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Biomedical subjects

K Kearney

Publications and source records attributed to K Kearney.

At least 19 recordsLinked to original sources
PubMed2003

Prehension in young children with Down syndrome.

Prehension was examined in 3-year old children with Down syndrome (DS, n = 3) and in typically-developing children matched in chronological age (3-year olds; n = 3) or mental age and motor experience (2-year olds; n = 3). The task required reaching to grasp dowels. Video-based movement analysis yielded temporal and kinematic measures. Children with DS were hypothesized to have deficits in feedback-dependent components of prehension (anticipatory grip-closure and deceleration of reach), whereas feedforward components (reach's acceleration phase; grasp's preshaping) were assumed to be unimpaired [Latash, 1993, Control of human movement, pp. 283-292; Latash, 1994, What is clumsiness? In: Motor Control and Down Syndrome II Proceedings of the second international conference, pp. 68-71]. The findings supported these hypotheses. In comparison to control groups, children with DS had significantly: (a) less time in deceleration of reaching, (b) fewer anticipatory grip-closures, and (c) longer movement times for dowel-lift. Young children with DS appeared to use dowel-contact to decelerate the limb and initiate grip-closure. In contrast, reach-acceleration time and grasp-preshaping did not differ across groups. These findings suggest that children with DS display qualitative differences in motor capabilities rather than simply a delayed rate of typical developmental progression.

Child, Preschool↗
PubMed2001

Effect of intragenic rearrangement and changes in the 3' consensus sequence on NSP1 expression and rotavirus replication.

The nonpolyadenylated mRNAs of rotavirus are templates for the synthesis of protein and the segmented double-stranded RNA (dsRNA) genome. During serial passage of simian SA11 rotaviruses in cell culture, two variants emerged with gene 5 dsRNAs containing large (1.1 and 0.5 kb) sequence duplications within the open reading frame (ORF) for NSP1. Due to the sequence rearrangements, both variants encoded only C-truncated forms of NSP1. Comparison of these and other variants encoding defective NSP1 with their corresponding wild-type viruses indicated that the inability to encode authentic NSP1 results in a small-plaque phenotype. Thus, although nonessential, NSP1 probably plays an active role in rotavirus replication in cell culture. In determining the sequences of the gene 5 dsRNAs of the SA11 variants and wild-type viruses, it was unexpectedly found that their 3' termini ended with 5'-UGAACC-3' instead of the 3' consensus sequence 5'-UGACC-3', which is present on the mRNAs of nearly all other group A rotaviruses. Cell-free assays indicated that the A insertion into the 3' consensus sequence interfered with its ability to promote dsRNA synthesis and to function as a translation enhancer. The results provide evidence that the 3' consensus sequence of the gene 5 dsRNAs of SA11 rotaviruses has undergone a mutation causing it to operate suboptimally in RNA replication and in the expression of NSP1 during the virus life cycle. Indeed, just as rotavirus variants which encode defective NSP1 appear to have a selective advantage over those encoding wild-type NSP1 in cell culture, it may be that the atypical 3' end of SA11 gene 5 has been selected for because it promotes the expression of lower levels of NSP1 than the 3' consensus sequence.

Amino Acid Sequence↗
PubMed2000

Identification and characterization of an active plasmid partition mechanism for the novel Lactococcus lactis plasmid pCI2000.

The replication region of the lactococcal plasmid pCI2000 was subcloned and analyzed. The nucleotide sequence of one 5.6-kb EcoRI fragment which was capable of supporting replication when cloned on a replication probe vector revealed the presence of seven putative open reading frames (ORFs). One ORF exhibited significant homology to several replication proteins from plasmids considered to replicate via a theta mode. Deletion analysis showed that this ORF, designated repA, is indeed required for replication. The results also suggest that the origin of replication is located outside repA. Upstream and divergently transcribed from repA, an ORF that showed significant (48 to 64%) homology to a number of proteins that are required for faithful segregation of chromosomal or plasmid DNA of gram-negative bacteria was identified. Gene interruption and transcomplementation experiments showed that this ORF, designated parA, is required for stable inheritance of pCI2000 and is active in trans. This is the first example of such a partitioning mechanism for plasmids in gram-positive bacteria.

