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J L Duncan

Publications and source records attributed to J L Duncan.

At least 37 records · Page 2Linked to original sources
PubMed2000

Safety of a single duplex scan to exclude deep venous thrombosis.

BACKGROUND: Guidelines advocate that a negative ultrasonographic scan needs to be followed by venography, or a repeat scan after 1 week, to detect potentially missed calf vein thrombosis. This study aimed to evaluate whether anticoagulation can safely be withheld on the basis of a single negative duplex scan in patients presenting with suspected deep venous thrombosis (DVT). METHODS: Duplex scan reports, case notes and questionnaires returned by general practitioners of patients with suspected DVT were analysed retrospectively. The main outcome measure was occurrence of an adverse thromboembolic event, a symptomatic DVT or a pulmonary embolism, within 3 months after a negative duplex scan. RESULTS: Some 537 patients had 706 leg scans performed, the majority because of leg symptoms or to look for indirect evidence of pulmonary embolism. Among 352 patients, who had 429 negative leg scans, four possible adverse events were identified. The rate of adverse outcome was therefore 1.1 per cent per patient and 0.9 per cent per leg. CONCLUSION: Withholding anticoagulation in patients who had a single, complete, negative duplex scan is safe. A repeat scan should be performed if there is ongoing high clinical suspicion and considered in patients in whom the calf veins could not be visualized.

Aged↗
PubMed2000

Evaluation of the bacterial flora of the prostate using a 16S rRNA gene based polymerase chain reaction.

PURPOSE: The role of bacteria in the chronic pelvic pain syndrome (nonbacterial prostatitis and prostatodynia) is controversial and difficult to assess because the bacterial flora of the prostate is not well defined. Polymerase chain reaction (PCR) is a highly sensitive molecular method of bacterial detection. It confirms the sterility of tissue with a high level of confidence and detects small numbers of microbial agents that may represent pathogens. We performed PCR to determine bacterial colonization of the prostate in presumably healthy men and in those undergoing simple or radical prostatectomy. MATERIALS AND METHODS: We analyzed 28 prostate samples from 18 organ donors from whom prostate tissue was obtained under sterile surgical conditions at organ withdrawal, 14 sterile surgical prostate specimens from 7 patients undergoing radical prostatectomy for prostate cancer who previously underwent transrectal biopsy and 6 sterile surgical specimens from 2 men who underwent simple prostatectomy for benign prostatic hyperplasia (BPH), including 1 with an indwelling catheter for several weeks. For PCR we used 2 sets of primers to detect bacterial 16S rRNA gene sequences. Normal prostate tissue seeded in vitro with known numbers of Escherichia coli was used to assess the sensitivity of PCR. RESULTS: Only 3 of the 28 organ donor samples had histological signs of minimal inflammation and all other samples appeared to be normal without evidence of inflammatory reaction. All of these samples were PCR negative. Of several PCR control reactions the mixture of prostate tissue seeded with known numbers of E. coli demonstrated the high sensitivity of the assay, allowing the detection of as few as 6 bacteria in the presence of 25 mg. of prostate tissue. A focal and heterogeneous distribution of inflammation and infection was noted in the 14 radical prostatectomy specimens. In the prostate cancer and BPH groups there was a strong association of inflammation with positive PCR findings. Of 11 samples 3 without but all 9 with inflammation were PCR positive. CONCLUSIONS: PCR is a highly sensitive method for detecting bacteria in the prostate. In our study negative PCR reactions in the prostate tissue of apparently healthy men made the presence of normal bacterial flora in the prostate extremely unlikely. The presence of bacteria and/or inflammation in radical prostatectomy specimens was found to be a localized process. Concordance between inflammation and positive PCR results in simple and radical prostatectomy specimens suggests that bacteria may frequently have a role in histologically inflammatory prostatitis.

Adolescent↗
PubMed2000

Characterization of an immortalized human vaginal epithelial cell line.

