Origins and function of 3-ribosylurate in bovid erythrocytes.

3-Ribosylurate is a dominant feature on high performance liquid chromatography (HPLC) profiles of acid extracts of erythrocytes from cows and buffalo, but is HPLC-undetectable in acid extracts of erythrocytes from all other species examined to date. Various aspects of this unique low molecular weight substance remain unexplored since it was first identified. In this study, the mutation(s) responsible for the appearance of ribosylurate in these cells is shown to be specific to members of both tribes of the Bovinae subfamily (Bovidae family), being detectable in the erythrocytes of both the cow and the buffalo (Bovini tribe) as well as in the kudu (Strepsicerotini tribe), but not in representative species from the other subfamilies of the Bovidae family. More specifically, expression of the mutation(s) seems to be restricted to the erythrocyte lineage of these species, ribosylurate being undetectable in cow white blood cells and primary cultures of fibroblasts. Novel evidence is presented that ribosylurate has antioxidant activity. Accumulation of high levels specifically within the haemoglobin-rich milieu of circulating erythrocytes may serve to protect perfused tissues by removing pathophysiological levels of hydrogen peroxide from plasma. Maintenance of ribosylurate levels may be important in conditions associated with oxidative stress in Bovinae.

Horse microsatellites and their amenability to comparative equid genetics.

We investigated the applicability of microsatellite primers, designed in horses, for use in plains and mountain zebras. Fifteen of the 20 tested horse-isolated primer pairs reliably amplified polymorphic loci in two wild equid species. We used this information to assess whether levels of genetic variation and repeat size differed in species from which microsatellites were isolated and in closely related target species. Target equid species exhibited similar levels of genetic variation to the horse, the species from which primers were originally isolated. We show that ascertainment bias results in lower mean and modal repeat size in target species. The data also provide evidence for a bi-directional mutational constraint in allele size across three equid species.

Elevated free tyrosine in rhinoceros erythrocytes.

Red blood cells of African black rhinoceroses (Diceros bicornis) are highly sensitive to oxidant-induced hemolysis and they possess a number of enzymatic and biochemical features that differ radically from other mammals. Here we show concentrations of free tyrosine in rhinoceros red blood cells which can approach levels as high as 1 mM, 50-fold higher than in human red blood cells. Elevated levels of tyrosine are also observed in red blood cells of other members of the order Perissodactyla such as the horse and zebra. Captive black rhinoceroses have significantly lower levels of red blood cell tyrosine than black rhinoceroses in the wild. Tyrosine transport studies indicate that black rhinoceros red blood cells have lost the ability to transport tyrosine as efficiently as human red blood cells.

Post-bottleneck genetic diversity of elephant populations in South Africa, revealed using microsatellite analysis.

Widespread hunting had fragmented and severely reduced elephant populations in South Africa by 1900. Elephant numbers increased during the 1900s, although rates of recovery of individual populations varied. The Kruger National Park elephant population increased rapidly, to more than 6000 by 1967, with recruitment boosted by immigration from Mozambique. The Addo Elephant National Park population was reduced to 11 elephants in 1931 and remains relatively small (n = 325). Loss of genetic variation is expected to occur whenever a population goes through a bottleneck, especially when post-bottleneck recovery is slow. Variation at nine polymorphic microsatellite loci was analysed for Kruger and Addo elephants, as well as museum specimens of Addo elephants shot prior to the population bottleneck. Significantly reduced genetic variation and heterozygosity were observed in Addo in comparison to Kruger (mean alleles/locus and H(E): Addo 1.89, 0.18; Kruger 3.89, 0.44). Two alleles not present in the current Addo population were observed in the museum specimens. Addo elephants represent a genetic subset of the Kruger population, with high levels of genetic differentiation resulting from rapid genetic drift. The Kruger population is low in genetic diversity in comparison to East African elephants, confirming this population also suffered an appreciable bottleneck.

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.

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)

Phylogenetic relationships in Disa based on non-coding trnL-trnF chloroplast sequences: evidence of numerous repeat regions.

Sequence data from the intron and spacer of the trnL-F chloroplast region elucidate the phylogenetic relationships of the tribe Diseae (Orchidoideae: Orchidaceae). Within Diseae, 41 species of Disa, two of Brownleea, three of Satyrium, and two of Corycium were included, with five species of Habenaria sensu lato (Orchideae) and one epidendroid as outgroups. The sequences revealed substitutions and considerable length variation, due mainly to the presence of repeat motifs. Phylogenetic analysis using parsimony revealed five distinct clades. The branching order of the five weakly supported the paraphyly of Diseae, with the successive divergence of Brownleea, Corycium, Habenaria, Satyrium, and Disa. Within the monophyletic Disa, three main groupings appeared, two strongly supported clades representing sect. Racemosae and sect. Coryphaea and the third grouping containing several clades currently grouped into sections based on morphological phylogenies. Some discrepancies between the molecular phylogeny and the phylogeny based on morphological characters may require reevaluation of some of the morphological characters. The presence of different numbers of repeat motifs, both among different taxa and within taxa, indicates that these characters may be phylogenetically informative at the population level.

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.

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.

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.

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.

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.

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.

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.