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Biomedical subjects

E H Harley

Publications and source records attributed to E H Harley.

At least 19 recordsLinked to original sources
PubMed2001

Genetic basis of hemolytic anemia caused by pyrimidine 5' nucleotidase deficiency.

Pyrimidine 5' nucleotidase (P5'N-1) deficiency is an autosomal recessive condition causing hemolytic anemia characterized by marked basophilic stippling and the accumulation of high concentrations of pyrimidine nucleotides within the erythrocyte. It is implicated in the anemia of lead poisoning and is possibly associated with learning difficulties. Recently, a protein with P5'N-1 activity was analyzed and a provisional complementary DNA (cDNA) sequence published. This sequence was used to study 3 families with P5'N-1 deficiency. This approach generated a genomic DNA sequence that was used to search GenBank and identify the gene for P5'N-1. It is found on chromosome 7, consists of 10 exons with alternative splicing of exon 2, and produces proteins 286 and 297 amino acids long. Three homozygous mutations were identified in this gene in 4 subjects with P5'N-1 deficiency: codon 98 GAT-->GTT, Asp-->Val (linked to a silent polymorphism codon 92, TAC-->TAT), codon 177, CAA-->TAA, Gln-->termination, and IVS9-1, G-->T. The latter mutation results in the loss of exon 9 (201 bp) from the cDNA. None of these mutations was found in 100 normal controls. The DNA analysis was complicated by P5'N-1 pseudogenes found on chromosomes 4 and 7. This study is the first description of the structure and location of the P5'N-1 gene, and 3 mutations have been identified in affected patients from separate kindreds. (Blood. 2001;97:3327-3332)

5'-Nucleotidase↗
PubMed2001

Radiometric assessment of hexose monophosphate shunt capacity in erythrocytes of rhinoceroses.

OBJECTIVES: To measure metabolic rates of the hexose monophosphate shunt (HMPS) in erythrocytes of rhinoceroses, and to test the hypothesis that low concentrations of endogenous ATP in erythrocytes impair HMPS capacity, thereby increasing susceptibility to oxidant-induced hemolysis. ANIMALS: 13 black and 3 white rhinoceroses, free-ranging in several regions of southern Africa, and 1 Sumatran rhinoceros in US captivity. PROCEDURE: HMPS fluxes were measured in rhinoceros erythrocytes with carbon-labeled glucose in the presence and absence of known HMPS activators. RESULTS: Compared with values for human erythrocytes, mean basal state HMPS fluxes were appreciably lower (22 to 46%) in all 3 rhinoceros species studied. Shunt activators increased HMPS rates approximately 5-fold over basal rates in rhinoceros erythrocytes, compared with increases in humans of 10-fold with ascorbate and 15-fold with methylene blue. Stimulated HMPS rates in human erythrocytes were quantitatively 5- to 10-times greater than those observed in rhinoceros erythrocytes. Overall HMPS catabolic rates were completely independent of intracellular ATP concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: HMPS glycolytic and recycling rates and responses to activators are inherently low in erythrocytes from 3 species of rhinoceros, likely contributing to (but not solely responsible for) the high susceptibility of black rhinoceroses to oxidant-induced hemolysis. Slow erythrocyte HMPS capacities were independent of intracellular ATP concentrations, invalidating a current hypothesis regarding the pathogenesis of hemolytic anemia in captive black rhinoceroses. Limitations in HMPS capacities emphasize the importance of protecting rhinoceroses from exposure to drugs, chemicals, toxins, foodstuffs, and other conditions known to increase production of oxidizing metabolites, reactive oxygen species, and free radicals.

Adenosine Triphosphate↗
PubMed1999

Birth trauma in the head and neck.

