Radiation-induced acute dysphagia : Prospective observational study on 42 head and neck cancer patients.

PURPOSE: Acute toxicity in head and neck (H&N) cancer patients treated with definitive radiotherapy (RT) has a crucial role in compliance to treatments. The aim of this study was to correlate doses to swallowing-associated structures and acute dysphagia. METHODS: We prospectively analyzed 42 H&N cancer patients treated with RT. Dysphagia (grade ≥ 3) and indication for percutaneous endoscopic gastrostomy (PEG) insertion were classified as acute toxicity. Ten swallowing-related structures were considered for the dosimetric analysis. The correlation between clinical information and the dose absorbed by the contoured structures was analyzed. Multivariate logistic regression method using resampling methods (bootstrapping) was applied to select model order and parameters for normal tissue complication probability (NTCP) modelling. RESULTS: A strong multiple correlation between dosimetric parameters was found. A two-variable model was suggested as the optimal order by bootstrap method. The optimal model (Rs = 0.452, p < 0.001) includes V45 of the cervical esophagus (odds ratio [OR] = 1.016) and Dmean of the cricopharyngeal muscle (OR = 1.057). The model area under the curve was 0.82 (95% confidence interval 0.69-0.95). CONCLUSION: Our results suggested that the absorbed dose to the cricopharyngeal muscle and cervical esophagus might play a relevant role in the development of acute RT-related dysphagia.

Monothalamous soft-shelled foraminiferal image dataset from the Kveithola Trough (NW Barents Sea).

We present an image dataset of monothalamous soft-shelled Foraminifera (Monothalamea, [1]), an important component of benthic foraminiferal assemblage in sediment cores collected during two oceanographic expeditions that contributed to the MSM30-CORIBAR project (Ice dynamics and meltwater deposits: coring in the Kveithola trough, NW Barents Sea). 9 subsamples of sediment cores were collected during different years (2013-2016) in the Kveithola Trough, a glacially carved system in the NW Barents Sea. Cores were retrieved using a multi-corer (MUC) and a giant box-corer (GBC) and the subcores for foraminiferal analyses were obtained using Plexiglas tubes inserted manually into the cores. These subcores were sliced at 0.5 cm intervals down to 2 cm sediment depth and then every 1 cm down to 10 cm. Two staining methods, Cell Tracker Green (CTG) and Rose Bengal (RB), were used to distinguish between living and dead individuals. Then, the fixed sediment samples were sieved through 63 and 150 µm mesh screens and preserved in 10 % borax-buffered formalin. Six species and 37 undescribed morphotypes were recognized and included in this image dataset. Relatively few species of soft-shelled, monothalamous foraminifera have been described compared to a much larger number of undescribed morphotypes recognised from across the marine realm. Few researchers study with their taxonomy because of the time and difficulties that morphological identification involves. In addition, because "soft", delicate monothalamids rarely fossilize, they are generally overlooked by micropaleontologists. However, they are abundant and diverse and represent an important faunal component of marine as well as freshwater ecosystems. Further information about these frequently overlooked protists will help to address important knowledge gaps and enhance our ability to manage and conserve the planet's resources responsibly. In particular, our image dataset highlights the importance of monothalamous soft-shelled foraminifera in this peculiar Arctic environment and contributes to the first species/morphotype checklist for the area. We hope it will serve to fill gaps in knowledge regarding the ecology and biodiversity of benthic foraminifera, helping users to identify monothalamids species and morphotypes in Arctic waters and beyond. This data article is associated with the research papers: "Benthic foraminiferal assemblages and environmental drivers along the Kveithola Trough (NW Barents Sea)" by [2].

Connexin 26 Expression in Mammalian Cardiomyocytes.

