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Biomedical subjects

J F Murphy

Publications and source records attributed to J F Murphy.

At least 37 records · Page 2Linked to original sources
PubMed2000

Altering the NICU and measuring infants' responses.

UNLABELLED: The aim of the study was to measure the impact of a designated Quiet period on the NICU environment and its influence on the infants' physiological and movement responses. The study group comprised 10 preterm infants on assisted ventilation (mean gestational age 28.7 wk (range 24-32 wk), mean birthweight 1,322 g (range 600-2,060 g), mean age 5.2 d). The environment in which the infants were nursed was altered in terms of reduced light, noise, staff activity and infant handling. The infants' heart rate, blood pressure, oxygen saturation and movement responses were recorded during this Quiet period and compared with a period of Normal activity. When the Quiet period was compared with the Normal period (median values), the NICU environment had significantly altered in terms of Light: Quiet period 3.0 Lux, Normal period 254.5 Lux (p < 0.01); Noise: Quiet period 54.0 dB, Normal period 58.0 dB (p < 0.01); Alarm events: Quiet period 491.5 sec, Normal period 1,180.5 sec (p < 0.01); Staff conversation: Quiet period 16.0 occasions per hour, Normal period 60.0 occasions per hour (p < 0.01); Staff activity: Quiet period 25.5 occasions per hour, Normal period 59.0 occasions per hour (p <0.01); Infant handling: Quiet period 0.0 events per hour, Normal period 4.5 events per hour (p < 0.01). Infants' diastolic blood pressure and mean arterial pressure: median reduction of 2 mmHg for both during the Quiet period (p < 0.05). Infants' movements: Quiet period 14.5 movements per hour, Normal period 84.0 movements per hour (p < 0.05). DISCUSSION: This study demonstrates that Quiet periods are feasible for infants undergoing neonatal intensive care. The NICU environment was altered significantly for light, noise, infant handling and staff activity for a specified time period. These changes were associated with a reduced median diastolic blood pressure and mean arterial pressure and a decrease in infant movements.

Blood Pressure↗
PubMed1998

Importance of exercise capacity in the interpretation of a myocardial ischemic response to exercise testing. Multicenter Study of Myocardial Ischemia Group (MSMI).

Patients who were stable 1 to 6 months after a cardiac event underwent routine exercise testing with thallium scintigraphy. The prognosis of patients with good exercise capacity (Bruce stage 3) was similar whether or not ischemia was demonstrated and similar to patients with reduced exercise capacity and no ischemia, whereas the presence of both ischemia and a reduced exercise tolerance identified patients with a significantly poorer prognosis.

Aged↗
PubMed1998

Senescent human neutrophil binding to thrombospondin (TSP): evidence for a TSP-independent pathway of phagocytosis by macrophages.

This study investigated the interaction of apoptotic polymorphonuclear neutrophils (PMN) with thrombospondin (TSP), an important event mediating the clearance of apoptotic neutrophils by macrophages. We developed an in vitro assay to examine this interaction. Based on this assay, we found that apoptotic but not fresh PMN bound specifically to surface-immobilized TSP (33 +/- 0.03 x 10(3) cells/well) compared to fibrinogen, fibronectin or laminin (8.0 +/- 0.3 x 10(3) cells/well). Moreover, the binding was specific for surface bound but not soluble TSP and appeared to be divalent cation dependent, was not significantly inhibited by heparin and was sensitive to cycloheximide (CHX) treatment of senescent PMN (>90%) inhibition at 10 microM CHX). In contrast to the binding studies, phagocytosis of senescent PMN by macrophages was not affected by EDTA or cycloheximide. Phosphatidyl-L-serine liposomes, phospho-L-serine, glucosamine, galactosamine, and the acetylated sugars had no effect on phagocytosis. We conclude that: (i) there was specific binding of senescent human PMN to immobilized TSP, which is divalent cation dependent and requires new protein synthesis in the PMN during senescence; (ii) in addition to the recently defined TSP-dependent pathway, there is a TSP-independent pathway mediating phagocytosis of senescent PMN by macrophages. The identity of this pathway remains to be defined.

