PubMed Health⌕ Search

Biomedical subjects

C J Ferguson

Publications and source records attributed to C J Ferguson.

At least 19 recordsLinked to original sources
PubMed2003

Experience with femoro-popliteal vein as a conduit for vascular reconstruction in infected fields.

OBJECTIVE: to review the outcome of femoro-popliteal vein grafts for arterial reconstruction in the presence of sepsis. PATIENTS AND METHODS: twenty-six patients underwent 27 arterial reconstructions with femoro-popliteal vein in the presence of infection. Five had mycotic aneurysms (3 aortic, 1 iliac and 1 femoral), 21 had prosthetic graft infections (9 aortic, 8 femoro-femoral, 2 axillo-femoral, 1 ilio-femoral and 1 femoral dacron patch) and one underwent superior mesenteric artery reconstruction following ischaemic small bowel perforation.Arterial reconstruction followed debridement of infected tissue, removing any infected graft, povidone iodine washout and appropriate antibiotic cover. Where possible, new grafts were placed in a clean field or wrapped in omentum. Four femoral anastomoses were covered by rectus femoris flaps. RESULTS: there was one early postoperative death (4%) and no limb loss. All others remained free from infection with patent grafts at 1 month to 5 years (median 22 months). Three major wound infections healed without exposing the graft. One infarcted rectus femoris flap required removal. Donor limb swelling was transient. Five required percutaneous angioplasty and one underwent open profundaplasty within 3 months. CONCLUSION: femoro-popliteal vein reconstruction with debridement and appropriate antibiotic therapy is recommended for the treatment of arterial or graft infections.

Aged↗
PubMed2001

Expression and immunolocalization of aquaporin water channels in rat exocrine pancreas.

Both the acinar and ductal cells of the pancreas secrete a near-isotonic fluid and may thus be sites of aquaporin (AQP) water channel expression. Northern blot analysis of mRNA from whole rat pancreas revealed high levels of AQP1 and AQP8 expression, whereas lower levels of AQP4 and AQP5 expression were just detectable by RT-PCR Southern blot analysis. Immunohistochemistry showed that AQP1 is localized in the microvasculature, whereas AQP8 is confined to the apical pole of the acinar cells. No labeling of acinar, ductal, or vascular tissue was detected with antibodies to AQP2-7. With immunoelectron microscopy, AQP8 labeling was observed not only at the apical membrane of the acinar cells but also among small intracellular vesicles in the subapical cytoplasm, suggesting that there may be regulated trafficking of AQP8 to the apical plasma membrane. To evaluate the contribution of AQPs to the membrane water permeability, video microscopy was used to measure the swelling of acinar cells in response to hypotonic stress. Osmotic water permeability was reduced by 90% following exposure to Hg(2+). Since AQP8 is confined to the apical membrane, the marked effect of Hg(2+) suggests that other water channels may be expressed in the basolateral membrane.

Algorithms↗
PubMed2001

Cellular localization of divalent metal transporter DMT-1 in rat kidney.

We have demonstrated that the kidney plays an important role in iron balance and that metabolically significant reabsorption of this ion occurs in the loop of Henle and the collecting ducts [Wareing M, Ferguson CJ, Green R, Riccardi D, and Smith CP. J Physiol (Lond) 524: 581-586, 2000]. To test the possibility that the divalent metal transporter DMT1 (Gunshin H, Mackenzie B, Berger UV, Gunshin Y, Romero MF, Boron WF, Nussberger S, Gollan JL, and Hediger MA. Nature 388: 482-488, 1997) could represent the apical route for iron entry in the kidney, we raised and affinity-purified an anti-DMT-1 polyclonal antibody and determined DMT-1 distribution in rat kidney by Western analysis, immunofluorescence, and confocal microscopy. The strongest DMT1-specific (i.e., peptide-protectable) immunoreactivity was found in the collecting ducts, in both principal and intercalated cells. Thick ascending limbs of Henle's loop and, more intensely, distal convoluted tubules exhibited apical immunostaining. Considerable intracellular DMT-1 immunoreactivity was seen throughout the nephron, particularly in S3 segments. The described distribution of DMT-1 protein is in agreement with our previous identification of nephron sites of iron reabsorption, suggesting that DMT-1 provides the molecular mechanism for apical iron entry in the distal nephron but not in the proximal tubule. Basolateral iron exit may be facilitated by a different system.

