Impact of nonmalignant ascites on outcomes of open inguinal hernia repair in the USA.

PURPOSE: Studies on inguinal hernia repair in patients with ascites are limited, small, and inconsistent, exacerbating a challenging clinical dilemma for surgeons. To fill this gap in the literature, this retrospective cohort study used a national US database to examine the impact of ascites on the outcomes of open inguinal herniorrhaphy. METHODS: Patients who underwent open inguinal herniorrhaphy between 2005 and 2019 were identified in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Two groups were defined by the presence or absence of nonmalignant preoperative ascites. Ascites patients were propensity matched 1:10 with non-ascites patients. Surgical outcomes at 30 days for the matched groups, stratified by electiveness of procedure, were compared, with the primary end points of mortality and the NSQIP composite outcome "serious complication". RESULTS: The study included 682 patients with ascites. Compared to matched controls, those with ascites had significantly increased odds of mortality (OR 3.3, 95% CI 1.5-7.0) after elective repair, but not after nonelective repair. Ascites was associated with increased odds of serious complication after both elective (OR 1.7, 1.2-2.3) and nonelective (OR 2.0, 1.3-3.0) surgery. Among ascites patients, age ≥ 65 years was associated with increased mortality (risk-adjusted OR 3.8, 1.2-14.4) and serious complication (OR 2.2, 1.2-3.9). CONCLUSION: In this largest study to date on patients with ascites undergoing open inguinal herniorrhaphy, ascites increased the odds of mortality after elective repair and of serious complication after elective and nonelective repair. Age ≥ 65 was a risk factor for poor outcome. Inguinal herniorrhaphy is fraught with complications in this population.

Acute Mesenteric Ischemia Remains a Highly Morbid Diagnosis after Initial Hospitalization Survival.

Acute mesenteric ischemia (AMI) remains a vascular emergency. Our aim was to explore readmission for AMI. We identified all patients admitted for AMI from the state of California through the Healthcare and Utilization Project from 2005 to 2011. Our primary end point was the rate and etiology for readmission. Our secondary end points were the length of hospitalization and in-hospital mortality. Cox proportional hazard regression was utilized to assess risk of 30-day readmission. There were 534 (9.9%) readmissions at 30 days. The mean age was 67 ± 17 years and 209 (39.1%) were male. The five most common etiologies for readmission were AMI (7.6%), cardiac events (5.3%), severe sepsis (1.2%), dehydration (1.1%), and acute kidney failure (1.1%). Once readmitted, these patients were most likely to experience cardiac catheterizations (25.4%), red blood cell transfusions (23.6%), intubation and mechanical ventilation (17.6%), biopsy of the large intestine (13.9%), reoperation for small bowel resection (10.9%), administration of total parenteral nutrition (10.5%), and transfusion of other blood products (6.9%). This hospitalization was 8.8 ± 12.7 days long. In-hospital mortality was 36 patients (6.7%). On multivariable Cox-regression analysis, severe (hazard ratio [HR]: 2.1 [1.4-3.2], p = 0.0005) and moderate (HR: 1.5 [1.03-2.13], p = 0.04) Elixhauser Comorbidity Group, complications (HR: 1.5 [1.2-1.9], p = 0.0007), and longer index hospitalization (HR: 1.02 [1.01-1.02], p < 0.0001) were predictors of readmission. Conclusion AMI remains a vascular emergency. Readmissions have a significant rate of morbid invasive procedures and can lead to an in-hospital mortality of 6.7%. The adoption of guidelines similar to the European Society for Trauma and Emergency Surgery should be considered.

An update on prevalence and risk of snus and nicotine replacement therapy during pregnancy and breastfeeding.

AIM: In parallel with falling smoking rates, use of the oral moist tobacco product snus increases among women in reproductive age. We report an update on prevalence and effects of maternal use of snus and nicotine replacement therapy (NRT) during pregnancy and breastfeeding. METHODS: A literature search of human studies in Medline, PubMed and EMBASE was conducted from September 2016 to May 2018, with stepwise screening of abstracts and subsequent relevant full-text papers for inclusion in Scandinavian and English languages. RESULTS: Based on three studies, the prevalence of snus use in pregnancy was up to 3.4% in the first trimester and 2.1% in the third trimester. In 12 studies, we found increased risk of several adverse effects, especially preterm delivery, stillbirth and small for gestational age associated with maternal snus use during pregnancy. Knowledge on effects of NRT during pregnancy was conflicting and inconclusive in 10 studies. We did not identify any studies on prevalence or potential health effects of snus or NRT during breastfeeding. CONCLUSION: Few studies with updated data on the prevalence and adverse health effects of maternal use of snus and NRT during pregnancy were found. No studies during breastfeeding were identified.

