Esophageal intramural pseudodiverticulosis: a characteristically unusual path to diagnosis.
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Alcoholism↗
Biomedical subjects
N Roos
Publications and source records attributed to N Roos.
Gastrojejunal kinetics and the digestion of [15N]beta-lactoglobulin and casein in humans: the influence of the nature and quantity of the protein.
The evolution and luminal effects of different quantities of casein and beta-lactoglobulin were investigated in the upper jejunum of 35 volunteers who ingested 400 mL water with either beta-lactoglobulin or casein in either low or high doses (72.6 mmol N, Lbetalg; 71.7 mmol N, LCas; 368.2 mmol N, Hbetalg; 386.8 mmol N, HCas). The flow rate of the liquid effluents as well as the nitrogen movements were measured and the exogenous ([15N]) and endogenous nitrogen fractions analyzed in the upper jejunum after milk protein ingestion. The basal jejunal liquid flow rate (mL/min) was 3.88+/-1.84 and peaked in the 0-20 min period for water (9.92+/-3.72) and Lbetalg (7.27+/-3.08) and during the 20-40 min period for LCas (5.69+/-2.49), HCas (6.32+/-1.85), and Hbetalg (6.11+/-2.31). One hour after water, LCas, Lbetalg, Hbetalg, and HCas ingestion, 100%, 95%, 85%, 71%, but only 38% of the liquid phase of the meal were passed through the jejunum, respectively. The flow rate of the endogenous nitrogen was 12.93+/-5.22 mmol N/h before meal ingestion; remained unchanged after water, LCas or Hbetalg ingestion; but increased significantly (P<0.05) after Lbetalg and HCas ingestion. The net disappearance of exogenous nitrogen in the upper jejunum 240 min after HCas, Lbetalg, LCas and Hbetalg ingestion was 82.6+/-9.5%, 61.6+/-9.6%, 58.4+/-14.7%, and 44.7%+/-24.4%, respectively. The exogenous fraction of protein nitrogen recovered in the upper intestinal lumen represented 43.3% of the ingested Hbetalg nitrogen, but only 4.9% of the ingested HCas nitrogen. In conclusion, casein and beta-lactoglobulin present differences in both the intestinal kinetics of amino acid delivery and in the nature of the products in the intestinal lumen. These differences have to be taken into account from both nutritional and physiologic points of view for the utilization of these proteins in humans.
Adult↗
Density shift of endocytic vesicles induced by uptake of colloidal gold particles in rat hepatocytes.
The aim of this study was to demonstrate the influence of endocytosed asialoorosomucoid gold complexes (ASOR-Au10, 10 = diameter of gold particles) on the density of endocytic compartments in rat hepatocytes when fractionated on linear sucrose gradients. We show that by loading hepatocytes with ASOR-Au10 for different time intervals, organelles containing gold particles are denser than organelles containing unconjugated asialoorosomucoid (ASOR). This density shift was observed in endosomes, which were loaded with a short pulse (15 minutes) of ASOR- Au10. Also lysosomes, loaded with ASOR-Au10 for 120 minutes at 37 degrees C, display a similar density shift.
Animals↗
Inhibition of asialoglycoprotein endocytosis and degradation in rat hepatocytes by protein phosphatase inhibitors.
