Application of an Arbitrary Lagrangian-Eulerian Method to Modelling the Machining of Rigid Polyurethane Foam

Rigid polyurethane (PUR) foam, which has an extensive range of construction, engineering, and healthcare applications, is commonly used in technical practice. PUR foam is a brittle material, and its mechanical material properties are strongly dependent on temperature and strain rate. Our work aimed to create a robust FE model enabling the simulation of PUR foam machining and verify the results of FE simulations using the experiments' results. We created a complex FE model using the Arbitrary Lagrangian-Eulerian (ALE) method. In the developed FE model, a constitutive material model was used in which the dependence of the strain rate, damage initiation, damage propagation, and plastic deformation on temperature was implemented. To verify the FE analyses' results with experimentally measured data, we measured the maximum temperature during PUR foam drilling with different densities (10, 25, and 40 PCF) and at various cutting speeds. The FE models with a constant cutting speed of 500 mm/s and various PUR foam densities led to slightly higher Tmax values, where the differences were 13.1% (10 PCF), 7.0% (25 PCF), and 10.0% (40 PCF). The same situation was observed for the simulation results related to various cutting speeds at a constant PUR foam density of 40 PCF, where the differences were 25.3% (133 mm/s), 10.1% (500 mm/s), and 15.5% (833 mm/s). The presented results show that the ALE method provides a good match with the experimental data and can be used for accurate simulation of rigid PUR foam machining.

Experimental Measurements of Mechanical Properties of PUR Foam Used for Testing Medical Devices and Instruments Depending on Temperature, Density and Strain Rate

Rigid polyurethane (PUR) foam is products used as a biomedical material for medical device testing. Thermal stability is a very important parameter for evaluating the feasibility of use for testing surgical instrument load during drilling. This work aimed to perform experimental measurements to determine the dependence of the mechanical properties of a certified PUR on temperature, strain rate and density. Experimental measurements were realised for three types of the PUR samples with different density 10, 25 and 40 pounds per cubic foot. The samples were characterised in terms of their mechanical properties evaluated from tensile and compression tests at temperatures of 25 °C, 90 °C and 155 °C. Furthermore, the structures of the samples were characterised using optical microscope, their thermal properties were characterised by thermogravimetric analysis, and their density and stiffness with the effect of temperature was monitored. The results show that it is optimal not only for mechanical testing but also for testing surgical instruments that generate heat during machining. On the basis of experimental measurements and evaluations of the obtained values, the tested materials are suitable for mechanical testing of medical devices. At the same time, this material is also suitable for testing surgical instruments that generate heat during machining.

Prospective evaluation of contrast-enhanced ultrasound of breast BI-RADS 3-5 lesions

BACKGROUND

To determine the benefit of contrast-enhanced ultrasound (CEUS) in the assessment of breast lesions.

METHODS

A standardized contrast-enhanced ultrasound was performed in 230 breast lesions classified as BI-RADS category 3 to 5. All lesions were subjected to qualitative and quantitative analysis. MVI (MicroVascular Imaging) technique was used to derive qualitative analysis parameters; blood perfusion of the lesions was assessed (perfusion homogeneity, type of vascularization, enhancement degree). Quantitative analysis was conducted to estimate perfusion changes in the lesions within drawn regions of interest (ROI); parameters TTP (time to peak), PI (peak intensity), WIS (wash in slope), AUC (area under curve) were obtained from time intensity (TI) curves. Acquired data were statistically analyzed to assess the ability of each parameter to differentiate between malignant and benign lesions. The combination of parameters was also evaluated for the possibility of increasing the overall diagnostic accuracy. Biological nature of the lesions was verified by a pathologist. Benign lesions without histopathological verification (BI-RADS 3) were followed up for at least 24 months.

RESULTS

Out of 230 lesions, 146 (64%) were benign, 67 (29%) were malignant, 17 (7%) lesions were eliminated. Malignant tumors showed statistically significantly lower TTP parameters (sensitivity 77.6%, specificity 52.7%) and higher WIS values (sensitivity 74.6%, specificity 66.4%) than benign tumors. Enhancement degree also proved to be statistically well discriminating as 55.2% of malignant lesions had a rich vascularity (sensitivity 89.6% and specificity 48.6%). The combination of quantitative analysis parameters (TTP, WIS) with enhancement degree did not result in higher accuracy in distinguishing between malignant and benign breast lesions.

