infiltrating adjacent tissue with eosinophils and sometimes Reed-Sternberg-like cells mimicking Hodgkin lymphoma). Malignant cells were CD30-positive, showed a variable staining for EMA and were ALK negative. Most cases had a cytotoxic T-cell immunophenotype with variable T-cell antigen loss and pSTAT3 nuclear expression. T-cell receptor genes were clonally rearranged in 13 out of 13 tested cases. After 18 months of median follow-up, the 2-year overall survival for in situ and infiltrative i-ALCL was 100% and 52.5%, respectively. CONCLUSIONS: In situ i-ALCLs have an indolent clinical course and generally remain free of disease after implant removal. However, infiltrative i-ALCLs could have a more aggressive clinical course that might require additional therapy to implant removal.

TPM3 deletions cause a hypercontractile congenital muscle stiffness phenotype.

OBJECTIVE: Mutations in TPM3, encoding Tpm3.12, cause a clinically and histopathologically diverse group of myopathies characterized by muscle weakness. We report two patients with novel de novo Tpm3.12 single glutamic acid deletions at positions ΔE218 and ΔE224, resulting in a significant hypercontractile phenotype with congenital muscle stiffness, rather than weakness, and respiratory failure in one patient. METHODS: The effect of the Tpm3.12 deletions on the contractile properties in dissected patient myofibers was measured. We used quantitative in vitro motility assay to measure Ca(2+) sensitivity of thin filaments reconstituted with recombinant Tpm3.12 ΔE218 and ΔE224. RESULTS: Contractility studies on permeabilized myofibers demonstrated reduced maximal active tension from both patients with increased Ca(2+) sensitivity and altered cross-bridge cycling kinetics in ΔE224 fibers. In vitro motility studies showed a two-fold increase in Ca(2+) sensitivity of the fraction of filaments motile and the filament sliding velocity concentrations for both mutations. INTERPRETATION: These data indicate that Tpm3.12 deletions ΔE218 and ΔE224 result in increased Ca(2+) sensitivity of the troponin-tropomyosin complex, resulting in abnormally active interaction of the actin and myosin complex. Both mutations are located in the charged motifs of the actin-binding residues of tropomyosin 3, thus disrupting the electrostatic interactions that facilitate accurate tropomyosin binding with actin necessary to prevent the on-state. The mutations destabilize the off-state and result in excessively sensitized excitation-contraction coupling of the contractile apparatus. This work expands the phenotypic spectrum of TPM3-related disease and provides insights into the pathophysiological mechanisms of the actin-tropomyosin complex.

Persons injured during acute chemical incidents­Hazardous Substances Emergency Events Surveillance, nine states, 1999-2008.

PROBLEM/CONDITION: Persons exposed to chemicals during acute chemical incidents (i.e., uncontrolled or illegal release or threatened release of hazardous substances lasting <72 hours) can experience both acute and chronic health effects. Surveillance of toxic substance incidents provides data that can be used to prevent future incidents and improve the emergency response to those that occur, leading to a decrease in morbidity and mortality from chemical releases. REPORTING PERIOD: 1999-2008 DESCRIPTION OF SYSTEM: The Hazardous Substances Emergency Events Surveillance (HSEES) system was operated by the Agency for Toxic Substances and Disease Registry (ATSDR) during January 1991-September 2009 to describe the public health consequences of chemical releases and to develop activities aimed at reducing the harm. This report summarizes the data collected on injured persons from the nine states (Colorado, Iowa, Minnesota, New York, North Carolina, Oregon, Texas, Washington, and Wisconsin) that participated in HSEES during its last 10 full years of data collection (1999-2008). RESULTS: A total of 57,975 chemical incidents were reported by these states during the 10-year surveillance period. In 4,621 (8%) of these incidents, 15,506 persons were injured. Among them, 354 deaths occurred. The most commonly reported category of injured persons included employees of the responsible party (7,616 [49%]), members of the general public (4,737 [31%]), students exposed at school (1,730 [11%]), and responders to the incident (1,398 [9%]). Deaths occurred among members of the general public (190 [54%]), employees (154 [44%]), and responders (10 [3%]). The most frequent health effects experienced as a result of these incidents included respiratory irritation (7,443), dizziness or central nervous system problems (3,186), and headache (3,167). The three chemicals associated with the largest number of persons injured were carbon monoxide (2,364), ammonia (1,153), and chlorine (763). INTERPRETATION: Company employees, followed by members of the general public, are frequently injured in acute chemical incidents. The chemicals most often associated with these injuries are carbon monoxide, ammonia, and chlorine, all of which are hazardous gases that can be found in various locations including schools and homes. Respiratory irritation is the most common health effect. PUBLIC HEALTH IMPLICATIONS: By understanding the types of persons injured in chemical release incidents, as well as how they are injured and the injuries sustained, prevention outreach activities can be focused to protect the health of these groups in the future. Improved awareness among and training for not just employees but also the public is needed, particularly regarding carbon monoxide, ammonia, and chlorine. Appropriate measures to provide protection from respiratory effects of chemical incidents could prevent injuries.