Animals↗
PubMed2000

In vivo characterization of renal iron transport in the anaesthetized rat.

1. In vivo microinjections of 55FeCl3 were made to assess renal iron (Fe2+/3+) transport in the anaesthetized rat. 2. Following microinjection into proximal convoluted tubules (PCTs), 18.5 +/- 2.9 % (mean +/- s.e.m., n = 11) of the 55Fe was recovered in the urine. This recovery was not dependent on the injection site indicating that iron is not reabsorbed across the surface convolutions of the proximal tubule. 3. Following microinjection into distal convoluted tubules (DCTs) 46.1 +/- 6.1 % (n = 8) of the injected 55Fe was recovered. Taken together the recovery data from the PCT and DCT microinjection studies indicate that the transport of iron occurs in the loop of Henle (LH) and collecting duct system. 4. In vivo luminal microperfusion was used to examine iron transport by the LH in more detail. In tubules perfused with 7 micromol l-1 55FeCl3, 52.7 +/- 8. 3 % (n = 8) of the perfused 55Fe was recovered in the collected fluid, indicating significant iron reabsorption in the LH. Addition of copper (Cu2+ as 7 micromol l-1 CuSO4), manganese (Mn2+ as 7 micromol l-1 MnSO4) or zinc (Zn2+ as 7 micromol l-1 ZnSO4) to the perfusate did not affect reabsorption of water, Na+ or K+, but increased recovery of 55Fe to 83.5 +/- 6.8 % (n = 8, P < 0.04), 75.8 +/- 5.9 (n = 6, not significant, n.s.) and 67.9 +/- 3.8; (n = 9, n.s. ), respectively. 5. Thus, iron transport in the LH can be reduced by the addition of copper or manganese to the luminal perfusate suggesting that these ions may compete with iron for a common transport pathway. However, this pathway may not be shared by zinc.

Anesthesia↗
PubMed2000

Use of superficial femoropopliteal vein for suprainguinal arterial reconstruction in the presence of infection.

BACKGROUND: Conventional treatment of mycotic aneurysms or graft infections of the aortoiliac segment by in situ or extra-anatomic prosthetic reconstruction has a high mortality and morbidity rate, with a substantial risk of persistent graft infection. The use of autologous vein may reduce this. METHODS: Eleven patients with suprainguinal arterial infections including two with mycotic aortic aneurysms, four with aortic graft infections, four infected femorofemoral grafts and an infected axillofemoral graft were treated by debridement and in situ reconstruction with autologous superficial femoropopliteal vein. All patients received appropriate antibiotic therapy and were followed by regular postoperative duplex imaging. Preoperative femoral vein duplex imaging was performed in eight of the 11 patients. RESULTS: Ten of the 11 patients survived with a functioning graft and without limb loss or evidence of infection at 4-33 months. One patient died from myocardial infarction after operation. Three patients had minor swelling of one leg. Four patients required subsequent angioplasty of anastomotic stenoses detected by duplex surveillance. CONCLUSION: Superficial femoropopliteal vein is an excellent conduit for suprainguinal reconstruction in the presence of infection. Duplex imaging is useful for confirming the suitability of deep veins for use as a graft and for postoperative surveillance.

Aged↗
PubMed2000

Polemoniaceae phylogeny and classification: implications of sequence data from the chloroplast gene ndhF.

