Biological reference materials for extracellular vesicle studies.

Extracellular vesicles (EVs) mediate normal physiological homeostasis and pathological processes by facilitating intercellular communication. Research of EVs in basic science and clinical settings requires both methodological standardization and development of reference materials (RM). Here, we show insights and results of biological RM development for EV studies. We used a three-step approach to find and develop a biological RM. First, a literature search was done to find candidates for biological RMs. Second, a questionnaire was sent to EV researchers querying the preferences for RM and their use. Third, a biological RM was selected, developed, characterized, and evaluated. The responses to the survey demonstrated a clear and recognized need for RM optimized for the calibration of EV measurements. Based on the literature, naturally occurring and produced biological RM, such as virus particles and liposomes, were proposed as RM. However, none of these candidate RMs have properties completely matching those of EVs, such as size and refractive index distribution. Therefore, we evaluated the use of nanoerythrosomes (NanoE), vesicles produced from erythrocytes, as a potential biological RM. The strength of NanoE is their resemblance to EVs. Compared to the erythrocyte-derived EVs (eryEVs), NanoE have similar morphology, a similar refractive index (1.37), larger diameter (70% of the NanoE are over 200nm), and increased positive staining for CD235a and lipids (Di-8-ANEPPS) (58% and 67% in NanoE vs. 21% and 45% in eryEVs, respectively). Altogether, our results highlight the general need to develop and validate new RM with similar physical and biochemical properties as EVs to standardize EV measurements between instruments and laboratories.

Human umbilical cord blood-derived mesenchymal stromal cells display a novel interaction between P-selectin and galectin-1.

Human multipotent mesenchymal stromal/stem cells (MSCs) have been shown to exert immunomodulatory properties that have great potential in therapies for various inflammatory and autoimmune disorders. However, intravenous delivery of these cells is followed by massive cell entrapment in the lungs and insufficient homing to target tissues or organs. In targeting to tissues, MSCs and other therapeutic cells employ similar mechanisms as leucocytes, including a cascade of rolling and adhesion steps mediated by selectins, integrins and their ligands. However, the mechanisms of MSCs homing are not well understood. We discovered that P-selectin (CD62P) binds to umbilical cord blood (UCB)-derived MSCs independently of the previously known sialyl Lewis x (sLex)-containing ligands such as P-selectin glycoprotein ligand-1 (PSGL-1, CD162). By biochemical assays, we identified galectin-1 as a novel ligand for P-selectin. Galectin-1 has previously been shown to be a key mediator of the immunosuppressive effects of human MSCs. We conclude that this novel interaction is likely to play a major role in the immunomodulatory targeting of human UCB-derived MSCs.

Effect of site of lactate infusion on regional lactate exchange in pigs.

BACKGROUND: The rate of extra-hepatic lactate production and the route of influx of lactate to the liver may influence both hepatic and extra-hepatic lactate exchange. We assessed the dose-response of hepatic and extra-hepatic lactate exchange during portal and central venous lactate infusion. METHODS: Eighteen pigs randomly received either portal (n=5) or central venous (n=7) lactate infusion or saline (n=6). Sodium lactate was infused at 33, 66, 99, and 133 µmol kg⁻¹ min⁻¹ for 20 min each. Systemic and regional abdominal blood flows and plasma lactate were measured at 20 min intervals until 1 h post-infusion, and regional lactate exchange was calculated (area under lactate uptake-time curve). RESULTS: Total hepatic lactate uptake [median (95% confidence interval)] during the experimental protocol (140 min) was higher during portal [8198 (5487-12 798) µmol kg(-1)] than during central venous lactate infusion [4530 (3903-5514) µmol kg⁻¹, P<0.05]. At a similar hepatic lactate delivery (∼400 µmol kg⁻¹ min⁻¹), hepatic lactate uptake [mean and standard deviation (sd)] was higher during portal [118 (sd 55) µmol kg⁻¹ min⁻¹] than during central venous lactate infusion [44 (12) µmol kg⁻¹ min⁻¹, P < 0.05]. Time courses of arterial lactate concentrations and lactate uptake at other measured regions were similar in both groups. CONCLUSIONS: Higher hepatic lactate uptake during portal compared with central venous lactate infusion at a similar total hepatic lactate influx underlines the role of portal vein lactate concentration in total hepatic lactate uptake capacity. Arterial lactate concentration does not depend on the site of lactate infusion. At higher arterial lactate concentrations, all regions participated in lactate uptake.

