Modeling Environmental Influences in the Psyllaephagus bliteus (Hymenoptera: Encyrtidae)-Glycaspis brimblecombei (Hemiptera: Aphalaridae) Parasitoid-Host System.

Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) is an invasive psyllid introduced into the Mediterranean area, where it affects several species of Eucalyptus. Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) is a specialized parasitoid of this psyllid that was accidentally introduced into Italy in 2011. We developed a model of this host-parasitoid system that accounts for the influence of environmental conditions on the G. brimblecombei population dynamics and P. bliteus parasitism rates in the natural ecosystem. The Lotka-Volterra-based model predicts non-constant host growth and parasitoid mortality rates in association with variation in environmental conditions. The model was tested by analyzing sampling data collected in Naples in 2011 (before the parasitoid was present) and defining several environmental patterns, termed Temperature-Rain or T-R patterns, which correspond to the host growth rate. A mean value of the host growth rate was assigned to each T-R pattern, as well as a variation of the parasitoid mortality rate based on temperature thresholds. The proposed model was applied in simulation tests related to T-R patterns carried out with a data series sampled between June 2014 and July 2015 in five Italian sites located in Campania, Lazio, Sicily, and Sardinia regions. The simulation results showed that the proposed model provides an accurate approximation of population trends, although oscillation details may not be apparent. Results predict a 64% reduction in G. brimblecombei population density owing to P. bliteus parasitoid activity. Our results are discussed with respect to features of the host-parasitoid interaction that could be exploited in future biological control programs.

Primary clarithromycin resistance in Italy assessed on Helicobacter pylori DNA sequences by TaqMan real-time polymerase chain reaction.

BACKGROUND: Helicobacter pylori clarithromycin resistance is increasing worldwide and different mutations are involved in its mechanisms. Recently, molecular methods have been proposed to assess these mutations. AIM: To assess prevalence of primary clarithromycin resistance in two Italian areas, and the distribution of involved mutations, by using a novel method for real-time polymerase chain reaction. METHODS: Two hundred and thirty-two H. pylori-positive patients undergoing oesophagogastroduodenoscopy in two Italian towns (Rome, centre Italy; Foggia, south Italy) were enrolled. Helicobacter pylori infection was detected by histology, rapid urease and urea breath tests. Clarithromycin resistance was assessed by TaqMan real-time polymerase chain reaction on paraffin-embedded antral biopsies. Results Primary clarithromycin resistance was detected in 62 (26.7%) patients. Its prevalence did not differ between the two areas (31.5%, centre vs. 23.3%, south; P=0.17) and between non-ulcer dyspepsia and peptic ulcer patients (28.4% vs. 20.7%, P=0.2). The A2143G point mutation was detected in 35 (56.4%) patients, A2142G in 14 (22.6%), A2142C in eight (12.9%), whilst a double mutation (A2143G plus A2142C or A2142G) was present in the remaining five (8.1%) cases. CONCLUSIONS: Our study found that primary clarithromycin resistance is highly prevalent in both central and southern Italy, and that A2143G is the most frequent point mutation involved in these areas.

Epithelial cell proliferation of the colonic mucosa in diverticular disease: a case-control study.

BACKGROUND: A higher risk of both advanced adenoma and carcinoma occurs in the sigmoid colon of patients with diverticular disease, for which bacterial carcinogens have been claimed to play a role. AIM: To assess epithelial cell proliferation in colonic mucosa of diverticular disease patients before and after rifaximin treatment. METHODS: Twelve consecutive patients with a new endoscopic diagnosis of left-sided diverticular disease and 12 matched controls were enrolled. Epithelial cell proliferation in the sigmoid mucosa was assessed by using proliferating cell nuclear antigen. The proliferating cell nuclear antigen index of the whole crypt and of the upper third was separately evaluated before and after 10-day rifaximin (400 mg b.d.) therapy. RESULTS: Proliferating cell nuclear antigen index in the upper third of the crypt was significantly higher in the diverticular patients (median: 25, range: 14-32) as compared with controls (median: 15, range: 5-20) (P = 0.038), and it was not reverted by rifaximin therapy. No difference of the proliferating cell nuclear antigen index of the whole crypt was detected between cases (median: 27, range: 23-44) and controls (median: 25, range: 18-42) (P = 0.6). CONCLUSIONS: Our data showed an upward shifting of cellular proliferation in the sigmoid mucosa of patients with diverticular disease. Because of rifaximin failure in reversing this alteration, factors other than the bacterial load should probably be investigated.

