Ischemic jejunal stricture following endovascular abdominal aortic aneurysm repair -- a case report

Endograft repair has rapidly become an alternative to conventional open repair of abdominal aortic aneurysms. Various trials continue to show decreased morbidity when compared to open repair. However, as with any new procedure, complications specifically related to this technique are being described. Herein, we report a case of an isolated ischemic jejunal stricture presenting as a small-bowel obstruction secondary to cholesterol emboli following endograft repair of an abdominal aortic aneurysms.     

Recombinant C fragment of botulinum neurotoxin B serotype (rBoNTB (HC)) immune response and protection in the rhesus monkey

Botulinum neurotoxin B (BoNTB) is a distinct protein subtype of a family of neurotoxins with the potential for use in biological warfare or terrorist attacks. This study is one in a series evaluating the immunogenicity and protective effects of recombinant vaccines against the different subtypes of botulinum toxin. The recombinant subunit vaccines encoding the C fragment portion (50 kDa) of the toxins are produced in the yeast, Pichia pastoris. In this study, groups of rhesus monkeys were vaccinated with three doses (1 and 5 μg per dose) of rBoNTB(H_c) vaccine. Total and neutralizing antibody titers were determined at various times during and postvaccination. Two groups of vaccinated monkeys plus non-vaccinated controls were actively challenged with B toxin by aerosol exposure. All monkeys receiving vaccine were protected from the toxin and no clinical signs of disease were observed, while controls displaying classic signs of botulism succumbed to the toxin challenge. Two additional groups of monkeys receiving the same vaccine regiment as the first two groups had significant levels of circulating neutralizing antibody titers up to 24 months postvaccination. This non-human primate study demonstrated the short- and long-term immunity afforded by the rBoNTB(H_c) vaccine.     

Better Visualization of Transbronchial Biopsy Using CT Fluoroscopy

Purpose: Computed tomography fluoroscopy (CTF) provides the capability for continuous CT imaging and has been increasingly used in interventional procedures. Our objective was to assess the usefulness of CTF in the monitoring of transbronchial biopsy procedures. Methods: We evaluated nine patients in whom yield of “conventional” transbronchial biopsies had failed. CTF was performed on a Somatom Plus 4 Power scanner (CARE Vision CT, Siemens, Forchheim, Germany) using 120 kV, 50 mA at a frame rate of eight images per second on a matrix of 256 × 256. Image reconstruction was based on a partial scan with an acquisition time of 0.5 sec. The maximal time without interruption was 79 sec; after stopping for a few seconds a new period of 79 sec was available. The number of biopsies, procedure times, applied dose, and histologic results were documented. Results: With CTF-guided transbronchial biopsy, the yield of the biopsies was improved. In seven patients biopsy yielded bronchial cancer; in one patient histopathologic examination showed tuberculosis. Only in one patient did CTF-guided transbronchial biopsy fail. The mean number of biopsies was four in each patient. Mean fluoroscopy time was 165 ± 92 sec (range 111–272 sec) and mean procedure time was 800 ± 302 sec (range 480–1081 sec). The applied dose ranged between 500 and 1224 mSv; the mean applied dose was 743 ± 414 mSv. There were no fatal complications. Conclusion: Computed tomography fluoroscopy appears to facilitate visualization of transbronchial biopsy procedures, with the drawback of increased radiation exposure. To compare the “conventional” method versus CTF a randomized prospective study is necessary.     

Erste Ergebnisse der neoadjuvanten simultanen Radiochemotherapie bei fortgeschrittenen Rektumkarzinomen