In isolated rat hepatocytes, a radiolabelled tyramine-cellobiose conjugate of asialo-orosomucoid, 125I-TC-AOM, was rapidly taken up by receptor-mediated endocytosis and proteolytically degraded in the lysosomes, where radioactive degradation products accumulated. Okadaic acid and other protein phosphatase inhibitors (microcystin-LR, calyculin A) strongly reduced the fraction of asialoglycoprotein (ASGP) receptors localized to the cell surface, and correspondingly inhibited the uptake of 125I-TC-AOM. In addition, the inhibitors suppressed 125I-TC-AOM degradation strongly (90% at 150 nM) and potently (half-maximal effect at 20 nM okadaic acid), indicating an involvement of protein phosphorylation, and of a protein phosphatase of type 2A, in the regulation of intracellular endocytic flux. The effects of okadaic acid on 125I-TC-AOM accumulation, as well as on degradation, could be eliminated by the protein kinase inhibitor genistein. Okadaic acid prevented the transfer of 125I-TC-AOM to a non-recycling endocytic compartment, causing its retention in a recycling compartment from which about one-third of the endocytosed 125I-TC-AOM could be returned to the cell surface and detached from its receptor in the presence of EGTA. ASGP receptors recycled extensively both in the presence and absence of okadaic acid, as indicated by a sustained uptake of 125I-TC-AOM. Sucrose density gradient analysis and sedimentation studies indicated that okadaic acid caused accumulation of 125I-TC-AOM in light endosomes (1.11 g/ml), preventing its transfer to dense endosomes (1.14 g/ml) and lysosomes (1.18 g/ml). The lysosomes could be identified in density gradients by their contents of lysosomal marker enzymes and acid-soluble radioactivity, and by their sensitivity towards the lysosome-disrupting agent glycyl-L-phenylalanine-2-naphthylamide. By using endocytosed AOM-gold particles as an ultrastructural endocytic marker, it could be shown that the light endosomes accumulating ASGP in the presence of okadaic acid had the morphological appearance of small endocytic vesicles/tubules and multivesicular endosomes. Whereas in control cells 4% of the AOM-gold was in small vesicles/tubules, 55% in multivesicular endosomes and 41% in lysosomes, the corresponding figures for okadaic acid-treated cells were 17%, 73% and 11%. Our results thus indicate that protein phosphatase inhibitors have two effects on ASGP endocytosis: (1) an early inhibition of ligand uptake, due to a reduction in the fraction of ASGP receptors at the cell surface, and (2) an inhibition of ASGP transfer from a recycling compartment consisting of light, small endocytic vesicles and multivesicular endosomes, to a non-recycling compartment consisting of dense multivesicular endosomes.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Housing subsidies and pediatric undernutrition.
OBJECTIVE: To test the hypothesis that receipt of housing subsidies by poor families is associated with improved nutritional status of their children. DESIGN: Cross-sectional study. SETTING: Pediatric emergency department of an urban municipal hospital. PATIENTS: Convenience sample of 203 children younger than 3 years and their families who were being seen during one of twenty-seven 24-hour periods. MAIN OUTCOME MEASURES: Anthropometric indicators (z scores of weight for age, weight-for-height, and height-for-age), and the proportion of children with low growth indicator (weight-for-height below the 10th percentile or height-for-age below the fifth percentile, or both, of the reference population). RESULTS: Multivariate analysis controlling for demographics and program participation showed that receipt of housing assistance contributed significantly to z scores for weight-for-age (P = .03) and weight-for-height (P = .04). The risk of a child's having low growth indicators was 21.6% for children whose families were on the waiting list for housing assistance compared with 3.3% for those whose families received subsidies (adjusted odds ratio = 8.2, 95% confidence interval = 2.2 to 30.4, P = .002) CONCLUSION: Receiving a housing subsidy is associated with increased growth in children from low-income families, an effect that is consistent with a protective effect of housing subsidies against childhood undernutrition.
Child Nutrition Disorders↗
Involvement of early and late lysosomes in the degradation of mannosylated ligands by rat liver endothelial cells.
The intracellular transport and degradation of endocytosed mannosylated albumin (Man-BSA) was studied in cell cultures of rat liver endothelial cells by subcellular fractionation, fluorescence microscopy, and electron microscopy. The ligand used for subcellular fractionation experiments was labeled with 125I-labeled tyramine cellobiose or 131I-labeled tyramine cellobiose. The labeled degradation products are trapped in the degradative compartments and may therefore serve as markers for these compartments. Cell fractionation was performed using Nycodenz gradients. The cell fractionation experiments demonstrated that the ligand sequentially occupied three compartments of increasing density. After 15 min it was mainly found in large cisternal organelles that banded in the gradient at about 1.09 g/ml. These organelles were rab5 positive and showed a peripher distribution in the fluorescence microscope. Degradation of ligand started after 30-60 min and this coincided with its transfer to a electron lucent vesicle with a density of 1.12 g/ml. After > 1 h, degradation products started to accumulate in perinuclear, electron-dense lysosomes that banded in the gradient at 1.15 g/ml. The density distribution of lysosomal beta-acetylglucosaminidase coincided with the densest organelle. The results obtained show that the degradation of ligand takes place sequentially in two types of lysosomes. The early lysosome is an electronlucent vesicle of low density, whereas the terminal lysosome is an electron-dense organelle with higher density and a more perinuclear distribution. The main degradation of the ligand takes place in the early lysosome. The transfer of ligand and degradation products from the early to the late lysosome is slow. Texas red-labeled ovalbumin (OVA) coincided with lysosomes labeled with OVA-Bodipy 24 h in advance only after 4-6 h.