PURPOSE: Adherence of type 1 piliated Escherichia coli to vaginal mucosa plays a major role in the pathogenesis of ascending urinary tract infections (UTIs) in women. Progress in understanding the mechanism of adherence to the vaginal surface could be enhanced by the utilization of well-characterized vaginal epithelial cells. The objective of this study was to immortalize vaginal epithelial cells and study their bacterial adherence properties. MATERIALS AND METHODS: Primary vaginal cells were obtained from a normal post-menopausal woman, immortalized by infection with E6/E7 genes from human papillomavirus 16 (HPV 16) and cultured in serum free keratinocyte growth factor medium. RESULTS: Positive immunostaining with a pool of antibodies to cytokeratins 1, 5, 10 and 14 (K1, K5, K10 and K14) and to K13 confirmed the epithelial origin of these cells. The immortalized cells showed binding of type 1 piliated E. coli in a pili specific and mannose sensitive manner. CONCLUSION: This model system should facilitate studies on the interaction of pathogens with vaginal mucosal cells, an essential step in the progression of ascending UTIs in women.

Bacterial Adhesion↗
PubMed2000

Benign diagnosis by image-guided core-needle breast biopsy.

Image-guided core-needle breast biopsy (IGCNBB) is widely used to evaluate patients with abnormal mammograms; however, information is limited regarding the reliability of a benign diagnosis. The goal of this study was to demonstrate that a benign diagnosis obtained by IGCNBB is accurate and amenable to mammographic surveillance. Records of all patients evaluated by IGCNBB from July 1993 through July 1996 were reviewed. Biopsies were classified as malignant, atypical, or benign. All benign cases were followed by surveillance mammography beginning 6 months after IGCNBB. Of the 1110 patients evaluated by IGCNBB during the study period, 855 revealed benign pathology. A total of 728 of the 855 patients (85%) complied with the recommendation for surveillance mammography. A total of 196 IGCNBBs were classified as malignant; 59 cases were classified as atypical. The atypical cases were excluded from the statistical analysis. Only two patients have demonstrated carcinoma after a benign IGCNBB during the 2-year minimum follow-up period. The sensitivity and specificity of a benign result were 100.0 and 98.9 per cent, respectively. A benign diagnosis obtained by IGCNBB is accurate and therefore amenable to mammographic surveillance. The results of this study support IGCNBB as the preferred method of evaluating women with abnormal mammograms.

Adult↗
PubMed2000

Laparoscopic adrenalectomy is superior to an open approach to treat primary hyperaldosteronism.

We reviewed our institutional experience with primary hyperaldosteronism to compare clinical outcomes after laparoscopic versus open adrenalectomy. All patients surgically treated for primary hyperaldosteronism from 1988 through 1999 are included in this study. Patients were assigned to either the LA (laparoscopic) or OA (open) group depending on the initial surgical approach selected for treatment. Records were reviewed to determine demographics, operative results, and complications. Twenty-four patients were surgically treated for primary hyperaldosteronism. There were no significant differences between groups with respect to age, weight, number of preoperative antihypertensive medications, or preoperative potassium level. The results of adrenalectomy with respect to number of postoperative antihypertensive medications or serum potassium level were also similar. Operative times were not significantly different (191 +/- 53 minutes for OA and 205 +/- 88 minutes for LA) between groups, but four LA patients were converted to OA. Estimated blood loss was 401 +/- 513 cm3 for OA and 127 +/- 131 cm3 for LA (P = 0.07). Hospital length of stay was 6.7 +/- 3.7 days for OA and 3.3 +/- 2.7 days for LA (P = 0.02). Complications were nine for OA and three for LA (P = 0.001 by Pearson's Chi square). LA is similar to OA in the treatment of primary hyperaldosteronism. The significantly fewer complications and shorter length of hospital stay associated with LA makes the laparoscopic approach the preferred method for treating primary hyperaldosteronism.

Adrenalectomy↗
PubMed1999

Preliminary clinical results of a biphasic waveform and an RV lead system.