Carbohydrates↗
PubMed1997

Retinopathy of prematurity screening, stress related responses, the role of nesting.

AIMS/BACKGROUND: In a prospective study the degree of distress caused by retinopathy of prematurity (ROP) screening in a cohort of preterm infants was assessed and the modifying effects of nesting in reducing their discomfort was evaluated. METHODS: 38 preterm infants were included in the study. 19 infants were placed in a nest with boundaries (intervention group) and 19 infants were placed on a cot blanket (control group). Observations were made 2 minutes before, throughout, and 2 minutes after ROP examination. The factors observed were crying responses, neurobehavioural activity, and physiological changes (heart rate, oxygen saturation). Recordings were made using a video camera for crying and neurobehavioural activity and an Oxypleth monitor for heart rate and oxygen saturation. RESULTS: During ROP screening, the total group of 38 infants (nested and non-nested combined) displayed increased neurobehavioural activity (p < 0.01) and crying (p < 0.01). The increased activity and crying coincided with the invasive part of the procedure. The distress caused by ROP screening was significantly less for the nested group compared with the non-nested group for both movement activity (p < 0.01) and crying (p < 0.01). The physiological data, heart rate, and oxygen saturation were not statistically significant. CONCLUSION: ROP screening is distressing for preterm infants. Nesting can significantly reduce this discomfort. The findings in this study are of value in designing more optimal ROP examination schedules for infants.

Beds↗
PubMed1997

Comparison of liveborn and stillborn low birthweight babies and analysis of aetiological factors.

A retrospective study was performed at a tertiary maternity hospital, to define the incidence of low birthweight (LBW) and its associated risk factors in term liveborn infants and in term stillbirths, to ascertain the antenatal detection rate in each and to assess the role of ultrasound in antenatal detection. One hundred and ninety-four term liveborn LBW infants and twenty stillborn LBW infants were studied. Fifty-six percent of the liveborn infants were detected antenatally compared to 5% of the stillborn LBW infants. Previous LBW, the extremes of maternal age, cigarette smoking and pre-eclampsia were the main risk factors for the development of LBW, not all of which were present to the same extent in each group. Ultrasound scanning antenatally increases the detection rate. Knowledge of abnormal growth antenatally significantly increases obstetric intervention. Detection of LBW antenatally remains difficult. The main risk factors for LBW were similar in both groups.

Adult↗
PubMed1996

Replacement of the tyrosine residue that links a potyviral VPg to the viral RNA is lethal.

Mutants of tobacco vein mottling virus (TVMV) were constructed in which the tyrosine residue (Tyr1860) that links the VPg to the viral RNA was changed to phenylalanine or serine or was inverted in position with the adjacent glycine residue. In another mutant, the tyrosine residue nearest to Tyr1860 (Tyr1867) was changed to a phenylalanine residue. The resulting mutants were tested for their ability to infect Nicotiana tabacum plants or protoplasts. The Tyr1860 mutants did not accumulate to detectable levels in infected plants when tested by ELISA and Northern blot analysis. Moreover, the Tyr1860-associated mutants were not infectious in protoplasts, indicating that mutations involving the linking amino acid of the TVMV VPg abolished viral replićation. In contrast to the Tyr1860 mutants, transcripts from the mutation of Tyr1867 to a phenylalanine residue infected both protoplasts and plants. Analysis of progeny RNA from plants inoculated with the Tyr1867 mutant indicated that a reversion to wild type had occurred in systemically infected leaves.

Amino Acid Sequence↗
PubMed1996

Age and gender differences in health services utilization.