Nitrogen reduction in wastewater treatment using different anox-circulation flow rates and ethanol as a carbon source.

We studied the optimization of nitrogen reduction from municipal wastewater in a laboratory-scale modified Ludzack-Ettinger activated sludge wastewater treatment plant (WWTP). The unit consisted of primary denitrification, secondary nitrification, a sludge clarifier and a post-denitrification unit. The process simulates the Kuopio WWTP, which provided the influent utilized. We describe the effect of varying anox-circulation schemes on the nitrogen removal efficiency. We further compare the denitrification efficiencies of ethanol and methanol applied in the post-denitrification unit, and compare the properties and costs of these chemicals as carbon sources. Maximum efficiency of total nitrogen removal (70.8%) was obtained with 256% anox-circulation. The process was, however, not very sensitive, as a wide range of 150-400% of anox-circulations gave good results for nitrogen reduction. The unit achieved high BOD, and COD reductions of wastewater also when nitrogen reduction was moderate. The addition of 40 mg/L/day of ethanol to the post-denitrification tank meant that the nitrate-levels of effluent could be controlled to below 10 mg/L of nitrate nitrogen. Methanol and ethanol were equally effective for denitrification. The use of ethanol instead of methanol could reduce treatment costs by 30% to 0.02 E/m3 of treated wastewater according to 2008 market prices.

On-line microwave total solids sensoring in sewage characterization.

We describe a novel application for a microwave on-line sensor to measure the total solids (TS) load entering a municipal wastewater treatment plant (WWTP) from slaughterhouse sewage and some sanitary wastewaters. Measuring this kind of wastewater stream is very challenging, because it contains a high, but varying organic load with nitrogen, phosphorus and microorganisms. The reliability of the measured signal was studied by comparison with laboratory analyses and a correlation is presented of TS-value with other parameters that are typically followed in a wastewater treatment process. The results suggest that on-line microwave sensoring could be used to monitor total solids in wastewater influent. Our results show that the on-line microwave sensor and laboratory reference analyses give similar results with a good correlation between the two techniques. Furthermore, we demonstrate that the total solids values correlate well with conductivity, total nitrogen and BOD(7) values but not with phosphorus, pH and temperature.

Dust sampling methods for endotoxin - an essential, but underestimated issue.

Exposure to farming environment in early life has been associated with lower risk for allergic diseases possibly caused by increased exposure to endotoxin. The aims of this study were to compare the reproducibility of different sampling methods for endotoxin, and to determine whether environmental characteristics have different effect on endotoxin levels of different sample types. The reproducibility of sampling methods (bed dust, floor dust, vacuum cleaner dust bag dust, settled dust and air samples) was studied with repeated sampling (five visits during 1 year) in five farming and five urban homes. To examine determinants of endotoxin for different types of dust sample, sampling was conducted once in 12 farming and 17 urban homes. Endotoxin was analyzed using Limulus Amebocyte Lysate assay. Bed dust samples had the best reproducibility (intraclass correlation, ICC=66%), but the difference between farming and non-farming homes was not clear with this sample type. The reproducibility of floor (ICC=52%) and settled dust (ICC=51%) was moderate. With these sample types the difference between farming and non-farming homes was clear. Settled dust had some seasonal variation. Based on this study, the best compromise for sampling for endotoxin appears to be floor dust sample followed by bed and settled dust samples. Practical Implications Endotoxins have been widely measured, even though the validity of different sample types to reflect the endotoxin exposure level of an indoor environment is poorly known. This study shows that bed dust samples have the best reproducibility, but they do not reflect the differences in exposure due to environmental factors such as farming. Floor dust samples with moderate reproducibility may be the best choice for sampling of endotoxin in large field studies.

