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Berntsen A, Geertsen P, Trepiakas R, Wenandy L, Andersen MH, Straten PT, Lorentzen T, Johansen JS, Johnsen HE, Svane IM. Dendritic cell based vaccination in combination with IL-2 as a treatment for advanced renal cell carcinoma patients: Results from a phase I/II trial. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.2575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
2575 Background: Autologous dendritic cells (DC) pulsed with tumor-associated antigens as peptides or tumor lysate derived proteins can induce generation of cytotoxic T-cells in cancer patients. Survivin and telomerase are tumor-associated antigens overexpressed in renal cell carcinoma, and telomerase and survivin derived HLA-A2 binding peptides are able to induce effector T-cells cytotoxic to tumor cells. Tumor lysate can be generated from allogeneic renal carcinoma cell lines and has a natural high amount of antigens potentially enabling the induction of a polyclonal immune response against multiple targets on tumor cells. Methods: Twenty-two patients with progressive metastatic renal cell carcinoma were included and toxicity and efficacy of DC-based immunotherapy were evaluated. HLA-A2 positive patients were treated with mature autologous DCs pulsed with a broad panel of HLA binding telomerase and survivin peptides and PADRE; HLA-A2 negative patients received DCs pulsed with allogeneic tumor lysate and KLH. The vaccines were administered intradermally or intranodally weekly/biweekly ten times and repeated monthly until tumor progression. Patients received low dose IL-2 as an adjuvant. Immune response was monitored using ELISPOT assay. IL-6 and the biomarker YKL-40 were measured in serum using ELISA assay. Results: Vaccinations were well tolerated. 17/22 patients were evaluable and 10 patients had stable disease (SD) for up to 11+ months (range 2–11+ months). Interestingly, serum IL-6 increased in patients with progressive disease compared with a decrease in patients with SD. After vaccination mean values of YKL-40 were 91ng/ml in patients with SD and 208ng/ml in patients with PD. Immune monitoring is ongoing and preliminary data demonstrate that peptide specific CTLs are induced by the treatment. Conclusions: This pilot study demonstrates, that vaccination with autologous DCs pulsed with tumour antigens is safe and without severe toxicity. Disease stabilization was observed in half of the treated patients. Serum IL-6 and YKL-40 values might be useful parameters to predict clinical response during vaccination therapy. No significant financial relationships to disclose.
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Poulsen HF, Nielsen SF, Lauridsen EM, Schmidt S, Suter RM, Lienert U, Margulies L, Lorentzen T, Juul Jensen D. Three-dimensional maps of grain boundaries and the stress state of individual grains in polycrystals and powders. J Appl Crystallogr 2001. [DOI: 10.1107/s0021889801014273] [Citation(s) in RCA: 279] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A fast and non-destructive method for generating three-dimensional maps of the grain boundaries in undeformed polycrystals is presented. The method relies on tracking of micro-focused high-energy X-rays. It is verified by comparing an electron microscopy map of the orientations on the 2.5 × 2.5 mm surface of an aluminium polycrystal with tracking data produced at the 3DXRD microscope at the European Synchrotron Radiation Facility. The average difference in grain boundary position between the two techniques is 26 µm, comparable with the spatial resolution of the 3DXRD microscope. As another extension of the tracking concept, algorithms for determining the stress state of the individual grains are derived. As a case study, 3DXRD results are presented for the tensile deformation of a copper specimen. The strain tensor for one embedded grain is determined as a function of load. The accuracy on the strain is Δ∊ ≃ 10−4.
