Serum insulin and lipogenesis in the suckling ‘fatty’ fa/fa rat

Summary Preobese fatty fa/fa rats identified by their decreased rectal temperature were either given access to high carbohydrate chow or maintained on a suckling only diet till 20 days of age. Serum insulin, hepatic and adipose tissue fatty acid synthesis and lipogenic enzyme activities were low in suckling preobese fa/fa. In animals with access to chow diet, hepatic lipogenesis was unaltered, serum insulin rose to similar levels in lean and preobese fa/fa (lean 62±5; preobese 69±4 U/ml), but adipose tissue lipogenesis was increased to higher levels in the preobese than lean rats (lean 0.56±0.12; preobese 1.80±0.22 mol. tissue^-1. h^-1). The activities of glucose-6-phosphate dehydrogenase, acetyl coenzyme A carboxylase and fatty acid synthetase were increased in adipose tissue of preobese fa/fa rats. Neither streptozotocin treatment nor pretreatment with Triton WR 1339 abolished the difference in adipose tissue lipogenesis between lean and preobese fa/fa rats. Preobese fa/fa rats showed an enhanced insulin secretory response to a glucose load.     

A Three-dimensional Analysis of Blood Vessels in Bronchioloalveolar Carcinoma

The three-dimensional architecture of blood vessels within lung adenocarcinomas has not been well studied. In 19 cases with bronchioloalveolar carcinoma with central fibrosis, we three-dimensionally examined blood vessel architecture in 150 m thick sections stained with elastin staining and anti-CD34 antibody. We examined four regions: normal alveoli and three regions within the tumor including an area adjacent to the normal alveoli (external area), an area in which tumor cells were replacing epithelial cells (replacement area), and a central fibrotic area (fibrotic area). Elastin staining showed that elastic fibers formed the framework of the alveoli, and the alveolar structure shrank more strongly to the center of the tumor due to folding of alveolar walls invaded by adenocarcinoma cells. We also measured three vessel parameters in these four regions. The vessel diameters were 4.08±1.10 m, 3.95±1.02 m, 5.04±1.56 m, and 6.11±2.23 m, the circumferences of those vessels seen as complete circles were 43.11±12.78 m, 43.71±12.87 m, 95.21±39.32 m, and 126.77±54.65 m; the lengths between vessel bifurcations were 13.28±3.08 m, 13.47±4.58 m, 24.91±9.66 m, and 41.82±28.08 m in the normal alveoli, and the external, replacement, and fibrotic areas, respectively. Blood vessel architecture changed such that the vessels became larger and coarser towards the center of the tumor. Our three-dimensional analysis suggests continuous remodeling of alveolar capillaries rather than angiogenesis within bronchioloalveolar carcinoma.     

Lavage Administration of Dilute Surfactant in a Piglet Model of Meconium Aspiration

Maldistribution of exogenous surfactant may preclude any clinical response in acute lung injury associated with surfactant dysfunction. Our previous studies have shown the effectiveness of surfactant lavage after homogenous lung injury. The present study utilizes a histologically confirmed non-homogeneous lung injury model induced by saline lung-lavage followed by meconium injected into a mainstem bronchus. Piglets were then treated with Infasurf® or Exosurf® by lavage (I-LAVAGE, n=7; E-LAVAGE, n=5) or bolus (I-BOLUS, n=8; E-BOLUS, n=5), or went untreated (CONTROL, n=4). Lavage administration utilized a dilute surfactant (35 ml/kg; 4 mg phospholipid/ml) instilled into the lung, followed by gravity drainage. The retained doses of the respective surfactant in the lavage and bolus groups were similar. Results showed that the surfactant distribution was more uniform in the lavage groups compared to the bolus groups. Significant and consistent increases in PaO₂ were observed in the lavage groups compared to the bolus groups and the controls. PaO₂ (mmHg) at 240 min posttreatment: I-LAVAGE=297±54, E-LAVAGE= 280±57; I-BOLUS=139±31; E-BOLUS=152±29; C=119±73 (mean± SEM). Other improved pulmonary function parameters favored lavage administration. We conclude that better surfactant distribution achieved by lavage administration can be more effective than bolus administration in this type of non-homogeneous lung injury.     