OBJECTIVES: To review the medical records of neonates found to have birth-associated trauma of the head and neck region. To describe the anomalies, physical findings, and possible sequelae of these injuries and to bring attention to the cause of mechanical birth injury as a potential cause of anomalies in the infant. DESIGN: Case-controlled retrospective chart review of a cohort of patients identified with birth-associated trauma to the head and neck from January 1, 1991, to March 1, 1997. SETTING: Academic tertiary care medical center. PATIENTS: Medical records from infants born or transferred with the diagnosis of birth trauma were reviewed. Medical records from a control group of 148 uninjured full-term infants born during the same period were reviewed for comparison. Neonatal charts, including labor and delivery records, were analyzed. MAIN OUTCOME MEASURES: Each patient record was reviewed for diagnosis, associated injuries, maternal statistics, gestational age, birth weight and size, Apgar scores, type of delivery, length of labor, complications of labor, and length of hospital stay. RESULTS: One hundred sixty-four infants (incidence, 0.82%; prevalence, 9.5 per 1000 live-births) were identified with 175 birth-associated injuries to the head and neck. The most common finding was cephalhematoma (56.6%). Other findings included scalp and/or facial lacerations (12%) and hematomas (2.3%), facial nerve paresis (8.6%), brachial plexus injuries (5.1%), clavicular (9.1%) and skull fracture (2.9%), nasal septal dislocation (0.6%), and phrenic (1.7%) and laryngeal nerve injuries (0.6%). Risk factors included birth weight (P = .001) , vaginal delivery (P = .001), primiparity (P = .02), forceps delivery (P = .005), vacuum delivery (P = .001), infants categorized as large for gestational age (P = .02), and male infant sex (P = .03). Apgar scores were also noted to be lower in our study population (P = .001). Risk factors for specific types of injuries varied. However, facial nerve paralysis was associated with multiple birth injuries (P = .001), and 2 of 3 phrenic nerve injuries co-occurred with brachial plexus injuries. Correlation coefficients for factors such as maternal age, gravidity, and race were low. CONCLUSION: Birth-associated head and neck trauma is rare. However, mechanical birth-associated trauma must be considered when assessing anomalies, injuries, respiratory difficulty, or feeding difficulties in the neonate or infant. A comprehensive approach is required to diagnose and manage these patients.

Birth Injuries↗
PubMed1999

Isolation and characterization of microsatellite loci in black rhinoceros (Diceros bicornis).

The black rhinoceros (Diceros bicornis) is currently one of the most endangered African mammals as a direct result o habitat destruction and intensive poaching. A microsatellite library was constructed to address a number of population genetic questions. This paper describes the isolation of five black rhinoceros microsatellite loci. Three of these loci were found to be polymorphic. In addition, the paper demonstrates the utility for cross-hybridization of these primers in other species of rhinoceros.

Animals↗
PubMed1998

Ibuprofen for tonsillectomy pain in children: efficacy and complications.

We designed a prospective, randomized, double-blind study to test the efficacy and safety of ibuprofen compared with acetaminophen with codeine for pediatric posttonsillectomy/adenotonsillectomy patients. Twenty-seven children, aged 6 to 16 years, were enrolled. We collected information on pain control, return to normal sleep pattern, return to normal diet, and duration for which medication was required. Coagulation profiles were measured before surgery and on postoperative day 3. Acetaminophen with codeine was more effective in controlling pain on days 1 and 3 (p = 0.0475 and 0.0328, respectively). However, we detected no difference between the treatment groups (p = 0.2216) with regard to pain control on day 5. The ibuprofen group required medication for a longer period (p = 0.0464). We detected no statistically significant differences between groups with regard to return to normal diet (p = 0.2346) and return to normal sleep pattern (p = 0.9554). The postoperative hemorrhage rate was 0% in the acetaminophen-with-codeine group and 12.5% in the ibuprofen group. The ibuprofen group demonstrated a mean increase in bleeding time of 2.07 minutes on the third postoperative day (p = 0.0379). The mean change in postoperative bleeding time between the two groups was statistically significant (p = 0.0140). We found no statistically significant differences in prothrombin time and partial thromboplastin time between groups. On the basis of the findings of this pilot study, we conclude that acetaminophen with codeine is safer and more efficacious than ibuprofen in the management of posttonsillectomy/adenotonsillectomy pain in children.