DNA sequences and proteic antigens of H. pylori in cholecystic bile and tissue of patients with gallstones.

BACKGROUND: Although Helicobacter pylori DNA sequences have been detected in cholecystic bile and tissue of patients with gallstones, controversial results are reported from different geographic areas. AIM: To detect H. pylori in cholecystic bile and tissue of patients with gallstones from a previously uninvestigated geographic area, southern Italy. Detection included both the bacterial DNA and the specific antigen (H. pylori stool antigen) identified in the stools of infected patients for diagnostic purposes. PATIENTS AND METHODS: The study enclosed 33 consecutive patients undergoing laparoscopic cholecystectomy for gallstones. DNA sequences of H. pylori were detected by polymerase chain reaction in both cholecystic bile and tissue homogenate. Moreover, we assayed H.pylori stool antigen on gall-bladder cytosolic and biliary proteins after their extraction. Bacterial presence in the stomach was assessed by urea breath test in all patients and Deltadelta13CPDB value assumed as marker of intragastric load. Fisher's exact probability and Student's t-tests were used for statistical analysis. RESULTS: DNA sequences of H. pylori in bile were found in 51.5% and significantly correlated with its presence in cholecystic tissue homogenate (P<0.005), H. pylori stool antigen in gall-bladder (P=0.0013) and bile (P=0.04) proteins, gastric infection (P<0.01) and intragastric bacterial load (P<0.001). No correlation was found, however, with sex and age of the patients. CONCLUSIONS: Our prevalence value of bacterial DNA in bile and gall-bladder of patients with gallstones agreed with that of the only other Italian study. The simultaneous presence of both bacterial DNA and proteic antigen suggests that the same prototype of bacterium could be located at both intestinal and cholecystic level and, therefore, the intestine represents the source of biliary contagion.

In situ detection of PCR-amplified HIV-1 nucleic acids in lymph nodes and peripheral blood in patients with asymptomatic HIV-1 infection and advanced-stage AIDS.

This study determined the in situ detection rate of polymerase chain reaction (PCR)-amplified human immunodeficiency virus type 1 (HIV-1) DNA and RNA in lymph nodes and peripheral blood CD4+ cells in six patients with asymptomatic HIV-1 infection and from six people who died of advanced AIDS. The lymph nodes of patients with asymptomatic infection showed expanded germinal centers where, on average, 20% of the CD21+ dendritic cells contained HIV-1 DNA. From 5 to 80% of the CD4+ cells in these lymph nodes contained HIV-1 DNA, as compared with 1-11% of the CD4+ peripheral blood mononuclear cells. The infection in most cells was latent in the asymptomatic group. In contrast, the lymph nodes of patients with advanced AIDS showed marked depletion of both dendritic and CD4+ cells. The majority of the remaining CD4+ cells in the lymph nodes and blood showed PCR-amplified viral DNA and cDNA sequences suggesting the presence of genomic and multiple spliced transcripts. It is concluded that asymptomatic HIV-1 infection is associated with a wide range of latent to active viral-positive CD4+ lymphocytes and dendritic cells in the lymph nodes. Progression to AIDS is characterized by active viral replication in many of the remaining CD4+ cells in the lymph nodes and blood.

Histological distribution of polymerase chain reaction--amplified human papillomavirus 6 and 11 DNA in penile lesions.