Mechanisms linked to differences in the mutagenic potential of 1,3-dinitropyrene and 1,8-dinitropyrene.

This study explores and characterizes the toxicity of two closely related carcinogenic dinitro-pyrenes (DNPs), 1,3-DNP and 1,8-DNP, in human bronchial epithelial BEAS-2B cells and mouse hepatoma Hepa1c1c7 cells. Neither 1,3-DNP nor 1,8-DNP (3-30 µM) induced cell death in BEAS-2B cells. In Hepa1c1c7 cells only 1,3-DNP (10-30 µM) induced a mixture of apoptotic and necrotic cell death after 24 h. Both compounds increased the level of reactive oxygen species (ROS) in BEAS-2B as measured by CM-H2DCFDA-fluorescence. A corresponding increase in oxidative damage to DNA was revealed by the formamidopyrimidine-DNA glycosylase (fpg)-modified comet assay. Without fpg, DNP-induced DNA damage detected by the comet assay was only found in Hepa1c1c7 cells. Only 1,8-DNP formed DNA adduct measured by 32P-postlabelling. In Hepa1c1c cells, 1,8-DNP induced phosphorylation of H2AX (γH2AX) and p53 at a lower concentration than 1,3-DNP and there was no direct correlation between DNA damage/DNA damage response (DR) and induced cytotoxicity. On the other hand, 1,3-DNP-induced apoptosis was inhibited by pifithrin-α, an inhibitor of p53 transcriptional activity. Furthermore, 1,3-DNP triggered an unfolded protein response (UPR), as measured by an increased expression of CHOP, ATF4 and XBP1. Thus, other types of damage possibly linked to endoplasmic reticulum (ER)-stress and/or UPR could be involved in the induced apoptosis. Our results suggest that the stronger carcinogenic potency of 1,8-DNP compared to 1,3-DNP is linked to its higher genotoxic effects. This in combination with its lower potency to induce cell death may increase the probability of causing mutations.

Enniatin B-induced cell death and inflammatory responses in RAW 267.4 murine macrophages.

The mycotoxin enniatin B (EnnB) is predominantly produced by species of the Fusarium genera, and often found in grain. The cytotoxic effect of EnnB has been suggested to be related to its ability to form ionophores in cell membranes. The present study examines the effects of EnnB on cell death, differentiation, proliferation and pro-inflammatory responses in the murine monocyte-macrophage cell line RAW 264.7. Exposure to EnnB for 24 h caused an accumulation of cells in the G0/G1-phase with a corresponding decrease in cyclin D1. This cell cycle-arrest was possibly also linked to the reduced cellular ability to capture and internalize receptors as illustrated by the lipid marker ganglioside GM1. EnnB also increased the number of apoptotic, early apoptotic and necrotic cells, as well as cells with elongated spindle-like morphology. The Neutral Red assay indicated that EnnB induced lysosomal damage; supported by transmission electron microscopy (TEM) showing accumulation of lipids inside the lysosomes forming lamellar structures/myelin bodies. Enhanced levels of activated caspase-1 were observed after EnnB exposure and the caspase-1 specific inhibitor ZYVAD-FMK reduced EnnB-induced apoptosis. Moreover, EnnB increased the release of interleukin-1 beta (IL-1ß) in cells primed with lipopolysaccharide (LPS), and this response was reduced by both ZYVAD-FMK and the cathepsin B inhibitor CA-074Me. In conclusion, EnnB was found to induce cell cycle arrest, cell death and inflammation. Caspase-1 appeared to be involved in the apoptosis and release of IL-1ß and possibly activation of the inflammasome through lysosomal damage and leakage of cathepsin B.

Biotransformation enzymes and lung cell response to 2-hydroxyethyl-methacrylate.