The role of the orphan nuclear receptor Rev-Erb alpha in adipocyte differentiation and function.

Lipid and carbohydrate homeostasis in higher organisms is governed by an integrated system that has a capacity to rapidly respond to metabolic changes. Numerous signals reciprocally convey information about body fat status from the periphery to central nervous system in the attempt to maintain body weight nearly stable throughout life. The role of adipocyte in energy homeostasis extends its function as a simple energy storage cell. Indeed, adipose tissue not only secretes fatty acids, but is also an active endocrine and paracrine organ due to the production of secreted proteins and lipid indicators collectively called adipokines. These observations have spurred interest in the identification of the transcriptional and other regulatory pathways of adipocyte differentiation. The nuclear receptor, peroxisome proliferator-activated receptor gamma (PPAR gamma) (NR1C3) and members of the CCAAT enhancer-binding protein (C/EBP) family are central mediators controlling adipocyte differentiation and function. Rev-erb alpha (NR1D1) is an orphan nuclear receptor encoded on the opposite strand of the thyroid receptor alpha gene. Rev-erb alpha acts as a negative regulator of transcription binding to the same response element than another orphan nuclear receptor, ROR alpha. Rev-erb alpha is highly expressed in adipose tissue, skeletal muscle, heart, liver and brain. Rev-erb alpha expression increases during adipocyte differentiation of 3T3-L1 cells and is induced by PPAR gamma activation in both 3T3-L1 cells in vitro and in rat adipose tissue in vivo via a direct repeat (DR2) in the Rev-erb alpha promoter. Ectopic expression of Rev-erb alpha potentiates the adipocyte differentiation in 3T3-L1 cells. Recent results in vascular smooth muscle cells (VSMCs) indicate that Rev-erb alpha also controls inflammation by regulating NF-kappa B responsive genes, such as IL-6 and COX-2. Future studies on a potential role of Rev-erb alpha on glucose homeostasis and/or inflammation control are thus warranted.

Immunoglobulin G antibodies against indoor dampness-related microbes and adult-onset asthma: a population-based incident case-control study.

Immunoglobulin G (IgG) antibodies against microbes related to indoor dampness problems have been used as potential biomarkers of fungal exposure in clinical investigations. There is limited information on their relation to asthma. We conducted a population-based incident case-control study to assess the risk of asthma in relation to specific IgG antibodies to eight dampness-related microbes: Aspergillus fumigatus, A. versicolor, Cladosporium cladosporioides, Fusarium oxysporum, Sporobolomyces salmonicolor, Stachybotrys chartarum, Streptomyces albus and Trichoderma citrinoviride. We recruited systematically all new cases of asthma during a 2.5-year study period and randomly selected controls from a source population of adults 21-63 years of age living in the Pirkanmaa Hospital District, South Finland. The clinically diagnosed case series consisted of 521 adults with newly diagnosed asthma and the control series of 932 controls selected randomly from the source population. IgG antibodies were analysed with ELISA. An increased risk of developing asthma in adulthood was significantly related to IgG antibodies to T. citrinoviride, but not to the other moulds. There was no evidence of a dose-response relation between the IgG antibody level and the risk of asthma. T. citrinoviride may play a role in the aetiology of adult-onset asthma or serve as an indicator of other causal factors.

Immunoglobulin G antibodies to moulds in school-children from moisture problem schools.

