Biomedical subjects
T Geoghegan
Publications and source records attributed to T Geoghegan.
Percutaneous thrombin injection for the treatment of a post-pancreatitis pseudoaneurysm of the gastroduodenal artery.
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Retained appendicolith after laparoscopic appendectomy.
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Computed tomography in the imaging of colonic diverticulitis.
Colonic diverticulitis occurs when diverticula within the colon become infected or inflamed. It is becoming an increasingly common cause for hospital admission, particularly in western society, where it is linked to a low fibre diet. Symptoms of diverticulitis include abdominal pain, diarrhoea and pyrexia, however, symptoms are often non-specific and the clinical diagnosis may be difficult. In addition, elderly patients and those taking corticosteroids may have limited findings on physical examination, even in the presence of severe diverticulitis. A high index of suspicion is required in such patients in order to avoid a significant delay in arriving at the correct diagnosis. Imaging plays an important role in establishing an early and correct diagnosis. In the past, contrast enema studies were the principal imaging test used to make the diagnosis. However, such studies lack sensitivity and have limited success in identifying abscesses that may require drainage. Conversely computed tomography (CT) is both sensitive and specific in making a diagnosis of diverticulitis. In addition, it is the imaging technique of choice in depicting complications such as perforation, abscess formation and fistulae. CT-guided drainage of diverticular abscesses helps to reduce sepsis and to permit a one-stage, rather than two-stage, surgical operation. The purpose of this review article is to discuss the role of CT in the imaging of diverticulitis, describe the CT imaging features and complications of this disease, as well as review the impact and rationale of CT imaging and intervention in the overall management of patients with diverticulitis.
Air travel in pregnancy: the 'air-born' study.
An increasingly common question posed by patients antenatally is whether air travel can be considered safe in pregnancy. The aim of this study was to assess whether any agreed standards or policies exist between airlines with respect to flying in pregnancy. Sixty-eight international airlines were surveyed, of whom seventeen (25%) replied. Three of seventeen (17.5%) airlines applied no restrictions at all to pregnant passengers; the remainder applied restrictions to air travel with varying gestations (28 to 36 weeks). A full delivery kit was carried by 5/17 airlines (29%), and some form of training in the management of a delivery was provided to the cabin crew in 12/17 airlines (70%). Experience of in-flight obstetric emergencies was reported by 11/17 airlines (65%). This study highlights a lack of consensus regarding restrictions on air travel in pregnancy. The low response rate also suggests an unwillingness on the part of the airline industry to openly declare their policy on this issue.
Rupture of ureteropelvic junction-obstructed kidney.
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Dissection of vertebral artery (Feb'03 Vol 96 No 2).
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Transforming growth factor-alpha and epidermal growth factor messenger ribonucleic acid and protein levels in human placentas from early, mid, and late gestation.
OBJECTIVE: Human placenta expresses receptors for transforming growth factor-alpha and epidermal growth factor throughout pregnancy. Experiments were performed to determine whether epidermal growth factor or transforming growth factor-alpha might be synthesized by placental cells and act through an autocrine mechanism to influence functioning of placental cells in vivo. STUDY DESIGN: Human placentas from early, mid, and late gestations were analyzed for transforming growth factor-alpha and epidermal growth factor messenger ribonucleic acid and proteins. Polyadenylic acid-positive ribonucleic acid was isolated from placentas from 10, 11, 13, 21, 32, 38, 39, and 40 weeks of gestation and analyzed by Northern analysis for hybridization with complementary deoxyribonucleic acid probes specific for epidermal growth factor or transforming growth factor-alpha. Levels of immunoreactive epidermal growth factor and transforming growth factor-alpha were measured by specific radioimmunoassays in pools of placentas from early, mid, and late gestations, and levels of epidermal growth factor and transforming growth factor-alpha receptor-active protein were measured by radioreceptor assay. RESULTS: All placentas had a strong transforming growth factor-alpha hybridization band at 4.5 kb and a weak epidermal growth factor hybridization band at 5.2 kb. High levels of transforming growth factor-alpha immunoreactive protein (90 to 180 ng/mg protein) and low levels of immunoreactive epidermal growth factor (3 to 9 pg/mg protein) were detected in pools of placentas from early, mid, and late gestations. High levels of epidermal growth factor and transforming growth factor-alpha receptor-active protein (250 ng/mg protein) were also detected. CONCLUSION: Human placentas contain relatively high levels of immunoreactive and receptor-active transforming growth factor-alpha, as well as transforming growth factor-alpha messenger ribonucleic acid, throughout gestation. This finding suggests that transforming growth factor-alpha may act by an autocrine system to influence human placental cell function in vivo.
The use of low-dose cyclosporine A in combination with azathioprine and steroids in renal transplantation.
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Plasma exchange in acute renal allograft rejection. A controlled trial.
A controlled trial was carried out to assess the value of intensive plasma exchange in 27 renal transplant recipients with clinical and histological evidence of acute vascular rejection. In addition to standard immunosuppression, 13 patients received plasma exchange on six consecutive days at a mean exchange volume of 40.6 ml/kg of body weight each day using an intermittent cell separator. A further 14 patients received standard immunosuppression only. In addition, 10 patients exchanged prior to the controlled trial have been studied. Analysis of short-term benefit, as evidenced by a reduction in serum creatinine, and by subsequent graft survival revealed no significant difference in these parameters between the two groups in the controlled trial. This regimen of plasma exchange has not, therefore, been shown to modify acute renal allograft rejection.
Studies on the efficiency of translation and on the stability of actin messenger ribonucleic acid in mouse sarcoma ascites cells.
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Inactive mRNA-protein complexes from mouse sarcoma-180 ascites cells.