The aim of this in vitro study was to investigate possible involvement of cytochrome P450 (CYP) enzymes in modifying the toxic potential of 2-hydroxyethyl-methacrylate (HEMA). Primary cultures of CYP expressing rat alveolar type 2 cells were exposed to varying concentrations of HEMA. Nuclear translocation of aryl hydrocarbon receptor (AhR) after HEMA exposure (100 µM) was demonstrated by immunocytochemical staining. Using reverse transcriptase PCR, increased mRNA level of AhR-regulated genes encoding enzymes associated with detoxification of xenobiotics were found. Exposure to 1 mM HEMA rapidly (6 h) resulted in cells with an apoptotic like morphology as suggested by marked nuclear condensation. Cotreatment of the HEMA exposed cells with a CYP inhibitor (disulfiram) or an antioxidant (vitamin C) effectively rescued the cells from this fate. Despite this effect of vitamin C, no increased level of reactive oxygen species was observed in the HEMA exposed cells. Our results suggest that HEMA activates AhR regulated gene transcription and that CYP is involved in the formation of a highly reactive HEMA metabolite.

HEMA reduces cell proliferation and induces apoptosis in vitro.

OBJECTIVES: Methacrylate monomers have been identified in aqueous extracts of freshly cured compomers. Both cells in the pulpal cavity and various cells of the oral mucosa can potentially be exposed to these leachables. Short-term exposure to dental monomers at relatively high concentrations induces adverse biological effects in vitro. The mechanisms involved have not been fully elucidated although involvement of various signaling pathways including ROS formation, activation of MAP-kinases and caspases has been suggested. The aim of this study was to investigate potential cellular responses following long-term exposure to relatively low and potentially more clinical relevant HEMA concentrations. METHODS: A submandibular gland cell line was exposed to HEMA (20-600 microM) for up to 72h. The impact on cell proliferation, apoptosis, and possible underlying mechanisms was assessed by flow cytometry, microscopy and western blotting. RESULTS: Exposure to HEMA (600 microM) resulted in reduced cell proliferation after 24h and increased apoptosis after 60h. Further, we observed ATM dependent phosphorylation of p53, advocating an initial DNA damage in the HEMA exposed cells. SIGNIFICANCE: In conclusion, we show that exposure to relatively low concentration of HEMA for a prolonged time result in cell death, possibly as a consequence of DNA damage.

Importance of size and composition of particles for effects on cells in vitro.

A primary goal of current research on particle-induced health effects is to reveal the critical characteristics that determine their biological effects. Experimental studies have shown that smaller particles induce stronger biological effects than larger particles of similar composition, due to their larger surface area to mass ratio. However, correlation for variations in surface area could not account for variation in biological reactivity among particles of differential composition. Hence, the importance of size and surface area does not override the importance of particle composition. Moreover, different particle characteristics appear to be involved in different biological effects in vitro. Our studies show that mineral particle-induced apoptosis mostly seems to depend on particle size, whereas composition and surface reactivity appeared to be most important for the proinflammatory potential of the particles. The ability of the particles to generate reactive oxygen species in vitro was not correlated with either inflammatory markers or apoptosis, suggesting that other mechanisms are at play. A single, specific component of the mineral particles, explaining the differences in response, has not been identified. In European-wide studies such as the Respiratory Allergy and Inflammation due to Air Pollution (RAIAP) study, particles have been sampled in different locations to study season- and site-dependent variations in responses particles, such as markers of inflammatory and allergic reactions in cells and animals. The data indicate that coarse particles can induce at least as strong inflammatory responses as fine particles. The allergic responses tended to be more associated with the organic fraction (PAH) of particles, whereas the inflammatory reactions seemed to be more associated with metals and endotoxin. Overall, coarse PM was found to have an inflammatory potential similar to fine PM on an equal mass basis. Even though one has to take into account different concentrations in ambient air as well as differences in respiratory system deposition of the size fractions, the potential of coarse particles to induce pulmonary effects should not be neglected.

Mineral particles of varying composition induce differential chemokine release from epithelial lung cells: importance of physico-chemical characteristics.