Connexins are a family of membrane-spanning proteins named according to their molecular weight. They are known to form membrane channels mediating cell-cell communication, which play an essential role in the propagation of electrical activity in the heart. Cx26 has been described in a number of tissues but not in the heart, and its mutations are frequently associated with deafness and skin diseases. The aim of this study was to assess the possible Cx26 expression in heart tissues of different mammalian species and to demonstrate its localization at level of cardiomyocytes. Samples of pig, human and rat heart and H9c2 cells were used for our research. Immunohistochemical and molecular biology techniques were employed to test the expression of Cx26. Interestingly, this connexin was found in cardiomyocytes, at level of clusters scattered over the cell cytoplasm but not at level of the intercalated discs where the other cardiac connexins are usually located. Furthermore, the expression of Cx26 in H9c2 myoblast cells increased when they were differentiated into cardiac-like phenotype. To our knowledge, the expression of Cx26 in pig, human and rat has been demonstrated for the first time in the present paper.

Selective zircon accumulation in a new benthic foraminifer, Psammophaga zirconia, sp. nov.

Benthic foraminifera are single-celled eukaryotes that make a protective organic, agglutinated or calcareous test. Some agglutinated, single-chambered taxa, including Psammophaga Arnold, 1982, retain mineral particles in their cytoplasm, but the selective mechanism of accumulation is not clear. Here, we report the ability of a foraminiferal species to select and accumulate zircons and other heavy minerals in their cytoplasm. In particular, the use of Scanning Electron Microscope coupled with an Energy Dispersive X-ray microanalysis system (SEM-EDS) enabled a representative overview of the mineral diversity and showed that the analysed Psammophaga zirconia sp. nov. individuals contained dominantly crystals of zircon (51%), titanium oxides (27%), and ilmenite (11%) along with minor magnetite and other minerals. The studied specimens occur in the shallow central Adriatic Sea where the sediment has a content of zircon below 1% and of other heavy minerals below 4%. For that reason we hypothesize that: (i) P. zirconia may be able to chemically select minerals, specifically zircon and rutile; (ii) the chemical mechanism allowing the selection is based on electrostatic interaction, and it could work also for agglutinated foraminifera (whether for ingestion, like Xenophyophores, or incorporation in the test as in many other described taxa). In particular, this aptitude for high preferential uptake and differential ingestion or retention of zircon is reported here for the first time, together with the selection of other heavy minerals already described in members of the genus Psammophaga. They are generally counted among early foraminifera, constructing a morphologically simple test with a single chamber. Our molecular phylogenetic study confirms that P. zirconia is a new species, genetically distinctive from other Psammophaga, and occurs in the Adriatic as well as in the Black Sea.

Regulation of skeletal muscle AMP deaminase: lysine residues are critical for the pH-dependent positive homotropic cooperativity behaviour of the rabbit enzyme.

Reaction of rabbit skeletal muscle AMP deaminase with a low molar excess of trinitrobenzene sulfonic acid (TNBS) results in conversion of the enzyme into a species with about six trinitrophenylated lysine residues per molecule which no longer manifests positive homotropic cooperativity at pH 7.1 or at the optimal pH value of 6.5 in the presence of low K+ concentrations. Substitution of the reactive thiol groups with 5,5'-dithiobis-(2-nitrobenzoic acid) does not protect the enzyme from the TNBS-induced changes of the catalytic properties, indicating that cysteine residues modification is not at the basis of the effects of TNBS treatment on AMP deaminase and strongly suggesting the obligatory participation of lysine residues to the constitution of a regulatory anionic site to which AMP must bind to stimulate the enzyme at alkaline pH. The TNBS-treated enzyme is also completely desensitized to inhibition by ATP, but not to inhibition by GTP and stimulation by ADP. This observation suggests a connection between the operation of the hypothesized anionic activating site, responsible for positive homotropic cooperativity, and the inhibition exerted by anionic compounds that compete for the same site, among them the most efficient metabolite being probably ATP.

Binding of a monoclonal antibody E12 to Gc globulin (vitamin D-binding protein) is inhibited by actin.

A monoclonal antibody, E12, to human Gc globulin was raised in murine somatic cell using purified Gc. The antibody was subtyped IgG2b kappa and had a kd of 3.0 x 10(-8) M for antigen Gc. Monospecificity for Gc was demonstrated by Western blotting of normal human serum using nondenaturing polyacrylamide gel electrophoresis. As judged by ELISA, actin inhibited binding of E12 to Gc in dose-dependent fashion. Affinity chromatography studies further showed that ternary complexes of actin-Gc-E12 were not formed, and actin displaced Gc from Gc-E12 complexes. Proteolytic digestion of Gc with trypsin showed that the monoclonal antibody E12 reacted with the major 30-kDa tryptic fragment containing the amino terminal fragment of Gc, but actin did not react with this fragment. These results indicate that interaction of actin with Gc causes conformational changes which inhibit binding of E12.