Biphasic defibrillation waveforms have provided a reduction in defibrillation thresholds in transvenous ICD systems. Although a variety of biphasic waveforms have been tested, the optimal pulse durations and tilts have yet to be identified. A multicenter clinical study was conducted to evaluate the performance of a new ICD biphasic waveform and new RV active fixation steroid eluting lead system. Fifty-three patients were entered into the study. Mean age was 63 years with a mean ejection fraction of 36.8%. Primary indication for implantation was monomorphic ventricular tachycardia alone (54.7%). Forty-eight patients (90.6%) were implanted with an RV shocking lead and active can alone as the anodal contact. The ICD can was the cathode. In four cases (7.5%), an additional SVC or CS lead was used due to a high DFT with the RV lead alone. In an additional case, a chronic SVC lead was used although the RV-Can DFT was acceptable. DFT for all cases at implant was 9.8 +/- 3.7 J. Repeat testing at 3 months for a subset of patients showed a reduction in DFT (7.4 +/- 3.0 J), P value = 0.03. Sensing and pacing characteristics of the RV lead system remained excellent during the study period (acute 0.047 +/- 0.005 ms at 5.4 V and 9.9 +/- 6.2 mV R wave; chronic 0.067 +/- 0.11 ms at 5.4 V and 9.3 +/- 5.4 mV R wave). It is concluded that this lead system provides good acute and chronic sensing and pacing characteristics with good DFT values in combination with this waveform.

Cardiac Output, Low↗
PubMed1999

Roles of glycoproteins and oligosaccharides found in human vaginal fluid in bacterial adherence.

Adherence of type 1-piliated Escherichia coli to carbohydrate structures of vaginal mucosa plays a major role in the pathogenesis of ascending urinary tract infections in women. Colonization of the vaginal introitus is influenced by interactions between pathogens, vaginal fluid, and vaginal epithelium. In this study, the type and amount of carbohydrates and glycoproteins present in vaginal fluid were determined. Free and protein-bound oligosaccharides in vaginal fluid specimens were analyzed by fluorophore-assisted carbohydrate electrophoresis (FACE) and high-pressure liquid chromatography (HPLC). Two-dimensional electrophoretic separations of vaginal fluid glycoproteins were performed together with bacterial overlay assays. The results of FACE showed that the majority of the oligosaccharides are in the free state and the bound oligosaccharides are undetectable. HPLC analysis of free sugars revealed glucose as the major sugar (3.3 +/- 0.3 mM), and the concentrations of mannose and glucosamine were 0.065 +/- 0.04 and 0.02 +/- 0.001 mM, respectively. Radiolabeled E. coli bound three vaginal fluid glycoproteins with the following molecular masses and pIs: 82 kDa and pI 5.5, 55 kDa and pI 4.5, and 55 kDa and pI 6.5. The binding was inhibited by mannose and by deglycosylation of the proteins prior to the overlay assay. One of these putative receptors was identified to be the heavy chain of secretory IgA (S-IgA). These data suggest that the free mannose in the fluid is less than that required to affect E. coli-epithelial cell binding interactions and that S-IgA may bind E. coli in the vaginal introitus.

Adult↗
PubMed1999

Haemosuccus pancreaticus due to mucinous cystadenocarcinoma: the significance of recurrent abdominal pain, hyperamylasaemia and a pancreatic cyst in association with recurrent gastrointestinal bleeding.

Haemosuccus pancreaticus is a rare cause of gastrointestinal haemorrhage, and when it presents in otherwise healthy people, can prove difficult to diagnose. The cardinal features are episodic epigastric pain associated with a raised serum amylase and the passage of melaena. Failure to make the connection between recurrent gastrointestinal bleeding and apparently unrelated symptoms attributable to pancreatitis may lead to a significant delay in diagnosis.

Adenocarcinoma, Mucinous↗
PubMed1998

Elimination of mucosal cyathostome larvae by five daily treatments with fenbendazole.