Amino Acid Motifs↗
PubMed1998

Assessment of left ventricular diastolic function after single lung transplantation in patients with severe pulmonary hypertension.

OBJECTIVES: This study was designed to observe left ventricular filling by Doppler echocardiography before and after single lung transplantation in patients with severe pulmonary hypertension. BACKGROUND: Right ventricular pressure overload causes the deformation of the left ventricle by septal flattening toward its cavity, which may result in impaired left ventricular early filling. Recent studies have demonstrated the ability of single lung transplantation to restore right ventricular function in patients with severe pulmonary hypertension. However, changes in left ventricular filling after single lung transplantation have not been well studied. METHODS: We performed Doppler echocardiography in nine patients with severe pulmonary hypertension before, early (<3 months), and late (>1 year) after single lung transplantation. The study group consisted of eight female patients and one male patient with mean age of 32 years (range, 15 to 48 years). Six patients were diagnosed as having primary pulmonary hypertension and three as having secondary pulmonary hypertension. Nine age-matched normal subjects served as a control group. Doppler measurements included the following: transmitral flow early (E) and atrial (A) velocities, integrals (Ei and Ai), and left ventricular isovolumic relaxation time. The ratio of E/A and atrial filling fraction (Ai/Ei+Ai, AFF) were also determined. Left ventricular geometry was assessed from mid-short axis view with a circular shape factor (CSF). RESULTS: Early after lung transplantation, the left ventricular geometry became more circular with CSF (mean+/-SD) increasing from 0.63+/-0.09 to 0.88+/-0.05 (p<0.05). However, impaired early filling persisted in the patient group (E/A 0.7+/-0.1 vs preoperative 0.6+/-0.1, AFF 0.61+/-0.1 vs 0.64+/-0.1; both p=not significant). One year later, the left ventricular filling had returned to normal range with E/A 1.4+/-0.6 and AFF 0.35+/-0.1. CONCLUSIONS: This study observed that the impaired left ventricular early filling persisted shortly after single lung transplantation in patients with severe pulmonary hypertension, despite findings that left ventricular geometry was restored earlier after reversal of pulmonary hypertension. The abnormal filling pattern appeared to be resolved 1 year later. The findings suggest the impaired early filling may be caused by intrinsic left ventricular abnormalities other than ventricular interaction in these patients.

Adolescent↗
PubMed1995

On the relationship of the ATP-independent, mitochondrial associated DNA topoisomerase of Saccharomyces cerevisiae to the nuclear topoisomerase I.

A mitochondrial type I-like, ATP-independent, DNA topoisomerase, isolated from highly purified yeast mitochondria, is genetically related to nuclear topoisomerase I. We found that the mitochondrial topoisomerase activity cannot be detected in yeast mitochondrial extracts prepared from strains in which the topoisomerase I gene (TOP1) is disrupted. Thus, the topoisomerase activity associated with mitochondria is dependent upon the expression of the nuclear topoisomerase I gene.

Adenosine Triphosphate↗
PubMed1995

Effect of aspirin on spontaneous contrast in the brachial veins of normal subjects.

Blood cell aggregates are thought to be the cause of spontaneous echo contrast (SEC), although there is disagreement as to whether red cell or platelet aggregates produce this effect. One way to differentiate between these 2 possibilities is to evaluate the effect of aspirin on SEC because aspirin would not be expected to affect red cell aggregates. To eliminate the need to perform repetitive transesophageal echocardiographic studies, and the possible effect of the underlying disease process on SEC, the effect of aspirin on SEC in the brachial vein was studied in normal volunteers using a single-blind, before-and-after study design. Other factors known to affect blood echogenicity including hematocrit, sedimentation rate, and the presence of platelet aggregates by microscopy were also studied. The amount of SEC was quantitated by image analysis and expressed as the aggregate score. The results in 10 volunteers showed that all had SEC in brachial veins before aspirin, but there was no significant day-to-day variation in the amount of SEC during the control period (mean +/- SEM 104,248 +/- 23,088, 153,722 +/- 35,664, and 124,568 +/- 22,827 for days 1, 3, and 5, respectively). A significant decrease in the aggregate score occurred after 7 days of aspirin, 650 mg twice a day (51,690 vs 127,513, p = 0.002); this was accompanied by a striking decrement in the size of the largest platelet aggregate found in venous blood. Aspirin caused no significant change in the hematocrit or sedimentation rate. These results indicate that there is a component of SEC that is aspirin-sensitive and is likely to represent platelet aggregates.