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Torp-Pedersen S, Lorentzen T. [The rubric "Picture of the month"]. Ugeskr Laeger 2001; 163:630-1. [PMID: 11221460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Skjoldbye B, Nielsen AH, Court-Payen M, Nørgaard N, Rasmussen F, Løkkegaard H, Lorentzen T, Holm HH. Perioperative Doppler ultrasonography: renal detection of renal graft perfusion. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 1998; 32:345-9. [PMID: 9825398 DOI: 10.1080/003655998750015313] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Irreversible damage of renal transplants may be prevented if insufficient graft perfusion can be detected perioperatively. Colour and spectral Doppler ultrasonography were performed in 30 consecutive renal transplants. The perfusion of the graft and the Resistive Index (RI) were evaluated perioperatively (perioperatively and less than 15 min postoperatively) and 24 h after the operation in all patients. In four cases (13.3%) RI > 0.9 was detected and immediate surgical correction of the cause led to a normalization (RI < 0.8) in all four cases. A RI < 0.9 required no intervention in 26 cases (86.7%). All renal grafts in this series were functioning 1 month postoperatively. In a comparative group, 30 consecutive transplants carried out at our institution without perioperative Doppler ultrasonography evaluation, a loss of four renal grafts perioperatively was recorded retrospectively. We conclude that perioperative ultrasonography Doppler evaluation may provide an easy applicable and reliable method for early detection of insufficient renal graft perfusion, allowing surgical correction before irreversible damage of the graft occurs. RI > 0.9 is pathological. A continuation of the study is required to clarify the long-term value of perioperative Doppler ultrasonography graft monitoring.
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Wulff C, Lorentzen T. Extracranial arteriovenous malformation diagnosed on color Doppler imaging. EUROPEAN JOURNAL OF ULTRASOUND : OFFICIAL JOURNAL OF THE EUROPEAN FEDERATION OF SOCIETIES FOR ULTRASOUND IN MEDICINE AND BIOLOGY 1998; 7:205-208. [PMID: 9700217 DOI: 10.1016/s0929-8266(98)00039-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Arteriovenous (AV) malformations are rare and may occur at various locations, like in the brain, liver, lungs, or in the subcutaneous tissue. This case report describes an AV malformation from the right occipital artery. The value of combined B-mode ultrasonography and color Doppler mode imaging of masses in the neck region is discussed.
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Khattar S, Torp-Pedersen S, Horn T, Krogh-Pedersen I, Court-Payen M, Lorentzen T. Ultrasound-guided biopsy of palpable breast masses. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0929-8266(97)00030-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Poulsen HF, Garbe S, Lorentzen T, Juul Jensen D, Poulsen FW, Andersen NH, Frello T, Feidenhans'l R, Graafsma H. Applications of high-energy synchrotron radiation for structural studies of polycrystalline materials. JOURNAL OF SYNCHROTRON RADIATION 1997; 4:147-54. [PMID: 16699221 DOI: 10.1107/s0909049597002021] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The large penetration power of high-energy X-rays (>60 keV) raises interesting prospects for new types of structural characterizations of polycrystalline materials. It becomes possible in a non-destructive manner to perform local studies, within the bulk of the material, of the fundamental materials physics properties: grain orientations, strain, dislocation densities etc. In favourable cases these properties may be mapped in three dimensions with a spatial resolution that matches the dimensions of the individual grains. Imbedded volumes and interfaces become accessible. Moreover, the high energies allow better in-situ studies of samples in complicated environments (industrial process optimization). General techniques for research in this energy range have been developed using broad-band angle-dispersive methods, on-line two-dimensional detectors and conical slits. Characterizations have been made at the level of the individual grains and grain boundaries as well as on ensembles of grains. The spatial resolution is presently of the order of 10-100 micom. Four examples of applications are presented along with an outlook.
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Lorentzen T, Christensen NE, Nolsłe CP, Torp-Pedersen ST. Radiofrequency tissue ablation with a cooled needle in vitro: ultrasonography, dose response, and lesion temperature. Acad Radiol 1997; 4:292-7. [PMID: 9110027 DOI: 10.1016/s1076-6332(97)80031-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
RATIONALE AND OBJECTIVES Radiofrequency (RF) tissue ablation with a cooled needle electrode (probe) can produce large lesions. By using this technique on ex vivo calf livers, the authors evaluated the role of ultrasound (US), dose response, and temperature course with time. METHODS RF ablation was produced with a 14-gauge probe with a 2-cm exposed tip. The lesions were examined with US and macroscopically after various treatment durations. Tissue temperature was measured with thermosensors inserted 1, 2, and 3 cm from the probe. RESULTS Before treatment the tip of the probe was easy to visualize with US, but treatment microbubbles obscured the lesion and probe. After treatment, the lesions appeared hypoechoic. Lesion size was underestimated based on US findings. Lesion size was logarithmically correlated to treatment duration. Lesion temperature increased at an increased rate with higher wattage applied and with decreased distance from the probe. CONCLUSION US is useful for probe placement before treatment and might be of value after treatment. Lesion size increases reproducibility with treatment duration.
