Biomedical subjects
Publications and source records attributed to C L Taylor.
Imiquimod 5% cream, an immune response modifier licensed for treatment of external ano-genital warts and superficial basal cell carcinomata, is known to cause local erythema, oedema and, rarely, exacerbation of psoriasis. We describe a case of exacerbation of eczema following application of this cream in a man with penile warts.
The mechanisms through which the oncoprotein c-Myc initiates locus-specific gene amplification are not understood. When analysing the initiation mechanism of c-Myc-dependent amplification of the mouse ribonucleotide reductase R2 (R2) gene, we observe c-Myc-dependent initiation of illegitimate DNA replication of the R2 gene. We demonstrate multiple simultaneous c-Myc-induced R2 replication forks, whereas R2 normally replicates with a single fork. In contrast, cyclin C replicates with only a single replication fork irrespective of c-Myc deregulation. In addition to de novo replication forks, c-Myc also initiates bi-allelic replication of R2, abrogating its normal mono-allelic replication pattern. Moreover, several chromosomal regions also display c-Myc-induced illegitimate replication profiles. Thus, c-Myc can act as an illegitimate replication-licensing factor that promotes de novo replication initiation and illegitimate replication timing that adversely impacts upon genomic stability.
cDNA encoding a marsupial polymeric immunoglobulin receptor (pIgR) was isolated from Macropus eugenii (tammar wallaby) mammary lymph node primarily by reverse transcriptase coupled polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) PCR. This resulted in a 5' truncated clone and, in order to obtain the full-length sequence, genomic walking PCR was utilized. The complete sequence consists of 2696 bp of cDNA and encodes a predicted polypeptide of 732 amino acids. The wallaby sequence is highly conserved in relation to the only other reported marsupial pIgR sequence, that of Trichosurus vulpecula (brushtail possum), having a nucleotide identity of 86.7% and a deduced amino acid identity of 79.9%. The wallaby nucleotide sequence also has a moderate degree of similarity with the pIgR sequences of eutherian mammals, being most similar to that of the rat, with an identity of 63.1%. At the amino acid level, in comparison to eutherian sequences, the wallaby pIgR is most similar to that of humans with an identity of 52.6%. pIgR phylogenetic trees were constructed for tammar wallaby, brushtail possum and several eutherian mammal cDNA and deduced amino acid sequences. In both DNA and protein analyses, the eutherian sequences formed a sister clade to the exclusion of the marsupial sequences, in agreement with the current view of mammalian evolution.
Nonoxynol-9 (N-9) containing spermicides and other N-9 containing products are commonly used as lubricants during rectal intercourse. We have previously demonstrated that rectal application of N-9 products in mice can cause exfoliation of epithelial cells, increasing the probability of infection by HSV-2. To determine if N-9-containing products would have a similar effect on the rectal epithelium in humans, the application of K-Y Plus and ForPlay, both over-the-counter (OTC) N-9 products, were compared to the application of two formulations, carrageenan and methyl cellulose, that do not contain N-9. The effects of each formulation were evaluated in 4 human participants. Light and electron microscope examination of rectal lavage specimens collected 15 min post application of N-9 products revealed the presence of sheets of epithelium. Each sheet contained hundreds of epithelial cells that included columnar and goblet cells, varieties of cells typical of rectal epithelial morphology. Sheets of epithelium were not observed in rectal lavage specimens collected 8 to 12 hr post N-9 product use or in either of the timed lavages involving non-N-9 containing formulations. In addition, no sheets of epithelial cells were observed in the baseline lavage specimens. We conclude that the rectal use of N-9-containing products causes a rapid exfoliation of extensive areas of the rectal epithelium. Exfoliation of the epithelium is no longer observed at 8 hr. It is reasonable to assume that the loss of the protective epithelium would render a person more at risk for infection by HIV and other sexually transmitted pathogens. We, therefore, caution against the use of N-9-containing products during rectal intercourse.
The purpose of this research was to obtain the sensitivity and specificity of transient evoked otoacoustic emission (TEOAE) screening procedures compared with conventional audiometric pure-tone screening and tympanometry. Pass/refer values were obtained from a group of 297 ears of 152 preschool and school-aged children, 3 to 8 years of age. The sensitivity and specificity of the TEOAE screenings compared with the pure-tone screenings were 81% and 95%, respectively. The sensitivity and specificity of TEOAE screenings compared with tympanometric screenings were 60% and 91%, respectively.
Measurement of exhaled nitric oxide (FE(NO)) is a noninvasive and practical method for assessing airway inflammation. We conducted this investigation to determine the most appropriate flow rate for FE(NO) measurement and to obtain normal values for FE(NO). We determined which expiratory flow was easy to sustain, generated reproducible values, and provided good correlation between offline and online measurements. Thirty-two healthy subjects (15- 18 yr old) underwent spirometry and FE(NO) measurements, using a chemiluminescent NO analyzer at expiratory flow rates of 46, 31, 23, 15, 10, 7, 5, and 4 ml/s. The major findings were as follows: (1) FE(NO) increased as flow rates decreased, with strong correlation between FE(NO) values and flow rates at the four highest flows (0. 85- 0.93, p < 0.001); (2) there were no significant differences and good agreement between offline bag and online FE(NO) values for the four highest flows (p < 0.09-0.83); (3) online FE(NO) values increased with age 15-17 yr at all flow rates, but decreased at age 18 yr; and (4) using multiple regression, significant predictors of FE(NO) were flow, body surface area, age, and FEF(25-75). On the basis of these results, we provide FE(NO) values for healthy adolescents and propose that the ideal flow rate for children is between 30 and 50 ml/s.
