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Biomedical subjects

S Hart

Publications and source records attributed to S Hart.

At least 73 records · Page 4Linked to original sources
PubMed1995

Patterns of limb laterality and gross-motor agility in children.

This study examined the association of nine patterns of limb preference (combination hand/foot), described as congruent or cross-lateral, with gross-motor agility of 302 4- to 6-yr-old boys. Based on contemporary reports of handedness and motor coordination, it was hypothesized that persons exhibiting a right-hand/foot congruent pattern would outperform their peers in other groups. However, analyses indicated no significant differences on total motor performance between groups with different limb patterns. Further nonsupport of the hypothesis was evident since the best performance was exhibited by the mixed-hand/left-foot group. In view of past studies and these results, it appears that additional inquiry is warranted before any consensus regarding the association between limb laterality and motor coordination can be established.

Child↗
PubMed1995

Foot performance of right- and left-handers: a question of environmental influence.

Prior research has shown that right-handed adults perform better on a speed-tapping task with the right hand and right foot, while left-handers execute more rapidly with the left hand and right foot. Speculation is that environmental influence, most likely driving experience, may account for the right-foot bias. To examine this hypothesis further, 48 young right- and left-handed children were tested on a similar protocol. Analyses indicated no significant differences in foot performance within hand-preference groups. Since these findings do not complement reports for adults, factors such as experience or maturation might contribute to the difference. Were patterns similar, the effect of environmental influence would be assumed to be small. However, much more evidence is needed before an adequate explanation can be developed. The issue of possible environmental influence is discussed from various theoretical perspectives.

Child↗
PubMed1995

Limb laterality and motor proficiency in children.

This investigation examined the premise derived from recent reports, that children who are consistent right-handers are better coordinated than their left- and mixed-sided (inconsistent) peers. The observation of limb laterality was extended to include footedness. Two samples of children (N = 273) (foot laterality/hand laterality), matched for age and sex, were assessed for motor proficiency and compared according to limb preference (right, mixed, left). Overall, results indicated no significant group differences (ps > .05) in composite scores (upper-limb, lower-limb, combination) and total performance, within foot and hand laterality. In view of recent studies (noting differences between laterality groups) and these nonsupportive results, it appears that additional inquiry is warranted before any consensus regarding the association between limb laterality and motor coordination can be established. Suggestions for further inquiry are presented.

Child, Preschool↗
PubMed1995

Alcohol intoxication in young children.

This article presents two cases of severe ethyl alcohol intoxication in pediatric patients, with one of these cases resulting in the death of a child. A review of the current literature is provided along with a comparison of our regional poison control centers and the national intoxication statistics regarding pediatric alcohol ingestion. Medical evaluation is recommended for all symptomatic children; hourly observations x 6 h are recommended for asymptomatic children.

Alcoholic Intoxication↗
PubMed1995

[Effect of acetylsalicylic acid on platelet aggregation and capillary bleeding in healthy cats].

The influence of acetylsalicylic acid (ASA) in vitro and in vivo on several parameters of the hemostatic system was evaluated in healthy cats. The aggregation response of cat platelets in vitro was not influenced by 10 micrograms ASA/ml plasma, whereas ASA concentrations of 35, 70, 100 micrograms/ml and of 1 mg/ml consistently inhibited the platelet aggregation induced by 0.1 (n = 4 cats) and 0.25 micrograms collagen/ml (n = 6 cats). The aggregation response to ADP and thrombin was partially (n = 2) or completely (n = 8) inhibited by an ASA concentration of 5 mg/ml. Administration of ASA at a dosage of 10 and 25 mg/kg BW orally and intravenously yielded a plasma concentration of salicylic acid of 30-42 micrograms/ml (10 mg/kg BW) and 50-70 micrograms/ml (25 mg/kg BW). All the dosages of ASA produced an inconsistent inhibition of the collagen-induced platelet aggregation (1/5 and 2/5 for the respective groups), whereas the response to ADP and thrombin was not altered. Capillary bleeding time was not significantly altered after the ASA administration. Platelet count and screening tests were not influenced by ASA application. According to the results of this study, ASA as a platelet aggregation inhibitor is not useful for the prophylaxis of thromboembolism in cats.

Adenosine Diphosphate↗
PubMed1994

Infant home apnoea monitors in Christchurch: an audit.

AIM: To audit parental perception of the apnoea monitor service given to neonatal graduates and infants surviving an apparent life threatening event in Christchurch. METHODS: Seventy-five of 103 sets of parents (74%), who had monitored their infants, between November 1990 and November 1992, were interviewed using a structured telephone questionnaire (apparent life threatening event (ALTE) n = 44, significant recurrent apnoea (NNU) n = 31. RESULTS: Anxiety present in most parents (83%) was relieved by monitoring (89%). Parents (97%) were satisfied with the instruction in monitor use. Eighty-nine percent had good contact with the technician, 73% called her to solve a problem. Most parents (84%) thought that initial instruction in cardiopulmonary resuscitation (CPR) was adequate. Sixty-eight percent would have liked a refresher course which only 7% of NNU and 22% of ALTE parents received. Sixty percent of parents had at least one significant alarm. Nine percent performed CPR to abort an apnoea. Ten percent of parents would have liked to monitor their child longer. CONCLUSIONS: Apnoea monitoring allays parental anxiety and may save the lives of a few infants. A technician is essential to coordinate all aspects of the service. Improvements could be made to instruction for cardiopulmonary resuscitation.