Effects of dietary additives (potassium diformate/organic acids) as well as influences of grinding intensity (coarse/fine) of diets for weaned piglets experimentally infected with Salmonella Derby or Escherichia coli.

The aim of this study was to examine whether and to what extent the addition of potassium diformate (pdf) or free organic acids (fpa) to the diet and the grinding intensity might affect the course of infection and the passage of orally applied Salmonella and Escherichia coli in pigs. Experiments were carried out using 80 reared piglets allotted to four groups. Pigs were fed pelleted diets ad libitum (except during a 15 h feed-withholding-period before infection). The control diet contained finely ground cereals (2 mm screen). To two test diets (also finely ground) 1.2% pdf, 0.9% organic acids (75% formic and 25% propionic acid, fpa) respectively were added. The fourth diet (without acids) was based on coarsely ground cereals (6-mm screen). After experimental infection alternately with S. Derby or E. coli, the course of infection was examined (rectal swab technique). Pigs were sacrificed 4-5 h after a further oral application of approximately 10(9)-10(10) CFU S. Derby or E. coli to determine the counts of Salmonella or E. coli in chyme (classical culture methods). Adding pdf or fpa to the diet led to reduced Salmonella shedding and resulted in significantly lower counts of Salmonella and E. coli in the stomach content indicating an improved efficacy of the stomach barrier. In the distal parts of the digestive tract, the effect was less obvious concerning counts of E. coli, whereas counts of Salmonella were reduced markedly as well. The diet based on coarsely ground cereals failed to demonstrate positive effects concerning infection and passage of orally applied bacteria as well, but this diet was also pelleted and showed unintentionally, comparable amounts of fine particles. Results obtained in this study allow the recommendation of using pdf or organic acids as additives when dietary measures against Salmonella or E. coli in pigs are required.

Nano-carriers for DNA delivery to the lung based upon a TAT-derived peptide covalently coupled to PEG-PEI.

Gene therapy aimed at the respiratory epithelium holds therapeutic potential for diseases such as cystic fibrosis and lung cancer. Polyethylenimine (PEI) has been utilized for gene delivery to the airways. In this study, we describe a new modification of PEI, in which an oligopeptide related to the protein transduction domain of HIV-1 TAT was covalently coupled to 25 kDa PEI (PEI) through a heterobifunctional polyethylenglycol (PEG) spacer resulting in a TAT-PEG-PEI conjugate. Improved DNA reporter gene complexation and protection was observed for small (approximately 90 nm) polyplexes as well as significantly improved stability against polyanions, Alveofact, bronchial alveolar lining fluid and DNase. To determine polyplex toxicity in vitro, MTT assays were performed and, for in vivo testing, the mice bronchial alveolar lavage was investigated for total cell counts, quantity of neutrophils, total protein and TNF-alpha concentration. All parameters suggest significantly lower toxicity for TAT-PEG-PEI. Transfection efficiencies of both PEI and TAT-PEG-PEI polyplexes with DNA were studied under in vitro conditions (A549) and in mice after intratracheal instillation. While luciferase expression in A549 cells was much lower for TAT-PEG-PEI (0.2 ng/mg protein) than for PEI (2 ng/mg), significantly higher transfection efficiencies for TAT-PEG-PEI were detected in mice. Reporter gene expression was distributed through bronchial and alveolar tissue. Thus, TAT-PEG-PEI represents a new approach to non-viral gene carriers for lung therapy, comprising protection for plasmid DNA, low toxicity and significantly enhanced transfection efficiency under in vivo conditions.

Muscle mass during childhood--relationship to skeletal development.

Bone densitometric data often are difficult to interpret in children and adolescents because of large inter- and intraindividual variations in bone size. Here, we propose a functional approach to bone densitometry that addresses two questions: Is bone strength normally adapted to the largest physiological loads, that is, muscle force? Is muscle force adequate for body size? To implement this approach, forearm muscle cross-sectional area (CSA) and bone mineral content (BMC) of the radial diaphysis were measured in 349 healthy subjects from 6 to 19 years of age (183 girls), using peripheral quantitative computed tomography (pQCT). This functional approach to pediatric bone densitometric data should be adaptable to a variety of densitometric techniques.