Acetaminophen↗
PubMed1997

Acute mastoiditis in children: a 12-year retrospective study.

We undertook a retrospective study to examine our experience with acute mastoiditis over a 12-year period. Fifty-eight cases were identified in children aged 3 months to 15 years. Acute mastoiditis was the first evidence of otitis media in 54% of our patients. Pain and fever lasting for more than a median period of 4 days were most likely to be the harbingers of incipient acute mastoiditis. Streptococcus pneumoniae was the most common organism recovered from the cultures. All children were treated with intravenous antibiotics; 41 children were managed with an adjunctive drainage procedure. No statistically significant differences were observed between the cure rates and failure rates for children treated surgically with myringotomies with or without tubes and children managed more aggressively with mastoidectomies. One infant had bacterial meningitis. Cholesteatoma was diagnosed in two children. We conclude from our study that acute mastoiditis occurs mainly in young children and may be the first evidence of ear disease. Pain and fever that persist despite appropriate treatment for acute otitis media are the two most important symptoms. Intravenous antibiotics combined with myringotomy with or without tube insertion are as appropriate as intravenous antibiotics with mastoidectomy for initial management of acute mastoiditis in the absence of a subperiosteal abscess or central nervous system extension.

Acute Disease↗
PubMed1997

Liquid household bleach ingestion in children: a retrospective review.

Current literature and some standard reference textbooks fail to adequately delineate the management of liquid household bleach (sodium hypochlorite) as different from other caustic agents. A literature review and retrospective study were conducted to focus attention on the clinical course and the low potential for development of long-term sequelae secondary to liquid household bleach ingestion in children. The records of 19 patients were reviewed. The mean age of children ingesting bleach was 24 months. Most children obtained the liquid from an open container such as a cup. There were no short- or long-term sequelae. We introduce an algorithm for the management of accidental ingestion of liquid household bleach in children. We conclude that in the United States accidental bleach ingestion in children is usually associated with a benign clinical course and usually does not require hospitalization, corticosteroids, or antibiotics unless there is severe dysphagia or signs of significant injury. Esophagoscopy may not be necessary, but fiberoptic examination of the pharynx and larynx should be included in the assessment of these children.

Algorithms↗
PubMed1996

Two siblings with episodic ketoacidosis and decreased activity of succinyl-CoA:3-ketoacid CoA-transferase in cultured fibroblasts.

Succinyl-CoA:3-ketoacid CoA-transferase deficiency leads to a severe ketoacidosis presenting in infancy. We describe two siblings of African ancestry who presented with repeated episodes of ketoacidosis. Both had a positive test for salicylate in the absence of salicylate ingestion. Analysis of urine for organic acids revealed the presence of acetoacetate and 3-hydroxybutyrate. Succinyl-CoA:3-ketoacid CoA-transferase activities in cultured fibroblasts were 11% and 18% of control values.

Acidosis↗
PubMed1995

Systematics of cetaceans using restriction site mapping of mitochondrial DNA.

Phylogenetic analysis of 14 cetacean species, including members from two baleen whale families and three toothed whale families, was undertaken using restriction site mapping of mitochondrial DNA and using cladistic and distance measures to infer phylogenies. The amount of between-taxa sequence divergence inferred from the data was lower than expected from the standard interpretation of the fossil record, but more consistent with some recent estimates of sequence divergence in cetacean mitochondrial DNA or nuclear DNA. This implies either that the rate of molecular evolution of cetacean DNA is much lower than that of other mammalian orders or that the fossil record of cetaceans requires reinterpretation. The incompleteness of the cetacean fossil record precludes resolution of the paradox at the present time. However, this discrepancy could in part be attributed to the sampling error inherent in the restriction site mapping technique, as comparative studies using the complete mtDNA genome and restriction site data of the blue and fin whales (genus Balaenoptera) indicate that the restriction site maps underestimate sequence divergence by about 40%. In contrast to a recent study suggesting that toothed whales were paraphyletic, with the sperm whales being more closely related to the rorquals than to the other toothed whales, the restriction data tend to support the monophyly of the baleen and the toothed whales, a finding which is consistent with a recent molecular-based study and with morphological and paleontological data. Topologies of the subfamily and generic levels are generally consistent with morphologically based schemes.