Animals↗
Ultrastructural and immunocytochemical characterization of autophagic vacuoles in isolated hepatocytes: effects of vinblastine and asparagine on vacuole distributions.
The interactions between the autophagic and the endocytic degradation pathways were investigated by means of immunogold labeling of autophagic vacuoles (AVs) in ultrathin frozen sections from isolated rat hepatocytes. AVs were identified by their autophagocytosed contents of the degradation-resistant cytosolic enzyme CuZn-superoxide dismutase (SOD). Another cytosolic enzyme, carbonic anhydrase (CAIII), was rapidly degraded in the lysosomes, making the vacuolar CAIII/SOD ratio useful as a rough indicator of the progress of autophagic-lysosomal degradation. Lysosomes could be recognized by the presence of the lysosomal membrane glycoprotein lgp120, which was absent from hepatocytic endosomes. Endocytic inputs into the AVs were detected by the presence of gold-conjugated bovine serum albumin (BSA-gold), taken up by fluid-phase endocytosis. All vacuoles recognized morphologically as AVs were SOD-positive, as were essentially all of the lysosomes (96%). The majority (72%) of the lysosomes also labeled positively for BSA within 2 h of endocytosis. The data are thus compatible with the notion that all lysosomes can engage in both autophagic and endocytic degradation. Lgp120 appeared to distinguish well between lysosomes and nonlysosomal AVs: the lgp120-negative AVs (nonlysosomes) had a CAIII/SOD ratio identical to that of the cytosol, indicating that no degradation had occurred. In the lgp120-positive AVs (lysosomes), the ratio was only 43% of the cytosolic value, consistent with substantial CAIII degradation. Among the nonlysosomal AVs (about one-third of all AVs), one-half were BSA-positive, suggesting that early AVs (autophagosomes) and suggesting that early AVs (autophagosomes) and intermediary AVs (amphisomes) that had fused with endosomes were equally abundant. These morphological data thus support previous biochemical evidence for a prelysosomal meeting of the autophagic and endocytic pathways. The microtubule inhibitor vinblastine inhibited the autophagic influx to the lysosomes, causing an accumulation of autophagosomes and a reduction in average lysosomal size. Vinblastine also inhibited the endocytic flux, thereby precluding the formation of amphisomes and of BSA-positive lysosomes. High concentrations (20 mM) of asparagine induced swelling of amphisomes and of BSA-positive lysosomes, probably reflecting an acidotropic effect of ammonia generated by asparagine deamination. Asparagine also caused an accumulation of autophagosomes, amphisomes, and BSA-negative lysosomes, presumably as a result of impaired fusion with the swollen BSA-positive lysosomes. The two agents thus appear to perturb the autophagic-endocytic-lysosomal vacuole dynamics by different mechanisms, making them useful in the further study of these complex organelle interactions.
Animals↗
Pulmonary fungal infections in patients with hematological malignancies--diagnostic approaches.
In a retrospective study of 56 patients with hematological malignancies and fungal pneumonia we have analyzed the value of different diagnostic procedures. In all patients (Candida n = 29, Aspergillus n = 23, mixed fungal infection n = 4) bronchoscopy and/or high-resolution computed tomography of the lungs was performed. Cultural detection of fungi in bronchoalveolar lavage was successful in 23/32 Candida and 11/23 Aspergillus pneumonias. Other relevant pathogens were identified by bronchoscopy in 21 cases. Thorax CT scans showed diagnostic evidence of fungal pneumonia in 10/13 Candida and in 16/18 Aspergillus infections. Blood cultures were positive in 9/33 Candida pneumonias and in none of aspergillosis cases. Serological testing and surveillance cultures had only limited value for the early diagnosis of pulmonary mycosis. Our data suggest that bronchoscopy and high resolution CT scans are mutually complementary diagnostic tools with high sensitivity in patients with hematological malignancies and new pulmonary infiltrates. These procedures facilitate the early and reliable recognition of invasive fungal disease which may have a bearing on the initiation, length, and differential therapy of antimycotic drugs.