Anxiety↗
PubMed1994

Unexpected neurological deficits following recovery from anaesthesia.

Two cases of neurological dysfunction are presented. Neurological deficits after recovery from anaesthesia are unusual in young women perioperatively. In the first case, a 39-yr-old woman presented at 36-wk gestation with antepartum haemorrhage and in labour. Pregnancy had been complicated by pre-eclampsia and she underwent emergency Caesarean section under general anaesthesia without complication. The trachea was extubated when she was awake but almost immediately she became hypertensive, obtunded and reintubation was required. Her pupils became fixed and dilated but the Computerised Axial Tomogram (CT) was normal. A coagulopathy was evident. She made a full neurological recovery within 24 hr. On the same day, a previously healthy 41-yr-old woman who had undergone uneventful surgery for uterine prolapse 24 hr previously developed headache, nausea and over the next four hours signs of progressive brainstem ischaemia. The CT scan showed oedema of the mid- and hindbrain. Brainstem death was confirmed 12 hr later and the post-mortem revealed acute dissection of the vertebral artery secondary to cystic medial necrosis. Such dramatic neurological sequelae are rare but the importance of identifying "at risk" groups is underlined as is early recognition of neurological injury postoperatively.

Adult↗
PubMed1994

Quantitation of multidrug resistant MDR1 transcript in acute myeloid leukaemia by non-isotopic quantitative cDNA-polymerase chain reaction.

Drug resistance in acute myeloid leukaemia (AML) may be caused by overexpression of the P glycoprotein (PGP), an efflux pump encoded by the multidrug resistance mdr 1 gene. Previous studies have suggested that increased PGP expression in the leukaemic blasts is of prognostic significance, and that use of PGP antagonists may be beneficial in treatment. We describe preliminary results with a non-isotopic quantitative MDR 1 cDNA-PCR assay, using an artificial RNA construct sharing primer recognition sites with the target MDR 1 mRNA (MDR 1 nucleic acids 483-504 and 624-644) as an internal control. KB 3.1 parent and KB 8.5 MDR positive cell lines expressed 0.004 and 1.96 molecules MDR 1 mRNA/pg total RNA. Semiquantitative screening of 60 RNA samples from 53 AML cases detected MDR 1 transcript ranging from 0 to 1.81 molecules per pg RNA. The median value at presentation (33 patients) was 0.055 and was higher in 14 patients at relapse (0.13) and in seven patients with refractory disease (0.14). Quantitation of MDR 1 transcript in serial samples in seven treated patients between presentation and relapse showed the decrease in three patients (0.18-0.02 x) to be as marked as the increase in three other patients (3-16 x). The method described is well suited for the study of clinical samples because it is sensitive, specific, rapid and requires small amounts of clinical material.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Expression of shared idiotypes by paraproteins from patients with monoclonal gammopathy of undetermined significance.

We have previously demonstrated the expression of shared idiotypes by the paraproteins from approximately one-quarter of patients with multiple myeloma (MM). We have now investigated whether similar cross-reactivity is expressed in the paraproteins of patients with monoclonal gammopathy of undetermined significance (MGUS), using a panel of 32 monoclonal antibodies (MAB) generated against follicular B cell lymphomas. The paraproteins from 76/409 (19%) patients with MGUS reacted with at least one of 23 different anti-idiotypic antibodies used in this study. 18 MABs demonstrated reactivity with more than one patient's paraprotein. Moreover, 10 MABs reacted frequently (with 5-22 paraproteins). Over half (41/76) of the reactive patients' paraproteins reacted with more than one MAB from this panel. This frequency of anti-idiotypic reactivity was similar to that of previously studied patients with myeloma, chronic lymphocytic leukaemia (CLL), and follicular B-cell lymphomas. There was no correlation between specific anti-idiotypic reactivity and the propensity to develop serious disease (MM, macroglobulinaemia, amyloidosis, or other lymphoproliferative disorders) in patients with MGUS. These results suggest that MGUS is derived from cells producing antibodies that are similar to those of other B-cell malignancies and that the pattern of idiotype expression is irrelevant to malignant potential.

Antibodies, Monoclonal↗
PubMed1993

Hand preference consistency and fine motor performance in young children.

Recent investigations suggest that children who establish handedness early are better coordinated than those who lack this characteristic. To test this assumption, 160 4- to 6-year-olds were classified by consistent (established) and inconsistent (mixed) hand preference behavior and tested for fine motor performance using a finger tapping task. Analysis of the data revealed no significant differences existed between groups in finger tapping performance in relation to total sample, age or sex. Thus, contrary to recent reports, children with consistent and inconsistent hand preferences do not appear to differ in motor behavior as revealed by performance on a fine motor task. Furthermore, it appears that the performance of those with inconsistent hand preference presents a significant challenge to current theoretical notions of the genesis of handedness.