Animals↗
PubMed1995

Uptake of purine substrates shows major physiological variations in mammalian skin fibroblasts.

Uptake of the purine bases hypoxanthine and adenine were studied in skin fibroblast cultures from three different mammalian species. Marked variation in uptake was observed, and using an analysis of variance, the main component of this variation was found to be at the between experiment level as opposed to the between replicate or between individual level. After allowing for this variation, significant between species differences in uptake were found. Uptake of both purines decreased proportionately with passage number, and increased markedly after viral transformation of the fibroblast cultures. These results demonstrate significant metabolic differences in purine anabolic pathway fluxes between mammalian species but also have serious implications for the use of these methods in a diagnostic context.

Adenine↗
PubMed1995

Absence of geographic chromosomal variation in the roan and sable antelope and the cytogenetics of a naturally occurring hybrid.

The determination of geographic chromosomal variation in rare or endangered species, or those of special management concern, is important, since geographically defined cytotypes can negatively influence breeding programs involving founders drawn from widely divergent localities. We cytogenetically analyzed specimens of the roan (Hippotragus equinus) and sable antelope (H. niger) collected from widely divergent localities throughout their respective ranges. Each species was characterized by a diploid number of 60 and an invariant karyotype. In contrast to the absence of intraspecific variation, however, the two species differ with respect to centromeric constitutive heterochromatin and numbers of nucleolar organizer regions. These cytogenetic landmarks were subsequently used to verify an anecdotal account of a naturally occurring roan x sable hybrid. The data show that, despite their markedly distinct phenotypes, the roan and sable antelope are nonetheless sufficiently similar genetically to produce viable offspring. Hybridization, although a rare event between these species, is probably partly promoted by behavioral differences which are not always sufficient to prevent mating between them.

Africa↗
PubMed1994

Neurologic sequelae secondary to atlantoaxial instability in Down syndrome. Implications in otolaryngologic surgery.

OBJECTIVE: A comprehensive overview of atlantoaxial instability in Down syndrome as it relates to head and neck surgery and recommendations as derived from a review of the literature. DATA SOURCES: English-language literature: otolaryngologic problems in Down syndrome and atlantoaxial biomechanics. DATA SYNTHESIS: Children affected with Down syndrome frequently require otolaryngologic procedures such as myringotomy with ventilation tubes or adenotonsillar surgery. Atlantoaxial instability occurs in 10% to 20% of patients with Down syndrome who are at risk for atlantoaxial subluxation and subsequent complications during anesthetic induction and during positioning and manipulation associated with surgery. To identify patients who are at risk for atlantoaxial subluxation, guidelines have been adapted from the recommendations of the American Academy of Pediatrics and the Special Olympics Inc, which include preoperative neurologic assessments and cervical roentgenograms in the neutral, flexion, and extension positions. Children with an atlantodental interval of greater than 4.5 mm or with peripheral neurologic findings should have further evaluation. CONCLUSIONS: A small percentage of patients with Down syndrome are at risk for atlantoaxial instability and subluxation. All patients with Down syndrome should have a preoperative neurologic assessment screening by the operating surgeon and/or a cervical roentgenogram in the lateral, extension, and flexion positions. Any abnormality should be investigated before surgery.

Anesthesia, Inhalation↗