Adolescent↗
Exogenous and endogenous nitrogen flow rates and level of protein hydrolysis in the human jejunum after [15N]milk and [15N]yoghurt ingestion.
Milk and yoghurt proteins were 15N-labelled in order to measure the flow rate of exogenous N during digestion in the human intestine. After fasting overnight, sixteen healthy volunteers, each with a naso-jejunal tube, ingested either [15N]milk (n 7) or [15N]yoghurt (n 9). Jejunal samples were collected every 20 min for 4 h. A significant stimulation of endogenous N secretion was observed during the 20-60 min period after yoghurt ingestion and the 20-40 min period after milk ingestion. The endogenous N flows over a 4 h period did not differ between the groups (44.3(SEM 6.5) mmol for milk and 63.5(SEM 5.9) mmol for yoghurt). The flow rates of exogenous N indicated a delayed gastric emptying of the yoghurt N compared with N from milk. The jejunal non-protein N (NPN) flow rate increased significantly after milk and yoghurt ingestion due to an increase in the exogenous NPN flow rate. The NPN fraction of exogenous N ranged between 40 and 80%. The net gastro-jejunal absorption of exogenous N did not differ significantly between milk (56.7(SEM 8.5)%) and yoghurt (50.9(SEM 7)%). The high level of exogenous N hydrolysis is in accordance with the good digestibility of milk products. Fermentation modifies only the gastric emptying rate of N and does not affect the level of diet hydrolysis, the endogenous N stimulation or the digestibility rate.
Adult↗
15N-labeled immunoglobulins from bovine colostrum are partially resistant to digestion in human intestine.
To evaluate true ileal digestibility of bovine immunoglobulins, seven healthy human adults ingested a 15N-labeled preparation of an immunoglobulin concentrate. After fasting overnight, subjects drank 400 mL of immunoglobulin concentrate (77 mmol), and ileal effluents were collected for 8 h at 20-min intervals using a naso-intestinal intubation technique. In addition to osmolality and pH, the concentrations of exogenous and endogenous nitrogen and ions (Na+, K+, Cl-, Ca2+, Mg2+) in the effluents were measured. Bovine immunoglobulin concentrations (IgG, IgM, IgA) were estimated by a radial immunodiffusion technique. The mean flow rate of the liquid phase was 22.3 +/- 6.1 mL/20 min and did not vary significantly during the collection period. No change was observed for osmolality, pH or Na+, K+ and Cl- concentrations. Two hours after meal ingestion, Ca2+ and Mg2+ concentrations increased significantly (P < 0.05). The recoveries of nitrogen of ingested IgG and IgM still immunologically active were 19 +/- 3% and 19 +/- 4%, respectively. No IgA was detected in the ileum. Mean digestibility of the exogenous nitrogen fraction was 79 +/- 3%. In comparison to literature data, which show that other milk proteins have ileal digestibilities of > 90%, our results demonstrate a lower ileal digestibility of bovine immunoglobulins in humans.
Adult↗
Pulmonary infiltrates in patients with haematologic malignancies: clinical usefulness of non-invasive bronchoscopic procedures.
In a prospective study 90 patients with haematologic malignancies (57 acute leukaemias, 6 Hodgkin's Diseases, 15 Non-Hodgkin Lymphomas, 12 other diseases), with fever exceeding 38.4 degrees C and newly developed pulmonary infiltrates underwent bronchoscopy obtaining bronchoalveolar lavage, bronchial washings and protected brush specimen (n = 71). Pneumonias due to gram-negative bacteria (n = 38) and fungi (n = 34) were most frequent. Bronchoscopic specimens yielded 226 isolates (2 different organisms/bronchoscopy on average). 112 organisms were finally regarded as causing pneumonia. Sensitivity of bronchoscopy in diagnosing infectious episodes was 66%, but only 4 out of 13 non-infectious pulmonary infiltrates could be identified. Bronchoscopy was most effective in the diagnosis of pneumocystis carinii and herpes virus pneumonia, whereas sensitivity and specificity of detecting fungal and bacterial pneumonia were low. Empirical antimicrobial therapy was verified by evaluation of bronchoscopic samples in 25 out of 90 cases. Empirical therapy was successfully changed according to the results of invasive samplings in 34 out of 90 cases. Early identification of causative pathogens had a significant impact on survival.