The accurate diagnosis of acute ischemic stroke is possible using clinical skills and diagnostic tools that are familiar to all neurosurgeons. Avoidance of immediate complications relies on the fundamentals of critical care. Effective treatment for ischemic stroke is available in the form of intravenous thrombolysis, but many stroke patients are denied this therapy because of the narrow window of opportunity for safe administration. Intra-arterial delivery may extend this benefit to a greater number of patients and may eventually prove more effective than intravenous treatment. Surgical treatment in a small number of ischemic stroke patients can be lifesaving and may afford reasonable functional recovery. This article discusses typical clinical presentations and differential diagnosis, diagnostic imaging for ischemic stroke, and possible treatments.
Neuronal activity was recorded in the cingulate cortex and the limbic thalamus in Dutch-belted rabbits (Oryctolagus cuniculus) exposed to cocaine (8 mg/kg/day i.v.) or saline in utero during acquisition and reversal learning of a discriminative avoidance response. Anterior cingulate cortical excitatory training-induced activity (TIA) was attenuated in cocaine-exposed female rabbits during acquisition and reversal learning, but only during reversal learning in male rabbits. Posterior cingulate cortical excitatory TIA was lessened in cocaine-exposed rabbits during acquisition, whereas discrimination between the positive and negative cues was enhanced. Neuronal firing was attenuated in the anterior ventral thalamus in cocaine-exposed rabbits during acquisition and reversal learning. Behavioral learning was normal in cocaine-exposed rabbits. Other data suggest that rabbits exposed to cocaine in utero exhibit a learning deficit when trained with nonsalient cues.
We compared intracranial pressure (ICP) and cerebral blood flow (CBF) in dogs after inflating a subdural intracranial balloon to increase ICP to 20 mm Hg, inducing hemorrhagic shock (mean arterial pressure [MAP] of 55 mm Hg), and infusing a single bolus of fluid consisting of either 54 mL/kg of 0.8% saline (SAL), 6 mL/kg of 7.2% hypertonic saline (HS), 20% hydroxyethyl starch (HES) in 0.8% SAL, or a combination fluid (HS/HES) containing 20% HES in 7.2% saline. Twenty-six dogs were ventilated with 0.5% halothane in N2O and O2 (60:40 ratio). As ICP was maintained at 20 mm Hg, rapid hemorrhage reduced MAP to 55 mm Hg (time interval of zero [T0]) which was maintained at that level for 30 minutes (until T30). Subsequently, over a 5-minute interval (T30-T35), one of the four randomly assigned resuscitation fluids was infused. Data were collected at baseline; after subdural balloon inflation; at T0, T30, T35, and 30-minute intervals thereafter for 2 hours (T65, T95, T125, and T155). CBF and ICP were compared using repeat-measure ANOVA. Cerebral blood flow was greater at T35 in the HS and HS/HES groups than in the HES group (P = .025). In the SAL group, ICP increased significantly from T0 to T35, remaining unchanged thereafter. At T35, ICP in the HS group was significantly lower than in the SAL group (P < .05) but subsequently increased. ICP in the HS/HES group exceeded that in all other groups at T95 and T125 (P < .05). After a severe reduction in cerebral perfusion pressure (CPP), HS solutions (both HS and HS/HES) were associated with a delayed rise in ICP and did not improve global forebrain CBF in comparison with conventional saline solutions.
We have used a modified direct selection technique to detect transcripts that are both evolutionary conserved and developmentally expressed. The enrichment for homologous mouse cDNAs by use of human genomic DNA as template is shown to be an efficient and rapid approach for generating transcript maps. Deletions of human 22q11 are associated with several clinical syndromes, with overlapping phenotypes, for example, velocardiofacial syndrome (VCFS) and DiGeorge syndrome (DGS). A large number of transcriptional units exist within the defined critical region, many of which have been identified previously by direct selection. However, no single obvious candidate gene for the VCFS/DGS phenotype has yet been found. Our technique has been applied to the DiGeorge critical region and has resulted in the isolation of a novel candidate gene, Cdc45l2, similar to yeast Cdc45p. [The sequence data described in this paper have been submitted to the EMBL data library under accession nos. AJ0223728 and AF0223729.]
Neurocytomas are uncommon intracranial neoplasms that have only recently been characterized pathologically. Neurocytomas are histologically benign neoplasms that are often quite large when diagnosed, and previous reports have commonly described presentation with mass effect or cerebrospinal fluid outflow obstruction. We describe the first case of neurocytoma presenting with intraparenchymal cerebral hemorrhage.