A calpain-like proteolytic activity produces the limited cleavage at the N-terminal regulatory domain of rabbit skeletal muscle AMP deaminase: evidence of a protective molecular mechanism.

On storage at 4 degrees C, rabbit skeletal muscle AMP deaminase undergoes limited proteolysis with the conversion of the native 85-kDa enzyme subunit to a 75-kDa core that is resistant to further proteolysis. Further studies have shown that limited proteolysis of AMP deaminase with trypsin, removing the 95-residue N-terminal fragment, converts the native enzyme to a species that exhibits hyperbolic kinetics even at low K+ concentration. The results of this report show that a 21-residue synthetic peptide, when incubated with the purified enzyme, is cleaved with a specificity identical to that reported for ubiquitous calpains. In addition, the cleavage of a specific fluorogenic peptide substrate by rabbit m-calpain is inhibited by a synthetic peptide that corresponds to residues 10-17 of rabbit skeletal muscle AMP deaminase; this peptide contains a sequence (K-E-L-D-D-A) that is present in the fourth subdomain A of rabbit calpastatin, suggesting that the N-terminus of AMP deaminase shares with calpastatin a regulatory sequence that might exert a protective role against the fragmentation-induced activation of AMP deaminase. These observations suggest that a calpain-like proteinase present in muscle removes from AMP deaminase a domain that holds the enzyme in an inactive conformation and which also contains a regulatory region that protects against unregulated proteolysis. We conclude that proteolysis of AMP deaminase is the basis of the large ammonia accumulation that occurs in skeletal muscle subjected to strong tetanic contraction or passing into rigor mortis.

Phenotypic characteristics and tendency to apoptosis of peripheral blood mononuclear cells from HIV+ long term non progressors.

The aim of this study was to analyze (i) phenotype, (ii) in vitro spontaneous and induced apoptosis, (iii) glutathione (GSH) intracellular content and (iv) inhibitors of apoptosis of potential therapeutical use in peripheral blood mononuclear cells (PBMC) from HIV+ long term non progressors (LTNP), in comparison with progressors (HIV+P) and seronegative controls (HIV-). Three groups of subjects were studied: 15 HIV+P (patients losing >150 CD4+/year), 9 LTNP (subjects infected by HIV for at least 7 years without clinical and immunological signs of progression, with a mean of 898 CD4+/microL) and 18 HIV-. All subjects were living in a large community for former drug addicts, and were matched for age and sex. We used flow cytometry for analyzing PBMC phenotype and apoptosis; high performance liquid chromatography for measuring intracellular GSH content. PBMC phenotype of LTNP shared characteristics with those of both HIV- and HIV+P. Indeed, LTNP showed a normal number CD4+ cells (an inclusion criteria), but significantly increased numbers of CD8+ lymphocytes, activated T cells, CD19+, CD5+ B lymphocytes and CD57+ cells, as well as a decrease in CD19+, CD5- B lymphocytes and CD16+ cells. In LTNP, spontaneous apoptosis was similar to that of HIV- and significantly lower than that of HIV+P. Adding interleukin-2 (IL-2) or nicotinamide (NAM) significantly decreased spontaneous apoptosis in LTNP and HIV+P. Pokeweed mitogen-induced apoptosis was also similar in LTNP and HIV-, but significantly lower than that of HIV+P. In HIV+P, but also in LTNP, spontaneous apoptosis was inversely correlated to the absolute number and percentage of CD4+ cells and directly correlated to the number and percentage of activated T cells present in peripheral blood. GSH intracellular content was greatly decreased in PBMC from HIV+P and slightly, but significantly, reduced in LTNP. Adding 2-deoxy-D-ribose, an agent provoking apoptosis through GSH depletion, to quiescent PBMC resulted in similar levels of massive cell death in the three groups. This phenomenon was equally prevented in the three groups by N-acetyl-cysteine but not by IL-2. A complex immunological situation seems to occur in LTNP. Indeed, PBMC from LTNP are characterized by a normal in vitro tendency to undergo apoptosis despite the presence of a strong activation of their immune system, unexpectedly similar to that of HIV+P. Our data suggest that NAM and IL-2 are possible candidates for reducing spontaneous apoptosis in HIV infection.