CONCLUSIONS

We have demonstrated that contrast-enhanced breast ultrasound has the potential to distinguish between malignant and benign lesions. In particular, this method could help to differentiate lesions BI-RADS category 3 and 4 and thus reduce the number of core-cut biopsies performed in benign lesions. Qualitative analysis, despite its subjective element, appeared to be more beneficial. A combination of quantitative and qualitative analysis did not increase the predictive capability of CEUS.

Study of Different Printing Design Type Polymer Samples Prepared by Additive Manufacturing

3D printing is one of the most progressive additive technologies today. It finds its application also in industry. In terms of mechanical properties, the printing design of the product is an important parameter. The presented study investigates the effects of the printing design of a thin-walled 3D polymer model on the mechanical properties of the model. The material used for printing was acrylonitrile-butadiene-styrene (ABS) and the 3D print method was Fused Deposition Modeling (FDM). ABS was tested at various die temperatures and with various printing designs at a constant 3D print speed and identical print bed temperature. We examined the effect of printing temperature and product printing design on the resulting mechanical properties. We compared theoretical and experimental results by CAE–FEM Advanced Simulation modules. Results tensile deformations at maximum load by experiment and simulations are comparable. The best results of testing the mechanical properties were found in the pattern printed at a 45° angle at temperature 285 °C.

Activation of Adenylyl Cyclase Causes Stimulation of Adenosine Receptors

BACKGROUND/AIMS

Signaling of Gs protein-coupled receptors (GsPCRs) is accomplished by stimulation of adenylyl cyclase, causing an increase of the intracellular cAMP concentration, activation of the intracellular cAMP effectors protein kinase A (PKA) and Epac, and an efflux of cAMP, the function of which is still unclear.

METHODS

Activation of adenylyl cyclase by GsPCR agonists or cholera toxin was monitored by measurement of the intracellular cAMP concentration by ELISA, anti-phospho-PKA substrate motif phosphorylation by immunoblotting, and an Epac-FRET assay in the presence and absence of adenosine receptor antagonists or ecto-nucleotide phosphodiesterase/pyrophosphatase2 (eNPP2) inhibitors. The production of AMP from cAMP by recombinant eNPP2 was measured by HPLC. Extracellular adenosine was determined by LC-MS/MS, extracellular ATP by luciferase and LC-MS/MS. The expression of eNPP isoenzymes 1-3 was examined by RT-PCR. The expression of multidrug resistance protein 4 was suppressed by siRNA.

RESULTS

Here we show that the activation of GsPCRs and the GsPCRs-independent activation of Gs proteins and adenylyl cyclase by cholera toxin induce stimulation of cell surface adenosine receptors (A2A or A2B adenosine receptors). In PC12 cells stimulation of adenylyl cyclase by GsPCR or cholera toxin caused activation of A2A adenosine receptors by an autocrine signaling pathway involving cAMP efflux through multidrug resistance protein 4 and hydrolysis of released cAMP to AMP by eNPP2. In contrast, in PC3 cells cholera toxin- and GsPCR-induced stimulation of adenylyl cyclase resulted in the activation of A2B adenosine receptors.

CONCLUSION

Our findings show that stimulation of adenylyl cyclase causes a remarkable activation of cell surface adenosine receptors.

Osteopontin: A non-invasive parameter of portal hypertension and prognostic marker of cirrhosis

AIM: To investigate the relationship between osteopontin plasma concentrations and the severity of portal hypertension and to assess osteopontin prognostic value.

METHODS: A cohort of 154 patients with confirmed liver cirrhosis (112 ethylic, 108 men, age 34-72 years) were enrolled in the study. Hepatic venous pressure gradient (HVPG) measurement and laboratory and ultrasound examinations were carried out for all patients. HVPG was measured using a standard catheterization method with the balloon wedge technique. Osteopontin was measured using the enzyme-linked immunosorbent assay (ELISA) method in plasma. Patients were followed up with a specific focus on mortality. The control group consisted of 137 healthy age- and sex- matched individuals.

