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Biomedical subjects

A Lee

Publications and source records attributed to A Lee.

At least 631 records · Page 35Linked to original sources
PubMed1990

A randomised double-blind study of interpleural analgesia after cholecystectomy.

Continuous interpleural analgesia provided by 4 hourly injections of 20 ml bupivacaine 0.5% with adrenaline 5 micrograms/ml was compared with placebo in a randomised, double-blind study after cholecystectomy. All patients self-administered intravenous morphine using a patient-controlled analgesia device. There was a highly significant difference in mean morphine consumption between the groups (72 mg as compared with 22 mg). Visual analogue pain scores tended to be lower in the bupivacaine group throughout and this was significant at 2 hours. Respiratory function measurements were not significantly different between the groups. The mean peak venous plasma bupivacaine concentration after the sixth dose was 3.03 micrograms/ml and no symptoms suggestive of local anaesthetic toxicity occurred. It is concluded that this regimen can provide effective and continuous analgesia after cholecystectomy and that combined administration of interpleural bupivacaine and systemic morphine is more effective than morphine alone in the immediate postoperative period. The doses of bupivacaine required for optimal use of the technique lead to significant total plasma bupivacaine concentrations within 24 hours.

Adult↗
PubMed1990

Helicobacter pylori gastric infection in gnotobiotic beagle dogs.

Establishment of infection with Helicobacter pylori and gastritis in nonhuman species is currently only successful in gnotobiotic piglets. This study was designed to determine whether H. pylori will colonize the gastrointestinal tract of gnotobiotic dogs. Gnotobiotic beagle pups were derived by standard methods. Group A (five dogs) was orally challenged with 3 x 10(8) H. pylori at 7 days of age. Group B (two dogs) received only peptone water but was contact-exposed beginning on day 23 postinfection (p.i.). Necropsy was performed on dogs on day 30 p.i. H. pylori colonized the stomach of all dogs (groups A and B). Urease map analysis correlated with the microbiologic findings and indicated that the density of colonization was less than that observed in human tissue. Organisms were also recovered from the pharynx, esophagus, duodenum, and rectum of 1, 2, 2, and 1 dog, respectively. All group A and one group B dog developed serum immunoglobulin G specific for H. pylori by day 30 p.i. Gross lesions were restricted to the stomach and consisted of small (less than 1 mm) lymphoid follicles. Microscopically, there were focal to diffuse lymphoplasmacytic infiltrates with follicle formation and mild to moderate infiltration of neutrophils and eosinophils in the gastric lamina propria. With the Warthin-Starry silver stain, organisms were seen on the surface of the gastric epithelial cells, beneath the mucus layer. We conclude that H. pylori colonizes the stomachs of gnotobiotic dogs for at least 1 month and the lesions resemble those seen in humans. H. pylori is transmissible by contact from infected to noninfected dogs.

Animals↗
PubMed1990

Isolation and characterization of Bacillus stearothermophilus 30S and 50S ribosomal protein mutations.

Bacillus stearothermophilus mutations which confer resistance to or dependence on a variety of ribosome-targeted antibiotics have been isolated. Many of these mutations produce ribosomal proteins with altered mobilities in a two-dimensional gel electrophoresis system. This collection of altered thermophilic ribosomal proteins will be useful in examining ribosomal structure and function.

Bacterial Proteins↗
PubMed1990

White noise and sleep induction.

We studied two groups of 20 neonates, between 2 and 7 days old, in a randomised trial. Sixteen (80%) fell asleep within five minutes in response to white noise compared with only five (25%) who fell asleep spontaneously in the control group. White noise may help mothers settle difficult babies.

Acoustic Stimulation↗
PubMed1990

Transfection of cells from patients with leukocyte adhesion deficiency with an integrin beta subunit (CD18) restores lymphocyte function-associated antigen-1 expression and function.