A simultaneous outbreak of Serratia marcescens and Klebsiella pneumoniae in a neonatal intensive care unit.

We describe two concurrent outbreaks of Serratia marcescens and Klebsiella pneumoniae in a neonatal intensive care unit (NICU). Over a 16-month period, a total of 27 infants were either colonized (N=14) or infected (N=13). There were 15 cases of S. marcescens and 11 cases of K. pneumoniae. Both micro-organisms were involved in one fatal case. Seven preterm babies developed septicaemia, two had bacteraemia, three had respiratory infections and one had purulent conjunctivitis. The S. marcescens and K. pneumoniae isolates were investigated by three molecular methods: enterobacterial repetitive intergenic consensus polymerase chain reaction (PCR), arbitrary primed PCR with M13 primer, and random amplification of polymorphic DNA. Different patterns were found in the 16 S. marcescens epidemic isolates from 16 newborn infants. The major epidemic-involved genotype was linked to the first nine cases and this was subsequently replaced by different patterns. Eight different typing profiles were also determined for the 13 K. pneumoniae isolates from 12 newborn infants. Four K. pneumoniae bacteraemic strains proved to be identical. In conclusion, the typing results revealed that two different micro-organisms (S. marcescens and K. pneumoniae) were simultaneously involved in invasive nosocomial infections in preterm newborns. Two simultaneous clusters of cases were documented. Heterogeneous genotypes among both species were also demonstrated to be present in the NICU at the same time. A focal source for both micro-organisms was not identified but cross-transmission through handling was probably an important route in this outbreak. Strict adherence to handwashing policies, cohorting, isolation of colonized and infected patients, and rigorous environmental hygiene were crucial measures in the containment of the epidemic.

Mitochondria alterations and dramatic tendency to undergo apoptosis in peripheral blood lymphocytes during acute HIV syndrome.

OBJECTIVE: To study alterations of mitochondrial membrane potential (delta psi) and the propensity to undergo apoptosis in peripheral blood lymphocytes (PBL) from subjects with acute HIV syndrome; and to evaluate possible modulations of these phenomena by antioxidants that can be used in therapy, such as N-acetyl-cysteine (NAC), nicotinamide (NAM), or L-acetyl-carnitine (LAC). METHODS: Mitochondrial function and the tendency of PBL to undergo spontaneous apoptosis were studied on freshly collected PBL from patients with symptomatic, acute HIV-1 primary infection, which were cultured for different durations in the presence of absence of NAC. NAM or LAC. By a cytofluorimetric method allowing analysis of delta psi in intact cells, we studied the function of these organelles under the different conditions. PBL apoptosis was evaluated by the classic cytofluorimetric method of propidium iodide staining, capable of revealing the typical DNA hypodiploid peak. RESULTS: Significant delta psi alterations and tendency to undergo apoptosis were present in PBL from the subjects we studied. Indeed, when cultured even for a few hours in the absence of any stimulus, a consistent number of cells died. However, the presence of even different levels of NAC, NAM or LAC was able to rescue most of them from apoptosis. Both a fall in delta psi and apoptosis were evident in PBL collected in the earliest phases of the syndrome (before seroconversion), and changed significantly after a few days. A significant correlation was found between spontaneous apoptosis and tumour necrosis factor (TNF)-alpha or p24 plasma levels, as well as between apoptosis and the percentages of circulating CD4+ or CD8+ T cells. CONCLUSIONS: PBL from patients with acute HIV syndrome are characterized by both significant mitochondrial alterations and a dramatic tendency to undergo apoptosis. The use of NAC, NAM or LAC seems to rescue cells through a protective effect on mitochondria, a well-known target for the action of TNF-alpha and for reactive oxygen species, the production of which is strongly induced by this cytokine. Thus, our data could provide the rationale for the use of such agents in addition to antiviral drugs in primary infection.