RESULTS: The mean value of HVPG was 16.18 ± 5.6 mmHg. Compared to controls, the plasma levels of osteopontin in cirrhotic patients were significantly higher (P < 0.001). The plasma levels of osteopontin were positively related to HVPG (P = 0.0022, r = 0.25) and differed among the individual Child-Pugh groups of patients. The cut-off value of 80 ng/mL osteopontin distinguished patients with significant portal hypertension (HVPG above 10 mmHg) at 75% sensitivity and 63% specificity. The mean follow-up of patients was 3.7 ± 2.6 years. The probability of cumulative survival was 39% for patients with HVPG > 10 mmHg and 65% for those with HVPG ≤ 10 mmHg (P = 0.0086, odds ratio (OR), 2.92, 95% confidence interval (CI): 1.09-7.76). Osteopontin showed a similar prognostic value to HVPG. Patients with osteopontin values above 80 ng/mL had significantly lower cumulative survival compared to those with osteopontin ≤ 80 ng/mL (37% vs 56%, P = 0.00035; OR = 2.23, 95%CI: 1.06-4.68).

CONCLUSION: Osteopontin is a non-invasive parameter of portal hypertension that distinguishes patients with clinically significant portal hypertension. It is a strong prognostic factor for survival.

Use of non-invasive parameters of non-alcoholic steatohepatitis and liver fibrosis in daily practice--an exploratory case-control study

Background

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of a metabolic syndrome. To date, liver biopsy has been the gold standard used to differentiate between simple steatosis and steatohepatitis/fibrosis. Our aim was to compare the relevance of serum non-invasive parameters and scoring systems in the staging of liver fibrosis and non-alcoholic steatohepatitis (NASH) in patients with NAFLD.

Methods and Findings

A total of 112 consecutive patients diagnosed with NAFLD were included. A liver biopsy was performed on 56 patients. The Kleiner score was used for the staging and grading of the histology. Non-invasive parameters for fibrosis (hyaluronic acid; AST/ALT; fibrosis scoring indexes OELF, ELF, BARD score, APRI, NAFLD fibrosis score); and inflammation (M30 and M65 cytokeratin-18 fragments) were measured and calculated. The same analyses were performed in 56 patients diagnosed with NAFLD, who were not indicated for liver biopsy. Based on the liver histology, NASH was diagnosed in 38 patients; simple steatosis in 18 patients. A cut-off value of 750 U/L of serum M65 discriminated patients with and without NASH with a 80% sensitivity and 82% specificity (95% CI:57–95). Fibrosis stage F0–F2 was present in 39 patients; F3–F4 in 17 patients. Serum concentrations of hyaluronic acid were higher in patients with advanced fibrosis (p<0.01); a cut-off value of 25 µg/l discriminated patients with F3–F4 with a 90% sensitivity and 84% specificity from those with F0–F2 (95% CI:59–99). When applying the non-invasive criteria to those patients without a liver biopsy, NASH could only be diagnosed in 16%; however, advanced fibrosis could be diagnosed in 35% of them.

Conclusions

In patients with NAFLD, non-invasive serum parameters with a high accuracy can differentiate those patients with NASH and/or advanced fibrosis from those with simple steatosis. A substantial portion of those patients not indicated for liver biopsy might have undiagnosed advanced fibrosis.

The prevalence of nonalcoholic liver steatosis in patients with type 2 diabetes mellitus in the Czech Republic

AIMS

Nonalcoholic fatty liver disease (NAFLD) is associated with components of the metabolic syndrome (MS) but the prevalence of NAFLD in the Czech Republic is unknown. The aim of this study was to assess the latter in patients with type 2 diabetes (DM2) and to compare the noninvasive fibrosis scores with ultrasound findings in those patients.

METHODS

180 consecutive patients with DM2 (mean age 64.2±9.3 years, 63% men) were examined for liver biochemistry, MS parameters and had liver ultrasound. MS was diagnosed according to the International Diabetes Federation. The diagnosis of NAFLD was based on liver ultrasound. Other aetiology of liver lesion was ruled out. Additionally, AST/ALT ratio, APRI, NAFLD fibrosis score, FIB4 and BARD scores were calculated.

RESULTS

93% of patients met the MS criteria, 79% had NAFLD and 13% had ultrasound signs of fibrosis/cirrhosis. NAFLD patients had greater weight (96.9±19.3 vs 84.7±14.7 kg; P=0.003), BMI (32.6±5.2 vs 29.4±5.4 kg/m(2); P=0.007), waist circumference (113.8±12.8 vs 107.1±10.3 cm; P=0.033), ALT (0.73±0.57 vs 0.55±0.53 µkat/L, P=0.007) and triglyceridaemia (1.9±1.4 vs 1.4±1 mmol/L; P=0.005) than patients without NAFLD. There were no significant differences in age, sex, cholesterol, fasting glycaemia or glycated haemoglobin. Of calculated scores only the NAFLD fibrosis score revealed significant differences between patients with and without ultrasound signs of fibrosis/cirrhosis (1.027±2.228 vs -0.118±1.402, P=0.026).