Hintergrund: Bei lokal weit fortgeschrittenen Rektumkarzinomen ist das Erreichen eine R0-Resektion schwierig. Muss jedoch makroskopisch oder mikroskopisch Tumorrest zurückgelassen werden, ist die Prognose der Patienten schlecht. In den Leitlinien empfiehlt die Deutsche Krebsgesellschaft deshalb bei Patienten mit T4-Tumoren eine präoperative simultane Radiochemotherapie. Patienten und Methodik: Vom 1.5.1997 bis 30.11.1999 wurde bei 22 Patienten eine neoadjuvante Radiochemotherapie durchgeführt. Appliziert wurde eine Dosis von 45 Gy zuzüglich eines Boostes von 5,4 Gy. In der ersten und fünften Bestrahlungswoche erhielten die Patienten an fünf aufeinander folgenden Tagen eine Dosis von täglich 1000 mg/m² 5-FU als intravenöse Dauerinfusion über 24 Stunden. Bei auftretender Kardiotoxizität wurde die Chemotherapie auf 5-FU-Bolusinfusion oder Ralitrexed umgestellt. Ergebnisse: 19/22 Patienten konnten einer Operation zugeführt werden. Bei 16/19 (84%) der operierten Patienten konnte eine R0-Resektion erreicht werden. Eine funktionserhaltende Behandlung war bei 9/19 (47%) Patienten möglich. Ein Downstaging um mindestens eine T-Kategorie wurde bei 12/19 (63%) Patienten erzielt. Bei einer medianen Nachbeobachtungszeit von 16 Monaten ist bisher kein lokales Rezidiv bei den operierten Patienten aufgetreten. Das progressionsfreie Überleben der operierten Patienten (R0/R1) beträgt nach zwei Jahren 62%, die Überlebensrate 89%, bezogen auf alle Patienten 76%. Schlussfolgerung: Die präoperative simultane Radiochemotherapie kann zu einer verbesserten Rate an R0-Resektionen und sphinktererhaltenden Eingriffen betragen. Purpose: In locally advanced rectal cancer tumor-negative margins often cannot be obtained by surgery alone. Nevertheless only patients with complete tumor resection can be cured. Due to the poor prognosis of patients with R1/R2 resection the "Deutsche Krebsgesellschaft" recommends concurrent preoperative radiochemotherapy for patients with locally advanced rectal cancer. Patients and Methods: Between May 1997 and November 1999 22 patients were treated with preoperative radiochemotherapy. A total dose of 45 Gy with a small-volume boost of 5.4 Gy was delivered in conventional fractionation (single dose 1,8 Gy). On days 1 to 5 and 29 to 33 patients received concurrently 5-fluorouracil (5-FU) as continuous infusion of 1,000 mg/m². If there was any sign of cardiac toxicity chemotherapy was changed to 5-FU/folinic acid or ralitrexed. Results: Surgery following radiochemotherapy was performed in 19/22 patients. Resections with negative margins were achieved in 16/19 (84%) patients. Sphincter-conserving surgery was possible in 9/19 (47%) patients. A downstaging of at least 1 T category was found in 12/19 (63%) patients. With a median follow-up of 16 months no locoregional recurrences occurred in patients who underwent surgery. Two-year disease-free survival of resected patients is 62%, 2-year overall survival is 89%, of the whole population 76%. Conclusion: Preoperative radiochemotherapy followed by surgery is able to achieve clear resection margins in more than 70% of patients with locally advanced rectal cancer and may improve the rate of sphincter-conserving surgery.     

Developmental role of static, dynamic, and contextual cues in speech perception.

The purpose of the current study was to examine the role of syllable duration context as well as static and dynamic acoustic properties in child and adult speech perception. Ten adults and eleven 4-5-year-old children identified a syllable as [ba] or [wa] (stop-glide contrast) in 3 conditions differing in synthetic continua. The 1st condition tested the potential existence of the syllable duration effect in young children, whereas the 2nd and 3rd conditions examined the developmental role of static and dynamic cues, respectively, as related to syllable duration context effects. In the 1st condition, the 1st and 2nd formant transition duration of stimuli varied from those appropriate for [ba] to those appropriate for [wa]. For the 2nd condition, a static burst was added to Condition 1 stimuli. For the 3rd condition, the dynamic transition frequency and transition duration for the first 3 formants varied as appropriate for [ba] and [wa]. In each condition, 3 syllable context durations of 105 ms, 170 ms, and 315 ms were tested. The results indicated that syllable duration context effects were present across all conditions for both adults and children. However, the adults and children did differ in the 3rd condition, in which both the transition frequency and the transition duration were altered. Thus, children used the dynamic formant transitions differently than adults when transition frequency was varied along with transition duration. These findings show that children have a bias toward formant transitions and indicate that young children of 4-5 years of age attend differently than adults to changes in dynamic cues such as formant transitions, as predicted by the developmental cue weighting shift model.     

The biological effectiveness of antiproton irradiation.