Child↗
PubMed1993

Laser-assisted enterocystoplasty in rats.

The employment of laser welds to anastomose bowel to bladder in urological surgery has never been described. Using rats, we compared laser-assisted enterocystoplasty (LAE) with conventional sutured enterocystoplasty (CSE). A "patch" ileocystoplasty was performed using distal ileum. Operative time, intraluminal bursting pressure and histologic changes were evaluated. Operative time was 38% less in the LAE (p < 0.001). No statistically significant differences in bursting pressure between LAE and CSE groups was demonstrated (p = 0.654) in rats sacrificed 2 weeks postoperatively. Histologic findings in the laser-assisted enterocystoplasties included early loose granulation tissue and later organization of the granulation tissue with significant collagen deposition. In our preliminary study, laser welding of bowel within the urinary stream was safe, efficacious and rapid and resulted in a mechanically comparable surgical outcome.

Anastomosis, Surgical↗
PubMed1993

Foot-tapping speed in children ages 4 to 6 years.

This investigation examined the performance and measurement characteristics of foot-tapping speed in 155 4- to 6-year-olds. Analysis suggested that, while the task does not differentiate between preferred and nonpreferred limbs, performance does appear to be age-related, that is, subjects tapped significantly faster with increasing age. Considering type of task and population, reliability was judged as moderate.

Age Factors↗
PubMed1992

Selective expression of mitogen-inducible cyclooxygenase in macrophages stimulated with lipopolysaccharide.

Two forms of cyclooxygenase are known to be present in eukaryotic organisms: a cyclooxygenase (COX-1) first purified from ram seminal vesicles encoded by a 2.8-kilobase mRNA, and a newly discovered mitogen-inducible cyclooxygenase (COX-2) encoded by a 4-kilobase mRNA. Expression of these two forms of the enzyme in rat alveolar macrophages stimulated with lipopolysaccharide was investigated by 1) determining the activity of newly synthesized enzyme after inactivating the endogenous enzyme with aspirin; 2) comparing levels of newly synthesized enzyme proteins in cells treated with or without lipopolysaccharide; and 3) assessing the expression of the mRNAs encoding COX-1 and COX-2. Levels of enzyme proteins were assessed by Western blot analysis and immunoprecipitation of 35S-labeled enzyme using two different antibodies, one specific for COX-2 and the other recognizing both forms of the enzyme but preferentially recognizing COX-1. We report here that the enhanced cyclooxygenase activity induced by the bacterial lipopolysaccharide in rat alveolar macrophages is caused by selective expression of the COX-2. Expression of COX-2 in macrophages stimulated by lipopolysaccharide was completely inhibited by dexamethasone, whereas COX-1 was unaffected. In resting unstimulated macrophages, only COX-1 but not COX-2 was detected. Levels of mRNA for the COX-2 in macrophages were increased, but those of the COX-1 were not affected by lipopolysaccharide as assessed by reverse transcription coupled with polymerase chain reaction. These results indicate that increased synthesis of prostaglandins and thromboxanes in lipopolysaccharide-stimulated macrophages results from selective expression of COX-2.

Animals↗
PubMed1992

Induction of immune responses in patients with B-cell lymphoma against the surface-immunoglobulin idiotype expressed by their tumors.

BACKGROUND: The idiotypic determinants of the surface immunoglobulin of a B-cell lymphoma can serve as a clonal tumor-specific marker, which may have implications for immunotherapy. We sought to determine whether idiotype-specific immune responses against this autologous antigen could be induced in patients with B-cell lymphoma. METHODS: Nine patients were selected who had minimal residual disease or a complete remission after chemotherapy. Each received a series of subcutaneous injections of the immunoglobulin derived from his or her tumor cells (immunoglobulin-idiotype protein), which had been conjugated to a protein carrier and mixed with an immunologic adjuvant. RESULTS: In seven of the nine patients the injections induced sustained idiotype-specific immunologic responses of the humoral type (two patients), the cell-mediated type (four patients), or both (one patient). The use of an adjuvant was essential for these immune responses. The induced antibodies bound specifically to autologous immunoglobulin idiotype, inhibited the binding of murine monoclonal antiidiotype antibodies, and bound autologous tumor cells. Cell-mediated responses were demonstrated by the specific proliferation of immune peripheral-blood mononuclear cells to the soluble immunoglobulin-idiotype protein in vitro. The tumors of both of the patients with measurable disease regressed completely. Toxicity associated with the vaccine was minimal and consisted only of mild reactions at the site of intramuscular injection. CONCLUSIONS: These results demonstrate that autologous immunoglobulin idiotype can be formulated into an immunogenic, tumor-specific antigen in humans with B-cell lymphoma, and they provide the background for large-scale trials of active specific immunotherapy of this disease.

Adjuvants, Immunologic↗