The efficacy of five daily treatments with 7.5 mg fenbendazole/kg bodyweight against mucosal cyathostome larvae was evaluated in 20 12- and 24-month-old ponies with naturally acquired cyathostome infections. After three weeks communal grazing on infected pasture and six weeks indoors, one group of 10 ponies were treated. Six weeks later, both groups of ponies were humanely destroyed and their burdens of large intestinal cyathostome worms, including luminal parasites and mucosal larvae, were assessed. In the control animals approximately 7 per cent of the total worm burden was present in the gut lumen and 93 per cent was present as larvae in the large intestinal mucosa. The efficacy of fenbendazole against the luminal cyathostomes was 90.7 per cent (P < 0.01). The total numbers of mucosal larvae, recovered after digestion, were reduced by 95.3 per cent (P < 0.0005); mucosal late third and fourth stage larvae were reduced by 99.4 per cent (P < 0.0001), and early inhibited third stage larvae by 91.5 per cent (P < 0.005).

Animals↗
PubMed1998

Experimental study of tetrodotoxin, a long-acting topical anesthetic.

PURPOSE: To determine the effectiveness and toxicity of tetrodotoxin for use as a long-acting topical anesthetic. METHODS: Four groups of six rabbits each received a 40-microl aliquot of either tetrodotoxin in one of three concentrations (10 mM, 1 mM, or 0.1 mM) or proparacaine 0.5% into the inferior conjunctival cul-de-sac of one eye, with the fellow eye of each rabbit receiving 40 microl of a 60-mM, pH 4.3 sodium citrate vehicle as a control. Corneal sensation was tested for up to 8 hours after administration of drugs, and response was noted by no blink, partial blink without full eyelid closure, and full blink. Slit-lamp examination at 12 and 24 hours after administration and pachymetry before and 24 hours after administration were performed to detect corneal toxicity. RESULTS: Rabbits receiving all three concentrations of tetrodotoxin did not demonstrate any ocular irritation, corneal thickening, or signs of systemic toxicity. At a dose of 10 mM, tetrodotoxin produced an anesthetic effect lasting up to 8 hours. At 1 mM, tetrodotoxin was an effective but shorter-acting anesthetic. At 0.1 mM, tetrodotoxin had no significant anesthetic effect. Proparacaine-treated rabbits initially were anesthetic, but this effect was largely gone by 1 hour and completely gone by 3 hours. CONCLUSIONS: Tetrodotoxin is a long-acting topical anesthetic in the rabbit cornea. Although additional toxicity studies are required, tetrodotoxin may provide an effective, long-lasting topical anesthetic for use in pain control after corneal procedures such as photorefractive keratectomy.

Anesthesia, Local↗
PubMed1998

Intraorifice sealing of gutta-percha obturated root canals to prevent coronal microleakage.

A study was conducted to evaluate Cavit, Intermediate Restorative Material, and Super-EBA as intraorifice filling materials to prevent coronal microleakage. Root canal instrumentation and obturation was done on 74 extracted single-rooted teeth. Three and one-half millimeters of the gutta-percha was removed from the coronal aspect of the root canal and replaced with one of the three filling materials. The teeth were suspended in scintillation vials containing trypticase soy broth, and human saliva was added to the pulp chambers. Microbial penetration was detected as an increase in turbidity of the broth corresponding to bacterial growth. At the end of 90 days, the results showed that 15% of the Cavit-filled orifices leaked, whereas 35% of the Intermediate Restorative Material and Super-EBA-filled orifices leaked. The gutta-percha obturated root canals that received an intraorifice filling material leaked significantly less than the obturated, unsealed control group--all of which leaked in < 49 days.

Calcium Sulfate↗
PubMed1998

Complex limbal choristomas in linear nevus sebaceous syndrome.