Presently, little is known about the potential health effects of mineral particles other than asbestos and quartz. In this study, a human epithelial lung cell line (A549), primary human small airway epithelial cells (SAECs) and primary rat type 2 (T2) cells were exposed to stone quarry particles of two size fractions (<10 and <2.5 microm) from nine different rock samples. The ability to induce the release of chemokines from lung cells was investigated and compared with the particles' mineral and element composition and the amount of soluble elements. The stone particles induced the release of only low levels of interleukin (IL)-8 from A549 cells. In contrast, some of the other particles induced the release of high levels of macrophage inflammatory protein (MIP)-2 from T2 cells, and high levels of IL-8 from SAECs. Differences in particle surface area could account for differences in activity between the <10 and <2.5 microm fractions of six out of the nine rock samples. For two samples the <2.5 microm fraction was most active and for one sample the <10 microm fraction was most active. Content of the mineral plagioclase displayed a strong, negative correlation with the potential to induce MIP-2, whereas the mineral pyroxene was positively correlated with MIP-2 induction. However, neither plagioclase nor pyroxene content was sufficient to explain differences in bioactivity between the particles. No statistically significant correlation was found between the amounts of total or soluble elements and MIP-2 release. In conclusion, the results suggest that mineral particles with a high content of plagioclase have a low potential to induce a pro-inflammatory response. However, a particular mineral or element responsible for eliciting strong increases in chemokine release could not be identified. Thus, at present it appears that analysing mineral and element content is insufficient to predict stone particle bioactivity, and that biological testing is a necessity.

Rat lung inflammatory responses after in vivo and in vitro exposure to various stone particles.

Rat lung alveolar macrophages and type 2 cells were exposed for 20 h in vitro to various stone particles with differing contents of metals and minerals (a type of mylonite, gabbro, feldspar, and quartz). The capability to induce the release of the inflammatory cytokines interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), and macrophage inflammatory protein-2 (MIP-2) was investigated. We found marked differences in potency between the various particles, with mylonite being most potent overall, followed by gabbro, and with feldspar and quartz having an approximately similar order of lower potency. The results also demonstrated differences in cytokine release pattern between the two cell types. For all particle types including quartz, type 2 cells showed the most marked increase in MIP-2 and IL-6 secretion, whereas the largest increase in TNF-alpha release was observed in macrophages. To investigate possible correlations between in vitro and in vivo inflammatory responses, rats were instilled with the same types of particles and bronchoalveolar lavage (BAL) fluid was collected after 20 h. The results demonstrated a correlation between the in vitro cytokine responses and the number of neutrophilic cells in the BAL fluid. The BAL fluid also showed a strong MIP-2 response to mylonite. However, this was the only particle type to give a significant cytokine response in the BAL fluid. We further examined whether a similar graded inflammatory response would be continued in type 2 cells and alveolar macrophages isolated from the exposed animals. Again a differential cytokine release pattern was observed between type 2 cells and macrophages, although the order of potency between particle types was altered. In conclusion, various stone particles caused differential inflammatory responses after both in vitro and in vivo exposure, with mylonite being the most potent stone particle. The results suggest the alveolar type 2 cell to be an important participant in the inflammatory response following exposure to particles.

Role of signal transduction pathways in lung inflammatory responses.

A variety of cell types participate in lung inflammation. Macrophages and epithelial cells play an important role in the inflammatory process by releasing cytokines in a complex cell to cell network. Interleukins are important mediators of this cell signalling. The interleukins IL-6 and IL-8 are released from epithelial cells in response to noxious agents such as particles, bacterial and fungal toxins and various chemicals. Though the involvement of, e.g. NF-IL-6 (C/EBP-beta) in the regulation of interleukins has been reported, the role of different signal transduction pathways in the regulation of these mediators has not been thoroughly investigated in lung epithelial cells. The involvement of different signal transduction pathways in the release of inflammatory markers is discussed with special emphasis on the effect of lung toxic compounds in human and rat lung epithelial cells.

Fluoride-induced interleukin-6 and interleukin-8 synthesis in human epithelial lung cells.

Exposure to fluorides has been associated with asthmatic symptoms among workers in the aluminium industry. In a recent experimental study hydrogen fluoride (HF) was found to induce a weak inflammatory response in humans. In the present study the potential of sodium fluoride (NaF) and HF to induce cytokine response was examined and how these responses are modulated by Al3+ in a human epithelial lung cell line (A549). Dose-response experiments showed a maximal release of IL-6 and IL-8 at a concentration of 5 mM NaF 24 h after addition. The responses to HF were of a similar magnitude as for NaF. Time-course experiments showed a NaF-induced IL-6 response at 5 h, whereas an IL-8 response was observed after 10 h. Cycloheximide treatment completely abolished the NaF-induced cytokine responses. A marked increase in the mRNA level for IL-6 was observed already 2 h after exposure to 5 mM NaF, and presumably is a prerequisite for the subsequent increase of IL-6. The fluoride-induced effects on IL-6 and IL-8 release were strongly reduced by pretreatment with deferoxamine (an Al3+-chelator), and enhanced by addition of Al3+. This indicates that an AlF4-- complex, a known activator of GTP-binding proteins, is involved in fluoride-induced IL-6 and IL-8 responses in A549 cells.