BACKGROUND: The purpose of the present study was to evaluate mould-specific immunoglobulin G (IgG) antibodies in children exposed to moisture and mould problems in their school, and the association between IgG antibodies and mould allergy, active or passive smoking and respiratory symptoms. METHODS: IgG antibodies were studied to 24 moulds in 93 children from three moisture problem schools and in 33 children from a reference school. The antibodies were measured by enzyme-linked immunosorbent assay and compared to positive adult sera. RESULTS: There were no significant differences in mould-specific IgG concentrations between exposed and non-exposed school-children. Antibodies to moulds common in moisture damaged buildings were associated with allergic diseases, as well as with mould-specific immunoglobulin E (IgE) or skin prick test (SPT) findings. Aspergillus fumigatus and A. versicolor were the moulds with the most consistent findings. Active and passive smoking were associated with low levels of antibodies to many moulds. Though the association between asthma, wheezing or cough symptoms, and IgG to moulds was not significant, 7 (39%) of the 18 children with multiple (> 7) elevated IgG findings suffered from asthma or wheezing. CONCLUSIONS: Allergy was, but asthma was not, associated with IgG antibodies to the moulds that can be found in moisture damaged buildings. However, no association was found between IgG antibodies to moulds and exposure to moisture and moulds in school.

Evaluation of exposure to airborne bacterial endotoxins and peptidoglycans in selected work environments.

The aim of this study was to assess workers' exposure to endotoxins and peptidoglycans, as well as associations between workers' reported symptoms and the detected bacterial exposures. From the filter samples, biologically-active endotoxins were analysed with the Limulus amebocyte lysate (LAL) assay. The total amount of endotoxins was analysed as 3-hydroxy (OH) fatty acids with a gas chromatography-mass spectrometry (GC-MS) assay, which was also used to assess peptidoglycans as muramic acid. Biologically-active endotoxins related better to the self-reported symptoms than total endotoxins. Specific 3-OH-14:0 fatty acid in the total endotoxin samples associated better with the symptoms than other 3-OH fatty acids. Half of the surveyed 77 workers reported respiratory symptoms, 27% eye symptoms, and 10% fever or shivering. The proportion of workers with respiratory symptoms was greater when the concentration of endotoxins was over 25 ng/m3. These endotoxin levels were occasionally found in the air of most studied occupational environments. The muramic acid concentrations of peptidoglycans were highest (medians over 100 ng/m3) in the garbage-handling plant and in the grain/vegetable storage houses. The LAL assay for endotoxins, as well as the GC-MS assay analysing muramic acid for peptidoglycans or specific 3-OH fatty acids for endotoxins, seem to be suitable methods for evaluating workers' exposure to airborne bacteria.

The OSBP-related protein family in humans.

Oxysterols are oxygenated derivatives of cholesterol that have a number of biological effects and play a key role in the maintenance of the body cholesterol balance. In this study, we describe the cDNA sequences and genomic structures of the recently identified human oxysterol-binding protein (OSBP)-related protein (ORP) family (Laitinen, S. et al. 1999. J. Lipid Res. 40: 2204-2211). The family now includes 12 genes/proteins, which can be divided into six distinct subfamilies. The ORP have two major structural features: a highly conserved OSBP-type sterol-binding domain in the C-terminal half and a pleckstrin homology domain present in the N-terminal region of most family members. Several ORP genes are present in S. cerevisiae, D. melanogaster, and C. elegans, suggesting that the protein family has functions of fundamental importance in the eukaryotic kingdom. Analysis of ORP mRNA levels in unloaded or acetylated LDL-loaded human macrophages revealed that the expression of ORP genes was not significantly affected by the loading, with the exception of ORP6, which was up-regulated 2-fold. The present study summarizes the basic characteristics of the OSBP-related gene/protein family in humans, and provides tools for functional analysis of the encoded proteins.

Effects of systemic arterial hypoperfusion on splanchnic hemodynamics and hepatic arterial buffer response in pigs.

