The computation of fluid balances (FBs) by subtracting fluid outputs from inputs is a common critical care practice. Limited information exists about the accuracy and consistency of nurse-registered ...cumulative FBs and regarding the value of suggested corrections for non-measurable losses.
From 147 ICU patients, we prospectively evaluated the cumulative FBs and their relationship to changes in body weight (BW). Standardised measurements of BW were performed on admission and discharge. FB charts were accurately reviewed and arithmetic errors corrected. Net cumulative FBs and adjusted cumulative FBs (considering sensible or insensible fluid losses/fever/liquid faeces) were analysed for all patients and 3 subgroups (cardiac-cerebral, septic, and others). Agreement between FBs and BW changes was calculated according to the defined subgroups and confounding variables.
Cumulative FBs were inaccurate in 49 cases (33%) with errors ranging from -3606 mL to +2020 mL. The total (average daily) difference between measured BW and FBs (mean ± SD) was 0.185±1.874 kg (0.101±1.020 kg). Correlation (r(2)) and Bland-Altman agreement was poor between BW changes and net cumulative FBs (0.552 and -1.26±5.41 kg) and slightly better between BW changes and adjusted cumulative FBs (0.714 and +0.18±3.68 kg). Standard deviations of the average daily differences between BW changes and FBs were always >1 L. Correction of the net FBs as suggested in the literature were not useful. New multiple regression models only modestly improved correlation.
For a large portion of patients nurse-registered cumulative FBs are neither accurate nor do they agree with standardised BW measurements. Patient care and clinical decision-making should be based on more objective techniques.
Aims/hypothesis In vitro studies point to a toxic effect of high glucose and non-esterified fatty acids on beta cells. Whether elevated levels of glucose and lipids induce beta cell loss in vivo is ...less clear. The domestic cat has recently been proposed as a valuable animal model for human type 2 diabetes because feline diabetes shows several similarities with diabetes in humans, including obesity-induced insulin resistance, impaired beta cell function, decreased number of beta cells and pancreatic amyloid deposition. Methods We infused healthy cats with glucose or lipids for 10 days to clamp their blood concentrations at the approximate level found in untreated feline diabetes (glucose: 25-30 mmol/l; triacylglycerols: 3-7 mmol/l). Results Glucose and lipid levels were adequately targeted. Plasma non-esterified fatty acids were increased by lipid infusion 1.7-fold. A dramatic and progressive decline of plasma insulin levels was observed in glucose-infused cats beginning after 2 days of hyperglycaemic clamp. In contrast, plasma insulin concentration and glucose tolerance test were not affected by hyperlipidaemia. Compared with controls, glucose-infused cats had a 50% decrease in beta cells per pancreatic area. Apoptotic islet cells and cleaved caspase-3-positive beta cells were observed in glucose-infused cats only. Conclusions/interpretation Sustained hyperglycaemia but not hyperlipidaemia induces early and severe beta cell dysfunction in cats, and excess glucose causes beta cell loss via apoptosis in vivo. Hyperglycaemic clamps in cats may provide a good model to study the pathogenesis of glucose toxicity in beta cells.
Aims/hypothesis
Glucagon-like peptide-1 (GLP-1) receptors are highly overexpressed in benign insulinomas, permitting in vivo tumour visualisation with GLP-1 receptor scanning. The present study ...sought to evaluate the GLP-1 receptor status in vitro in other pancreatic disorders leading to hyperinsulinaemic hypoglycaemia, specifically after gastric bypass surgery.
Methods
Fresh frozen pancreatic tissue samples (
n
= 7) from six gastric bypass surgery patients suffering from hyperinsulinaemic hypoglycaemia were evaluated for GLP-1 receptor content using in vitro receptor autoradiography, and compared with normal pancreas and with pancreatic insulinoma tissues.
Results
GLP-1 receptor analysis of the pancreatic tissues, which histopathologically were compatible with nesidioblastosis and originated from post-bypass hypoglycaemic patients, revealed a mean density value of GLP-1 receptors in the islets of 1,483 ± 183 dpm/mg tissue. Pharmacological characterisation indicated the presence of specific GLP-1 receptors. The density of islet GLP-1 receptor in post-gastric bypass patients did not differ from that of normal pancreas (1,563 ± 104 dpm/mg tissue,
n
= 10). Receptor density in pancreatic acini was low in post-bypass and control conditions. In contrast, benign insulinomas showed a high density of GLP-1 receptors, with a mean value of 8,302 ± 1,073 dpm/mg tissue (
n
= 6).
Conclusions/interpretation
In contrast to insulinoma, hyperinsulinaemic hypoglycaemia after gastric bypass surgery is not accompanied by overexpression of GLP-1 receptor in individual islets. Thus, patients with post-gastric bypass hyperinsulinaemic hypoglycaemia are not candidates for GLP-1 receptor imaging in vivo using radiolabelled exendin. These GLP-1 receptor data support the notion that the islet pathobiology of post-gastric bypass hypoglycaemia is distinctly different from that of benign insulinomas.
A new mircoelectrochemical method was applied to perform potentiodynamic polarisation experiments on areas in the range of 10 μm. For the first time, the individual corrosion behaviour of both single ...phases in super duplex stainless steels was determined. The results show a good correlation with the empirical pitting resistance equivalent number (PREN) of the corresponding single phase. The microelectrochemical experiments have revealed two different kinds of interactions between the ferrite and the austenite phase at the phase boundary, namely a superposition or a separation of the two polarisation curves of the single phases.