Maintenance treatment with medroxyprogesterone acetate in patients with advanced breast cancer responding to chemotherapy: results of a randomized trial. Essen Breast Cancer Study Group.

The purpose of this randomized phase III trial was to study whether medroxyprogesterone acetate (MPA) maintenance treatment prolongs the time to progression in advanced breast cancer patients responding to an induction chemotherapy. Patients with progressive advanced breast cancer previously untreated with anthracylines and progestins were given epirubicin (30 mg/m2) and ifosfamide (2 g/m2) on days 1 and 8 at 3-weekly intervals. Patients without disease progression after 6 cycles of chemotherapy were randomly assigned to receive, until progression, either no treatment or MPA at a daily total dose of 500 mg. Ninety patients were randomized: 46 to the MPA arm and 44 to the observation arm. Median time to progression was longer in the MPA arm: 4.9 months versus 3.7 months in the intent-to-treat analysis (p = 0.02), and 4.9 months versus 3.0 months in the secondary efficacy analysis (p = 0.012). Seven patients were removed from MPA due to side effects. The changes in patient-rated quality of life scores were similar in both groups. The median length of survival from randomization was 17.4 months for patients receiving MPA and 18.3 months for patients randomized to observation (p = 0.39). In conclusion, in patients with advanced breast cancer achieving remission or non-progression with 6 cycles of epirubicin and ifosfamide chemotherapy, MPA maintenance treatment led to a significant, though modest, prolongation of the time to progression without affecting overall survival of the study patients.

Cis-acting sequences from the rat cytochrome P450 2B1 gene confer pulmonary and phenobarbital-inducible expression in transgenic mice.

Specific cytochrome P450 enzymes show tissue-specific induction, and different regulatory units for expression of these enzymes have been identified. The regulation of the phenobarbital (PB)-inducible P450 genes has been relatively well characterized in terms of PB induction, but less so with regard to tissue-specific expression. CYP2B2 is not expressed in the rat lung, whereas cytochrome P450 2B1 (CYP2B1) is a dominating enzyme in the same tissue. The constitutive expression of CYP2B1 and CYP2B2 in liver is low, but inducible by PB, whereas the pulmonary expression of CYP2B1 is not induced by PB. This indicates utilization of different regulating mechanisms in the two organs. A gene construct consisting of the structural gene for LacZ coupled to a 1.3-kb 5' fragment of the rat CYP2B1 gene was used to generate transgenic mice in order to further elucidate the mechanism behind tissue-specific expression and PB induction of the CYP2B1 gene. Using reverse transcriptase-polymerase chain reaction on total RNA extracted from lung and liver tissue, a lung-specific transcription of the transgene was observed. Transcription of the construct was also observed in livers from PB-treated transgenic animals. By histochemical staining of lung sections with 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-gal), we demonstrated expression at the protein level in bronchiolar cells. In conclusion, our results revealed that the region extending to -1. 3 kb in the 5' flanking region of the CYP2B1 gene included sequences that could partly account for the lung-specific transcription of CYP2B1 and the hepatic induction of CYP2B1 transcription by PB.

The role of enteroclysis in the diagnosis of unexplained gastrointestinal symptoms: a prospective assessment.