The purpose of this study was to examine the health service utilization patterns of elderly male and female enrollees of a large urban staff model Health Maintenance Organization (HMO). This HMO offered a wide spectrum of managed care services for its beneficiaries. A cross-sectional design was employed. The 759 randomly sampled elderly enrollees ranged in age from 66 to 99, with an average of 77.15 years. Approximately 60% were male and 40% were female; thus, the sample was not representative of the national older adult population. Three utilization patterns indicated that there were (a) nonsignificant relationships between age or gender and urgent care visits, prescribed pharmaceuticals, and out-of-pocket costs for pharmaceuticals; (b) linear relationships between age and gender and visits to HMO primary care providers (-), home-health care visits (+), emergency care visits (+), hospitalizations (+), and MD visits during hospitalizations (+); and (c) age was curvilinearly related to use of both HMO specialists and non-HMO specialists. These findings suggest that use of acute care services, including hospitalizations, inpatient physician visits, and emergency services increase with age but the use of primary care providers decreases with age. Gender was not a significant modifier of the relationship between age and utilization.

Age Factors↗
PubMed1996

Caring for the caregivers.

The relationship between disabled elderly veteran care receivers' functional status and their in-home family caregivers' strain was examined in this study. The convenience sample was composed of 93 dyads. Data were obtained from care receivers' health care records and included the Folstein Mini-Mental State Examination (MMS), Activities of Daily Living (ADL), Instrumental Activities of Daily Living (ADL), and Robinson's Caregiver Strain Index (CSI). Major findings were: 52% of caregivers experienced significant strain; 59% of care receivers were cognitively impaired to some extent and were severely impaired in IADL and ADL; and the relationships between care receivers' functional status (cognitive, ADL and IADL) and caregiver strain were statistically significant.

Activities of Daily Living↗
PubMed1995

A potyvirus polymerase interacts with the viral coat protein and VPg in yeast cells.

The two-hybrid system was used to test for pairwise interactions between the tobacco vein mottling virus (TVMV)-encoded RNA-dependent RNA polymerase (or NIb protein) and two other TVMV-encoded proteins: the NIa protein, which consists of genome-linked protein (VPg) and proteinase domains, and the viral coat protein (CP). Using this approach, we find that the NIb protein interacts with both the NIa protein and the CP in yeast cells. Moreover, we find that a mutation in the conserved GDD domain of the NIb protein diminishes the NIb-CP interaction but not the NIb-NIa interaction. Likewise, mutations in the vicinity of the NIa protein to which the genomic RNA is covalently attached eliminate the NIb-NIa interaction. We conclude that the NIb protein interacts with the VPg domain of the NIa protein and that this interaction requires a functional RNA attachment site. This interaction may be important for the initiation of viral RNA synthesis in infected cells. We also conclude that the CP interacts with the NIb in a manner that is sensitive in changes in the highly conserved GDD motif. The role of this interaction in the functioning of the NIb protein or the CP is unclear, but may involve regulation of viral RNA synthesis in infected cells.

Amino Acid Sequence↗
PubMed1995

Functional expression of an epitope-tagged G protein-coupled K+ channel (GIRK1).

An epitope-tagged form of an inwardly rectifying and G protein-coupled K+ channel (GIRK1-cp) was expressed at high levels in transfected mammalian cells. Immunoblot analysis of transfected human embryonic kidney cells (HEK293) and mouse insulinoma cells (beta TC3) revealed several GIRK1-cp polypeptides, including the major 59-kDa band, corresponding to the predicted mass of the GIRK1 polypeptide plus the epitope tag. Immunohistochemical staining using two anti-tag antibodies showed abundant immunoreactive material, which was predominantly concentrated in the perinuclear area in both transfected cell types. While functional GIRK1-cp message was present in poly(A)+ RNA prepared from HEK293 cells expressing GIRK1-cp protein, appropriate K+ currents could not be detected. In contrast, whole cell recordings made directly from transfected beta TC3 cells expressing GIRK1-cp revealed inwardly rectifying, pertussis toxin-sensitive currents activated by norepinephrine and galanin. Single channel recordings in excised patches of beta TC3 cells expressing GIRK1-cp showed rectifying K+ currents when activated by 50 microM guanosine 5'-O-(thiotriphosphate), with a slope conductance of 39.1 +/- 1.0 picosiemens. This is the first report of stable heterologous expression of a functional G protein-coupled K+ channel in mammalian cells. The activity of an epitope-tagged channel in insulinoma cells demonstrates the utility of this system for further biochemical and biophysical analyses of G protein-K+ channel interactions.

Animals↗