CONCLUSION

Patients with DM2 had in the majority of cases NAFLD which was related to weight, BMI, waist circumference and serum triglycerides. The validity of the liver fibrosis scoring system has to be assessed in those patients in the future.

Functional variants of eNOS and iNOS genes have no relationship to the portal hypertension in patients with liver cirrhosis

OBJECTIVE

Nitric oxide is an important vasoactive mediator. Changes in NO production, caused by functional variants of both endothelial and inducible NO synthase (eNOS, iNOS), might play a role in portal hypertension. The aim was to study the significance of functional eNOS and iNOS gene variants in cirrhotic patients and their interrelationship to both inflammatory and endothelial activation parameters.

MATERIAL AND METHODS

One hundred and thirty-two patients with liver cirrhosis (age 36-72 years) and 101 controls were examined for functional variants of eNOS (E298D, 27bpintr4, 786T/C) and iNOS (R221W, S608L) genes. Inflammatory (IL6, IL8, IL10) and vasoactive (sVCAM-1, E-selectin) cytokines were measured using ELISA kits.

RESULTS

The frequency of E298D (GG 12%, GT 41%, TT 47%), 28bpintr4 (AA 6%, AB 28%, BB 66%), 786T/C genotypes (CC 17%, CT 45%, TT 38%), as well as R221W (CC 93%, CT 7%, TT 0%), and S608L (CC 65%, CT 32%, TT 3%) genotypes in cirrhotic patients did not differ from the controls (p > 0.05 for all comparisons). No relationship was found between the frequency of these genotypes and the severity of portal hypertension, or either inflammatory or vasoactive cytokines. A positive correlation was found between hepatic venous pressure gradient and cytokine concentration: sVCAM-1, IL6, IL8, IL10.

CONCLUSIONS

Examined eNOS and iNOS variants have no relationship to pathogenesis of liver cirrhosis. Severity of portal hypertension was associated with the changes in endothelial activation.

Alcoholic liver disease

Alcohol use disorders affect millions of individuals worldwide. Alcohol consumption is directly associated with liver disease mortality and accounts for elevated social and economic costs. Alcoholic liver disease (ALD) may take the form of acute involvement (alcoholic hepatitis) or chronic liver disease (steatosis, steatohepatitis, fibrosis and cirrhosis). The severity and prognosis of alcohol-induced liver disease depends on the amount, pattern and duration of alcohol consumption, as well as on the presence of liver inflammation, diet, nutritional status and genetic predisposition of an individual. While steatosis is an almost completely benign disease, liver cirrhosis is associated with marked morbidity, mortality and life expectancy shortening. The median survival of patients with advanced cirrhosis is 1-2 years. Severe acute alcoholic hepatitis (AH) is associated with mortality as high as 50%. It has been managed with corticoids, pentoxifylline and enteral nutrition, although evidence based data are still conflicting. Some author suggest that pentoxifylline could be a better first-line treatment in patients with severe AH. Absolute abstinence is a basic condition for any treatment of acute or chronic ALD, the other therapeutical procedure being of a supportive nature and questionable significance. Acamprosate appears to be an effective treatment strategy for supporting continuous abstinence in alcohol dependent patients. Patients with advanced liver cirrhosis who demonstrably abstain can be considered for liver transplantation, which leads to a markedly prolonged life expectancy. The crucial step in ALD prevention is in the prevention of alcohol abuse, whereas the prevention of liver injury in active alcohol abusers is not clinically applicable.