Recent trends in the HIV epidemic among injecting drug users in Northern Italy, 1993-1999.

OBJECTIVE: To monitor and describe the time trends of the HIV epidemic among intravenous drug users (IDU) attending drug dependence treatment centres (DDTC) in Northern Italy. DESIGN: A cohort of all seronegative IDU attending DDTC in Lombardy between 1993 and 1999; all had been tested for HIV at least twice. Periodic sample interview surveys were done to assess risk behaviours. METHODS: The incidence rates of HIV infection were calculated using the person-year (PY) method and expressed as the number of cases per 1000 PY at risk. Background HIV prevalence was calculated by dividing the number of positive cases by the total number of IDU tested at all DDTC in Lombardy. RESULTS: Between 1993 and 1999, 135 seroconversions occurred in 7945 subjects followed for 19 671 PY, yielding an incidence rate of 6.9/1000 PY. Ninety seroconversions occurred among the 6563 males and 45 seroconversions among 1382 females (incidence rates 5.5 and 14.0, respectively). Among the males, the incidence of HIV was 4.5 in those aged less than 25 years and 5.8 in those aged 25 years or more. Among the females, the corresponding figures were 21.1 and 10.3. HIV prevalence decreased over time, and it was higher among females. Sexual behaviours at risk were more common among females. CONCLUSIONS: The incidence of HIV infection among IDU in Northern Italy was stable between 1993 and 1999. The higher incidence and prevalence among females and the different prevalence of risk behaviours between genders suggest an increasing role of heterosexual transmission.

Vitamin D binding protein is produced by human monocytes.

The expression of the DBP (vitamin D binding protein) gene was investigated in monocytes and in peripheral blood lymphocytes. DBP message was amplified through 35 cycles of PCR amplification using specific oligonucleotide primers. PCR products of the expected size were further identified by Southern blotting using a specific DBP probe. No expression of the DBP gene could be detected in peripheral blood lymphocytes, nor in the monocyte-derived U 937 cell line. In contrast, message for DBP was identified in monocytes activated with lipopolysaccharide when analyzed between 6 and 10 h following stimulation. These results suggest that the temporal expression of the DBP gene could play a major role in the activation of monocytes by 1-25(OH)2D3.

The vitamin D-binding protein gene: quantitation of amplified nucleic acids by ELISA.

We have utilized enzyme-linked immunosorbent assay (ELISA) to quantitate PCR-amplified DNA. This method was used to measure mRNA for the vitamin D-binding protein (Gc), beta-actin and the transferrin receptor (TR) gene in the Hep3B cell line. Total RNA from Hep3B cells was reverse transcribed to obtain cDNA, which was amplified in the presence of digoxigenin-dUTP by PCR. The PCR products were then hybridized in liquid phase to a biotinylated, nested capture probe for the respective sequences. The hybridized products were bound to a streptavidin-coated ELISA plate and were detected by an alkaline-phosphatase-conjugated antibody to digoxigenin. ELISA standard curves for Gc and control genes, beta-actin and TR, were obtained after PCR amplification of serial dilutions of Hep3B total RNA. As an external standard, an ELISA standard curve for Gc was obtained after PCR amplification of serial dilutions of a full-length Gc cDNA insert obtained from a recombinant plasmid. Thus, we were able to develop a non-isotopic quantitation assay for PCR-amplified DNA that is highly sensitive and has the specificity of hybridization-based methods.

Presence in human skeletal muscle of an AMP deaminase-associated protein that reacts with an antibody to human plasma histidine-proline-rich glycoprotein.

