The objective of this research is to evaluate the usefulness of a macroscopic, fluorescent, imaging technique to quantify spatiotemporal mass transport parameters in in vitro solid tumor tissues ...taken from rat models. Fluorescent images captured during the experiments are digitally analyzed to determine the concentration of a fluorescent marker dye as it diffuses into tissue specimens taken from rat tumors. The collected concentration data are used to estimate local diffusion coefficients. An analysis of the distribution of the local diffusion data indicates that the local diffusion coefficient is spatially dependent within the tumor tissue. When mass transfer is restricted to one dimension, the current technique can be used to determine the concentration distribution of fluorescent molecules on the tissue surface and to estimate the mass transfer parameters within the heterogeneous tumor tissue.
The effects of variations in the venous valve anatomy are studied experimentally using an artificial system that mimics the bicuspid valves normally found in veins in the lower extremities. The ...artificial valves are constructed from thin‐walled, latex tubing and polyurethane film. The experimental variables in the study are the gap width between the leaflet attachments at the vein wall and the ratio of the sinus depth to vein diameter. The results show that the antegrade mass flow rate is not affected to the same degree when compared to retrograde flow by the various valve configurations examined in this study. The results also indicate that increases in the gap width, which serve to increase the degree of imperfect wall attachment, have less effect on retrograde mass flow rate in valves with deeper sinuses.
Several human milk oligosaccharides inhibit human pathogens in vitro and in animal models. In an infant, the ability of these oligosaccharides to offer protection from enteric pathogens would require ...that they withstand structural modification as they pass through the alimentary canal or are absorbed and excreted in urine. We investigated the fate of human milk oligosaccharides during transit through the alimentary canal by determining the degree to which breast-fed infants' urine and fecal oligosaccharides resembled those of their mothers' milk. Oligosaccharide profiles of milk from 16 breast-feeding mothers were compared with profiles of stool and urine from their infants. Results were compared with endogenous oligosaccharide profiles obtained from the urine and feces of age-, parity-, and gender-matched formula-fed infants. In all cases, oligosaccharides were extracted, purified, reduced, and separated into acidic and neutral species; the latter were perbenzoylated and subjected to reversed-phase high-performance liquid chromatography. Structures were determined by mass spectrometry after debenzoylation. Among breast-fed infants, concentrations of oligosaccharides were higher in feces than in mothers' milk, and much higher in feces than in urine. Urinary and fecal oligosaccharides from breast-fed infants resembled those in their mothers' milk. Those from formula-fed infants did not resemble human milk oligosaccharides, were found at much lower concentrations, and probably resulted from remodeling of intestinal glycoconjugates or from intestinal bacteria. Most of the human milk oligosaccharides survived transit through the gut, and some were absorbed and then excreted into the urine intact, implying that inhibition of intestinal and urinary pathogens by human milk oligosaccharides is quite likely in breast-fed infants.
Over a 10-year period, 276 pulmonary arteriovenous malformations (PAVMs) were occluded with balloon embolotherapy in 76 patients, 67 (88%) of whom had hereditary hemorrhagic telangiectasia. Eleven ...patients (14%) were discovered by means of family screening with measurement of arterial blood gases and chest radiography. Epistaxis, dyspnea, hemoptysis, and hemothorax occurred in 79%, 71%, 13%, and 9% of patients, respectively. Clinical histories of strokes and transient ischemic attacks were present in 18% and 37% of patients, respectively. Computed tomographic scans of 59 patients showed stroke in 36%. Sixty-five percent of PAVMs were located in the lower lobes, which correlated with the finding of more pronounced hypoxemia in the upright position. After embolotherapy, symptomatic hypoxemia was corrected, and serial values have remained constant for 5 years. Complications were minimal, and no patient required surgery. Balloon embolotherapy is effective long-term therapy for PAVMs, and family screening should be pursued because of the possibility of a higher frequency of paradoxical embolization (stroke) than previously recognized.
Two regions of cauliflower mosaic virus DNA were designed as markers to study pathogen transmission in a child care home (CCH) and child care center (CCC) and in homes of CCC children. The DNA ...markers were stable for 1 month in the environment. The DNA markers were introduced into the environment through sensitized objects, and spread in the environment was traced by detection of the markers with polymerase chain reaction. The DNA markers spread rapidly in both the CCH and CCC after introduction and spread more rapidly in the toddler room than in the infant room of the CCC. Hand touching of contaminated areas was the major factor leading to spread of the markers. Hand washing and surface wiping decreased spread of the markers. The markers spread minimally from room to room in the CCC but were detected in the children's homes after introduction of markers in the CCC.
The goal of the present study was to analyze long-term results of fractionated stereotactic radiotherapy (SRT) in patients with a meningioma. A total of 72 patients treated between 1996 and 2008 in ...MAASTRO clinic (n=45) and University Hospital Zurich (n=27) were included. SRT was given as primary treatment (n=46), postoperatively (n=19) or at recurrence (n=7); 49 tumours (68%) were located in the skull base. Median total dose was 54 Gy. Median follow-up was 4.13 years (range 0.66-11 years). The 3- and 5-year overall survival were 92 and 79% for grade 0 and I meningioma. Progression-free survival for grade 0 and I was 95% at 3 and 5 years, and 40% for grade II and III at 3 years. In 98.4% of patients, clinical symptoms were stable or improved. The majority of symptoms improved within 24 months after SRT. Local control is significantly better if patients are irradiated immediately after diagnosis compared to a watchful waiting policy (p=0.017). Grade IV toxicity was low (4.2%, n=3) SRT is an effective treatment with high local and clinical control. Early SRT resulted in better outcome than late treatment at progression.PUBLICATION ABSTRACT
To evaluate the role of energy state in pulmonary vascular responses to hypoxia, we exposed isolated pig lungs to decreases in inspired PO2 or increases in perfusate NaCN concentration. Lung energy ...state was assessed by 31P nuclear magnetic resonance spectroscopy or measurement of adenine nucleotides by high-pressure liquid chromatography in freeze-clamped biopsies. In ventilated lungs, inspired PO2 of 200 (normoxia), 50 (hypoxia), and 0 Torr (anoxia) did not change adenine nucleotides but resulted in steady-state pulmonary arterial pressure (Ppa) values of 15.5 +/- 1.4, 30.3 +/- 1.8, and 17.2 +/- 1.9 mmHg, respectively, indicating vasoconstriction during hypoxia and reversal of vasoconstriction during anoxia. In degassed lungs, similar changes in Ppa were observed; however, energy state deteriorated during anoxia. An increase in perfusate NaCN concentration from 0 to 0.1 mM progressively increased Ppa and did not alter adenine nucleotides, whereas 1 mM reversed this vasoconstriction and caused deterioration of energy state. These results suggest that 1) pulmonary vasoconstrictor responses to hypoxia or cyanide occurred independently of whole lung energy state, 2) the inability of the pulmonary vasculature to sustain hypoxic vasoconstriction during anoxia might be associated with decreased energy state in some lung compartment, and 3) atelectasis was detrimental to whole lung energy state.
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