Protective effects of glycoursodeoxycholic acid in Barrett's esophagus cells

Barrett's esophagus (BE) is a premalignant condition associated with the development of esophageal adenocarcinoma (EAC). Previous studies have implicated hydrophobic bile acids and gastric acid in BE and EAC pathogenesis. In this study, we tested the hypothesis that DNA damage, cytotoxicity and oxidative stress induced by bile acids and gastric acid can be attenuated by the cytoprotective, hydrophilic bile acid glycoursodeoxycholic acid (GUDCA). Non-dysplastic BE cells were exposed for 10 min to pH 4 and/or bile acid cocktail or to pH 4 and a modified cocktail consisting of a mixture of bile acids and GUDCA. DNA damage was evaluated by the comet assay; cell viability and proliferation were measured by trypan blue staining and the MTS assay; reactive oxygen species (ROS) were measured using hydroethidium staining; oxidative DNA/RNA damage was detected by immunostaining with antibody against 8-OH-dG; thiol levels were measured by 5-chloromethylfluorescein diacetate (CMFDA) staining; and the expression of antioxidant proteins was evaluated by western blotting. DNA damage and oxidative stress were significantly increased, while thiol levels were decreased in BE cells treated with pH 4 and bile acid cocktail compared with cells treated with pH 4 alone or untreated cells. Bile acids and low pH also significantly decreased cell proliferation. Expression of the antioxidant enzymes, MnSOD and CuZnSOD, was elevated in the cells treated with bile acids and low pH. When GUDCA was included in the medium, all these effects of pH 4 and bile acids were markedly reduced. In conclusion, treatment of BE cells with acidified medium and a bile acid cocktail at physiologically relevant concentrations induces DNA damage, cytotoxicity, and ROS. The cytoprotective bile acid, GUDCA, inhibits these deleterious effects by inhibiting oxidative stress.

Inhibition of the equilibrative nucleoside transporter 1 and activation of A2A adenosine receptors by 8-(4-chlorophenylthio)-modified cAMP analogs and their hydrolytic products

Cyclic AMP analogs containing hydrophobic modification of C(8) at the adenine ring such as 8-(4-chlorophenylthio)-cAMP (8-pCPT-cAMP) and 8-(4-chlorophenylthio)-2'-O-methyl-cAMP (8-pCPT-2'-O-methyl-cAMP) can penetrate membranes due to their high lipophilicity and directly activate intracellular cAMP effectors. Therefore, these cAMP analogs have been used in numerous studies, assuming that their effects reflect the consequences of direct activation of cAMP effectors. The present study provides evidence that 8-pCPT-modified cAMP analogs and their corresponding putative hydrolysis products (8-(4-chlorophenylthio)-adenosine (8-pCPT-ado) and 8-(4-chlorophenylthio)-2'-O-methyl-adenosine (8-pCPT-2'-O-methyl-ado)) inhibit the equilibrative nucleoside transporter 1 (ENT1). In PC12 cells, in which nucleoside transport strongly depended on ENT1, 8-pCPT-ado, 8-pCPT-2'-O-methyl-ado, and, to a smaller extent, 8-pCPT-2'-O-methyl-cAMP caused an increase of protein kinase A substrate motif phosphorylation and anti-apoptotic effect by an A(2A) adenosine receptor (A(2A)R)-dependent mechanism. In contrast, the effects of 8-pCPT-cAMP were mainly A(2A)R-independent. In HEK 293 showing little endogenous ENT1-dependent nucleoside transport, transfection of ENT1 conferred A(2A)R-dependent increase in protein kinase A substrate motif phosphorylation. Together, the data of the present study indicate that inhibition of ENT1 and activation of adenosine receptors have to be considered when interpreting the effects of 8-pCPT-substituted cAMP/adenosine analogs.

Esophageal acid exposure at pH < or = 2 is more common in Barrett's esophagus patients and is associated with oxidative stress

Barrett's esophagus (BE) patients demonstrate a higher distal esophageal acid exposure profile than other gastroesophageal reflux disease patients. Cellular oxidative stress has been proposed to contribute to the development of BE and esophageal adenocarcinoma. However, a relationship between low esophageal pH and oxidative stress has yet to be elucidated. The aim of this study was to determine the duration of low pH exposure in the esophagus of BE patients compared to those with erosive esophagitis (EE) and to test if brief exposure to low pH leads to the induction of reactive oxygen species (ROS). Seventy-three patients with BE or EE were evaluated by 24-hour esophageal pH monitoring and the percentage of time during which there was exposure to pH < or = 4 and pH < or = 2 was recorded. In vitro, Seg-1 and Het-1A cells were evaluated after brief exposure to pH4 or pH2 by flow cytometry and fluorescent microscopy for the production of ROS. BE patients demonstrated a significantly higher exposure to low pH values (pH < or = 2) than EE patients. The mean percent total time, duration and mean number of reflux episodes at pH < or = 2 were 2.8 +/- 0.53%, 28.8 +/- 3.6 seconds and 79 +/- 11.4 episodes in BE patients, whereas in EE patients they were significantly less, 1.16 +/- 0.3%, 15.6 +/- 1.2 seconds and 48.3 +/- 8.8 episodes, respectively (P < 0.05). In vitro experiments indicate that esophageal cells, when exposed to pH 2, produce ROS. In vitro studies using brief pH 2 exposure are biologically relevant to the clinical situation. Our studies indicate that such exposure induces oxidative stress. This stress may cause DNA damage, mutations and progression to cancer.