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Wulff C, Lorentzen T, Christensen E, Pedersen EB. [Phlegmasia alba dolens diagnosed with Doppler ultrasonography]. Ugeskr Laeger 1996; 158:6623-4. [PMID: 8966831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Differential diagnostic problems may occur in a patient with a cold, pale and swollen leg. Especially when the peripheral blood pressure is reduced, it is particularly difficult to distinguish cases caused by venous thrombosis from those caused by arterial embolism. Colour-Doppler ultra-sonography might be helpful for establishing the correct diagnosis. A case history is presented.
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Skjoldbye B, Horn T, Torp-Pedersen S, Court-Payen M, Khattar S, Lorentzen T. Ultrasound guided fine needle aspiration biopsies, from the liver. How many needle passes? ACTA ACUST UNITED AC 1996. [DOI: 10.1016/0929-8266(95)00155-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lorentzen T. A cooled needle electrode for radiofrequency tissue ablation: thermodynamic aspects of improved performance compared with conventional needle design. Acad Radiol 1996; 3:556-63. [PMID: 8796717 DOI: 10.1016/s1076-6332(96)80219-4] [Citation(s) in RCA: 181] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
RATIONALE AND OBJECTIVES I developed and tested a cooled needle electrode (CNE) for radiofrequency (RF) tissue ablation in vitro. METHODS A 2-mm needle electrode with two lumina for internal water perfusion and irrigation of the needle tip and a conventional needle electrode were tested in ex vivo calf liver during different levels of output power (wattage). RF lesions produced by the two needle types were further evaluated with a thermal camera. RESULTS When the CNE was used, a significant increase in the duration of ablation was observed, which caused a significant increase in delivered energy and lesion size when compared with the conventional needle electrode. The largest lesion produced with the CNE was almost spherical and measured 41 x 37 mm (longitudinal x transverse). The cooling effect was reflected in the image obtained with the thermal camera. CONCLUSION This technique produced very large lesions compared with conventional methods and may have a role in many different kinds of RF needle ablation.
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Lorentzen T. The loop electrode: in vitro evaluation of a device for ultrasound-guided interstitial tissue ablation using radiofrequency electrosurgery. Acad Radiol 1996; 3:219-24. [PMID: 8796668 DOI: 10.1016/s1076-6332(96)80444-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
RATIONALE AND OBJECTIVES I developed and tested in vitro a device for ultrasound-guided monopolar radiofrequency (RF) electrosurgical interstitial tissue ablation. METHODS The current was applied to an electrode with a distal loop form (radius = 1 cm). The superelastic properties of the electrode allowed cannula introduction in the experimental medium (calf liver) before subsequent rotation of the electrosurgical cutting electrode, resulting in cutting off and isolation of a spherical lesion interstitially. The optimal setting of the RF unit and the optimal cutting speed were evaluated. Under ultrasonographic guidance and monitoring, approximately 150 lesions were produced with different loop designs and sizes. The gross appearance was evaluated and correlated to ultrasonography. RESULTS An output effect of 200 W was optimal for resection and cutting with the loop electrode. An ellipsoid loop configuration could produce an almost spherical lesion with a diameter of 2.0 cm interstitially. Ultrasonography could guide the introduction of the loop electrode into tissue and visualize the upper part of the lesion. CONCLUSION The loop electrode is a technique for percutaneous ultrasonographically guided tissue ablation. It was proved to be efficient in vitro by producing 2-cm liver lesions.
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Lorentzen T, Nolsøe CP, Torp-pedersen ST, Holm Christensen NE, Pedersen S, Horn T, Andersen PH. The loop electrode: A new device for US-guided interstitial tissue ablation using radiofrequency electrosurgery - an animal study. MINIM INVASIV THER 1996. [DOI: 10.3109/13645709609152693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Skjoldbye B, Lorentzen T, Holm HH. [Ultrasonic angiography: principles and clinical use]. Ugeskr Laeger 1995; 157:5530-5533. [PMID: 7571094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A new technique for detecting blood flow called Colour Doppler Energy (CDE), Power Doppler or Ultrasound Angio, is based on the integrated power spectrum of the standard Doppler signal used for Colour Flow Mapping (CFM). CDE is independent of the insonation angle, has no aliasing artefacts and improves the sensitivity with respect to detection of the presence or absence of flow compared to CFM. However, CDE provides no directional or quantitative information about the flow. CDE is superior to CFM in detection of low velocity flow, perfusion in small vessels, flow in torsioned vessels and flow in multiple vessels in the same image plane. The clinical applications are reviewed. Complicated stenosis, renal perfusion, penile Doppler and scanning of the vessels of the extremities are examples where CDE improves sensitivity in detecting flow compared to CFM.