Unusual craniocerebral injury caused by a pneumatic nail gun.

A man was found unconscious near a ladder in a house. After resuscitation he was brought to a hospital and X-rays of the skull showed that two 12-cm long nails had completely penetrated the cranial cavity. The nails were operatively removed and after treatment for 5 weeks, the patient was transferred to a rehabilitation centre with a decreasing hemiparesis on the left side and general deterioration and then, after an attempted suicide to a psychiatric hospital. The perforating cranio-cerebral injury from a pneumatic nail gun known to reach only low muzzle velocities is a very unusual finding.

The crystal and molecular structures of diferric porcine and rabbit serum transferrins at resolutions of 2.15 and 2.60 A, respectively.

The serum transferrins are monomeric proteins with a molecular mass of around 80 kDa and are responsible for the transport of iron in vertebrates. The three-dimensional structures of diferric porcine and rabbit serum transferrin have been refined against X-ray diffraction data extending to 2.15 and 2.60 A, respectively. Data for both proteins were collected using synchrotron radiation at temperatures of 277 K. The porcine protein crystallizes in the space group C2, with unit-cell parameters a = 223.8, b = 44.9, c = 78.9 A, beta = 105.4 degrees with one molecule in the asymmetric unit. The structure was solved by molecular-replacement methods using rabbit serum transferrin as the search model. The structure was refined using REFMAC, with a final residual of 13.8% (R(free) = 18.2% for a 5% data sample) for all data to 2.15 A. The final model comprises 5254 protein atoms, two Fe(3+) cations and two CO(3)(2-) anions, one N-acetyl glucosamine moiety and 494 water molecules. The rabbit protein crystallizes in space group P4(3)2(1)2, with unit-cell parameters a = 127.2, c = 144.9 A and one molecule per asymmetric unit. The structure was solved using the method of multiple isomorphous replacement and refined using REFMAC to give a final residual of 18.6% (R(free) = 22.2% for a 5% data sample) for all data to 2.60 A. The final model comprises 5216 protein atoms, two Fe(3+) cations and two CO(3)(2-) anions, a Cl(-) anion and 206 solvent molecules; there is no clear indication of the carbohydrate moiety attached to Asn490 (rabbit serum numbering). Both molecules adopt a bilobal structure typical for members of the transferrin family. Each of the structurally homologous lobes contains two dissimilar domains with a single iron-binding site buried within the interdomain cleft. The porcine serum protein lacks an interdomain disulfide bridge close to the connecting peptide between the lobes, but this seems to have little effect on the overall orientation of the lobes. The N-lobes of both proteins possess lysine residues, one from each of the two domains, that lie in close proximity to one another to form the so-called dilysine trigger. The more acid-labile release of iron from serum transferrins than from lactoferrins is discussed.

Vasoactive treatment for hearing preservation in acoustic neuroma surgery.

OBJECT: Delayed hearing loss following surgery for acoustic neuroma indicates anatomical and functional preservation of the cochlear nerve and implies that a pathophysiological mechanism is initiated during surgery and continues thereafter. Intraoperative brainstem auditory evoked potentials (BAEPs) typically demonstrate gradual reversible loss of components in these patients. METHODS: Based on this BAEP pattern, a consecutive series of 41 patients with unilateral acoustic neuromas was recruited into a prospective randomized study to investigate hearing outcomes following the natural postoperative course and recuperation after vasoactive medication. Both groups were comparable in patient age, tumor size, and preoperative hearing level. Twenty patients did not receive postoperative medical treatment. In 70% of these patients anacusis was documented and in 30% hearing was preserved. Twenty-one patients were treated with hydroxyethyl starch and nimodipine for an average of 9 days. In 66.6% of these patients hearing was preserved and in 33.3% anacusis occurred. CONCLUSIONS: These results are statistically significant (p < 0.05, chi2 = 5.51) and provide evidence that these surgically treated patients suffer from a disturbed microcirculation that causes delayed hearing loss following removal of acoustic neuromas.

Is a proliferation index of cancer cells a reliable prognostic factor after hepatectomy in patients with colorectal liver metastases?