The chloroplast gene ndhF was used to study phylogenetic relationships of the Polemoniaceae at two levels: among members of the Ericales and among genera of the family. Sequence data for interfamilial analyses consisted of 2266 bp for 14 members of the Ericales, including four species of the Polemoniaceae, plus three outgroup taxa. The Polemoniaceae were found to be related to Diospyros, Fouquieria, the Primulales, Rhododendron, and Impatiens, but relationships among taxa were generally not well supported. The precise position of the Polemoniaceae within the Ericales remains obscure. Data for intrafamilial analyses consisted of 1031 bp for 27 species of the Polemoniaceae, including at least one species from most genera of the family, plus five outgroup taxa. A single most parsimonious tree was identified. The analyses suggested that subfamily Cobaeoideae, excluding Loeselia, is monophyletic and that Huthia is sister to Cantua. Acanthogilia was sister to the remainder of subfamily Cobaeoideae. Subfamily Polemonioideae plus Loeselia formed four subclades that were strongly supported as monophyletic and represent the major lineages of the subfamily.

Journal Article↗
PubMed1999

Molecular and functional identification of a Ca2+ (polyvalent cation)-sensing receptor in rat pancreas.

The balance between the concentrations of free ionized Ca2+ and bicarbonate in pancreatic juice is of critical importance in preventing the formation of calcium carbonate stones. How the pancreas regulates the ionic composition and the level of Ca2+ saturation in an alkaline environment such as the pancreatic juice is not known. Because of the tight cause-effect relationship between Ca2+ concentration and lithogenicity, and because hypercalcemia is proposed as an etiologic factor for several pancreatic diseases, we have investigated whether pancreatic tissues express a Ca2+-sensing receptor (CaR) similar to that recently identified in parathyroid tissue. Using reverse transcriptase-polymerase chain reaction and immunofluorescence microscopy, we demonstrate the presence of a CaR-like molecule in rat pancreatic acinar cells, pancreatic ducts, and islets of Langerhans. Functional studies, in which intracellular free Ca2+ concentration was measured in isolated acinar cells and interlobular ducts, show that both cell types are responsive to the CaR agonist gadolinium (Gd3+) and to changes in extracellular Ca2+ concentration. We also assessed the effects of CaR stimulation on physiological HCO3- secretion from ducts by making measurements of intracellular pH. Luminal Gd3+ is a potent stimulus for HCO3- secretion, being equally as effective as raising intracellular cAMP with forskolin. These results suggest that the CaR in the exocrine pancreas monitors the Ca2+ concentration in the pancreatic juice, and might therefore be involved in regulating the level of Ca2+ in the lumen, both under basal conditions and during hormonal stimulation. The failure of this mechanism might lead to pancreatic stone formation and even to pancreatitis.

Animals↗
PubMed1999

Test of parenting skills.

An item pool was developed to assess basic parenting skills in the areas of attachment, emotional capacity, judgment, knowledge of child development, and safety. Initially, 200 items were generated and completed by a sample of 15 parents. Item scores correlated with scores on a social desirability scale or having low variance were edited or eliminated. A sample of 56 parents completed the revised scale, a social desirability scale, and the Adult-Adolescent Parenting Inventory. The reliabilities of the final subscales of the Test of Parenting Skills were modest, ranging from .56 to .77. Scores on the subscales were also correlated with those subscales from the Adult-Adolescent Parenting Inventory. With the exception of the Judgment scores being correlated with the use of harsh discipline, the significant correlations suggested concurrent validity. The individual subscales require additional refinement to achieve adequate internal consistency, but they have potential for measuring competency in core parenting skills.

Adolescent↗
PubMed1999

Expression of aquaporin 1 (AQP1) water channels in human labial salivary glands.

