Search PubMedSearch

Biomedical subjects

R Crawford

Publications and source records attributed to R Crawford.

At least 19 recordsLinked to original sources

Urinary tract metastasis from renal carcinoma.

Five patients with urinary tract metastases from renal carcinoma are presented. In 4, urinary tract metastasis occurred in the absence of spread elsewhere. The initial presentation in 1 patient was ureteric obstruction; 3 others re-presented with haematuria and the fifth patient was diagnosed post mortem. Metastatic sites included ipsilateral ureter, contralateral ureter, ureteric stump, bladder and prostatic fossa. After previous nephrectomy for renal carcinoma, urinary metastases, although rare, should be considered and investigation of unexplained haematuria should include the ureteric stump. Useful palliation and possibly cure can be achieved by resection of these lesions.

Aged

Intracardiac therapy following emergency thoracotomy in the accident and emergency department: an experimental model.

For a select group of patients with penetrating chest trauma, immediate thoracotomy in the accident and emergency department offers the only chance of survival. Foley catheters have been used to achieve haemostasis in cardiac wounds but are not widely used for intracardiac fluid and drug administration during resuscitation. In an anatomical model designed to assess this procedure an average flow rate of 275 ml min-1 was achieved. The equipment required is readily available and easily assembled.

Animals

Trauma audit: experience in north-east Scotland.

The management of 125 patients with trauma treated at Aberdeen Royal Infirmary from 1 January 1988 has been analysed using a microcomputer-based hospital trauma registry incorporating trauma and injury severity scores (TRISS) methodology. These patients fulfilled the North American Major Trauma Outcome Study (MTOS) inclusion criteria and were the first for whom data were available. Sixty-six patients had multiple injuries, of whom 52 were suffering from major trauma (defined as an injury severity score of 16 or greater). There were 14 deaths in the series, three (21 per cent) of which were considered to be preventable. Surgery was required in 84 (67.2 per cent) patients, of whom 59 (70 per cent) were operated on by a consultant or senior registrar. Five of six critically injured patients who died from their injuries were operated on by a consultant.

Adolescent

Evaluation of tartar control dentifrices in in vitro models of dentin sensitivity.

The effects of anticalculus dentifrices were compared with other commercially available dentifrices in in vitro models of dentin sensitivity. Changes in the hydraulic conductance of dentin discs were measured with and without a smear layer before and after treatment and also after a post-treatment acid etch. The capacity of dentifrices to occlude open dentinal tubules in vitro was also assessed by scanning electron microscopy (SEM). There was good correlation (R = 0.98) between our test and values reported in the literature. Tartar control dentifrices gave reductions in fluid flow rates through the dentin discs comparable to those obtained with Promise, Sensodyne, Thermodent and Denquel. Additionally, tartar control dentifrices did not remove microcrystalline debris (smear layers) from the surfaces of dentin in vitro. These results were confirmed by SEM. Thus, according to the hydrodynamic theory of dentin sensitivity, these in vitro results suggest that pyrophosphate-containing dentifrices should reduce dentinal sensitivity.

Dental Calculus

Dermoid cyst of the scalp: intracranial extension.

Intracranial dermoids are rare and are usually associated with cutaneous scalp lesions. Five hundred forty-two scalp lesions were treated in a 22-year period, and were associated with intracranial lesions in three cases. High-risk cases can be identified by clinical and radiological features, confirmed by a computed tomography scan, and then referred for neurosurgical treatment.

Brain Neoplasms

Steroid hydroxylase gene expression in the ovine fetal adrenal gland following ACTH infusion.

Between 90 and 120 days of gestation (term = 147 +/- 5), when plasma cortisol concentrations in the fetus are at a minimum, levels of mRNA encoding the steroidogenic enzymes 17 alpha-hydroxylase (P-450(17 alpha] and cholesterol side-chain cleavage (P-450scc) are also very low. Over the following 30 days, P-450(17 alpha) and P-450scc gene expression increases concurrent with increasing fetal cortisol concentration. The hypothesis tested in this study was that cortisol biosynthesis is minimal in the period 90-120 days because of insufficient ACTH. Fetuses were cannulated between 98-102 days of gestation. Following recovery, 7 fetuses received 24-h ACTH infusions (12 micrograms/24 h) and 5 fetuses received 24-h vehicle infusions; 4 ACTH-infused and 4-vehicle-infused fetuses were then sacrificed immediately after cessation of the infusion. The other fetuses were left in utero for 3 days prior to sacrifice. Fetal blood samples were analysed for ACTH and cortisol and the adrenals processed for hybridization histochemistry and Northern blot analysis. ACTH, but not vehicle, induced significant increases in the width of the adrenal cortex and in the levels of P-450(17 alpha) and P-450scc mRNA. Concurrently, fetal plasma ACTH and cortisol concentrations also increased significantly. In adrenals from fetuses left in utero for 3 days after cessation of the ACTH infusion, P-450(17 alpha) and P-450scc mRNA levels returned to control levels. Plasma ACTH and cortisol levels also approximated basal values. P-450c21 mRNA levels did not vary significantly at any time with the treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands

Clinical value of ultrasonography in the detection and removal of radiolucent foreign bodies.