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Lorentzen T, Sengeløv L, Nolsøe CP, Khattar SC, Karstrup S, von der Maase H. Ultrasonically guided insertion of a peritoneo-gastric shunt in patients with malignant ascites. Acta Radiol 1995; 36:481-4. [PMID: 7640091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE A new method for internal drainage of malignant ascites is presented in 5 patients with symptomatic malignant ascites. MATERIAL AND METHODS US-guided percutaneous gastrostomy and paracentesis were performed using the Seldinger technique. A 2.5-mm Cope-loop catheter was inserted in the fluid-filled stomach. In the lower abdomen the proximal part of a Denver peritoneo-venous shunt was introduced after dilation up to 4.8 mm. The pump chamber was sutured to the skin. The distal part of the Denver shunt was cut a few cm from the pump chamber and connected to the gastrostomy catheter. When pumping, ascites is shunted to the stomach lumen. RESULTS The insertion presented no complications, and all shunt systems initially functioned well. However, the shunts had to be removed within the first 2 weeks because of mechanical problems such as clotting, leakage, and peritoneal septum formation. No infections were reported. CONCLUSION The peritoneo-gastric shunt may present a therapeutic alternative in selected patients, but the mechanical problems have first to be solved.
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Albertini G, Cernuschi F, Cicognani G, Ghia S, Lorentzen T, Rustichelli F. Residual strain measurements in welded steel Fe510D. Appl Radiat Isot 1995. [DOI: 10.1016/0969-8043(95)00144-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Lorentzen T, Skjoldbye B, Nolsøe C, Torp-Pedersen S, Mygind T. Percutaneous Gastrostomy Guided by Ultrasound and Fluoroscopy. Acta Radiol 1995. [DOI: 10.3109/02841859509173370] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Lorentzen T, Skjoldbye B, Nolsøe C, Torp-Pedersen S, Mygind T. Percutaneous gastrostomy guided by ultrasound and fluoroscopy. Acta Radiol 1995; 36:159-62. [PMID: 7710796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Percutaneous gastrostomy, utilizing a dedicated catheterization kit, with a combination of ultrasonographic (US) and fluoroscopic guidance, was carried out in 27 patients. The main indication for gastrostomy was the need for nutritional support in malignant esophageal stricture. After distending the stomach with water via a nasogastric tube, the gastric antrum was punctured under US guidance and a guide wire was inserted, followed by fluoroscopically guided tract dilatation and insertion of a 2.5-mm Cope-loop catheter. In all patients but one (96%) the procedure was successfully completed in one or 2 attempts. Two complications occurred: one case of a small subcutaneous abscess near the puncture site, and one late incident of dislodgement of a catheter without string-loop fixation, which had been inserted at a catheter exchange after 6 weeks. Percutaneous gastrostomy guided by US and fluoroscopy is a safe and efficacious alternative to endoscopic and surgical gastrostomy.
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Lorentzen T, Skjoldbye B, Nolsøe C, Torp-Pedersen S, Mygind T. Percutaneous Gastrostomy Guided by Ultrasound and Fluoroscopy. Acta Radiol 1995. [DOI: 10.1080/02841859509173370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Lorentzen T, Sengeløv L, Nolsøe CP, Khattar SC, Karstrup S, von der Maase H. Ultrasonically Guided Insertion of a Peritoneo-Gastric Shunt in Patients with Malignant Ascites. Acta Radiol 1995. [DOI: 10.1080/02841859509173413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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46
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Lorentzen T, Sengeløv L, Nolsøe CP, Khattar SC, Karstrup S, von der Maase H. Ultrasonically Guided Insertion of a Peritoneo-Gastric Shunt in Patients with Malignant Ascites. Acta Radiol 1995. [DOI: 10.3109/02841859509173413] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Draijer F, Lorentzen T, Nissen R, Havemann D. [Functional treatment of surgically treated empyema of the knee joint]. Unfallchirurg 1994; 97:273-7. [PMID: 8052866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Knee-joint empyema requires prompt surgical management. After debridement the joint needs to be irrigated for several days. Functional follow-up treatment with electromotive splints according to the CPM concept should begin soon after surgery. Follow-up examination of patients treated in this way for knee-joint empyema showed a protracted course with worse results for empyemas subsequent to arthrotomy, while joint infections after less severe injuries (skin lesions, puncture) healed successfully.