The purpose of this study was to ascertain the histological pattern of distribution of human papillomavirus (HPV) 6 and 11 DNA in penile lesions by in situ hybridization after amplification by the polymerase chain reaction (PCR). HPV DNA was routinely detected by in situ hybridization with or without PCR amplification in granular layer cells that showed perinuclear halos and nuclear atypia. Cells that lack these histological features rarely exhibited HPV DNA with conventional in situ hybridization. However, after PCR amplification, in situ analysis showed that many of the cells that lacked halos and atypia contained HPV DNA. The hybridization signal often localized to crevices in the epithelium where there was relative hyperkeratosis and a thickened granular layer. HPV DNA was not noted in the basal cells and was rarely identified in other parts of the lesion. It is concluded that penile tissues may contain HPV DNA when lacking the diagnostic features of a condyloma/low-grade intraepithelial lesions and that such tissues usually demonstrate specific histological changes characterized by a focally thickened granular layer often associated with epithelial crevices.

Microbiologic investigation on patients with cystic fibrosis subjected to bilateral lung transplantation.

BACKGROUND: In cystic fibrosis (CF) patients, lung transplantation is the only way to improve both quality and length of life. Data in the literature show that, in 80% of the cases, mortality after lung transplantation in CF patients is due to infections. METHODS: We microbiologically monitored 34 patients subjected to bilateral lung transplantation in during 1996 to 1999 to ascertain whether a change in the bacterial species isolated from the lower respiratory tract took place that might have influenced the clinical conditions of the patients. RESULTS: Our results show that the percentage of nonfermenting Gram-negative bacteria isolated from the lower respiratory tract remains high even in the posttransplantation phase. Nevertheless, the general clinical conditions of most of the patients were good and the three patients who died did not do as a consequence of an infection. CONCLUSIONS: Lung transplantation constitutes a valid therapeutic choice for CF patients because the microorganisms that we isolated from the lungs of the patients in our study behave mostly as contaminants rather than as colonizers. However, the transplanted patients remain at risk and thus require constant microbiological surveillance.

Second harmonic imaging improves trans-abdominal ultrasound detection of biliary sludge in 'idiopathic' pancreatitis.

BACKGROUND: Recently, biliary sludge has been strongly correlated with 'idiopathic pancreatitis'. It is often diagnosed by trans-abdominal ultrasonography, despite the low sensitivity of this investigation. New scanners, using second harmonic imaging, may improve the quality of the echographic picture. AIM: To verify the impact of this methodology on the detection of biliary sludge in patients with 'idiopathic' pancreatitis. METHODS: Fifty patients with 'idiopathic' pancreatitis observed over a 18-month period entered the study. Exclusion criteria were gall-bladder stones, polyps, clinical conditions related to biliary sludge development and haemolytic disorders. Patients were assessed blind by two operators using either conventional ultrasonography or second harmonic imaging. The parameters of diagnostic quality of both examinations were evaluated using, as the gold standard, microscopic examination of the gall-bladder content collected at endoscopy after cholecystokinin infusion. RESULTS: An improvement in sensitivity, specificity, efficiency and negative predictive value was obtained by second harmonic imaging compared with conventional ultrasonography. CONCLUSIONS: Second harmonic imaging, in our experience, is a reliable non-invasive tool for the diagnosis and follow-up of biliary sludge in the course of 'idiopathic' pancreatitis.

Sequential treatment for Helicobacter pylori does not share the risk factors of triple therapy failure.

BACKGROUND: Predicting factors for the outcome of conventional Helicobacter pylori triple therapy have been identified. Of these, the presence of the CagA gene is a strong predictor of successful treatment. Our preliminary data show that this factor becomes irrelevant when sequential therapy is used. AIM: To identify predicting factors for the outcome of H. pylori eradication using two therapeutic schemes (triple and sequential) of equal duration (10 days). METHODS: Ninety-six patients with H. pylori infection were randomly assigned to receive one of the following therapeutic schemes: group A: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) for 5 days, followed by rabeprazole (20 mg b.d.) plus tinidazole (500 mg b.d.) and clarithromycin (500 mg b.d.) for a further 5 days; group B: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) and clarithromycin (500 mg b.d.) for 10 days. Age, sex, smoking, endoscopic and histological findings, and CagA and VacA status were considered as candidates for a model of multivariate analysis which used therapeutic outcome as the dependent variable. CagA and VacA status were assessed by polymerase chain reaction on DNA isolated from gastric antral specimens. RESULTS: The sequential scheme was significantly more effective than prolonged triple therapy (P < 0.05). Smoking (P < 0.001) and the absence of the CagA gene (P < 0.05) were significantly associated with the failure of triple therapy, but the effectiveness of sequential treatment was not predicted by these factors. CONCLUSION: Our data suggest that sequential therapy is not affected by bacterial and host factors which have, until now, predicted the outcome of conventional eradication treatments.