A series of 39 consecutive patients with a suspected retained foreign body in the hand and in whom standard soft issue radiographs were negative were examined by real-time, high-resolution ultrasound scan. At operation 20 patients had radiolucent foreign bodies (18 wood, 2 thorns) removed. Ultrasound scan correctly localized 19 of the foreign bodies before surgery and failed to detect one. No foreign body was found in 19 patients. Ultrasound scan falsely predicted the presence of a foreign body in two of these cases. High-resolution ultrasound scanning is a sensitive, accurate technique for diagnosing foreign bodies which are otherwise difficult to demonstrate by conventional radiographic techniques, and provides accurate three-dimensional localization of the object which is of value to the surgeon at operation.

Adolescent

Fractures of the hook of the hamate.

Fractures of the hook of the hamate have been infrequently reported in the literature. A high index of suspicion is required if the correct diagnosis is to be established. We report three cases of fractures of the hook of the hamate and postulate a mechanism of injury in sportsmen. Once established, an excision of the hook is usually necessary to resolve the discomfort.

Adult

Tissue distribution and levels of gene expression of three steroid hydroxylases in ovine fetal adrenal glands.

Northern blotting and hybridization histochemistry were used to evaluate the ontogeny and cellular distribution of the mRNAs of the cytochrome P-450 enzymes: cholesterol side-chain cleavage (P-450scc), 17 alpha-hydroxylase (P-450(17 alpha] and 21-hydroxylase (P-450c21) in 40 ovine fetal adrenals from 42 days of gestation until term (151 days). The genes for P-450(17 alpha) and P-450scc were expressed strongly in tissue from young (40-60 days) and old fetuses (120 days to term), but to a very minor degree in 90-120 day fetuses. P-450c21 showed a steady increase throughout gestation. In the morphologically immature an unzoned adrenal of the 40-50 day fetus there was some differentiation in gene expression, all cells containing P-450scc and P-450c21 but a few lacking P-450(17 alpha). Once morphological zonation had occurred (80 days), P-450(17 alpha) was confined to the fasciculata. After 120 days there was a radial maturation pattern of the fasciculata cells morphologically, adult-type cells first appearing at the medullary border. However, P-450(17 alpha) and P-450scc mRNAs were equally well expressed in all sections of the fasciculata. The conclusions were: 1) the previously demonstrated triphasic cortisol biosynthetic capacity of ovine fetal adrenals was correlated with the presence, absence, and reappearance of mRNAs P-450(17 alpha) and P-450scc; 2) morphological appearance of fetal adrenocortical cells and expression of three major steroidogenic enzyme genes were not correlated.

Adrenal Cortex

Porcine relaxin. Gene structure and expression.

A porcine genomic cosmid library was constructed to study the structure and regulation of the porcine relaxin gene. Two overlapping cosmids containing relaxin-specific sequences were isolated, and a 9-kilobase BamHI fragment containing the porcine relaxin gene was sequenced. The sequence derived from these cosmids was used to characterize the relaxin gene transcription unit utilized in the pregnant ovary. Analysis of chromosomal and cosmid DNA has shown that porcine relaxin is encoded by a single copy gene, comprising two exons separated by a 5.5-kilobase intron. The gene contains elements representing two classes of repeated sequences homologous with the human Alu and Kpn families. The transcriptional initiation site of this gene was located by primed extension and direct sequencing of relaxin-specific cDNA. Furthermore, the promoter elements were mapped and sequenced, and transcriptional activity was demonstrated. The promoter contained sequences with homology to regions conserved within retroviral long terminal repeats and within the adenovirus E4 promoter.

Animals

Comparison of ligninase-I and peroxidase-M2 from the white-rot fungus Phanerochaete chrysosporium.

Ligninase-I (Mr 42,000-43,000; carbohydrate, 21%) and peroxidase-M2 (Mr 45,000-47,000; carbohydrate, 17%), two representative, hydrogen peroxide-dependent extracellular enzymes produced by ligninolytic cultures of the white-rot fungus Phanerochaete chrysosporium BKM-F-1767, were purified and their properties compared. Spectroscopic studies showed that both native enzymes are heme proteins containing protoporphyrin IX. EPR spectroscopy indicated that iron ions are coordinated with the enzymes' prosthetic groups as high-spin ferriheme complexes. We confirmed reports of others that the ligninase-hydrogen peroxide complex (activated enzyme) reverts to its native state on addition of dithionite or one of the enzyme's substrates (e.g., veratryl alcohol); however, we found that the peroxidase-M2-hydrogen peroxide complex required Mn2+ ions to accomplish a similar cycle. The peroxidase oxidized Mn2+ to a higher oxidation state, and the oxidized Mn acted as a diffusible catalyst able to oxidize numerous organic substrates. Unlike ligninase-I which is found free extracellularly, peroxidase-M2 appears to be associated closely with the fungal mycelium. In its peroxidatic reactions, ligninase-I oxidizes a variety of nonphenolic and phenolic lignin model compounds. In the presence of Mn2+, peroxidase-M2 oxidizes numerous phenolic compounds, especially syringyl (3,5-dimethoxy-4-hydroxyphenyl) and vinyl side-chain substituted substrates. Also, the peroxidase-Mn2+ system (without hydrogen peroxide) expresses oxidase activity against NADPH, GSH, dithiothreitol, and dihydroxymaleic acid, forming hydrogen peroxide at the expense of oxygen. Both enzymes were believed to play roles in lignin degradation, and these are discussed.

Amino Acids