BACKGROUND: In spite of many reports focusing on prognostic factors after hepatectomy in patients with colorectal liver metastases, few studies have investigated pathological factors, eg, fibrous pseudocapsulation, growth pattern at the tumor margin, and proliferation activity of cancer cells, other than histological type and surgical margin. The aim of the present study was to investigate whether absence of pseudocapsulation, infiltrative growth pattern of metastases, and higher proliferation of cancer cells shown by Ki-67 immunohistochemical reactivity were associated with poorer survival after hepatectomy among patients with colorectal liver metastases. METHODS: Between 1988 and 1998, 221 patients underwent hepatic resection of colorectal metastases with curative intent in our institution. Pathology analyses were focused on pseudocapsulation of liver metastases, growth pattern at the tumor edge, and Ki-67 labelling index (Ki-67 LI) of cancer cell nuclei. Univariate analyses of survival and of disease-free survival were performed for several clinicopathological factors, and multivariate analyses of survival and disease-free survival were also performed. RESULTS: The univariate survival analyses showed that pseudocapsulation, growth pattern, and Ki-67 LI were significant prognostic factors, besides synchronous versus metachronous occurrence of metastases, carcinoembryonic antigen level before hepatectomy, and number of metastases. A multivariate analysis showed that Ki-67 labeling index was the most reliable prognostic factor of survival. In addition, Ki-67 LI and microscopic growth pattern were multivariately predictive factors of disease-free survival. CONCLUSIONS: This large single-institution study showed that investigation of cancer cell proliferation and pathologic characteristics of the tumor margin are major prognostic factors.

Siderophore mediated plutonium accumulation by Microbacterium flavescens (JG-9).

Uptake of plutonium and uranium mediated by the siderophore desferrioxamine-B (DFOB) has been studied for the common soil aerobe Microbacterium flavescens(JG-9). M. flavescens does not bind or take up nitrilotriacetic acid (NTA) complexes of U(VI), Fe(III), or Pu(IV) or U(VI)-DFOB but does take up Fe(III)-DFOB and Pu(IV)-DFOB. Pu(IV)-DFOB and Fe(III)-DFOB accumulations are similar: only living and metabolically active bacteria take up these metal-siderophore complexes. The Fe(III)-DFOB and Pu(IV)-DFOB complexes mutually inhibit uptake of the other, indicating that they compete for shared binding sites or uptake proteins. However, Pu uptake is much slower than Fe uptake, and cumulative Pu uptake is less than Fe, 1.0 nmol of Fe vs 0.25 nmol of Pu per mg of dry weight bacteria. The Pu(IV)-DFOB interactions with M. flavescens suggest that Pu-siderophore complexes could generally be recognized by Fe-siderophore uptake systems of many bacteria, fungi, or plants, thereby affecting Pu environmental mobility and distribution. The results also suggest that the siderophore complexes of tetravalent metals can be recognized by Fe-siderophore uptake proteins.

Comparative evaluation of Celsior solution versus Viaspan in a pig liver transplantation model.

BACKGROUND: In a pig liver transplantation model, we compared the effects of Celsior solution (CS), an extracellular preservation solution, with Viaspan (University of Wisconsin solution, UW) on graft function and animal survival. METHODS: Pig livers were flushed with either CS or UW solution and cold-stored for 12 hr (group 1) or for 8 to 10 hr (group 2). Grafts were transplanted orthotopically. Intrahepatic reduced and oxidized glutathione and adenine nucleotides were evaluated 1 hr after reperfusion. Liver function of transplanted animals was monitored for up to 6 days by serum transaminases, total bilirubin, purine nucleoside phosphorylase, and prothrombin levels. RESULTS: In group 1, all animals died within 24 hr after reperfusion regardless of the preservation solution used. In group 2, no significant difference was seen in survival between the CS (72%) and the UW (67%) groups 6 days after transplantation, and there were no statistically significant differences in the biochemical data. There were no differences in histological evaluation of the livers at the time of death or killing of the animals between the CS and UW groups. CONCLUSION: Within the limits of this pilot study, CS is equivalent to UW in terms of graft function and animal survival.

Clinical and neurophysiological observations after superior petrosal vein obstruction during surgery of the cerebellopontine angle: case report.

IMPORTANCE: Preservation of venous drainage during surgery of the cerebellopontine angle has received little attention. CLINICAL PRESENTATION: We describe changes in brainstem auditory evoked potentials after temporary obstruction of the superior petrosal vein during surgical resection of a small meningioma at the petrous apex via a standard suboccipital-lateral approach. Temporary clipping of the petrosal vein resulted in deterioration of the brainstem auditory evoked potentials. The tumor was removed with preservation of the superior petrosal vein. CONCLUSION: A transient postoperative cochlear nerve deficit emphasizes the importance of venous drainage and its preservation during surgery for small lesions of the cerebellopontine angle that do not distort normal anatomic structures.

Engraftment and albumin production of intrasplenically transplanted rat hepatocytes (Sprague-Dawley), freshly isolated versus cryopreserved, into Nagase analbuminemic rats (NAR).