Adult↗
PubMed1994

The effect of limited handrail support on total treadmill time and the prediction of VO2 max.

Holding onto the front handrail during treadmill testing significantly increases total treadmill time (TT) and predicted VO2max when compared with tests without front handrail support. By limiting the amount of handrail support to the tips of two fingers of one hand, the difference in TT can be substantially reduced. In the present study, the difference in TT between tests with and without handrail support for healthy men was not significantly different. However, this was not true for healthy women and for male patients with coronary artery disease and myocardial infarction.

Aged↗
PubMed1994

Nucleotide sequence and structural organization of the small, broad-host-range plasmid pCI411 from Leuconostoc lactis 533.

The nucleotide sequence of the Leuconostoc lactis 533 cryptic plasmid pCI411 (2926 bp) was determined. Analysis revealed the presence of three open reading frames (ORFs). ORF 1 was capable of encoding a 24.9 kDa peptide which shared homology with the replication initiation protein (RepB) from a number of Gram-positive rolling circle plasmids. ORF 2 could encode a peptide of 6.6 kDa which was homologous to the RepC protein of the lactococcal plasmid pWV01. A function could not be assigned to ORF 3, which was capable of encoding a 12.1 kDa peptide. Transcription-translation analysis indicated the presence of three peptides of the predicted molecular masses. A putative double strand origin of replication (DSO) was identified which showed strong similarity with the DSO of a number of Gram-positive plasmids including pE194 from Staphylococcus. Structural analysis identified a number of direct and indirect repeats in addition to putative recombination-specific sites (RSA and RSB) in the non-coding region of pCI411. The observed characteristics suggest that this plasmid replicates using the rolling circle mechanism. pCI411, which could be introduced into Leuconostoc, Lactococcus, Streptococcus, Lactobacillus and Bacillus is the first plasmid from the genus Leuconostoc to be characterized in such detail.

Amino Acid Sequence↗
PubMed1992

A new era for hospital liability.

Hospitals are no longer merely facilities with equipment where autonomous physicians practice; they owe a direct duty of reasonable care to patients. This dramatic transition for hospitals will ensure a sea of change in the character of hospital medical practice and management.

Data Collection↗
PubMed1979

Patterns of intrauterine growth retardation.

A prospective study of 70 singleton pregnancies at high risk for intrauterine growth retardation (IUGR) was undertaken to determine 1) the differences in intrauterine growth patterns; 2) the diagnostic accuracy of obstetric techniques; and 3) the frequencies of perinatal complications. Thirty infants displayed signs of IUGR. Although only 14 infants had low birth weights, these 14, as well as the remaining 16 infants under study, displayed many other features of growth abnormalities, including a low ponderal index, short stature, and small head circumference. These data demonstrate various patterns of IUGR. Although the perinatal complications occurred primarily in the low-birth-weight group, the major growth abnormalities observed in the non-low-birth-weight group demonstrate the need for additional short- and long-term follow-up studies in both groups.

Adult↗
PubMed1978

Glucocorticoids and the rhesus fetal lung.

The effects of glucocorticoids on primate fetal lung function have not been clearly delineated. In this prospective study of preterm rhesus fetuses exposed in utero to betamethasone for 72 hours, the most significant alteration was a striking increase in maximum lung volumes. Functionally less significant increases in residual lung volumes were also noted. The lungs of the treated fetuses did not exhibit lower extract surface tensions or increased phospholipid concentrations. These findings suggest that the major effect of betamethasone is on lung connective tissue elements, with minimal effects on alveolar surfactant. Additional evidence of the multisystemic effects of glucocorticoids was obtained in that significant differences in fetal, adrenal, hepatic, and placental weights also were observed.

Amniotic Fluid↗