Leukocyte adhesion deficiency (LAD) is an inherited immunodeficiency disease that is characterized by the deficient expression of the leukocyte adhesion glycoproteins lymphocyte function-associated antigen-1 (LFA-1), Mac-1, and p150,95. This loss of expression is attributed to heterogeneous defects in the common beta subunit shared by these glycoproteins. Here we demonstrate that expression of the LFA-1 alpha beta heterodimer in EBV-transformed B lymphoblastoid cells from LAD patients can be recovered after transfection with the beta subunit cDNA contained in an EBV-based vector. Four patients with differing severities of LAD comprising three distinct classes of mutations were studied. Flow cytometry analysis of stably transfected patient cells revealed near normal levels of expression of both the alpha and beta chains of LFA-1, and immunoprecipitation studies confirmed that fully processed alpha and beta chains were being expressed at the cell surface. In addition, Northern analysis of mRNA expression also demonstrated that the transfected LAD patient cells were expressing high quantities of exogenous beta subunit mRNA. Functional studies such as homotypic adhesion and adhesion to a purified counterreceptor for LFA-1, intracellular adhesion molecule-1, demonstrated that LFA-1 function had been restored in the stably transfected LAD patient cell lines. These studies unequivocally show that the defect in cells from patients with LAD is in the leukocyte integrin beta subunit.

Animals↗
PubMed1990

Ultrastructural localization of blood-retinal barrier breakdown in diabetic and galactosemic rats.

Breakdown of the blood-retinal barrier (BRB) is an early event in diabetic and galactosemic rats, but the location and nature of the specific defect(s) are controversial. Using an electron microscopic immunocytochemical technique, the retinas of normal, diabetic, and galactosemic rats were immunostained for endogenous albumin. Normal rats showed little evidence of BRB breakdown at either the inner barrier (retinal vasculature) or the outer barrier (retinal pigment epithelium) (RPE). In diabetic and galactosemic rats, as was true in human diabetics, BRB breakdown occurred predominantly at the inner BRB, but in some cases at the outer barrier as well. Treatment with the aldose reductase inhibitor sorbinil largely prevented BRB failure in galactosemic rats. In the inner retina of diabetic and galactosemic rats, albumin was frequently demonstrated on the abluminal side of the retinal capillary endothelium (RCE) in intercellular spaces, basal laminae, pericytes, ganglion cells, astrocytes, and the perinuclear cytoplasm of cells in the inner nuclear layer. Albumin did not appear to cross RCE cell junctions; however, it was occasionally seen in RCE cytoplasm of galactosemic rats. In the outer retina, albumin was frequently detected in the subretinal space, in the intercellular space between photoreceptors, and in the perinuclear cytoplasm of photoreceptor cells, but was only infrequently found in the RPE cells constituting the barrier. Albumin derived from the choroidal vasculature did not appear to cross the tight junctions of the RPE. These findings suggest that specific sites of BRB compromise are infrequent but that once albumin has crossed the RCE or RPE it freely permeates the retinal tissue by filling intercellular spaces and permeating the membranes of cells not implicated in BRB formation. The diffuse cytoplasmic staining of some RCE and RPE cells suggests that the predominant means of BRB breakdown in diabetes and galactosemia involves increased focal permeability of the surface membranes of the RCE and RPE cells rather than defective tight junctions or vesicular transport.

Albumins↗
PubMed1990

Diabetes, hyperinsulinemia, and hyperlipidemia in small aboriginal community in northern Australia.

A small rural Aboriginal community in northern Australia was surveyed for diabetes, impaired glucose tolerance (IGT), hyperinsulinemia, and lipid levels. Of the 122 adults greater than 17 yr of age who participated (95% response rate), 11.5% had diabetes, 7.4% had IGT, and the remaining 81.1% had normal glucose tolerance. Both diabetes and IGT were strongly age related. This high frequency of diabetes occurred, despite the population being relatively lean. Although the body mass index (BMI) increased with age in both men and women, only 25% of the population overall had BMI greater than 25 kg/m2. There were wide ranges of insulin responses to glucose, with the upper tertile of 2-h insulin levels being more than seven times higher than the lower tertile (144 +/- 13 vs. 19 +/- 1 mU/L). Hyperinsulinemia was associated with IGT, elevated triglycerides, and lower high-density lipoprotein cholesterol levels. Lipid abnormalities were much more frequent among men than women. Cholesterol levels were an average of 0.55 mM higher and triglycerides an average of 1.05 mM higher in men than in women, and both increased with age. In conclusion, this small isolated Aboriginal population from northern Australia had an unexpectedly high frequency of diabetes (in view of their relative leanness) in association with a high frequency of metabolic abnormalities indicative of insulin resistance (hyperinsulinemia, IGT, hypertriglyceridemia).