OBJECTIVE: This study aimed to describe the clinical and histopathologic findings in four patients with complex limbal choristomas associated with linear nevus sebaceous syndrome (LNSS), a rare disorder including nevus sebaceous, seizures, and mental retardation, and often accompanied by ocular anomalies. DESIGN: Small observational case series. METHODS: A retrospective review of the clinical and histopathologic records of four patients. RESULTS: Each of four patients had complex limbal choristomas in the setting of clinical and histopathologic LNSS. The limbal choristomas were multiple in three patients and bilateral in two patients. Most choristomas involved the superotemporal limbus (6 of 10), although nasal (3 of 10) and inferior (1 of 10) limbal tumors also were present. Three patients had significant corneal astigmatism or involvement of the central cornea requiring surgical removal of their choristomas, one accompanied by a lamellar keratoplasty and another accompanied by two consecutive penetrating keratoplasties. Each graft eventually vascularized, reducing vision. One patient's vision was limited by amblyopia and another by occipital cortical dysgenesis with visual impairment. Histopathologic examination of the excised choristomas showed foci of lacrimal gland (3 of 4 patients), adipose tissue (3 of 4), neural tissue (1 of 4), cartilage (1 of 4), lymphoid follicles (1 of 4), skin adnexal tissue (1 of 4), and smooth muscle (1 of 4). Other associated ocular findings included an eyelid mass (1 of 4), colobomas of the eyelid (3 of 4), colobomas of the choroid and retina (2 of 4), nonparalytic strabismus (2 of 4), scleral ectasia (1 of 4), partial oculomotor palsy with ptosis and anisocoria (1 of 4), microphthalmia (1 of 4), hypertelorism (1 of 4), and cortical visual impairment (1 of 4). CONCLUSIONS: Complex limbal choristomas, although rare, can occur in the setting of LNSS and can be associated with multiple ocular and systemic abnormalities. Visual prognosis appears poor in most cases despite aggressive management.

Child, Preschool↗
PubMed1998

The influence of dietary supplementation with urea on resilience and resistance to infection with Haemonchus contortus.

Previous research has indicated that supplementing an apparently adequate diet with additional protein improves both host resistance and resilience in lambs infected with Haemonchus contortus. The present study tested the influence of supplementation with non-protein nitrogen (urea). Helminth-naive Hampshire Down lambs were given an apparently adequate basal diet or a diet supplemented with urea. The lambs were then infected with Haemonchus contortus for 10 weeks. Supplementation with urea had no discernible effect on resistance to infection; faecal egg counts, worm burdens, worm lengths and mean number of eggs per adult female worm did not differ between the 2 groups. However, lambs on the supplemented diet showed better resilience; they had greater packed red cell volumes, higher plasma albumin concentrations and increased liveweight gain compared to lambs on the basal diet. The loss of appetite following infection was less in lambs fed the urea-supplemented diet. The observed effect of urea supplementation was seemingly due to greater food consumption as well as the better diet.

Animal Nutritional Physiological Phenomena↗
PubMed1998

Image-guided core-needle breast biopsy is an accurate technique to evaluate patients with nonpalpable imaging abnormalities.

OBJECTIVE: The goal was to evaluate one institution's experience with image-guided core-needle breast biopsy (IGCNBB) and compare the pathologic results with wire-localized excisional breast biopsy (WLEBB) for patients with positive cores and the mammographic surveillance results for patients with negative cores. SUMMARY BACKGROUND DATA: IGCNBB is becoming a popular, minimally invasive alternative to WLEBB in the evaluation of patients with nonpalpable abnormalities. METHODS: This study includes all patients with nonpalpable breast imaging abnormalities evaluated by IGCNBB from July 1993 to February 1997. Patients with positive cores (atypical hyperplasia, carcinoma in situ, or invasive carcinoma) were evaluated by WLEBB. Patients with negative cores (benign histology) were followed with a standard mammographic protocol. IGCNBB results were compared with WLEBB results to determine the sensitivity and specificity for each IGCNBB pathologic diagnosis. RESULTS: Of 1440 IGCNBBs performed during the study period, 1106 were classified as benign, and during surveillance follow-up only a single patient was demonstrated to have a carcinoma in the index part of the breast evaluated by IGCNBB (97.3% sensitivity, 99.7% specificity). IGCNBB demonstrated atypical hyperplasia in 72 patients, 5 of whom refused WLEBB. The remaining 67 patients were evaluated by WLEBB: nonmalignant findings were found in 31, carcinoma in situ was found in 25, and invasive carcinoma was found in 11 (100% sensitivity, 88.8% specificity). IGCNBB demonstrated carcinoma in situ in 84 patients; WLEBB confirmed carcinoma in situ in 54 and invasive carcinoma in 30 (65.4% sensitivity, 97.7% specificity). IGCNBB demonstrated invasive carcinoma in 178 patients. Three were lost to follow-up. On WLEBB, 173 of the remaining 175 had invasive carcinoma; the other 2 patients had carcinoma in situ (80.8% sensitivity, 99.8% specificity). CONCLUSIONS: An IGCNBB that demonstrates atypical hyperplasia or carcinoma in situ requires WLEBB to define the extent of breast pathology. Mammographic surveillance for a patient with a benign IGCNBB is supported by nearly 100% specificity. An IGCNBB diagnosis of invasive carcinoma is also associated with nearly 100% specificity; therefore, these patients can have definitive surgical therapy, including axillary dissection or mastectomy, without waiting for the pathologic results of a WLEBB. Based on the authors' findings, IGCNBB can safely replace WLEBB in evaluating patients with nonpalpable breast abnormalities.