Aquaporin (AQP) water channels are widely expressed in the membranes of fluid-transporting epithelia. Despite the fact that salivary glands are the site of considerable water movement, relatively little is known about the role of aquaporins in human salivary glands. We have examined the expression of AQP1 in human parotid, sublingual and labial salivary glands. Total RNA was extracted from glandular tissue obtained from surgery or biopsy. The presence of AQP1 mRNA was demonstrated in each of the three glands by RT-PCR using primers specifically designed for human AQP1. The PCR product from the labial gland RNA was further amplified with nested primers and the sequence confirmed by automated fluorescent DNA sequencing. The cleaned first PCR product from these glands was then used as a 32P-labelled hybridization probe in a Northern analysis which confirmed the presence of significant amounts of AQP1 transcript in all three glands. AQP1 expression was also demonstrated in cryosections of human labial glands by immunohistochemistry using peroxidase-linked antibodies. Antibody labelling was most prominent in the capillaries but was also evident in the basal regions of the labial gland acini, and may therefore be associated with the serous demilunes which are believed to be a significant site of fluid movement.

Adult↗
PubMed1995

An abundant, trans-spliced mRNA from Toxocara canis infective larvae encodes a 26-kDa protein with homology to phosphatidylethanolamine-binding proteins.

A full-length mRNA encoding a secreted 26-kDa antigen of infective larvae of the ascarid nematode parasite Toxocara canis has been identified. This was characterized as a 1,082-base pair clone highly abundant (0.8-1.9%) in cDNA prepared from infective stage larvae but absent from cDNA from adult male worms. Sequence analysis revealed an open reading frame corresponding to a hydrophilic 263-amino acid residue polypeptide with a 20-residue N-terminal signal peptide, indicating that it is secreted. The 5' end of the cDNA was isolated by polymerase chain reaction using a primer containing the nematode-spliced leader sequence, SL1, showing that the mRNA is trans-spliced. The molecular mass of the putative protein with the signal peptide removed is 26.01 kDa, and antibody to the recombinant protein expressed in bacterial vectors reacts with a similarly sized protein in T. canis excretory/secretory (TES) products. An identical sequence was obtained from a genomic clone isolated by expression screening with mouse antibody to TES. The 72 amino acid residues adjacent to the signal peptide form two homologous 36-residue motifs containing 6 cysteine residues; this motif is found also in the T. canis-secreted glycoprotein TES-120 and in genes of Caenorhabditis elegans. Sequence data base searches revealed significant similarity to 7 other sequences in a newly recognized gene family of phosphatidylethanolamine-binding proteins that includes yeast, Drosophila, rat, bovine, simian, and human genes and a representative from the filarial nematode Onchocerca volvulus. Assays with the T. canis recombinant 26-kDa protein expressed as a fusion with maltose-binding protein have confirmed phosphatidylethanolamine-binding specificity for this novel product.

Amino Acid Sequence↗
PubMed1993

Low-dose cyclosporin nephrotoxicity in the rat.

The nephrotoxicity of cyclosporin (CsA) continues to be a clinical problem that detracts from its obvious benefits as an immunosuppressive agent. Animal models designed to study the problem have generally relied either on chronic administration of high doses of the drug or acute administration of single i.v. doses. The present study establishes a model of CsA nephrotoxicity using doses of the drug comparable to those used in man administered over a time period sufficient for haemodynamic and structural changes to become evident. The technique used measures glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) by the plasma clearance of chromium EDTA and iodohippuran respectively. This has the advantage of allowing sequential measurements in individual animals. Significant impairment of GFR was seen in animals treated intraperitoneally with doses of CsA as low as 5 mg/kg/day. CsA 7.5 mg/kg/day caused a significant reduction in ERPF, and at 10 mg/kg/day and greater filtration fraction also declined significantly. Detailed histological examination of the kidneys from these animals also revealed significant tubular dilatation at 10 mg/kg/day and above. This model of CsA toxicity circumvents many of the problems associated with other models. The animals can be studied longitudinally and the period of administration has relevance to clinic practice. This work provides the basis for further studies which can closely mimic the clinical situation using doses similar to those used for human maintenance immunosuppression.

Animals↗