Histidine-proline-rich glycoprotein (HPRG) is a protein that is synthesized by parenchimal liver cells. The protein has been implicated in a number of plasma-specific processes, including blood coagulation and fibrinolysis. We have recently reported the association of an HPRG-like protein with rabbit skeletal muscle AMP deaminase (AMPD). The results of the immunological analysis reported here demonstrate that an antibody against human plasma HPRG reacts with an AMPD preparation from human skeletal muscle. To probe the localization of the putative HPRG-like protein in human skeletal muscle, serial sections from frozen biopsy specimens were processed for immunohistochemical and histoenzymatic stains. A selective binding of the anti-HPRG antibody to Type IIB muscle fibers was detected, suggesting a preferential association of the novel protein to the AMPD isoenzyme contained in the fast-twitch glycolytic fibers.

Growth of human herpesvirus 6 in HEPG2 cells.

HepG2 cells, a well differentiated liver cell line, were shown to be permissive for both human herpesvirus 6 (HHV-6) A and B strains by three independent methods of analysis: detection of viral antigens, viral DNA sequences and infectious virus. HepG2 cell infection with HHV-6 resulted in functional damage as shown by the increased release in the culture medium of some hepatocyte markers. Cells surviving the acute infection were serially passaged without showing cytopathic effect, but, some months later, HHV-6 DNA was still present in the cells and virus induction with a phorbol ester was successful. A possible pathogenetic role of HHV-6 in liver diseases is discussed. Experiments of HepG2 infection with human herpesvirus 7 (HHV-7) were also carried out. The lack of an efficient virus replication suggested a difficulty for HHV-7 to infect hepatic cells.

Is binding of vitamin D binding protein related to cell differentiation?

Vitamin D binding protein (Gc) is present on the surface of several blood cells and may interfere with the activity of 1,25(OH)2D3. It has previously been reported that Gc may bind to the U-937 line which is known to differentiate upon exposition to 1,25(OH)2D3. In the present paper, we evaluate the expression of Gc on the surface of U-937 and HL-60 lines. Both cell lines did not express Gc on their surface but U-937 cells were able to bind human purified Gc added to the medium whereas HL-60 were not. After culturing with 1,25(OH)2D3, HL-60 became able to bind Gc. This property seems to be related to the monocytic differentiation induced by 1,25(OH)2D3. Conversely, when present together, 1,25(OH)2D3 reduces binding on U-937.

Herpesvirus DNA is frequently detected in liver tissue from hepatitis C patients.

BACKGROUND AND AIMS: Herpesviruses infect the liver and cause minor hepatitis. Our aim is to verify the presence of herpesviruses in the liver from hepatitis C patients and the possible influence of these viruses in the liver disease. METHODS: We searched for herpesvirus DNA in liver biopsies from patients with hepatitis C and from a control group without hepatitis by means of nested polymerase chain reaction. Serological investigations were carried out as well. RESULTS: Thirty-four liver specimens from hepatitis C patients were examined, 12 of which (35.3%) were positive for at least one herpesvirus DNA, whereas among the 19 control specimens only two were positive (10.5%; P = 0.049). Liver biopsies from seven patients, three with acute hepatitis of unknown origin, three with non-alcoholic steatohepatitis and one with autoimmune hepatitis were also investigated and three positive samples were found. CONCLUSIONS: The prevalence of herpesvirus DNA was found higher in patients with hepatitis C than in individuals without hepatitis. The influence of herpesviruses on the clinical course of hepatitis C is considered.

Fetal pancreatic function in infants of diabetic and rhesus-isoimmunized women.