The hepatic arterial buffer response (HABR) tends to maintain liver blood flow under conditions of low mesenteric perfusion. We hypothesized that systemic hypoperfusion impairs the HABR. In 12 pigs, aortic blood flow was reduced by cardiac tamponade to 50 ml. kg(-1). min(-1) for 1 h (short-term tamponade) and further to 30 ml. kg(-1). min(-1) for another hour (prolonged tamponade). Twelve pigs without tamponade served as controls. Portal venous blood flow decreased from 17 +/- 3 (baseline) to 6 +/- 4 ml. kg(-1). min(-1) (prolonged tamponade; P = 0.012) and did not change in controls, whereas hepatic arterial blood flow decreased from 2 +/- 1 (baseline) to 1 +/- 1 ml. kg(-1). min(-1) (prolonged tamponade; P = 0.050) and increased from 2 +/- 1 to 4 +/- 2 ml. kg(-1). min(-1) in controls (P = 0.002). The change in hepatic arterial conductance (DeltaC(ha)) during acute portal vein occlusion decreased from 0.1 +/- 0.05 (baseline) to 0 +/- 0.01 ml. kg(-1). min(-1). mmHg(-1) (prolonged tamponade; P = 0.043). In controls, DeltaC(ha) did not change. Hepatic lactate extraction decreased, but hepatic release of glutathione S-transferase A did not change during cardiac tamponade. In conclusion, during low systemic perfusion, the HABR is exhausted and hepatic function is impaired without signs of cellular damage.

Prognostic factors predicting survival in the treatment of retroperitoneal sarcoma.

METHODS: Retroperitoneal soft tissue sarcomas are rare tumours. The management of these tumours has been difficult because of low resectability and a high recurrence rate. A retrospective review of a prospectively compiled database of 32 consecutive patients with retroperitoneal sarcomas treated at Oulu University Hospital between 1977 and 1996 was performed. RESULTS: The resectability rate of primary tumours was 75%, and 44% of the patients underwent radical resection. The recurrence rate after radical resection was 57% and the resectability rate for recurrent tumours after radical primary operation, 50%. The actuarial overall 5-year survival rate was 31%, 10-year survival rate 19% and median survival 36 months. In univariate analysis the principal factors associated with prognosis were radical resection, recurrent disease, pre-operative loss of weight and histological tumour grade. Complete excision of the primary tumour was the only significant predictor of survival in multivariate analysis. CONCLUSIONS: Complete resection of retroperitoneal sarcoma continues to be the most important prognostic factor. The inefficiency of adjuvant therapy, the high recurrence rate and the very low chance of curing the patient after recurrence make the prognosis of these patients poor.

Survival after operations for colorectal cancer in patients aged 75 years or over.

OBJECTIVE: To define factors that predict mortality and survival in patients with colorectal cancer who are aged 75 or over. DESIGN: Retrospective study. SETTING: University hospital, Finland. SUBJECTS: 231 patients aged 75 or over who were admitted to hospital with colorectal cancer during the 14-year period 1980-93. MAIN OUTCOME MEASURES: Morbidity, mortality, recurrence, and survival. RESULTS: In-hospital mortality after any kind of operation was 8/211 (4%), and 8/175 (5%) of those who had their tumours resected. Morbidity was 35/175 (20%). Factors associated with mortality were weight loss, Dukes'stage, extent of resection, and type of operation. Overall 5-year survival was 28%, overall 10-year survival was 4%, and median survival was 33 months (range 0-150). Survival was most closely related to Duke's stage, extent of resection, and recurrent disease on univariate analysis, but multivariate analysis identified only mode of recurrence (p < 0.0001), recurrent disease (p < 0.004), and extent of resection (p < 0.009) as independent predictors of survival. The recurrence rate after radical resection was 49/141 (35%) and the median disease-free interval was 10 months (range 4-64). Mortality after resection for recurrent cancer was 3/17 (18%) and morbidity 5/17 (29%). CONCLUSION: Age alone is not a risk factor for postoperative mortality or a predictor of long-term survival. Low mortality and acceptable long-term survival can be achieved in patients aged 75 or over if those with extensive distant metastases, and those whose general condition is too poor to stand a major operation, are treated conservatively.

Bowel preparation with oral polyethylene glycol electrolyte solution vs. no preparation in elective open colorectal surgery: prospective, randomized study.