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Lorentzen T, Nolsøe CP, Khattar SC, Torp-Pedersen ST, Holm HH. Gastric and duodenal wall thickening on abdominal ultrasonography. Positive predictive value. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 1993; 12:633-637. [PMID: 8264011 DOI: 10.7863/jum.1993.12.11.633] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In a retrospective study, 79 patients with gastric (n = 59) or duodenal (n = 20) wall thickening on conventional abdominal ultrasonograms were included. To reduce bias, patients with a microscopic diagnosis of upper GI neoplasia present at the time of scanning were excluded. The final diagnosis was based upon endoscopy, operation, upper GI series, or autopsy. Among the 59 cases of gastric wall thickening, 33 (56%) proved to be gastric cancer, one (2%) was benign neoplasia, and 17 (29%) showed nonneoplastic pathology (ulcer, gastritis, fibrosis). In eight cases (13%) no gastric pathology was present in the final diagnosis, thus producing false-positive sonographic diagnoses. Among the 20 cases of duodenal wall thickening, five (25%) proved to be duodenal cancer and seven (35%) showed nonneoplastic duodenal pathology. We concluded that gastric or duodenal wall thickening shown on abdominal sonography is a significant finding indicating upper GI pathology (malignant or nonmalignant) in a high percentage of the gastric (86%) and duodenal (60%) cases.
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Krausse R, Lorentzen T, Erttmann M, Ullmann U. Prevalence of Helicobacter pylori in gastrointestinal disorders and concentrations of ciprofloxacin in serum and gastric mucosa. ZENTRALBLATT FUR BAKTERIOLOGIE : INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY 1993; 280:286-96. [PMID: 8280954 DOI: 10.1016/s0934-8840(11)80967-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Endoscopic antral biopsies were obtained from 30 patients with several gastrointestinal disorders and analysed for the presence of H. pylori. This bacterium was present in 80% and 58%, respectively, of patients with either gastric and duodenal ulcers and gastric neoplasm. In none of the healthy individuals, H. pylori could be found. Another 14 patients with various diseases of the stomach, undergoing a major gastric resection, had been treated with 200 mg ciprofloxacin intravenously immediately before the operation. Blood and various tissues samples were taken during the operation. The prevalence of IgG antibodies against H. pylori in these patients was 93%. H. pylori could be determined in 71% of the cases by the urease production; by culture, this was possible in only one case. The mean peak concentration of ciprofloxacin in serum was 5.31 mg/l and 1.17 mg/l, respectively, immediately and 60 min after the end of infusion; in tissues of antrum and duodenum, 1.59 to 1.64 mg/kg and 1.41 to 1.72 mg/kg, respectively, 45-270 min after the infusion. The results show that ciprofloxacin rapidly penetrates into tissues and attains concentrations greater than the MIC90 for H. pylori. However, these concentrations can inhibit the isolation of this microorganism but not its urease activity. This fact could be interpreted by the existence of a nonculturable but metabolically active form of H. pylori. This would explain the high rate of recrudescence following most types of currently applied therapeutic schemes.
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Abstract
Using a duplex Doppler technique, we investigated the effect of low doses of secretin on the portal blood flow. In eight healthy volunteers successive intravenous secretin infusions of 0, 8, and 32 pmol x kg-1 x h-1 resulted in proportional increases in plasma secretin levels. The portal venous flow, however, was unaffected. A bolus injection of 930 pmol of secretin caused plasma secretin levels to increase 100-fold, whereas blood flow in the portal vein increased only by a factor three. This suggests that secretin in the present dose range is of no quantitative importance as a regulator of portal venous flow under physiologic conditions.
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