Adolescent↗
Pulmonary aspergillosis: early diagnosis improves survival.
Bronchoscopy obtaining bronchoalveolar lavage (BAL) fluid and bronchial secretions (BS) and/or high-resolution computed tomography (CT) of the lungs were performed in 33 patients with pulmonary aspergillosis from 1987 to 1992. The sensitivity of BAL fluid or BS for detecting histologically proven fungal disease was 33 and 50%, respectively, whereas positive serologies were only documented in 8% of the cases. CT scans contributed to the early diagnosis of opportunistic fungal pneumonia: characteristic CT signs were found in 16 of 19 episodes. The more frequent use of bronchoscopy and CT scans between 1990 and 1992 compared to 1987-1989 for the differential diagnosis of new pulmonary infiltrates resulted in earlier appropriate treatment. The average introduction of intravenous (i.v.) antifungal therapy after the onset of pneumonia was shifted from 12 to 7 days (p < 0.05). The timely implementation of i.v. antimycotic therapy had a significant impact on survival. Initiation of antifungal treatment later than 10 days after the onset of pneumonia resulted in a mortality of 90%, as opposed to 41% with an earlier start of antimycotics (p < 0.01). The earlier use of appropriate antifungal therapy in the second treatment period improved survival from 33 to 50% (NS). Bronchoscopy and high-resolution CT scans are mutually complementary diagnostic tools and should be performed as early as possible in the course of pneumonia for patients at high risk for aspergillosis.
Adolescent↗
[Pulmonary varicose veins. Case report and review of the literature].
Pulmonary varicosis is a rare, presumably congenital localized dilatation of a pulmonary vein which is often associated with cardiac disease. We describe a case featuring enlargement of a pulmonary varix after mitral valve replacement, caused by mitral regurgitation, and discuss diagnostic possibilities, differential diagnosis and various development of this vascular malformation. A detailed review of the literature is given.
Adolescent↗
Using administrative data to describe casemix: a comparison with the medical record.
We compared the coding of comorbid conditions in an administrative database to that found in medical records for 485 men who had undergone a prostatectomy. Only a few specific conditions showed good agreement between charts and claims. Most showed poor agreement and appeared more frequently in the chart. A comorbidity index calculated from each of these sources was used to explore the differences in mortality for patients who had undergone transurethral vs open prostatectomy. The claims-based comorbidity index most often underestimated the index from the chart. Proportional hazards analysis showed that models including either comorbidity index were better than those without an index and models with information from both indices were best. No analysis eliminated the effect of type of prostatectomy on long-term mortality. Claims-based measures of comorbidity tend to underrepresent some conditions but may be an acceptable first step in controlling for differences across patient populations.
Comorbidity↗
Antibody penetration into LR-White sections.
The purpose of this investigation is to study the ability of antibodies to penetrate sections of LR-WHITE resin. The methods used in this study were the following: (1) Reembedding of sections labeled with immunogold (1 nm) and peroxidase/DAB/gold chloride, (2) tilting of ultrathin sections treated with immunogold (1 nm), (3) immunolabeling of cylindrical structures embedded in LR-WHITE, (4) application of primary and secondary antibodies on opposite sides of ultrathin sections. Fibrin and human pituitary tissue was embedded in LR-WHITE and treated with anti-fibrinogen or anti-ACTH respectively (ACTH = Adrenocorticotropic hormone). No indication of antibody penetration into the section were found with either of the methods, contrary to findings in earlier publications. The significance of this result is that antigens cannot be demonstrated in the interior of LR-WHITE sections with post-embedding techniques. Furthermore, LR-WHITE resin may be used for quantitative immunoelectron microscopy, and the resin may be used for double immunogold labeling since the application of immunoreagents on opposite sides of the sections is completely safe.