Sensitivity and detection efficiency of the peroxidase antiperoxidase (PAP), avidin-biotin peroxidase complex (ABC), and peroxidase-labeled avidin-biotin (LAB) methods.

The authors have examined the sensitivity and detection efficiency of the three peroxidase methods that currently have the widest application in diagnostic immunohistochemistry: the peroxidase-antiperoxidase (PAP), the avidin-biotin complex (ABC), and the labeled avidin-biotin (LAB) methods. Sensitivity was evaluated by determining the highest useful dilution of polyclonal antiglucagon antibodies applied to formalin-fixed, paraffin-embedded human pancreas. Detection efficiency was evaluated by tabulation of the total number of positive (three or more positive cells) islets. On direct comparison, the LAB method exceeded the PAP and ABC methods in both sensitivity and detection efficiency, which were essentially equal. Titration of linking antiserum of the PAP method boosted its sensitivity and detection efficiency above that of ABC; the PAP had equal sensitivity to the LAB and exceeded it in detection efficiency. The authors conclude that comparisons of immunohistologic methods are meaningful only if both sensitivity and efficiency are considered along with the unique requirements of any single method.

Rapid in situ detection of PCR-amplified HIV-1 DNA.

The low copy number of human immunodeficiency virus 1 (HIV-1) DNA infected cells precludes routine detection by in situ hybridization. The inability to detect cells latently infected by HIV-1 makes difficult the study of factors that induce viral transcription, an essential factor in the development of the acquired immune deficiency syndrome (AIDS). A sensitive and rapid technique to detect HIV-1 DNA could be used as a diagnostic test for AIDS and to differentiate latent versus active viral infection. We describe a 3-h technique whereby HIV-1 DNA is amplified by hot start polymerase chain reaction (PCR) and detected directly in infected cells. The specificity of the assay was demonstrated by double labeling the positive cells with CD4. Using a CR10 HIV-1-infected cell line, the 90% of cells that were HIV-1 DNA positive could be distinguished from the 10% that were actively expressing HIV-1 RNA. The PCR in situ technique should allow for the direct localization of DNA sequences in cells that would otherwise be undetectable by conventional in situ analysis.

Endothelial cells adherent to expanded polytetrafluoroethylene express the intercellular adhesion molecule-1.

BACKGROUND: The foreign body reaction caused by implanted biomaterials is not fully characterized. To evaluate the effect of an expanded polytetrafluoroethylene (ePTFE) surface on the binding of monoclonal antibodies against the intercellular adhesion molecule (ICAM-1) by adherent endothelial cells, an in vitro bioassay was developed. STUDY DESIGN: Human saphenous vein endothelial cells (HSVEC) and human umbilical vein endothelial cells (HUVEC) were grown to confluency on fibronectin-pretreated ePTFE and on fibronectin-pretreated polystyrene culture flasks used as controls. Cells were assayed for size, density, viability, and binding of anti-ICAM-1 antibodies. Human peripheral blood leukocytes (PBLs) were then cocultured with HUVEC adherent to ePTFE and control polystyrene and HUVEC were assayed for the binding of anti-ICAM-1 antibodies. RESULTS: The adherence of HSVEC and HUVEC to ePTFE resulted in a twofold increase in the binding of monoclonal antibodies against ICAM-1 compared with controls at 48 hours (p < 0.005). The addition of PBLs to the adherent HUVEC resulted in a four- to eightfold increase in anti-ICAM-1 antibody binding on ePTFE and polystyrene, respectively, at 24 hours. CONCLUSIONS: Adherence of endothelial cells to ePTFE results in an increase in the binding of anti-ICAM-1 antibodies. Coculture of adherent HUVEC and PBLs results in a marked increase in the number of cells binding ICAM-1 antibodies. These data support the conclusion that ePTFE is associated with the activation of adherent cells, which is one aspect of a multicellular inflammatory response.