BACKGROUND AND PURPOSE: Antiprotons travel through tissue in a manner similar to that for protons until they reach the end of their range where they annihilate and deposit additional energy. This makes them potentially interesting for radiotherapy. The aim of this study was to conduct the first ever measurements of the biological effectiveness of antiprotons. MATERIALS AND METHODS: V79 cells were suspended in a semi-solid matrix and irradiated with 46.7MeV antiprotons, 48MeV protons, or (60)Co gamma-rays. Clonogenic survival was determined as a function of depth along the particle beams. Dose and particle fluence response relationships were constructed from data in the plateau and Bragg peak regions of the beams and used to assess the biological effectiveness. RESULTS: Due to uncertainties in antiproton dosimetry we defined a new term, called the biologically effective dose ratio (BEDR), which compares the response in a minimally spread out Bragg peak (SOBP) to that in the plateau as a function of particle fluence. This value was approximately 3.75 times larger for antiprotons than for protons. This increase arises due to the increased dose deposited in the Bragg peak by annihilation and because this dose has a higher relative biological effectiveness (RBE). CONCLUSION: We have produced the first measurements of the biological consequences of antiproton irradiation. These data substantiate theoretical predictions of the biological effects of antiproton annihilation within the Bragg peak, and suggest antiprotons warrant further investigation.     

Systemic anthrax lethal toxin therapy produces regressions of subcutaneous human melanoma tumors in athymic nude mice.

PURPOSE: Anthrax Lethal Toxin (LeTx), composed of protective antigen and lethal factor, catalytically cleaves mitogen-activated protein kinase (MAPK) kinases and inhibits the MAPK signaling pathways. The majority of metastatic melanomas possess the V599E BRAF mutation, which constitutively activates MAPK1/2 signaling. LeTx is cytotoxic to BRAF mutant melanoma cell lines in vitro, whereas most normal cells are resistant to this toxin. In this study, we determine the in vivo potency and safety of systemically administered LeTx. EXPERIMENTAL DESIGN: A s.c. xenograft melanoma model in athymic nude mice was treated with different i.p. doses of LeTx. RESULTS: In this study, we show that in vivo systemic LeTx treatment of s.c. xenograft melanoma tumors in athymic nude mice yields partial and complete tumor regressions with minor toxicity to mice. When animal toxicity was observed, we did not find any histologic evidence of tissue damage. CONCLUSIONS: LeTx is one of the rare targeted agents to produce complete remissions of human melanomas in an animal model and thus warrants further preclinical development.     

Idiopathic segmental infarction of the greater omentum successfully treated by laparoscopy: Report of case

(Received for publication on Feb. 12, 1999; accepted on Nov. 11, 1999)     

Association of thrombocytopenia and delivery method with intraventricular hemorrhage among very-low-birth-weight infants.

OBJECTIVES: To investigate the significance of neonatal thrombocytopenia and delivery method on the incidence of intraventricular hemorrhage in infants weighing <1500 g. STUDY DESIGN: A total of 1283 infants weighing <1500 g who were admitted to six neonatal intensive care units over 21 months were analyzed prospectively. Illness severity was measured by the Score for Neonatal Acute Physiology (SNAP). RESULTS: Of the infants analyzed, 145 (11.3%) had thrombocytopenia (platelet count <100 x 10(9)/L). The incidence of intraventricular hemorrhage was greater among infants with thrombocytopenia than among those without (44.8% vs 23.9%, P <.0001). Non-thrombocytopenic infants who were delivered vaginally had a higher incidence of intraventricular hemorrhage than those delivered via cesarean section (35.8% vs 15.9%, P <.0001). Thrombocytopenic infants who were delivered vaginally had the highest incidence of intraventricular hemorrhage (63.4% vs 37.5% for cesarean section, P =.005). Vaginal delivery and platelets < 50 x 10(9)/L on day 1 were independent risk factors for intraventricular hemorrhage (OR 2.7, 95% CI 2.0-3.8 and OR 11.2, 95% CI 3.0-42.5, respectively). CONCLUSIONS: This multicenter study confirms that thrombocytopenia and intraventricular hemorrhage are not uncommon in neonates who weigh <1500 g, and that the incidence of intraventricular hemorrhage is higher in those thrombocytopenic infants delivered vaginally.