Human cold agglutinins against “Cryptic” erythrocyte antigens

Summary Two examples of human IgM cold agglutinins agglutinated human RBC only after enzyme treatment in vitro. Proteases were optimally effective, neuraminidase was also effective. The cold agglutinins did not coat native RBC but were directed against cryptic RBC determinants. The cold agglutinins belonged to the anti -I/-i complex indicating a new type of I/i determinants. They were strongly accessible to cold agglutinin interaction on native RBC of a patient with congenital dyserythropoietic anaemia. Enzyme treatment of RBC was shown to be not only suited for defining cold agglutinin specificities but also essential for detecting the new type of cold agglutinins, obviously causing autoimmune haemolytic anaemia in vivo.     

Activation of Tumor Necrosis Factor-α System in Chronic Hepatitis C Virus Infection

Tumor necrosis factor- (TNF-)plays a central role in the host's immunomodulatoryresponse to infective agents. To evaluate theTNF- system in patients with chronic hepatitis Cvirus (HCV) infection, plasma, serum, and peripheral bloodmononuclear cells (PBMC) were prospectively collectedfrom 53 patients and 33 healthy control subjects.Circulating TNF- and TNF receptors were assayed by their respective enzyme immunoassays. Inaddition, TNF- mRNA was quantitated in PBMC usinga branched DNA assay, and production of TNF- byPBMC with and without lipopolysaccharide was also assessed. Patients with chronic HCV infectionhad a higher level of circulating TNF- comparedto healthy control subjects (9.62 ± 6.01 vs 3.66± 1.23 pg/ml, P < 0.001). They also had highercirculating levels of TNF receptors compared to control(CD120a: 3323 ± 1267, pg/ml, N = 49 vs 1855± 422 pg/ml, N = 33, P < 0.001; CD120b: 1290± 650 pg/ml, N = 51, vs 863 ± 207 pg/ml,N = 33, P < 0.001). Plasma TNF- level correlated with circulatingCD120a (r = 0.52, N = 49, P < 0.001) and weakly withCD120b (r = 0.32, N = 51, P = 0.02). Plasma TNF-also correlated with markers of hepatocellular injury, including ALT (r = 0.34, N = 53, P = 0.01) and-GST (r = 0.31, N = 43, P = 0.042), but not withserum HCV RNA levels. There was no difference in theTNF- mRNA levels in PBMC between patients with chronic HCV infection (1.4 ± 1.9units/106 cells, N = 8) and healthy control subjects(2.1 ± 1.4 units/106 cells, N = 8, P = NS). Therewas also no difference in the spontaneous production ofTNF- by PBMC (1 × 10⁶ cells/ml)between patients with chronic HCV infection (14.2± 36.5 pg/ml, N = 11) and healthy subjects (11.9± 14.0 pg/ml, N = 14, P = NS). However, patientswith chronic HCV infection produced more TNF- upon stimulation withlipopolysaccharide compared to healthy control subjects(1278 ± 693 pg/ml, N = 11, vs 629 ± 689pg/ml, N = 14, P < 0.05). These data indicate thatthe TNF- system is activated in patients with chronicHCV infection.     

Intracoronary hyperosmotic mannitol during reperfusion does not affect infarct size in ischemic,reperfused porcine hearts

Summary We investigated the effect of reperfusion with hyperosmotic mannitol on the infarct size in porcine hearts. The distal half of the left anterior descending coronary artery was occluded in each of 21 anesthetized pigs for 75 min and was reperfused for 2 h. During reperfusion mannitol (1075 mosmol/kg) was intracoronarily infused at a dose of 0.5 ml/min in 6 pigs (low mannitol group), at a dose of 1.5 ml/min in another 6 pigs (high mannitol group), and at a dose of 5 ml/min in 3 pigs for the first 8 min of reperfusion (very high mannitol group). 6 pigs served as controls. Although mannitol infusion increased plasma osmolality in the ischemic, reperfused myocardium in all experiments, the infarct size expressed as the ratio of the infarcted tissue over the area at risk of necrosis was not significantly influenced. Infarct size amounted to 72±25% in the control group, to 75±14% in the low mannitol group, to 78±18% in the high mannitol group, and to 93±8% in the very high mannitol group. These results clearly indicate that reperfusion with hyperosmotic mannitol after 75 min of ischemia does not exert any beneficial effect on the infarct size.     