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Temporary artery occlusion is an effective way to reduce the detrimental effects of intraoperative aneurysm rupture and to facilitate aneurysm dissection. The major risk incurred is of cerebral infarction. Dilemmas in the use of this technique include the amount of time that arterial flow may be interrupted safely and whether or not there is benefit to intermittent reperfusion. Protocol for the use of temporary occlusion is described.
The effects of embryonic exposure on brain phospholipid levels were studied by injecting various concentrations of ethanol into fertile chicken eggs at 0 days of development. At 18 days of development, the levels of total phospholipids and various phospholipid classes were assayed in brain tissue and correlated to neuron densities within the cerebral hemispheres and the optic lobes. Although ethanol concentrations ranging from 0 to 3700 microns/Kg egg wt. failed to influence either total brain weight or total brain phospholipid levels, ethanol-induced changes in the levels of individual phospholipid classes were observed. When injected with 7 microns of ethanol/Kg egg wt., a 2- to 3-fold increase in brain phosphatidylethanolamine (PE) levels were observed with reduced levels of brain phosphatidylcholine (PC) and brain sphingomyelin (SP). When injected with 74 microns of ethanol/Kg egg wt., ethanol-induced increases in brain phosphatidylserine (PS) and PE were observed with ethanol-induced decreases in brain PC and SP. Cell fractionation studies demonstrated ethanol-induced increases in brain PE and PS and ethanol-induced decreases in brain PC and SP in nuclear, mitochondrial, and microsomal membranes. These ethanol-induced alterations in brain phospholipid profiles correlated with ethanol-induced reductions in neuron densities within the cerebral hemispheres and optic lobes.
The risk of disability and death and the cost of medical care are particularly high for patients with aneurysmal subarachnoid hemorrhage (SAH) who are 65 years of age or older. A retrospective analysis of 47,408 Medicare patients treated over an 8-year period was performed to determine whether a relationship exists between the mortality rate and surgical volume for older patients with SAH. The mortality rate, length of stay in the hospital, and cost of treatment for patients with SAH in California and New York state were also compared. The mortality rate was 14.3% for patients with SAH who were 65 years old or older and who were treated surgically in hospitals in which an average of five or more craniotomies were performed per year; in hospitals averaging between one and five craniotomies annually the mortality rate was 18.4%; and in those averaging less than one such operation per year the rate was 20.5% (trend p = 0.01). There was no difference in the mortality rate for patients in California versus the rate for those in New York. Surgically and medically treated patients, respectively, left the hospital an average of 6.7 and 5.1 days sooner in California than in New York. The unadjusted average reimbursement from Medicare to hospitals for surgically treated patients averaged $1468 more in New York than in California (p < 0.0001), but was equivalent for medically treated patients in the two states. The mortality rate in older patients who are treated surgically for SAH may be inversely correlated with the annual number of craniotomies performed for SAH in patients 65 years of age or older at a given institution. Hospital stays for patients with SAH are significantly shorter in California than in New York.
Intracerebral hemorrhage (ICH) accounts for one half of stroke-related deaths, with hypertensive hemorrhage being the primary etiology. The evolution of minimally invasive devices for removal of ICHs, and the earlier delivery of patients for medical attention may have a great impact on the management of hypertensive hemorrhage.
OBJECTIVE: This article describes the use of a slightly modified version of the Eating Disorders Examination (EDE) in children. METHODS: Sixteen children aged between 7 and 14 years attending an eating disorders clinic over a 5-month period were recruited to the study. The two main modifications to the EDE were (A) the inclusion of a sort task to assess overvalued ideas about weight and shape and (B) the reformulation of certain items to assess intent rather than actual behavior. The existing EDE scoring system was used, resulting in item, subscale, and global scores. RESULTS: Of the 16 children (10 F 6 M), 11 had a diagnosis of anorexia nervosa, and 5 of eating disorder not otherwise specified (EDNOS). There were interesting differences in responses on items assessing core overvalued ideas, with weight and/or shape concerns emerging as of great importance in terms of self-evaluation in the majority of children with anorexia nervosa. DISCUSSION: Results suggest that this may be a useful assessment tool in children, with some children obtaining global and subscale scores consistent with adult norms for females with eating disorders. Problems of the administration of the EDE to this patient group are discussed and details of the modifications used are outlined.
In this developmental study, idiom understanding was examined in Australian students from Grades 5 and 8 (n = 50 per group; mean ages = 10.7 and 13.8, respectively). Twenty-four idioms with familiarity ratings ranging from high to low (as judged by Australian adolescents) were each presented in a brief story context. The students read each story and selected the best interpretation of the idiom from a set of four answer choices. Results indicated that performance on the task improved as a function of increasing grade level and that idiom familiarity was significantly correlated to idiom understanding for both groups of students. These results, which were consistent with a previous study of American students of comparable educational levels (Nippold & Taylor, 1995), provide further support for the "language experience" hypothesis of figurative language development. In replicating the previous developmental study, evidence of external validity is provided.