PURPOSE: Efficient mechanical bowel preparation has been regarded as essential in preventing postoperative complications of colorectal surgery, but the necessity of bowel cleansing has been disputed recently. The aim of this study was to evaluate the outcome of elective colorectal surgery in patients with or without bowel preparation. METHODS: Altogether, 267 consecutive adult patients admitted for elective open colorectal surgery were randomly assigned either to the bowel preparation group with oral polyethylene glycol electrolyte solution (138 patients) or no preparation group (129 patients). Patients who were unable to drink polyethylene glycol electrolyte solution, those who had had bowel preparation within the previous week, and patients not needing opening of the bowel were excluded. Routine colorectal surgery was undertaken, and infectious and other complications were registered daily. Late complications were checked up one to two months after surgery. RESULTS: No deaths were recorded, and 76 percent of the patients in the polyethylene glycol electrolyte solution group and 81 percent in the unprepared group recovered without complication. Anastomotic leaks occurred in 4 percent of the polyethylene glycol electrolyte solution patients and in 2 percent of the other cases, and other surgical site infections occurred in 6 and 5 percent, respectively. None of the differences was statistically significant. There was no difference in restoration of bowel function. The median postoperative stay was eight days in both groups. CONCLUSIONS: Preoperative bowel preparation seems to offer no benefit in elective open colorectal surgery.

Survival after surgery for gastric cancer in patients over 70 years of age.

BACKGROUND AND AIMS: The increase of the elderly population in western societies will result in a considerable increase of gastric cancer patients older than 70 years requiring surgery. However, higher postoperative morbidity and mortality rates after major surgery in the elderly are well recognized. The aim of this study was to evaluate the risk factors of mortality and predictors of survival in elderly patients with gastric cancer. METHODOLOGY: We reviewed the data of the 165 patients evaluated for gastric cancer surgery in the Oulu University Hospital from January 1985 till December 1994 and made a computer analysis. RESULTS: Postoperative mortality was 12% both after all laparotomies and after all resections, and 6% after radical resections. Mortality after radical resection did not associate significantly with any clinical variable but morbidity was associated with the number of coexistent diseases. The median and cumulative 5-year survivals after radical resections were 40 months and 38%. Survival was closely related to diagnostic delay, preoperative loss of weight, two or more coexistent disease, location of tumor, and recurrence in univariate analysis, but multivariate analysis showed only preoperative weight loss and recurrent disease to be independent predictors of survival. CONCLUSIONS: Age alone is not a risk factor for postoperative mortality or a predictor of survival among elderly patients with gastric cancer. Early detection of malignancy and careful preoperative evaluation of the patients referred for resection are needed to improve survival.

Family of human oxysterol binding protein (OSBP) homologues. A novel member implicated in brain sterol metabolism.

Oxysterol binding protein (OSBP) is a cytosolic protein that undergoes ligand-induced binding to the Golgi apparatus and has been implicated in the regulation of cellular cholesterol metabolism. In the yeast Saccharomyces cerevisiae an OSBP homologue is involved in membrane trafficking through the Golgi complex. Prompted by the multitude of OSBP-related genes in the yeast genome, we carried out a search for human expressed sequence tags (ESTs) displaying homology to the sterol-binding domain of OSBP. This revealed a minimum of six novel OSBP-related proteins, designated ORP-1 to ORP-6. ORP cDNA probes were generated by reverse transcription-PCR from human liver mRNA, and used for Northern blot analysis of human tissue transcript panels. This verified that each of them represents a different gene product and showed that they display distinct tissue-specific expression patterns. The ORP-1 and -2 mRNA expression levels were similar to or higher than that of OSBP while the ORP-3 to -6 mRNAs were detected at lower levels in specific tissues. The most abundantly expressed new gene, ORP-1, was transcribed at strikingly high levels in the cortical areas of human brain and displayed sterol-regulated expression in a cultured human neuroblastoma cell line. This indicates that ORP-1 may play an important role in maintaining the sterol balance in cells of the central nervous system. Together with OSBP, the identified gene products constitute a novel human protein family that may provide a link between organellar sterol status and membrane dynamics.

Endotoxins and IgG antibodies as indicators of occupational exposure to the microbial contaminants of metal-working fluids.