Granulocyte Elastase in Cirrhotic Patients with Spontaneous Bacterial Peritonitis

Granulocyte elastase (GE) is a powerfulproteolytic enzyme that is released by PMNs whendegranulated in infectious processes. The aim of thisstudy was to measure GE in ascites and plasma ofcirrhotic patients with spontaneous bacterial peritonitis(SBP). We studied 29 cirrhotic patients, 17 of themhaving SBP (group A). Twelve patients with noninfectedascites formed the control group (group B). At the time of diagnosis of SBP, GE levels inascites (183.17 ± 86.11 g/liter) and plasma(114.6 ± 35.99 g/liter) were higher in groupA than in group B (27.41 ± 11.54 g/liter, P< 0.00001 and 82.54 ± 20.52 g/liter, P = 0.01,respectively). Levels of GE in ascites had a high valuefor discriminating between patients with and withoutSBP. In the patients who responded to the initialantibiotic treatment, these values significantly decreasedin ascites (67.69 ± 54.22 g/liter, P = 0.003)and plasma (67 ± 22.39 g/liter, P = 0.01) 48hr after therapy was started, in parallel with thedecrease of PMN in ascites. In patients who did notrespond, the production of GE remained elevated.Patients who developed renal insufficiency following SBPhad more marked elevation of GE in plasma (144.8± 33.43 g/liter) than those with normal renalfunction (99.5 ± 27.53 g/liter, P = 0.02).These results suggest that the measurement of GE may behelpful for the diagnosis of SBP in patients withcirrhosis and for assessing the efficacy of therapy. Inaddition, the release of GE into plasma may contributeto the impairment of renal function that follows SBP insome patients.     

Age-related Variations in the Neuroendocrine Control,More Than Impaired Receptor Sensitivity,Cause The Reduction in the GH-releasing Activity of GHRPs in Human Aging

The mechanisms underlying the reduction in the GH-releasing activity of GHRPs in aging are still unclear. Aim of our study was to verify in man whether age-related impairment of the neurohormonal control of GH secretion and/or receptor alterations are involved in the reduced GH response to GHRPs in aging. To this goal, in 16 normal elderly subjects (E, 66–81 yr) and 12 young controls (Y, 24–28 yr) we studied the effects of 1.0, 2.0 and 3.0 g/kg iv Hexarelin (HEX), a synthetic hexapeptide, or GHRH, as well as the interaction among HEX (2.0 g/kg), GHRH (2.0 g/kg) and arginine (ARG, 0.5 gr/kg) on GH secretion. In Y the GH response to increasing doses of HEX (1.0 vs. 2.0 vs. 3.0 g/kg; AUC0;v–120 ± SEM: 1728.4 ± 406.4 vs. 2265.9 ± 298.4 vs. 2934.3 ± 482.2 g//L/h, p < 0.05 for 1.0 vs. 2.0 g/kg) and GHRH (649.6 ± 111.4 vs. 792.2 ± 117.6 vs. 1402.6 ± 363.0 g/L/h) showed a progressive increase. Two g/kg HEX and 1 g/kg GHRH were the maximal effective doses. Similarly, in E the GH response to increasing doses of HEX (336.7 ± 50.0 vs. 742.8 ± 157.9 vs. 1205.1 ± 178.1 g/L/h, p < 0.05 for 1.0 vs. 2 g/kg, p < 0.001 for 1.0 vs. 3.0 g/kg and p < 0.03 for 2.0 vs. 3.0 g/kg) and GHRH (183.8 ± 27.3 vs. 260.9 ± 17.3 vs. 356.1 ± 46.3 g/L/h, p < 0.005 for 1.0 vs. 3.0 g/kg and p < 0.05 for 2.0 vs. 3.0 g/kg) showed a progressive increase. In E the GH response to 3 g/kg HEX or GHRH were clearly higher than those to 2 g/kg. However, at each dose the GH responses to HEX or GHRH in E were lower (p < 0.05) than those in Y. In Y the GH response to HEX + GHRH was synergistical (4259.2 ± 308.0 g/L/h, p < 0.05). ARG strikingly potentiated the GHRH-induced GH rise (2640.8 ± 273.6 g/L/h, p < 0.01) but not the HEX-induced one (2371.7 ± 387.2 g/L/h) as well as the synergistical effect of HEX and GHRH (4009.1 ± 360.8 g/L/h). In E the GH response to HEX and GHRH was still synergistical (1947.7 ± 306.0 g/L/h, p < 0.05) but these responses were lower than those in young (p < 0.01). On the other hand, in E ARG restored the GH response to GHRH (1858.9 ± 172.8 g/L/h, p < 0.01) and even those to HEX (2069.5 ± 528.7 g/L/h, p < 0.01) and HEX + GHRH (4406.0 ± 1079.2 g/L/h, p < 0.05). Our present results indicate that the impairment of GHRP and GHRH receptor activity may have a role in the reduction of the somatotrope responsiveness in aging. However, the age-related reduction in the GH-releasing activity of GHRPs seems mainly dependent on age-related variations in the neural control, i.e. concomitant GHRH hypoactivity and somatostatinergic hyperactivity.     