Mitochondrial perturbation attenuates bile acid-induced cytotoxicity

Hydrophobic bile acids such as deoxycholate (DOC) are known to damage liver cells during cholestasis and promote colon cancer. Cellular stresses induced by bile acids, which include mitochondrial and endoplasmic reticulum (ER) stresses, can result in apoptosis. We found that inhibition of mitochondrial complexes I-V with rotenone, thenoyltrifluoroacetone (TTFA), antimycin A, myxothiazol or oligomycin strongly protected against DOC-induced apoptosis of HCT-116 cells. To understand the mechanism of this protection, we explored the ability of these specific inhibitors to reduce DOC-induced mitochondrial and ER stresses. Different inhibitors markedly reduced DOC-induction of mitochondrial condensation, the DOC-induced decrease in mitochondrial membrane potential and the DOC-induced dilatation of the ER (evidence of ER stress). A dramatic induction of nucleolar segregation by antimycin A and myxothiazol, two distinct complex III inhibitors, was also observed. These findings strongly implicate mitochondrial crosstalk with apoptotic signaling pathways and mitochondrial-nucleolar crosstalk in the development of apoptosis resistance in the colon.

Deoxycholate induces mitochondrial oxidative stress and activates NF-kappaB through multiple mechanisms in HCT-116 colon epithelial cells

Nuclear factor kappa B (NF-kappaB) is a redox-associated transcription factor that is involved in the activation of survival pathways. We have previously shown that deoxycholate (DOC) activates NF-kappaB in hepatocytes and colon epithelial cells and that persistent exposure of HCT-116 cells to increasing concentrations of DOC results in the constitutive activation of NF-kappaB, which is associated with the development of apoptosis resistance. The mechanisms by which DOC activates NF-kappaB in colon epithelial cells, and whether natural antioxidants can reduce DOC-induced NF-kappaB activation, however, are not known. Also, it is not known if DOC can generate reactive oxygen species within mitochondria as a possible pathway of stress-related NF-kappaB activation. Since we have previously shown that DOC activates the NF-kappaB stress-response pathway in HCT-116 cells, we used this cell line to further explore the mechanisms of NF-kappaB activation. We found that DOC induces mitochondrial oxidative stress and activates NF-kappaB in HCT-116 cells through multiple mechanisms involving NAD(P)H oxidase, Na+/K+-ATPase, cytochrome P450, Ca++ and the terminal mitochondrial respiratory complex IV. DOC-induced NF-kappaB activation was significantly (P < 0.05) inhibited by pre-treatment of cells with CAPE, EGCG, TMS, DPI, NaN3, EGTA, Ouabain and RuR. The NF-kappaB-activating pathways, induced by the dietary-related endogenous detergent DOC, provide mechanisms for promotion of colon cancer and identify possible new targets for chemoprevention.

Chylothorax as a possible diagnostic pitfall: a report of 2 cases with cytologic findings

BACKGROUND

Chyothorax is an uncommon medical condition. To the best of our knowledge, there have been no detailed English-language report dealing with its cytopathologic findings and diagnostic pitfalls

CASES

A 12-year-old boy, hemodialysis dependent, with congenital nephrotic syndrome due to focal segmental glomerular sclerosis and a failed renal transplant, developed shortness of breath. Physical and radiologic examinations revealed a left pleural effusion. A 7-year-old boy developed shortness of breath, with a subsequent finding of a left pleural effusion. Multiple osteolytic skeletal lesions were found in this patient. Both patients underwent thoracocentesis. Cytologically, both fluids contained many relatively uniform, large lymphoid cells with high nuclear/cytoplasmic (N/C) ratio, condensed chromatin and occasional nucleoli, resembling blasts. Some nuclei were convoluted. Mitotic figures were present. Foamy macrophages were present in both cases. The differential diagnosis of these populations of cells included a lymphoproliferative disorder. However, the mature T-lymphocytic nature of the cells was confirmed by immunohistochemistry performed on cell block preparations, confirming the clinical impression of chylothorax in both cases. The first patient had chylothorax as a result of trauma due to therapeutic interventions (subclavian vein cannulation), in the second patient the chylothorax was a part of Gorham-Stout syndrome.