Banking of cryopreserved hepatocytes is a prerequisite for large-scale hepatocyte transplantation in the clinic. We compared the efficacy of intrasplenic transplantation into Nagase analbuminemic rats (NAR) of freshly isolated (FIH) and cryopreserved (CH) hepatocytes. Hepatocytes were cryopreserved using a controlled rate freezing protocol. Albumin production of thawed CH and FIH was measured in vitro in culture by ELISA and by Western blot. After in vivo intrasplenic transplantation of NAR with either FIH or CH we assessed 1) albumin in the serum of recipients by ELISA and by Western blotting analysis at different time intervals, and 2) hepatocyte engraftment by albumin immunohistochemical staining into spleens and livers at euthanasia. In vitro, albumin was produced up to day 4 of culture in both CH and FIH. In vivo, no intrasplenic engraftment of hepatocytes occurred. Intrahepatic engraftment of CH (cell number/mm2) was significantly (twofold) lower than that of FIH and appeared only as isolated cells and small (<10 cells) clusters, while bigger clusters (>10 cells) were observed with FIH. In the FIH group, serum albumin production was observed up to 32-49 days posttransplantation while in the CH group no serum albumin production was detected. Our results emphasize the need to improve 1) hepatocyte transplantation procedures either by repeated hepatocytes injections and/or by transplantation under a regeneration response, and 2) the freeze/thaw protocols of hepatocytes.

Actinide interactions with microbial chelators: the dioxobis[pyridine-2,6-bis(monothiocarboxylato)]uranium(VI) ion.

The title complex, bis(tetraphenylphosphonium) dioxobis(pyridine-2,6-dicarbothioato-O,N,O')uranium(VI), (C(24)H(20)P)(2)[UO(2)(C(7)H(3)NO(2)S(2))(2)], was prepared by reacting two equivalents of pyridine-2,6-bis(monothiocarboxylate) (pdtc) with uranyl nitrate. The geometry of the eight-coordinate U atom is hexagonal bipyramidal, with the uranyl O atoms in apical positions. This is the first reported complex in which this ligand binds a metal through the O and not the S atoms. Principal bond lengths include uranyl lengths of 1.774 (2) A, U--O distances of 2.434 (2) and 2.447 (3) A, and two U--N distances of 2.647 (3) A. The anion lies on an inversion centre.

Generalizability and clinical utility of a practice-based infant pain assessment instrument.

The purpose of this study was to determine the clinical usefulness and generalizability of an infant pain assessment instrument. Earlier work showed that this instrument--an algorithm derived from a model of infant pain assessment-possessed excellent content validity, criterion-like validity, and 3-month stability (test-retest reliability). In this study, generalizability was determined by comparing the percentage agreement between inexperienced pediatric nurses and one author, both using the tool to assess pain of infants in various clinical settings, and by comparing the percentage agreement between one author who used the tool to assess pain and the infant's pediatric nurse caretaker who used his or her clinical expertise, not the tool, to assess pain across various clinical settings. The results show excellent generalizability.

The impact of two transfer techniques used during skin-to-skin care on the physiologic and behavioral responses of preterm infants.

BACKGROUND: Conservation of energy assumes an important role in the care of infants requiring assisted ventilation, yet little research has been conducted on this group of infants in terms of thermoregulation, oxygenation, heart rate, or sleep states during skin-to-skin care. OBJECTIVES: To compare the impact of two different transfer techniques used in skin-to-skin care (nurse transfer and parent transfer) on physiologic stability and other descriptive measures of physiologic stability related to energy conservation in ventilated preterm infants during and after skin-to-skin care. METHOD: Fifteen ventilated preterm infants weighing a mean of 1,094 g were randomly assigned to receive either parent or nurse-to-parent transfer on the first of 2 consecutive days and the alternate method the following day. Temperature was taken before and after skin-to-skin care. Oxygen saturation and heart rate were recorded minute by minute, and the Assessment of Behavioral Systems Observation (ABSO) scale scores was used to measure physiologic organization, motor organization, self-regulation, and need for caregiver facilitation during transfer to and from the parent and during pre, post, and skin-to-skin periods. RESULTS: Temperature remained stable. Oxygen saturation decreased and heart rate increased when the infant was transferred to and from the parent, but returned to baseline levels during and after skin-to-skin care regardless of the transfer method. Infants showed more physiologic and motor disorganization, less self-regulation, and more need for caregiver facilitation during transfers to and from the parent than during the pre, post, and skin-to-skin care periods. CONCLUSIONS: Both transfer methods resulted in physiologic disorganization. However, during and after skin-to-skin care, infants exhibited no signs of energy depletion.