Effects of bile salts on plasma concentration of β-endorphin-like immunoreactivity in men

The effects of bile salts on the release of -endorphin-like immunoreactivity ( -END-LI) were investigated in men using a specific radioimmunoassay developed by the authors. Plasma -END-LI was determined after extraction by the acid-acetone method (recovery: 73±5%). Oral administration of 400 mg of sodium taurocholate caused a rise in plasma -END-LI from 9.9±0.5 pmol/liter to 21.3±1.2 pmol/liter after 30 min and 18.1 ±0.5 pmol/liter after 60 min, with return to the initial value after 90 min. Oral administration of chenodeoxycholic acid (CDCA) also increased plasma -END-LI from a basal level of 8.4±0.7 pmol/liter to 18.7±0.8 pmol/liter after 30 min. Oral administration of ursodeoxycholic acid (UDCA) increased plasma -END-LI from 7.3±0.3 pmol/liter to 30.6±0.2 pmol/liter after 30 min. In gel chromatography, the -END-LI released after UDCA administration separated into two components, which eluted in the same positions as human -lipotropin and human -endorphin, respectively. These results suggested that bile salts may participate the release of -END-LI.     

Selective A2A adenosine agonist ATL-146e attenuates acute lethal liver injury in mice

Background d-Galactosamine (GalN)/lipopolysaccharide (LPS)-induced liver injury is an experimental model of fulminant hepatic failure in which tumor necrosis factor- (TNF-) plays a pivotal role. We examined the effects of a highly selective adenosine A_2A receptor agonist (ATL-146e) on GalN/LPS-induced fulminant hepatic failure.Methods Mice were given an intraperitoneal dose of GalN (800mg/g body weight)/LPS (100ng/g body weight) with and without ATL-146e (0.01µg/kg) treatment. Liver injury was assessed biochemically and histologically. Also, TNF- levels in the serum were determined.Results The serum liver enzyme (ALT) level in vehicle-treated mice was 20960 ± 2800IU/ml and was reduced by 63% to 7800 ± 1670IU/ml by treatment with 0.01µg/kg per minute ATL146e, P < 0.05. Treatment with ATL-146e significantly reduced serum TNF- and greatly reduced inflammation assessed by histopathologic examination compared with control mice treated with GalN/LPS. ATL-146e also reduced lethality at 12h from 65% to 13%.Conclusion The present findings suggest that the highly selective adenosine A_2A receptor agonist (ATL-146e) prevents endotoxin-induced lethal liver injury by suppression of TNF- secretion.     

Gastric diversion or pylorus ligation for gastric mucosal integrity and acid secretion studies in the rat?

The advantages of gastric diversion over pylorus ligation in rat gastric mucosal integrity and acid secretion studies over 6 hr were investigated. Mucosal injury developed in 80% of pylorus-ligation controls. Atropine (5 mg/kg) or cimetidine (40 mg/kg) had no effect on this injury (2.9 mm²±0.9 and 2.8 mm²±0.7, respectively, vs 3.1 mm²±1, mean±sem, N=10; however vagotomy increased it (13.7 mm²±Pylorus-ligation H⁺ output was higher than that of gastric diversion (390.5 mol±54.8 vs 61 mol±2.5, mean±sem, N=10, P<0.001). Cimetidine (40 mg/kg) depressed H⁺ output of gastric diversion (21.3 mol±1.2 vs 61 mol±2.5, mean±sem, N=10, P<0.001), but not of pylorus ligation (424 mol±74.2 vs 390.5 mol±54.8, mean±sem, N=10). Vagotomy or atropine depressed pylorus-ligation H⁺ output (P<0.001), but each allowed an output (36.6 mol±5.5 and 120 mol±29, respectively, mean±sem, N=10) significantly (P<0.001) higher than that associated with it in gastric diversion (16 mol±1.4 and 17.1 mol±1.6, respectively, mean±sem, N=10). This study demonstrates that in the rat pylorus ligation, in contrast to gastric diversion, injures the gastric mucosa, stimulates H⁺ secretion, and overshadows the efficacy of antisecretory agents.     