Potentiodynamic polarisation of large areas with representative amounts of both phases are performed in hydrochloric acid electrolyte in order to compare the corrosion behaviour of the single phases with the corrosion behaviour of the entire alloy. Both, the pitting potentials, evaluated by means of macroelectrochemical experiments in pH-neutral lithium chloride electrolyte, and the critical crevice corrosion temperatures show a good correlation with the PREN of the weaker phase. Part I of this paper deals primarily with solution annealed materials. Solution annealing of the samples was performed at temperatures where minimal amounts of precipitates were formed and where the element partitioning determines the corrosion resistance of the single phases. Part II deals with the influence of precipitations on the corrosion behaviour.
Inappropriate heat treatment of super duplex stainless steels may cause the precipitation of undesired phases, which drastically decrease the corrosion resistance and which may also reduce the ...toughness.
The most important precipitates, namely sigma phase, chromium nitrides, and one type of secondary austenite are shortly described. Special attention is paid to their influence on the distribution of the main alloying elements, which is a crucial factor for the corrosion resistance.
A new microelectrochemical investigation method enables for the first time the local potentiodynamic measurements of areas in the range of 10 μm diameter and therefore reveals the influence of small precipitates on the corrosion resistance. The results are compared with macroelectrochemical measurements, critical crevice corrosion investigations and the element distribution. The depletion of chromium and molybdenum due to the formation of precipitates is related to a decrease in corrosion resistance.
Aims: The differentiation of adrenocortical carcinomas from adenomas may be difficult based on morphology alone. Differential expression of insulin‐like growth factor (IGF) II and cyclin‐dependent ...kinase (CDK) 4 has recently been described in these tumours. The aim of this study was to investigate the diagnostic usefulness of these markers immunohistochemically.
Methods and results: We examined 22 benign and 17 malignant adrenocortical tumours and compared IGFII and CDK4 expression with known immunohistochemical as well as morphological criteria of malignancy. Thirteen of 17 carcinomas showed immunohistochemical reactivity for IGFII, whereas all adenomas but one were negative. Intense CDK4 expression was detected in 11 of 17 carcinomas but was present in only three of 22 adenomas. The MIB1 index was > 5% in 14 of 16 carcinomas and was < 5% in all adenomas but one. The combination of IGFII immunohistochemistry with MIB1 index led to high sensitivity and specificity in detecting adrenocortical carcinomas.
Conclusions: IGFII and MIB1 are helpful immunohistochemical markers to predict malignancy in adrenocortical neoplasms. These markers can be used in addition to clinical, gross and morphological features to establish a diagnosis in difficult cases.
Background: Patients with a multiple endocrine neoplasia type 1 (MEN1)-associated Zollinger–Ellison syndrome (ZES) show multifocal duodenal gastrinomas and precursor lesions. Aims: To test these ...lesions for loss of heterozygosity (LOH) of the MEN1 gene locus on chromosome 11q13, and to investigate whether the MEN1-related endocrine cell changes also involved somatostatin cells. Material and methods: Tissue specimens from six patients with MEN1 and ZES were analysed by immunohistochemistry and immunofluorescence. LOH analysis was performed by fluorescence in situ hybridisation (FISH), using probes containing the MEN1 gene locus and the centromere 11 (C11) region. For simultaneous analysis of hormones and allelic deletions, a combined FISH/immunofluorescence protocol was established. Results: 28 of a total of 33 duodenal neuroendocrine tumours (NETs) were gastrin-producing tumours; 13/28 (46.4%) revealed LOH on 11q13 and/or C11. Five of the NETs were somatostatin-expressing tumours, two revealing LOH. Allelic loss was detected in tumours as small as 300 μm (gastrin) and 400 μm (somatostatin) in diameter. The gastrin-producing tumours showed different deletion/retention patterns. Hyperplastic somatostatin cell lesions, similar to those of the gastrin cells, were present in all patients. The hyperplastic lesions of both cell lines consistently retained both 11q13 alleles. Conclusions: Allelic deletion of the MEN1 gene may reflect a pivotal event in the development of multifocal gastrin and somatostatin cell neoplasms in the duodenum of patients with MEN1. The observation of distinct deletion patterns in small synchronous tumours supports the concept that each gastrin-producing tumour in an individual MEN1 patient arises from an independent cell clone.
Introduction: Therapeutic strategies to treat chronic pancreatitis (CP) are very limited. Other chronic inflammatory diseases can be successfully suppressed by selective cyclooxygenase 2 (COX-2) ...inhibitors. As COX-2 is elevated in CP, we attempted to inhibit COX-2 activity in an animal model of CP (WBN/Kob rat). We then analysed the effect of COX-2 inhibition on macrophages, important mediators of chronic inflammation. Methods: Male WBN/Kob rats were continuously fed the COX-2 inhibitor rofecoxib, starting at the age of seven weeks. Animals were sacrificed 2, 5, 9, 17, 29, 41, and 47 weeks later. In some animals, treatment was discontinued after 17 weeks, and animals were observed for another 24 weeks. Results: Compared with the spontaneous development of inflammatory injury and fibrosis in WBN/Kob control rats, animals treated with rofecoxib exhibited a significant reduction and delay (p<0.0001) in inflammation. Collagen and transforming growth factor β synthesis were significantly reduced. Similarly, prostaglandin E2 levels were markedly lower, indicating strong inhibition of COX-2 activity (p<0.003). If treatment was discontinued at 24 weeks of age, all parameters of inflammation strongly increased comparable with that in untreated rats. The correlation of initial infiltration with subsequent fibrosis led us to determine the effect of rofecoxib on macrophage migration. In chemotaxis experiments, macrophages became insensitive to the chemoattractant fMLP in the presence of rofecoxib. Conclusion: In the WBN/Kob rat, chronic inflammatory changes and subsequent fibrosis can be inhibited by rofecoxib. Initial events include infiltration of macrophages. Cell culture experiments indicate that migration of macrophages is COX-2 dependent.
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