Adolescent↗
PubMed1990

Goal-directed behavior in children with spina bifida.

A group of school-age children with spina bifida (n = 15) between the ages of 6 and 12 years were compared with an age- and IQ-matched control group of normal children (n = 15). Goal-directed behavior in these two groups was measured by videotaped observational measures of the number of different task-oriented play activities the children performed and the amount of time they spent in independent task-oriented activities. Measures of time spent off-task and in simple manipulation of the play materials were taken, as well as the number of social initiations the child directed to the examiner. The children with spina bifida spent less time in task-oriented activities than the control group, even though there were no group differences in the number of activities performed. The differences could not be explained by cognitive impairments or socioeconomic factors. These results suggest that children with spina bifida may have specific problems with sustaining goal-directed behavior, and need assistance in formulating and implementing a sequence of actions in order to achieve concrete short-term goals.

Attention↗
PubMed1990

Localization of blood-retinal barrier breakdown in human pathologic specimens by immunohistochemical staining for albumin.

Human pathologic specimens from eyes with several different disease processes were immunohistochemically stained with antisera directed against rat or human serum albumin. In 33 eyes with no known ocular disease and no pathologic abnormalities, positivity was seen in the choroid and within retinal vessels, but not within the retina, except in one case in which focal staining in an area of outer retina was noted. In eyes with a history of ocular disease and/or pathologic findings, extravascular albumin staining was seen in areas of the retina generally corresponding to pathologic abnormalities. Albumin in the inner retina appeared to emanate from retinal vessels, but often collected along the internal limiting membrane. Staining in the outer retina was frequently demonstrated along the external limiting membrane, but in some cases, was also seen between the photoreceptor outer segments and within the retinal pigment epithelium. Eyes with primary retinovascular disease showed staining more commonly in the inner retina (77%) than the outer retina (38%) as would be predicted on theoretical grounds, whereas eyes with other disease processes showed no difference in frequency of staining between inner and outer retina. These data suggest that immunohistochemical staining of extravascular albumin is a useful technique for localizing breakdown of the blood-retinal barrier and is applicable to several disease processes.

Blood-Retinal Barrier↗
PubMed1990

Variability of continuous-wave Doppler flow velocity waveform indices from the umbilical artery.

Using continuous-wave Doppler ultrasound, the reproducibility of umbilical artery blood flow velocity waveforms, recorded by two operators, was evaluated in 20 high-risk antenatal inpatients. Inter-operator variability was not significant for any index. The intra-operator coefficients of variation for resistance index, pulsatility index, and systolic/diastolic ratio were 7 and 7%, 12 and 12%, and 15 and 11%, respectively, for each operator. The intra-class coefficient of reliability, calculated by analysis of variance, indicated that the contribution of inter-patient variability to total variance was four times that of intra-operator variability.

Blood Flow Velocity↗
PubMed1990

Lyme disease in childhood: clinical and epidemiologic features of ninety cases.

In 1982 and 1983 practicing pediatricians in a Lyme disease-endemic county, reported 90 cases of Lyme disease among children 19 years of age and younger (median age, 9 years). Three-fourths of the children had initial symptom onset in the summer months, with peak incidence in July. Infection occurred twice as often in boys than in girls, and tick bites were recalled by less than half (49%) of the children or parents. Erythema chronicum migrans was present in two-thirds (67%) of the cases with median onset 7 days after a definite tick bite. Arthritis or arthralgia occurred in 59% and neurologic symptoms, especially seventh nerve palsy, occurred in 14%. Asymmetric involvement of a few large joints, especially the knee, was most commonly reported for those with joint involvement. antibiotics were prescribed for 79% of the children, three-fourths of whom were treated with oral penicillin. Initial diagnosis of Lyme disease is usually made on clinical grounds alone because serologic tests are often negative. Serologic tests for antibody to Borrelia burgdorferi were more often positive in cases with neurological or joint involvement, in addition to erythema chronicums migrans (80%), than in cases presenting with erythema chronicums migrans only.

Adolescent↗
PubMed1989

Management strategies for surgical treatment of dysrhythmias in infants and children.