Cellular ionic effects of insulin in normal human erythrocytes: a nuclear magnetic resonance study

Summary Elevated erythrocyte cytosolic free calcium, and suppressed free magnesium and pH values are associated with the hyperinsulinaemia and insulin resistance of hypertension, obesity, and Type 2 (non-insulin-dependent) diabetes mellitus. To determine the role of insulin in this process, we utilized ¹⁹F- and ³¹P-nuclear magnetic resonance spectroscopy to study the cellular ionic effects of insulin in vitro on normal human erythrocytes. Insulin elevated cytosolic free calcium levels in a dose- and time-dependent manner. The effect began at 10 U/ml, peaked at 200 U/ml, and continued at both the 500 U/ml and 1000 U/ml doses. At 200 U/ml, free calcium levels rose from 24.6±2.5 nmol/l to a peak value at 120 min of 66.4±11 nmol/l (p<0.05 vs basal), levels remaining elevated throughout the incubation (45.7±5.6 nmol/l at 60 min, and 47.9±9.1 nmol/l at 180 min, p<0.05 vs basal, respectively). Similarly, insulin also increased intracellular free magnesium at all time points (basal: 177± 11 mol/l; 60 min: 209±19 mol/l; 120 min: 206±22 mol/l; and 180 min: 202±12 mol/l; p<0.05 vs basal at all times). No insulin-induced changes in pH were observed. We conclude (i) that insulin in physiological concentrations may participate in regulating divalent cations in the mature human erythrocyte, (ii) that insulin per se cannot account for the previously described cellular ionic lesions of hypertension and diabetes, and (iii) that future clinical studies of cell ion metabolism should be conducted in the fasting state, be controlled for ambient circulating insulin levels, or both.     

A laser Doppler velocimetry study of the effect of hypoglycaemia on retinal blood flow in the minipig

Summary The effect of acute hypoglycaemia (plasma glucose <2.2mmol/l) on retinal venous blood flow in the minipig has been determined using bidirectional laser Doppler velocimetry and red free retinal photography. In six pigs the mean flow in a retinal vein increased from 19.3 (±2.8 SEM) l/min to 29.7 (±7.5) l/min during hypoglycaemia (p<0.05) with a return to 18.6 (±3.6) l/min when euglycaemia was restored. Retinal blood flow is affected by hypoglycaemia or its haemodynamic consequences.     

Analysis of lymphocyte subsets in patients with aplastic anemia before and during immunosuppressive therapy

Summary To define the contribution of T-lymphocyte subsets in the development of aplastic anemia (AA), T-cell subpopulations including T cells, T cells, and TCS1-positive T cells, were analyzed by cytophotometry in the peripheral blood (PB) and bone marrow (BM) of patients with AA before and after 6 weeks of therapy with anti-lymphocyte globulin (ALG), methylprednisolone, and cyclosporin A (CSA). In nine patients with AA a significant decrease of PB- and BM-derived T cells was observed after 6 weeks of therapy as compared with normal controls. At diagnosis, the CD4/CD8 ratio in PB and BM of the patients did not differ from the ratio in the control population; however, a reversed ratio (< 1) was present in PB as well as in BM after weeks of therapy. Interestingly, lymphocytes expressing the T-cell receptor (TCR) were significantly decreased both before (PB 1.2±0.1%; BM 0.8±0.1%) and after 6 weeks of therapy (PB 0.7±0.1%; BM 0.7±0.1%) as compared with healthy controls (PB 2.4±0.2%; BM 2.3±0.2%). However, the proportion of the -T-cell subpopulation expressing the TCS1 phenotype was markedly increased before (PB 42±3.5%; BM 31±3%) and especially after 42 days of therapy (PB 77±12%; BM 45±2%) as compared with that in normal subjects (PB 19±2%; BM 9.7±0.8%). At present, follow-up is under evaluation to correlate these findings with hematological response. The pathophysiological significance of the observed alterations within the T-cell subsets and especially the T-cell populations will require further functional analyses, in particular since TCS1-positive T cells exhibit autoimmunological capacity.Presented at the annual meeting of the German Society for Hematology and Oncology, 4–7 October 1992, Berlin     