Biopsy, Needle↗
PubMed1998

Experimental use of tetrodotoxin for corneal pain after excimer laser keratectomy.

PURPOSE: To determine the duration of anesthesia, effect on corneal reepithelialization, and systemic toxicity of topical tetrodotoxin (TTX) administered after excimer laser keratectomy. METHODS: Two groups of six rabbits each underwent excimer laser keratectomy in the right eye to create a 5-mm-diameter wound, 75 mm in depth. One group then received a 40-microl aliquot of topical 1 mM TTX into the injured eye, whereas the other group received 40 microl of the sodium citrate vehicle as a control. The rabbits were treated with TTX or vehicle again at 6, 12, 18, and 24 h. Corneal sensation was tested at 3, 6, 9, 12, 15, 18, 21, 24, 30, 32, and 40 h. To determine whether TTX inhibited corneal reepithelialization, compared with vehicle-treated control eyes, the healing rate of the epithelial defect was measured. RESULTS: Administration of TTX every 6 h for 24 h produced nearly complete anesthesia for > or = 30 h. At 32 h, 8 h after the final application of TTX, there was still significant anesthesia of the TTX-treated corneas (p = 0.0325, Wilcoxon test). Normal corneal sensation in all TTX-treated animals returned at 40 h, or 16 h after the final dose. In contrast, vehicle-treated eyes all had normal sensation for nearly the entire duration of the experiment. At 40 h, the TTX-treated eyes had slightly larger defects than vehicle-treated eyes, 7.85+/-1.74 versus 4.54+/-1.31 mm2 (p < 0.025, t test). However, at 49 h and thereafter, both groups were equally healed (p > 0.05, t test). No systemic toxicity was observed in any of the rabbits. CONCLUSION: Topical TTX is a long-acting and nontoxic local anesthetic in a rabbit model of excimer laser keratectomy.

Anesthesia, Local↗
PubMed1997

Do infectious agents cause interstitial cystitis?

The possibility that infectious agents play a role in the etiology of interstitial cystitis (IC) has been investigated for a number of years. Early studies were directed toward attempts to cultivate bacteria and fungi on routine culture media and microscopic examinations of urine or bladder tissue specimens for the presence of microorganisms. In more recent years, this approach has been expanded to include sophisticated culture techniques to search for the presence of fastidious and unusual organisms that would not be detected by routine culture methods. Similarly, the presence of viruses has been sought by incubating specimens from interstitial cystitis patients in mammalian cell cultures to detect cytopathic effects. None of these approaches has provided convincing evidence that micro-organisms or viruses are associated with IC. The latest attempts to search for the presence of bacteria have made use of the polymerase chain reaction (PCR) to amplify bacterial 16S rRNA genes that would be present if bacteria were present in bladder tissue or urine of IC patients. This approach allows bacteria to be detected and even identified without culture. However, the results from the great majority of bladder biopsy samples analyzed by these molecular techniques have been negative. PCR strategies have also been used to search for the presence of certain viruses in IC specimens, again without success. At this time, the results from laboratory culture, light and electron microscopy, and various molecular strategies to detect micro-organisms and viruses in IC specimens all argue against an infectious etiology for IC.

Bacteria↗