Mouse sarcoma ascites cells do not utilize fully their capacity for protein synthesis. A considerable portion of their ribosomes occur as inactive monomers. Also, a substantial amount of the cellular mRNA is in the form of ribonucleoprotein particles that sediment in the 20-70S range. This is indicated both by measurements of poly(A) content and by translation of the RNA in cell-free systems. The population of polypeptides synthesized under the direction of the RNA from these particles is less heterogeneous than that directed by RNA from polysomes. The mRNAs for some polypeptides are present predominantly in the small particles. Others are distributed to varying degrees between particles and polysomes. Incubation of the cells with cycloheximide drives most of the ribosomal monomers and a portion of the untranslated mRNA into polysomes. Some of the mRNAs that were predominantly in the inactive fraction seem to be refractory to this treatment. Particles released from polysomes in cells subjected to starvation are quite effective in promoting polypeptide synthesis in a reticulocyte cell-free system and cause the synthesis of a population of polypeptides similar to that coded by the polysomal RNA. The particles from cells exposed to cycloheximide are inactive but yield active RNA upon deproteinization. It is suggested that some mRNA species are maintained in an inactive state in the cell by a component of the nucleoprotein complex.
The composition of peptidochitodextrins from sarcophagid puparial cases.
1. N-Bromosuccinimide cleaved proteins and pigments from fly puparia, increasing the chitin:protein ratio from 0.5 to 1.5. The product afforded subfractions (ratio 5:1) of molecular weights of 1200 and 1600 devoid of aromatic residues and N-terminal beta-alanine, direct aryl links between polysaccharide chains being discounted. 2. The chitin-protein complex decreased in molecular weight when treated with Pronase, which suggested polypeptide bridges within the native chitin micelle. The limit dextrins generated by chitinase were mixtures of unsubstituted dextrins and peptidylated oligosaccharides, with the former predominating. 3. Peptidochitodextrins of similar molecular weight but markedly different solubility were prepared, which were indistinguishable with respect to amino acid, glucosamine, acetyl, X-ray or infrared characteristics. It is suggested that physical interactions contribute to the stability of the integument in addition to the covalent bonds that form during sclerotization.
Young injectors: a comparative analysis of risk behaviour.
This study compares the injecting and sexual risk-behaviour of young injectors, with injectors over the age of 25. All respondents presented for the first time at the Merchants' Quay Health Promotion Unit between May 1st 1997 and February 28th 1998. Analysis revealed that the young injectors were significantly more likely to report recently borrowing and lending used injecting equipment, and injecting paraphernalia. Regarding sexual risk behaviour, younger respondents were proportionately more likely to report being sexually active, having multiple sexual partners, and having a regular partner who is an injecting drug user. However, they were significantly more likely than older clients to report condom use. The suggestion is that the harm minimisation message, which reached its zenith in the early 1990s, has now been somewhat de-emphasised in both policy and practice. Consequently, it is not reaching the young injectors who have recently initiated intravenous drug use. Additional strategies are needed this group of drug users, in order to promote positive behaviour changes.
Small bowel obstruction secondary to a giant enterolith complicating Crohn's disease.
BACKGROUND: Enterolith formation associated with Crohn's disease is a very uncommon clinical entity. AIM: To describe a case of sub-acute small bowel obstruction secondary to a giant enterolith in a patient with Crohn's disease. RESULTS: A 54-year-old male with a history of Crohn's disease presented with sub-acute small bowel obstruction secondary to a giant enterolith. The diagnosis was confirmed utilising plain film radiography and computed tomography CONCLUSION: Plain film radiography and computed tomography play a central role in establishing the diagnosis of this rare complication of Crohn's disease and assist in planning surgical intervention.
Gunther Tulip retrievable inferior vena caval filters: indications, efficacy, retrieval, and complications.
PURPOSE: We evaluated the Gunther Tulip (GT) retrievable inferior vena cava (IVC) filter with regard to indications, filtration efficacy, complications, retrieval window, and use of anticoagulation. METHOD: A retrospective study was performed of 147 patients (64 men, 83 women; mean age 58.8 years) who underwent retrievable GT filter insertion between 2001 and 2005. The indications for placement included a diagnosis of pulmonary embolism or deep venous thrombosis with a contraindication to anticoagulation (n = 68), pulmonary embolism or deep venous thrombosis while on anticoagulation (n = 49), prophylactic filter placement for high-risk surgical patients with a past history of pulmonary embolism or deep venous thrombosis (n = 20), and a high risk of pulmonary embolism or deep venous thrombosis (n = 10). Forty-nine of the 147 patients did not receive anticoagulation (33.7%) while 96 of 147 patients did, 82 of these receiving warfarin (56.5%), 11 receiving low-molecular weight heparins (7.58%), and 3 receiving antiplatelet agents alone (2.06%). RESULTS: Filter placement was successful in 147 patients (100%). Two patients had two filters inserted. Of the 147 patients, filter deployment was on a permanent basis in 102 and with an intention to retrieve in 45 patients. There were 36 (80%) successful retrievals and 9 (20%) failed retrievals. The mean time to retrieval was 33.6 days. The reasons for failed retrieval included filter struts tightly adherent to the IVC wall (5/9), extreme filter tilt (2/9), and extensive filter thrombus (2/9). Complications included pneumothorax (n = 4), failure of filter expansion (n = 1), and breakthrough pulmonary embolism (n = 1). No IVC thrombotic episodes were recorded. DISCUSSION: The Gunther Tulip retrievable filter can be used as a permanent or a retrievable filter. It is safe and efficacious. GT filters can be safely retrieved at a mean time interval of 33.6 days. The newly developed Celect filter may extend the retrieval interval.