To elucidate the role of surgery in the management of refractory pediatric dysrhythmias, the investigators' 1987 experience with this therapy was reviewed. Sixteen patients (8 male, 8 female) had surgery. Age ranged from 3 months to 21 years (mean 7.7 years) with 2 being younger than 1 year of age. Eight patients had Wolff-Parkinson-White syndrome with supraventricular tachycardia (SVT), 6 had SVT alone and 2 had ventricular tachycardia. Patient symptoms fell into 3 distinct categories. Nine patients had frequent non-life-threatening tachycardia episodes despite aggressive medical management, 4 patients had life-threatening symptoms either related to frequent tachycardia episodes or due to side effects of drugs and 3 patients had minimal tachycardia symptoms but were judged to be at risk for sudden death. The mechanisms of the tachycardias included reentrant SVT using an accessory atrioventricular connection in 9, the permanent form of junctional reciprocating tachycardia in 2, atrioventricular node reentrant SVT in 2, atrial ectopic focus in 1 and ventricular ectopic foci in 2. Ablation techniques involved either surgical dissection or cryoablation of the arrhythmogenic substrates. There was no surgical mortality and follow-up shows 15 of 16 patients to have had no recurrence of symptomatic tachycardia without any therapy. Based on this experience, management strategies for surgical control of recalcitrant pediatric dysrhythmias are proposed. Surgery for infant dysrhythmias should be performed only for life-threatening symptoms. Beyond the first year of life, after failing 2 medications, surgical options for SVT should be considered. For patients with ventricular tachycardia, aggressive medical management with class II, IC and III agents should be attempted before surgical therapy.

Adolescent↗
PubMed1989

Transrectal ultrasound. A case report related to the natural history of prostate cancer.

This is a case report of a man with prostate cancer diagnosed 10 years ago by digital rectal examination and prostatic biopsy. He was followed with serial transrectal ultrasound examinations for the last 22 months. Transrectal ultrasound enabled us to observe the natural history of his cancer. Because of accelerated tumor growth, a radical prostatectomy was performed. The tumor was confined within the prostate capsule and thus considered a "cure." Transrectal ultrasound is an invaluable tool for continuous monitoring of patients with prostate cancer.

Adenocarcinoma↗
PubMed1989

Lithium carbonate intoxication. A case report and review of the literature.

Lithium carbonate is a widely used and invaluable drug in the treatment and prevention of manic-depressive illness. However, this medication has a low therapeutic index and, therefore, many attendant side effects. Acute lithium carbonate intoxication affects predominantly the central nervous system and the renal system and is potentially lethal. We studied a case of acute lithium carbonate intoxication characterized by a prolonged comatose state, severe nephrogenic diabetes insipidus, and glucose intolerance. Of interest, the patient's symptoms and signs of toxic reaction developed after normalization of the plasma lithium ion levels. We reviewed the multisystemic toxic effects of lithium carbonate as well as its teratogenic potential and guidelines for its use during pregnancy. The management of acute lithium carbonate intoxication should include hydration with normal saline, intensive care monitoring, and dialysis if indicated.

Humans↗
PubMed1989

Sequence analysis of mouse mitochondrial chloramphenicol-resistant mutants.

The nucleotide sequences of the 3' halves of the mitochondrial 16S rRNA genes from four independent mouse chloramphenicol-resistant (CAP-R) mutants were determined. Each contained a different, single base change that encodes the mutational phenotype. The mitochondrial rRNA gene from the SVA31 CAP-R mutant contains a G-to-A transition at nucleotide 2161 of the noncoding strand; the SVIS CAP-R mutant, a G-to-A transition at position 2375; the LA9 CAP-R mutant, an A-to-T transversion at position 2379; and the SVT2 CAP-R mutant, a T-to-C transition at position 2433. Three of these CAP-R mutants appear to be heteroplasmic as the mtDNA populations contain both wild-type and mutant copies of the rRNA gene. The SVIS CAP-R mutation has not been observed in other mammalian CAP-R mutants, although it occurs at a site homologous to one of the yeast mitochondrial CAP-R mutations. Based upon the locations of the mutated sites within the 16S rRNA, and their proximity to previously analyzed sites of mutations conferring increased inhibitor resistance, all these mutations occur within the ribosomal RNA peptidyltransferase domain. These results provide an explanation for the pleiotropic nature of mitochondrial CAP-R mutations in mammalian cells, particularly the observations that some of the mutant lines are partially respiration deficient.

Animals↗