Cholesterol and oxygenated cholesterol concentrations are markedly elevated in peripheral tissue but not in brain from mice with the Niemann–Pick type C phenotype

Niemann–Pick disease type C (NP-C) is a rare genetic disorder characterized by progressive neurodegeneration, frequent developmental delay and early death. Tissues of affected individuals accumulate large quantities of free cholesterol in lysosomes. Because cytotoxic oxygenated derivatives of cholesterol are known to form readily when cholesterol concentrations are elevated, we searched for these compounds in liver, kidney, spleen and brain from mice with the NP-C phenotype. In order of abundance, we identified 7- and 7-hydroxycholesterol, 5,6-epoxycholestan-3-ol, 4-hydroxycholesterol, cholest-4-en-3,7-diol and cholest-4-en-3,6-diol in most tissue samples. Cholesterol concentrations in affected mice were increased 3-fold in kidney and 7- to 8-fold in spleen and liver compared to controls (all p<0.001) but were unchanged in brain. Although oxysterol levels were markedly elevated in non-brain tissue, the oxysterol and cholesterol concentrations increased proportionally so that oxysterols expressed as percentage of total sterols were the same for all animals (0.34±0.19% averaged over all organs in affected animals vs 0.40±0.42% in control mice). In contrast to peripheral tissue, we could not detect any increase in either absolute or relative oxysterol levels in the brains of affected and control mice (49±61 vs 53±43 g/g wet weight and 0.45±0.52 vs 0.47±0.37%, respectively). Thus, brain sterols are normal in NP-C mice and it is unlikely that an accumulation of cytotoxic oxygenated derivatives of cholesterol could account for the progressive neuropathology seen in the disease.     

Hypomagnesaemia in Type 2 (non-insulin-dependent) diabetes mellitus is not corrected by improvement of long-term metabolic control

Summary Low levels of magnesium have frequently been reported in diabetes mellitus especially in poorly controlled Type 1 (insulin-dependent) diabetic patients. Furthermore hypomagnesaemia might contribute to insulin resistance in Type 2 (non-insulin-dependent) diabetes. As the influence of improved metabolic control on plasma magnesium levels is unknown in Type 2 diabetic patients we studied magnesium plasma levels in 50 patients 1) before, 2) one and 3) three months after the initiation of insulin therapy or intensified treatment with oral hypoglycaemic agents. Magnesium plasma levels were measured by a colorimetric method and were significantly reduced in diabetic patients compared to healthy control subjects (0.79±0.01 mmol/l vs 0.88±0.01 mmol/l; p<0.0001). Metabolic control was significantly improved as documented by reduced HbA_1C levels in both insulin-treated patients or the patients on oral hypoglycaemic agents (p<0.003). However, plasma magnesium levels remained unchanged during the follow-up in the insulin-treated group (10.79±0.02 mmol/l; 20.81±0.02 mmol/l; 30.79±0.01 mmol/l) as well as in the patients on oral hypoglycaemic agents (10.79±0.03 mmol/l; 20.78±0.02 mmol/ l; 30.84±0.04 mmol/l). This study shows that even marked improvement of glycaemic control does not correct hypomagnesaemia in Type 2 diabetes. We conclude that hypomagnesaemia might be related to the insulin-resistant state and that possible beneficial effect of chronic magnesium administration should be evaluated in these patients.     

Islet B-cell dysfunction and the time course of recovery following chronic overinsulinisation of normal rats