OBJECTIVES: The aim of this study was to evaluate workers' exposure to microbes and bacterial endotoxins during the use of metal-working fluids (MWF). METHODS: Air and bulk sampling with biomonitoring of workers' serum IgG antibodies were used to estimate the exposure to biological agents at 18 workplaces. The types of emulsified MWF used were synthetic fluid, mineral oil or rape seed oil, in grinding, turning and drilling work. RESULTS: The endotoxin concentrations in the air ranged from 0.04 to 600 ng/m(3) when the endotoxin levels in MWF were 0.03-25,000 ng/ml. A high correlation was found between the endotoxin levels and the bacterial counts from MWF, as well as between the total culturable bacteria and the gram-negative bacteria concentrations in the air. Comamonas testosteroni and C. acidovorans were the most common strains in the samples but also colonies of Ochrobactrum anthropi, Pantoea agglomerans and Stenotrophomonas maltophilia were isolated from the workplaces. Fungi like Aspergillus, Cladosporium and Penicillium species were identified in the air but only rarely in the MWF. Positive IgG antibodies were found in the sera of 22 of the 25 MWF workers examined. Antibodies against S. maltophilia, P. agglomerans and C. acidovorans were the most common, appearing in 72%, 64% and 64%, respectively, of the cases. The MWF workers showed significantly higher IgG antibody responses to bacterial antigens than did the controls. CONCLUSIONS: The results clearly proved that in occupational hygiene measurements, endotoxins serve as excellent indicators of exposure to the microbial contaminants of MWF. IgG antibodies against antigens identified from workplace samples could be a practical tool for occupational health physicians.

Exposure to airborne microorganisms and volatile organic compounds in different types of waste handling.

Occupational exposure of workers to airborne microorganisms and volatile organic compounds (VOC) in different types of waste treatment situations was examined during summer time. Microorganisms were collected as stationary samples using a six-stage Andersen impactor, while for VOCs both personal and stationary sampling was conducted. The exposure at the waste handling facility was considerably greater than at landfill sites or in waste collection. The concentrations of viable fungi were maximally 10(5) cfu/m3, and the concentrations of both total culturable bacteria and Gram-negative bacteria exceeded the proposed occupational exposure limit values (OELV), being 10(4) and 10(3) cfu/m3, respectively. Exposure to VOCs in the waste handling facility was three times higher than at the landfill sites, being at highest 3000 microg/m3, considered to be the limit for discomfort. The use of personal protective equipment at work, thorough hand washing and changing clothes after the work shift are strongly recommended in the waste handling facility and the landfill sites.

Clinicopathological features of primary gastric lymphoma.

BACKGROUND AND OBJECTIVES: Surgery has been the mainstay of the treatment of primary gastric lymphoma, but the value of surgical treatment needs reevaluation. METHODS: Thirty-two patients with primary non-Hodgkin B-cell lymphoma of the stomach were examined retrospectively to evaluate prognostic factors and their impact on survival. All patients had undergone abdominal exploration for radical surgery between 1979 and 1992. The prognostic factors in view of survival after treatment were determined with both univariate and multivariate analyses. RESULTS: The resectability rate was 66% (21/32) and radical resections had been performed on 53% (17/32). The overall median survival was 65 months and the overall 5-year survival was 56%. The 5-year survival rates related to a modified Ann Arbor classification as follows: I 1E, 86%; I 2E, 100%; II 1E, 44%; II 2E, 37%; IIIE, 20%; and IVE, 0%. Univariate analysis using Kaplan-Meier estimates showed that radical surgery, Ann Arbor stage, patient's age, and lymph node involvement were significant prognostic factors. According to Cox proportional regression analysis, only Ann Arbor stage, radical surgery, and age were significant independent variables. CONCLUSIONS: According to our experience, surgery is still needed for the treatment of primary gastric lymphomas, but the benefits of primary chemotherapy or adjuvant chemotherapy using cytotoxic drugs must be determined in large prospective controlled trials.