OBJECTIVE: To measure insulin and glucagon concentrations in amniotic fluid (AF) collected near term in basal conditions and after an arginine test in diabetic, rhesus-isoimmunized, and control pregnant women. METHODS: At baseline, AF was collected from 44 diabetic, 32 rhesus-isoimmunized, and 27 control pregnant women in late pregnancy. Fifty-two diabetic, six rhesus-isoimmunized, and nine control pregnant women had amniocentesis 2 hours after arginine infusion (30 g intravenous/30 minutes) at 33-36 weeks. RESULTS: Baseline AF glucose concentrations were significantly greater in diabetic women than the other conditions, and they related to the gestational age in the women with hemolytic disease of the newborn. Insulin and glucagon AF content of isoimmunized pregnancies overlapped controls, whereas insulin and insulin/glucagon molar ratios were significantly higher, and glucagon values lower, in diabetic pregnancies compared with isoimmunized and control pregnancies. In isoimmunized pregnancies, the AF concentrations of glucose, insulin, and glucagon were correlated with gestational age (less than 34, 34 weeks or more). The samples collected after arginine infusion, compared with those collected at baseline, showed significantly greater insulin and insulin/glucagon molar ratio values in diabetic (28 +/- 5 versus 11 +/- 1 microU/mL, P = .001; 29.4 +/- 1.7 versus 12.0 +/- 2.8, P = .001) and in Rh pregnant women (18 +/- 6 versus 7.7 +/- 0.7 microU/mL, P = .001; 30 +/- 9 versus 3.4 +/- 0.4 I/G, P = .001), whereas no significant difference was observed in the controls. CONCLUSION: Basal islet hormone concentrations in AF are modified by maternal diabetes and further influenced by arginine administration. Arginine produces an AF response that is similar in pregnancies complicated by diabetes mellitus and rhesus-isoimmunization, despite different (hyperglycemia and euglycemia) maternal blood glucose levels.

Pleural tent after upper lobectomy: a prospective randomized study.

BACKGROUND: The aim of the present study was to assess the cost/efficacy of the pleural tent procedure after upper lobectomy. METHODS: A prospective randomized analysis was performed on 50 patients submitted to upper lobectomy and divided into two groups: group 1 (25 patients) with pleural tent; group 2 (25 patients) without pleural tent. RESULTS: The univariate comparison between the two groups did not show any significant difference in terms of age, gender, spirometry, smoking history, chronic obstructive pulmonary disease index, side of tumor, arterial oxygen tension, arterial carbon dioxide tension, size and location of tumor, presence of pleural adhesions, length of the stapled parenchyma, and operative time. Pleural tent significantly reduced the days of postoperative air leak (1.2 versus 5.8, p = 0.01), chest tubes (5.4 versus 10.4, p = 0.01), and hospital stay (6.9 versus 10.8, p = 0.01). Moreover, no difference was noted between the two groups in terms of pleural effusion in the first postoperative 48 hours, need of postoperative blood transfusion, and occurrence of other complications. CONCLUSIONS: Pleural tenting after upper lobectomy is a safe and effective procedure and its routine use is warranted.

Use of human chondrocyte cell cultures to identify and characterize reactive antibodies in rheumatoid arthritis sera.

OBJECTIVE: To study the reactivity of rheumatoid arthritis (RA) sera with human chondrocyte populations isolated from normal cartilage and expanded in vitro. METHODS: Human articular chondrocytes were cultured as adherent (non-differentiated) cells on plastic dishes or in suspension (differentiated) on dishes previously coated with a thin layer of 1% agarose. Sera from 28 RA patients and 5 paired synovial fluids were tested on lysates from chondrocytes and fibroblasts as control by immunoblot. Antigen expression on the cell membrane was evaluated by flow cytometry in a few sera. RESULTS: In 9/28 RA sera IgG antibodies specific for chondrocyte antigens (97 kDa, 74 kDa, 67 kDa, 60 kDa, 54 kDa, 48 kDa and 37 kDa) were detected. Twelve sera reacted with proteins expressed both on chondrocytes and fibroblasts and 7 with fibroblasts only; two sera had no reactivity. When lysates from adherent or suspension chondrocytes were compared, RA sera reacted with higher intensity and detected more antigens on chondrocytes cultured in suspension. Flow cytometry assay demonstrated that RA sera are able to recognize antigens expressed on the cell membrane of the human chondrocytes. CONCLUSION: Our data indicate that: a) 32% of the RA sera contain antibodies reactive with antigens expressed exclusively by chondrocytes, but this value rises to 75% if antigens expressed both by chondrocytes and fibroblasts are considered; b) the reactivity of fully differentiated chondrocytes in suspension culture is higher than the reactivity of chondrocytes cultured in monolayer; and c) some of the chondrocyte-specific antigens identified are associated with the chondrocyte membrane. Thus, in vitro cultured chondrocytes may be used to study both the specificity and the biological activity of autoantibodies in RA.