The purpose of this prospective study performed at a non-university hospital was to assess the role of enteroclysis in the diagnosis of unexplained gastrointestinal symptoms such as abdominal pain, gastrointestinal bleeding, and chronic diarrhea done following inconclusive imaging or endoscopic procedures. 184 consecutive patients were subjected to enteroclysis over 25 months. 84 (46%) had abdominal pain, 52 (28%) gastrointestinal bleeding, and 48 (26%) chronic diarrhea. Findings were categorized as normal and abnormal (subdivided into main, i.e., explanatory of symptoms; and secondary, i.e., not explanatory of symptoms). Main findings were further divided into those exclusively detected by enteroclysis and those confirmed by this procedure. Normal enteroclysis investigations were obtained in 159 (86%) patients and abnormal in 25 (14%). Main findings were present in 19 (10%) patients, in ten (5%) of them exclusively detected by enteroclysis. Secondary findings were present in six (3%) patients, also detected only by enteroclysis. The highest rate of main findings exclusively detected by enteroclysis related to patients with chronic diarrhea (8%), compared with 6% and 2% with abdominal pain and gastrointestinal bleeding, respectively. For the inspection of the small bowel, enteroclysis shall remain the gold standard for detecting abnormal findings in the small bowel until user-friendly enteroscopes are developed.

Regulation of CCSP (PCB-BP/uteroglobin) expression in primary cultures of lung cells: involvement of C/EBP.

The Clara-cell secretory protein (CCSP) is a cell-specific differentiation marker for the bronchiolar Clara cell. Isolated rat Clara and alveolar type 2 cells kept in primary culture proliferate and dedifferentiate, providing the opportunity to study differentiation-dependent mechanisms. In freshly isolated Clara cells, high levels of CCSP and the corresponding mRNA were detected. During culture in vitro, these levels decreased. In the type 2 cell fraction, low levels of CCSP were detected, which decreased further during culture. A promoter fragment of the rat CCSP gene encompassing the sequence from -188 to +53 was able to drive high-level expression of reporter genes in transfected Clara cells. Reporter gene expression in transfected type 2 cells was markedly lower, and no expression could be detected in alveolar macrophages. Expression of transcription factors previously described to stimulate CCSP expression appeared not to parallel CCSP levels in the primary Clara cells. However, expression of the transcription factor C/EBP alpha correlated with the CCSP expression pattern. In electrophoretic mobility shift assays, we were able to demonstrate binding of C/EBP alpha from rat Clara cell nuclear extracts to an element located 85 bp upstream of the start site of transcription. Overexpression of C/EBP alpha increased expression from the CCSP -188 promoter fragment up to fivefold in NCI-H441-cells and 30-fold in A549-cells, establishing the functional importance of C/EBP alpha. Our results show that primary cultures of Clara cells constitute a useful model for investigating terminal airway differentiation and suggest a role for C/EBP-factor(s) in this process.

The significance of trisomy 8 in de novo acute myeloid leukaemia: the accompanying chromosome aberrations determine the prognosis. German AML Cooperative Study Group.

Trisomy 8 is the most frequent numerical chromosome aberration in acute myeloid leukaemia (AML). It occurs either as the sole anomaly or together with other clonal chromosome aberrations. We investigated whether accompanying chromosome anomalies influence the clinical outcome in patients with trisomy 8 and de novo AML. Since 1986, in 713 AML cases treated according to the protocols of the German AMLCG trials, chromosome analyses have been successfully performed. The overall incidence of trisomy 8 was 7.6%. Complete clinical follow-up data were available for 51 patients who were divided into three different categories: group 1: trisomy 8 as the sole cytogenetic anomaly (n = 20); group 2: trisomy 8 in addition to favourable chromosome aberrations (t(8;21)(q22;q22), t(15;17)(q22;q21), inv(16)(p13q22)) (n = 10); and group 3: trisomy 8 accompanied by other anomalies, in most cases of complex type (n = 21). Complete remission (CR) rates were 70%, 90% and 67% for groups 1, 2 and 3, respectively. Event-free survival (EFS) at 3 years differed significantly between patients with trisomy 8 only (37.5%), patients with trisomy 8 in combination with favourable aberrations (55.0%) and patients with trisomy 8 and other accompanying anomalies, mostly complex chromosome aberrations (9.0%) (group 1 v group 2: P=0.12; group 1 v group 3: P=0.005; group 2 v group 3: P=0.05). In this study patients with +8 as the sole cytogenetic anomaly had an intermediate prognosis, patients with +8 in addition to favourable chromosome aberrations maintained a good clinical outcome, and patients with +8 in combination with other abnormalities showed the worst prognosis.

Genotoxic effects of cyclopenta-fused polycyclic aromatic hydrocarbons in different types of isolated rat lung cells.