Role of adhesion molecules in leukocyte binding to endothelial cells adherent to vascular grafts.

BACKGROUND: The localization of leukocytes to vascular grafts is an essential part of healing and infection resistance. The mechanisms involved in this process are only partly understood. STUDY DESIGN: Human saphenous vein endothelial cells (HSVEC) were grown on control polystyrene culture ware and expanded polytetrafluoroethylene (ePTFE). The binding of monoclonal antibodies against the intercellular adhesion molecule (ICAM-1) and the E-selectin by adherent HSVEC was determined by flow cytometry. Peripheral blood leukocytes (PBL) were cocultured with HSVEC adherent to ePTFE and leukocyte binding was determined with and without the addition of a protein kinase C inhibitor. RESULTS: HSVEC adherent to ePTFE constitutively bound anti-ICAM-1 antibodies, which were attenuated by the protein kinase C inhibitor, H-7. HSVEC adherent to ePTFE bound significantly greater numbers of leukocytes than those on control (58 versus 41 percent, p < 0.05). Incubation with H-7 decreased leukocyte binding to HSVEC significantly (p < 0.005). Coculture of PBL with HSVEC adherent to ePTFE caused a tenfold increase in binding of anti-E-selectin antibodies (p < 0.0005). CONCLUSIONS: These data indicate that PBL binding to HSVEC adherent to ePTFE is, at least in part, ICAM-1 to HSVEC adherent to ePTFE is, at least in part, ICAM-1 and E-selection dependent.

Molecular mechanisms of augmenter of liver regeneration as immunoregulator: its effect on interferon-gamma expression in rat liver.

BACKGROUND: We have shown that the administration of exogenous Augmenter of Liver Regeneration protein in intact rats i) regulates mitochondrial gene expression by inducing the transcription and translation of the nuclear-encoded mitochondrial transcription factor A, and ii) inhibits the lytic activity of liver-resident Natural Killer cells. AIMS: The present investigation was carried out to study the effect, in intact rats, of exogenous administration of Augmenter of Liver Regeneration protein on Interferon-gamma, a cytokine produced by activated Natural Killer cells and known to control the expression of mitochondrial transcription factor A, a nuclear gene responsible for mitochondrial metabolism. METHODS: Interferon-gamma was measured as messenger RNA in liver-derived mononuclear leukocytes and as protein in liver-derived Natural Killer cells after a single injection of Augmenter of Liver Regeneration protein. RESULTS: The data obtained demonstrate that: i) in intact rats, Augmenter of Liver Regeneration protein administration induces a reduction of Interferon-gamma in the liver-resident Natural Killer cells and ii) the administration of Interferon-gamma in 70% hepatectomized rats is followed by a significant reduction both of the mitochondrial transcription factor A expression and of liver regeneration. CONCLUSIONS: These data demonstrate the pivotal role of Augmenter of Liver Regeneration as Growth Factor and as immunoregulator by controlling, through Interferon-gamma levels, the mitochondrial transcription factor A expression and the lytic activity of liver-resident Natural Killer cells.

The augmenter of liver regeneration induces mitochondrial gene expression in rat liver and enhances oxidative phosphorylation capacity of liver mitochondria.