CONCLUSION

The large T-lymphocytes that are the major cellular component of chylothorax may arouse suspicion of a lymphoproliferative disorder. Attention to the clinical history and immunophenotyping confirm the benign nature of the pleural space fluid. Also, abundant foamy macrophages can be considered a low-power clue to this diagnosis.

Autologous bone marrow transplantation using unfractionated cells cryopreserved in dimethylsulfoxide and hydroxyethyl starch without controlled-rate freezing

To develop a simplified method of bone marrow (BM) cryopreservation, changes were made in the standard method in three areas: the cryoprotectant, the method of cell freezing, and the storage temperature. Unfractionated BM cells from 60 patients were cryopreserved in 300-mL aliquots in both dimethylsulfoxide (DMSO) and hydroxyethyl starch (HES), a combination known to preserve granulocytes successfully. The cells were frozen without rate-controlled freezing by simple immersion into a -80 degrees C freezer where they remained until the time of reinfusion. The 60 patients underwent 72 autologous transplants after three high-dose chemotherapy regimens: 30 received high-dose carmustine in combination, five received high-dose busulfan and cyclophosphamide, and 37 received high-dose aziridinylbenzoquinone. The BM was infused for more than 30 minutes after rapid thawing at 37 degrees C. The mean post-thaw nucleated cell recovery was 96% +/- 11.6%, and Trypan blue dye exclusion was 82.2% +/- 9.2%. The mean postthaw CFU-GM and BFU-E recoveries were 81.9% +/- 39.0% and 90.5% +/- 41.2%. Complete count recovery occurred in 68 of 72 transplants. Median times to a WBC count greater than 1,000/microL, a granulocyte count greater than 1,000/microL and a platelet count greater than 20,000/microL were 15, 21, and 15 days, respectively. Risk factors for delayed recovery were not found. Unfractionated BM cells can be successfully cryopreserved in the DMSO/HES mixture rapidly and inexpensively, without rate-controlled freezing or storage at liquid nitrogen temperatures.

[Improved interpretation of renal-vein-renin-ratio by simultaneous determination of renal 131I-hippuric-acid-clearance-ratio in patients with renovascular hypertension (author's transl)]

In patients with unilateral vascular kidney disease and hypertension, ratio of renal-vein-renin was compared with 131I-Hippuric-acid clearance and change in blood pressure during Saralasininfusion. The ratio of renal-vein-renin was positively correlated with the ratio in renal plasma flow between the kidneys in all patients studied. The ratio of renins therefore is a result of two factors: The difference in renin secretion and the difference in blood flow in the two kidneys. In patients with angiotensin independent hypertension renin-ratios up to 2.0 were found without relevance to elevated blood pressure. When the difference in renal blood flow between both kidneys was small, even a slight difference in renal vein renin indicated hypertension related to increased renin secretion. Renin-ratios in the critical range between 1.5 and 2.5 should only be interpreted in respect to a similar ratio in renal blood flow.

[131I-cholesterol scanning of the adrenals: results in various adrenal diseases, especially unilateral adrenal turmours (author's transl)]

133I-cholesterol scanning of five patients with primary hyperaldosteronism due to adrenocortical adenoma, gave correct lateralization and localization in three, while in two cases lateralization was not definitively determined. In two patients with phaeochromocytoma unilateral localization was clear-cut in the scan. In two patients with hormone-producing adrenal carcinoma the adrenals were localized poorly or not at all on both sides, because of the size of the tumours and suppression of the healthy contralateral adrenal by the autonomous hormone production. In case of retroperitoneal tumour with destruction of the adrenal the scan demonstrated a hyperplastic but healthy adrenal on the other side. Because 133I-cholesterol scanning exposes the steroid-producing gonads to high radioactivity, the method should only be used for diagnosing which side a unilateral adrenal tumour is on. It should not be used to complement a diagnosis of bilateral adrenal disease achieved by other means.