Acrylic Resins↗
Gastric emptying regulates the kinetics of nitrogen absorption from 15N-labeled milk and 15N-labeled yogurt in miniature pigs.
Thirty-six miniature pigs divided into two groups of 18 animals were fed 15N-labeled milk or yogurt. Polyethylene glycol 4000 was added to the diets as a non-absorbable marker of the liquid phase. Animals were slaughtered 1, 2, 4, 8 and 12 h after meal ingestion, and the gastrointestinal tract was removed and divided into 10 parts. Polyethylene glycol, total nitrogen and 15N enrichment were measured in the digesta. Both the intestinal delivery of the liquid phase and the nitrogenous fraction of the chyme were delayed more in pigs fed yogurt than in pigs fed milk. No stimulatory effect of diet ingestion on endogenous nitrogen secretion was found. Both milk proteins and yogurt proteins were highly digestible: 93% of the exogenous nitrogen disappeared 12 h after feeding. The kinetics of exogenous nitrogen delivery into the intestine was correlated (r = 0.999 for milk and r = 0.974 for yogurt) with that of exogenous nitrogen absorption. These results suggest that milk proteins are rapidly absorbed after they reach the intestine. Gastric emptying is a major factor controlling the kinetics of milk nitrogen absorption.
Animals↗
Labeling with 15N as compared with homoarginine suggests a lower prececal digestibility of casein in pigs.
Calculations of prececal protein digestibility based on the stable isotope 15N and the chemical label homoarginine were compared, using casein doubly-labeled with both markers. After food was withheld overnight 24 miniature pigs were given a meal containing 15 g/100 g casein, including 4 g/100 g doubly-labeled protein, and chromic oxide as an indigestible marker. The intestine of eight animals each was removed 3, 6 or 12 h later, divided into 3 sections of equal length, and chyme was collected. Kjeldahl-N, 15N and homoarginine were determined in diet and chyme. Digestibility of casein in the distal third of the small intestine was 93.5 +/- 0.5% and 97.6 +/- 0.3% (P < 0.05) according to 15N and homoarginine label, respectively. Potential causes for this systematic difference were assessed. The data suggest that incorporation of 15N into endogenous proteins and re-entry into the intestinal lumen via secreta and desquamations is the major cause for the 4.2 +/- 0.4% lower digestibility based on the 15N as compared with the homoarginine labeling technique. A preferential occurrence of homoarginine in more easily digestible sections of the protein, faster release during the digestive process and absorption of homoarginine, or incorporation of 15N into proteins of intestinal bacteria are less likely to cause this difference.
Animals↗
True exogenous and endogenous nitrogen fractions in the human jejunum after ingestion of small amounts of 15N-labeled casein.
The purpose of this work was to determine exogenous and endogenous contributions to the overall nitrogen flux in the upper jejunum in humans. After the ingestion of water or 8 g of [15N]casein, the behavior of gastro-jejunal nitrogen and electrolyte (Na+, K+, Cl-) movements were studied in seven volunteers using the "slow marker" perfusion technique. The jejunal flow-rate of the chyme peaked during 0-20 min and 20-40 min periods following water and casein ingestion, respectively. Osmolarity, Cl- and Na+ concentrations decreased significantly (P < 0.05) during the first 20 min following meal ingestion and returned to the basal levels in the 20-60 min period. The gastric half-emptying times (min) of the liquid phase differed significantly (P < 0.05) for water (7.9 +/- 0.4) and casein (21.4 +/- 9.1). The basal flow rate of endogenous nitrogen was 9 +/- 3.3 mmol/h in the jejunum. After casein ingestion, the total nitrogen content reached maximum values in the 20-40 min period and then progressively returned to the initial level. The gastro-jejunal casein absorption was 58% and the remaining amount of casein in the jejunum was degraded more than 80% to alcohol-soluble compounds. After the ingestion of a low amount of casein no significant increase in the endogenous nitrogen fraction was observed. The 15N-dilution technique is an appropriate method in humans for the direct measurement of endogenous and exogenous contributions to the intestinal nitrogen fraction.
Adult↗