BACKGROUND: The mammalian augmenter of liver regeneration gene encodes a protein involved in the unique process of liver regeneration. The augmenter of liver regeneration respective protein stimulates hepatocyte proliferation in hepatectomized rats and inhibits cytotoxic activity of liver-derived Natural Killer cells from intact rats. Augmenter of liver regeneration protein shares homology with a Saccharomyces Cerevisiae protein essential for the viability, oxidative phosphorylation and cell-division cycle. AIMS: To demonstrate if augmenter of liver regeneration protein, like the homologous in the yeast, plays a role in the regulation of biogenesis of mitochondria. METHODS: Augmenter of liver regeneration protein was injected in intact rats and, in the hepatic tissue, the expression of two genes located in two different regions of the mitochondrial genome, mitochondrial ATPase 6/8, and ND1 subunit, and of a nuclear gene, mitochondrial Transcription Factor A, were considered. In addition, cytochrome content and oxidative phosphorylation capacity of liver-derived mitochondria were evaluated. RESULTS: The augmenter of liver regeneration protein administration induces an increase in the mitochondrial gene expression and enhances cytochrome content and oxidative phosphorylation capacity of liver-derived mitochondria. CONCLUSIONS: The present data demonstrate a comparable role in the regulation of mitochondria biogenesis in the eukaryotic cell like the yeast protein. This phenomenon could be part of the complex mechanism through which augmenter of liver regeneration regulates hepatocyte proliferation.

Different reactivity against HCV proteins (RIBA 3) according to progression of liver damage.

BACKGROUND: Aim of the study was to assess the correlation between clinical stage of HCV-related liver disease and viraemia to immune response to different viral antigens. METHODS: We considered 1330 patients with HCV chronic infection followed up from 6 months up to 6 years divided into two groups according to RIBA 3 (Abbott) response: Group I, 1231 patients with positivity for at least two bands (83 subjects with asymptomatic infection, 941 with chronic hepatitis, 201 with cirrhosis and 6 with HCC); Group II, 99 patients with positivity at only one band (45 with asymptomatic infection, 53 with chronic hepatitis and 1 cirrhotic). RESULTS: We noticed a major percentage of positive patients for at least three bands in more severe clinical forms (90% of chronic hepatitis or cirrhosis versus 60% of asymptomatics, p < 0.005, chi 2 test). Moreover we noticed a percentage increase of positivity for antibodies anti-c100 and anti-NS5 with the progression of liver damage, statistically significant differences between asymptomatics and patients with chronic forms. We also observed that viraemia is related neither to clinical stage nor to different reactivity to RIBA 3, albeit viraemia is usually detected more frequently among patients with liver damage, but unrelated to different reactivities. CONCLUSIONS: Our results show a clear correlation between number of reactivities towards HCV proteins and progression of liver damage, pointing out that immune response plays a direct role in the long-term outcome of HCV infection.

Peritoneoscintigraphy in the diagnosis of traumatic diaphragmatic rupture.

Current diagnostic modalities for traumatic diaphragmatic hernia (TDH) have limitations. Prior models differ from human injury. This study evaluates peritoneoscintigraphy in a rabbit model of TDH simulating human blunt injury. Ten adult New Zealand rabbits (two control, eight experimental) underwent tracheostomy and left thoracotomy under anesthesia. Experimental animals received a radial phrenotomy (1.0 to 3.5 cm). Incisions were closed over thoracostomy tubes, and ventilation was discontinued. Catheters were inserted intraperitoneally, and radiotracer in saline was injected. A gamma counter was used to take sequential images. Transdiaphraghmatic isotope was seen in only two animals. Both had large injuries; in one, the catheter was directed toward the diaphragmatic defect. We conclude that peritoneoscintigraphy is insensitive in the detection of TDH. It is unlikely to be an effective technique coupled with diagnostic peritoneal lavage. Further efforts to refine diagnostic capability for TDH should be directed elsewhere, such as laparoscopy.

[Prevalence of Helicobacter pylori antibodies in patients with kidney transplantation]. / Prevalenza della sieropositività anti Helicobacter pylori in soggetti con trapianto di rene.