The genotoxic effects of the environmental contaminants benz[j]aceanthrylene (B[j]A), benz[l]aceanthrylene (B[l]A) and benzo[a]pyrene (B[a]P), and the metabolism of radiolabelled B[j]A, were studied using rat lung microsomes and various types of isolated rat lung cells from control and Aroclor 1254 (PCB) treated animals. All three compounds (10 or 20 microg/plate) resulted in low, but detectable, levels of His+ revertants in the Salmonella assay when plated with control lung microsomes. The two cyclopenta polycyclic aromatic hydrocarbons (CP-PAH) B[j]A and B[l]A, gave increased levels of revertants when plated with microsomes from PCB-treated animals. Clara cells, type 2 cells and alveolar macrophages isolated from control rats were exposed to B[j]A, B[l]A or B[a]P (30 microg/ml, 1 h), but neither of the cell types showed any DNA damage when measured by alkaline filter elution. However, both B[j]A and B[l]A (30 microg/ml, 2 h) caused DNA adducts in all three cell types, measured by the 32P-post-labelling technique, whereas no B[a]P adducts were detected (30 microg/ml, 2 h). The total DNA adduct levels in Clara cells, type 2 cells and macrophages exposed to B[j]A were 0.085 +/- 0.033, 0.053 +/- 0.001 and 0.170 +/- 0.030 fmol/microg DNA, respectively, whereas the total levels in cells exposed to B[l]A were 0.140 +/- 0.070, 0.140 +/- 0.030 and 0.220 +/- 0.080 fmol/microg DNA, respectively. Cells exposed to B[j]A revealed only one adduct which corresponds with the B[j]A-1,2-oxide DNA adduct. Judged from high performance liquid chromatography (HPLC) analysis using radiolabelled B[j]A (30 microg/ml, 30 min), the major metabolite formed in control microsomes was B[j]A-1,2-diol. Thus, oxidation at the cyclopenta ring appears to be the most important activation pathway for B[j]A with control rat lung cells. Exposure of lung cells to CP-PAH (30 microg/ml, 2 h) isolated from PCB pretreated rats resulted in slightly increased DNA adduct levels in Clara cells and macrophages when compared to cells isolated from control rats. Furthermore, the adduct pattern had shifted, and no apparent B[j]A-1,2-oxide adduct could be detected on the thin layer chromatography (TLC) plate. In contrast, the major metabolite formed with microsomes from PCB-treated animals was still the B[j]A-1,2-diol.

Differential distribution and increased levels of ras proteins during lung development.

Differential localization of ras proteins and variations in their levels may be of importance during lung growth and differentiation. Abundant cell proliferation occurs during development of the fetal rat lung. As assessed by flow cytometry the proliferative activity declined near birth, followed by a gradual increase in cellular proliferation during the subsequent 8 days and a decline to basal levels by 15 to 18 days of age. During this period of substantial variations in proliferative activity, differences in both the protein content and localization of the different ras proteins were observed. The content of N- and K-ras proteins in lung homogenates increased 5 to 6-fold in rats 20 days or older, compared to fetal levels. The protein levels of the ras proteins remained elevated when cellular proliferation decreased to basal levels. As determined by immunohistochemistry, the localization of N-ras protein was restricted to keratin expressing cells of bronchiolar structures, apparently mainly ciliated cells. In contrast, K-ras was found in alveolar cells, probably type I and type 2 cells. H-ras, but not K- or N-ras, was localized to nonepithelial cells. Thus, different ras proteins were localized to different regions of the lung and increased in abundance during postnatal development.

Use of fluorescence in situ hybridization and comparative genomic hybridization in the cytogenetic analysis of testicular germ cell tumors and uveal melanomas.

Fluorescence in situ hybridization (FISH) with specific DNA probes and comparative genomic hybridization (CGH) are molecular cytogenetic methods that provide powerful supplementations of classical cancer cytogenetics. We present two examples of successful application of these new techniques in solid tumors in which basic information about specific cytogenetic aberrations had been gained previously by conventional karyotyping. In the first, testicular germ cell tumors (TGCT), FISH analysis allowed further characterization of the i(12p) marker chromosome. By CGH, chromosomal subregions that may harbor genes important for tumorigenesis or progression could be identified. In the second, uveal melanoma, CGH enabled a retrospective study in which monosomy 3 was statistically proved to be a relevant marker for poor prognosis.