Summary Appropriate insulin therapy may preserve or improve islet B-cell function whereas the effects of overinsulinisation are unclear. Pancreatic islet B-cell function was therefore studied after overinsulinisation of normal rats for 4 weeks (fed blood glucose 2.2–4.5 mmol/l, controls 4.1–7.0 mmol/l). Insulin secretion was assessed by a 3-h hyperglycaemic clamp (10.0 mmol/l) performed 1, 48, and 120 h after insulin withdrawal (n=6 in each group). When the clamp was performed 1 h after insulin withdrawal, clamp insulin concentration was 1.6±0.1 g/l, compared to 9.3±1.0 g/l in control rats. The integrated area under the plasma insulin concentration curve was also significantly decreased (4.8±0.4 vs 20.3±2.2 g·l^–1·h^–1, p<0.001), but recovered to 9.4±1.0 g·l^–1·h^–1 after 48 h, and to 17.5±1.4 g·l^–1·h^–1 after 120 h. Pancreatic insulin contents were decreased at 1 h (6±1 g/g wet wt) and 48 h (54±12 g/g wet wt) but not at 120 h (221±30 g/g wet wt) after withdrawal (controls, 303±29 /g wet wt) and there was a strong relationship with pancreatic preproinsulin mRNA and the clamp insulin response. Thus, overinsulinisation with prolonged periods of low blood glucose concentrations impairs islet B-cell function, but is reversible over 5 days.     

Estimating lumbar bone mineral density from routine radiographs of the lumbar spine

Summary To evaluate the information content of lateral lumbar films with respect to bone mineral content, we compared reading criteria with values obtained by quantitative computed tomography (CT) of L1 at baseline and after 5 years. The highest correlations with mineral content were found for the criteria overall assessment of the vertebra, vertebral body density versus soft tissue, and amount of trabeculations. These three reading criteria yielded higher correlations with CT scores in subjects with lower body mass index. Changes in mineral content over the 5-year period could not be read adequately, the average difference representing only a loss of about 10% in the study subjects. We conclude that a rough estimate of bone density can be obtained from lateral radiographs which, in the presence of eventual risk factors for osteoporosis, may serve as an additional indication to timely bone densitometry with methods which allow precise short-term follow-up measurements.     

Sampling Airway Surface Liquid: Non-Volatilesin the Exhaled Breath Condensate

Exhaled breath condensate (EBC) samples contain molecules that have no appreciable vapor pressure; such molecules likely derive from droplets of airway fluid. We analyzed EBC gathered from a total of 62 healthy volunteers in order to quantify the volume of airway liquid that was the source of the non-volatiles; saliva was analyzed as a reference secretion. EBC urea averaged 0.52±0.12 mol/L (n=18), an 8,600-fold dilution from predicted blood urea nitrogen levels. Protein averaged 2.3±0.3 g/ml (n=31), three orders of magnitude less than in saliva (1.4±0.1 mg/ml, n=15). EBC ammonia was 6.6±0.6 mmol/L (1/15 that of saliva) and EBC ammonium ion was 0.90±0.19 mol/L, concentrations that are incompatible with an 8,600-fold dilution from a biological source. Thus, urea-derived dilution factors may be used to interpret EBC non-volatile molecules, but not EBC volatiles.     

Isolierung von freien Nucleotiden aus verschiedenen Geweben

Zusammenfassung In Erweiterung früherer Mitteilungen wird über den Gehalt des Flexner-Jobling-Carcinoms der Ratte an freien Nucleosidmono- und-polyphosphorsäureestern berichtet.Die vorliegenden Untersuchungen wurden zum Teil dankenswerter-weise durch denAnna-Fuller-Fund und dieDeutsche Forschungsgemeinschaft unterstützt.In der Arbeit werden folgenden Abkürzungen verwendet Ad Adenosin - AMP Adenosin-5-monophosphat - ADP Adenosin-5-diphosphat - ATP Adenosin-5-triphosphat - GMP Guanosin-5-monophosphat - GDP Guanosin-5-diphosphat - GTP Guanosin-5-triphosphat - CMP Cytidin-5-monophosphat - CDP Cytidin-5-diphosphat - CTP Cytidin-5-triphosphat - UMP Uridin-5-monophosphat - UDP Uridin-5-diphosphat - UTP Uridin-5-triphosphat - UDPA Uridin-5-diphosphat-N-acetylglucosamin - UDPG Uridin-5-diphosphat-glucose - UDPGa Uridin-5-diphosphat-galaktose - UDPGl Uridin-5-diphosphat-glucuronsäure - IMP Inosin-5-monophosphat - DPN Diphosphopyridinnucleotid - HS Harnsäure - RNS Ribonucleinsäure - DNS Desoxyribonucleinsäure - TPN Triphosphopyridinnucleotid Mit 19 TextabbildungenDer überwiegende Teil der dieser Arbeit zugrunde liegenden Versuche wurde 1952/53 im McArdle Memorial Laboratory, University of Wisconsin durchgeführt.