INTRODUCTION: Our target was to verify if belonging to a selected group of patients, who have undergone a kidney transplantation and before that suffered from high level of uremia sometimes with border line levels , could be a risk factor for acquiring HP antibodies. MATERIALS AND METHODS: We evaluated in 23 patients, with an average age of 16.3, attending our Day-Hospital Unit to be followed up after a kidney transplant, the prevalence of anti-HP antibodies, measured in serum by the ELISA method. The prevalence in this group has been compared with that observed in a healthy cohort of 36 people. RESULTS: Antibodies were present in 31.8% of our patients without any correlation with age, age of transplant, serum urea level, cyclosporinemia, total lgG and IgA antibodies. DISCUSSION: In the end, kidney transplantation doesn't seem to be a risk factor for acquiring HP infection. Detecting HP antibodies can be a method to select patients that must undergo other strumental examinations.

[In vitro mucociliary clearance: observations in subjects exposed to acute inhalation of nitrous vapors]. / La clearance mucociliare in vitro: osservazioni su soggetti esposti ad inalazione acuta di vapori nitrosi.

Acute inhalation of nitrous vapours did not cause any damage to the respiratory apparatus detectable via spirometric or X-ray tests in the four workers who were actually exposed and kept under observation during the two months following the explosion of a tank containing nitric acid. However, measurement of the coefficient of relative transport speed in vitro of tracheo-bronchial secretions revealed alterations of the mucus related to specific situations, such as during acute inhalation of nitrous vapours and upon resuming work. The coefficient of relative speed, obtained with the in vitro technique on the palate of the frog, thus proved to be reliable in monitoring irritation of the mucus secreting apparatus of workers accidentally exposed to acute inhalation of nitrous vapours.

[Mucociliary clearance and respiratory function in foundry workers]. / Clearance mucociliare e funzionalità respiratoria in lavoratori di fonderia.

The aim of the study was to establish whether changes occur in respiratory function, particularly mucociliary clearance, among second fusion smeltery workers. The research covered 93 male smelters employed in steel forming and casting and 116 male workers of an electric power station, considered as non-exposed. Physiological, pathological and occupational histories of all subjects under study were available. An ECCS respiratory symptoms questionnaire was administered to all subjects ad the two groups also underwent a general medical examination, a spirometry and a chest X-ray. During the medical examination sputum was collected from the subjects to measure mucus transport rate on frog palate, expressed as Normalised Frog Palate Transport Rate (NFPTR). For the environmental research, dust, fumes and gas samplings were taken either at a fixed station or by means of personal dosimeters. Environmental research revealed very low concentrations of respiratory irritants (total dust: 0.2-6.8 mg/m3; respirable dust: 0.1-4.9 mg/m3; total silica: < 2-15.5%; respirable silica: < 0.004-0.3 mg/m3; iron: 0.008-0.085 mg/m3; chromium and manganese: < 0.001 mg/m3; fumes and gases: well below the TLV. The two groups were homogeneous with regard to age and smoking habits. Exposed workers showed rales, dyspnoea and spontaneous phlegm more frequently than non-exposed workers. NFPTR alterations were checked in 49 out of 81 exposed and in 18 out of 81 non-exposed subjects (chi squared = 22.9; p < 0.001). Stratification of the results according to smoking habits further confirmed the strong association between occupational exposure and NFPTR alterations. Smelters showed significantly lower mean NFPTR values compared to non-exposed subjects; also, the mean value of NFPTR in the exposed was below 0.70, which is considered the lowest individual limit in normal subjects. The only variable which explains a large part of the variability of NFPTR is past work in a smeltery rather than in an electric power station. The spirometries showed that only the mean PEF values were significantly lower among the exposed. Stratified analysis of the results according to smoking habits in the two groups revealed a close association between smeltery work and reduction of PEF to under 80% of the ECCS 1983 theoretical values, independently of smoking habits. We also compared the mean PEF values, both as measured values and as percent values of the ECCS 1983 theoretical values, stratified for occupational exposure and smoking; the results again showed that differences between these mean values were mainly due to current or past work in the foundry.(ABSTRACT TRUNCATED AT 400 WORDS)