Evaluation of data quality in the Spanish EURECCA Esophagogastric Cancer Registry

BACKGROUND

Although the number of nationwide clinical registries in upper gastrointestinal cancer is increasing, few of them perform regular clinical audits. The Spanish EURECCA Esophagogastric Cancer Registry (SEEGCR) was launched in 2013. The aim of this study was to assess the reliability of the data in terms of completeness and accuracy.

METHODS

Patients who were registered (2014-2017) in the online SEEGCR and underwent esophagectomy or gastrectomy with curative intent were selected for auditing. Independent teams of surgeons visited each center between July 2018 and December 2019 and checked the reliability of data entered into the registry. Completeness was established by comparing the cases reported in the registry with those provided by the Medical Documentation Service of each center. Twenty percent of randomly selected cases per hospital were checked during on-site visits for testing the accuracy of data (27 items per patient file). Correlation between the quality of the data and the hospital volume was also assessed.

RESULTS

Some 1839 patients from 19 centers were included in the registry. The mean completeness rate in the whole series was 97.8% (range 82.8-100%). For the accuracy, 462 (25.1%) cases were checked. Out of 12,312 items, 10,905 were available for verification, resulting in a perfect agreement of 95% (87.1-98.7%). There were 509 (4.7%) incorrect and 35 (0.3%) missing entries. No correlation between hospital volume and the rate of completeness and accuracy was observed.

CONCLUSIONS

Our results indicate that the SEEGCR contains reliable data.

Analysis of outcomes of emergency general and gastrointestinal surgery during the COVID-19 pandemic

BACKGROUND

Few surgical studies have provided adjusted comparative postoperative outcome data among contemporary patients with and without COVID-19 infection and patients treated before the pandemic. The aim of this study was to determine the impact of performing emergency surgery in patients with concomitant COVID-19 infection.

METHODS

Patients who underwent emergency general and gastrointestinal surgery from March to June 2020, and from March to June 2019 in 25 Spanish hospitals were included in a retrospective study (COVID-CIR). The main outcome was 30-day mortality. Secondary outcomes included postoperative complications and failure to rescue (mortality among patients who developed complications). Propensity score-matched comparisons were performed between patients who were positive and those who were negative for COVID-19; and between COVID-19-negative cohorts before and during the pandemic.

RESULTS

Some 5307 patients were included in the study (183 COVID-19-positive and 2132 COVID-19-negative during pandemic; 2992 treated before pandemic). During the pandemic, patients with COVID-19 infection had greater 30-day mortality than those without (12.6 versus 4.6 per cent), but this difference was not statistically significant after propensity score matching (odds ratio (OR) 1.58, 95 per cent c.i. 0.88 to 2.74). Those positive for COVID-19 had more complications (41.5 versus 23.9 per cent; OR 1.61, 1.11 to 2.33) and a higher likelihood of failure to rescue (30.3 versus 19.3 per cent; OR 1.10, 0.57 to 2.12). Patients who were negative for COVID-19 during the pandemic had similar rates of 30-day mortality (4.6 versus 3.2 per cent; OR 1.35, 0.98 to 1.86) and complications (23.9 versus 25.2 per cent; OR 0.89, 0.77 to 1.02), but a greater likelihood of failure to rescue (19.3 versus 12.9 per cent; OR 1.56, 95 per cent 1.10 to 2.19) than prepandemic controls.

CONCLUSION

Patients with COVID-19 infection undergoing emergency general and gastrointestinal surgery had worse postoperative outcomes than contemporary patients without COVID-19. COVID-19-negative patients operated on during the COVID-19 pandemic had a likelihood of greater failure-to-rescue than prepandemic controls.

Inflammation, edema and poor outcome are associated with hyperthermia in hypertensive intracerebral hemorrhages

Background and purpose

The deleterious effect of hyperthermia on intracerebral hemorrhage (ICH) has been studied. However, the results are not conclusive and new studies are needed to elucidate clinical factors that influence the poor outcome. The aim of this study was to identify the clinical factors (including ICH etiology) that influence the poor outcome associated with hyperthermia and ICH. We also tried to identify potential mechanisms involved in hyperthermia during ICH.

Methods

We conducted a retrospective study enrolling patients with non‐traumatic ICH from a prospective registry. We used logistic regression models to analyze the influence of hyperthermia in relation to different inflammatory and endothelial dysfunction markers, hematoma growth and edema volume in hypertensive and non‐hypertensive patients with ICH.

Results

We included 887 patients with ICH (433 hypertensive, 50 amyloid, 117 by anticoagulants and 287 with other causes). Patients with hypertensive ICH showed the highest body temperature (37.5 ± 0.8°C) as well as the maximum increase in temperature (0.9 ± 0.1°C) within the first 24 h. Patients with ICH of hypertensive etiologic origin, who presented hyperthermia, showed a 5.3‐fold higher risk of a poor outcome at 3 months. We found a positive relationship (r = 0.717, P < 0.0001) between edema volume and hyperthermia during the first 24 h but only in patients with ICH of hypertensive etiologic origin. This relationship seems to be mediated by inflammatory markers.

Conclusion

Our data suggest that hyperthermia, together with inflammation and edema, is associated with poor outcome only in ICH of hypertensive etiology.

[Dissociative disorder and traumatic events. A study of Spanish population]

Dissociative Disorder is relatively uncommon. It has been associated to the presence of traumatic events and especially to sexual abuse in childhood. Our study presents a clinical sample of 36 patients with Dissociative Disorder, prospectively evaluated with standardized scales in an outpatient department of general psychiatry. The sample is mainly made up of married (86.1%) women (34/36), from medium-low class with important comorbidity (38.9% affective disorders, 52.8% conversive disorders, 41.7% anxiety disorders and 38.9%, personality disorders). Our results show a high rate of childhood traumatic events (58.3%) and a background of sexual abuse (27.8%) in this population as well as other traumatic events in adulthood (55.6%). The prevalence of any traumatic event (27/36) is higher than in general spanish population. However sexual abuse is only slightly higher than the estimated rate of sexual abuse in childhood. Higher scores in the traumatic event scale are correlated with the severity of dissociative symptoms. Only traumatic sexual traumas in childhood correlate with the severity of dissociative features measured by the DES (Dissociative Experiences Scale). Age of the first traumatic event does not correlates with the severity of dissociative symptoms. A background of traumatic sexual abuse in childhood is the only factor related with higher presence of comorbid affective disorders and conversive disorders.

[Incidence and mortality due to cancer in Navarre, 1998-2002. Trends in the last 30 years]

Between 1998-2002, 16,952 new cases of cancer were registered in Navarre. In men, the most frequently diagnosed cancers were in the following order: prostate, lung, colon and rectum, bladder and stomach, which accounted for 63.2%. In women, the sites were breast, colon and rectum, corpus uteri, stomach and ovary, which accounted for 57.6% of the cases. In the same period, 1998-2002, 4,127 men and 2,470 women died from cancer. Sixty percent of all deaths due to malign tumours in men were due to cancer of the lung, prostate, colon and rectum, stomach and bladder. In women this was due to cancers of colon and rectum, breast, stomach, pancreas and lung, which accounted for 49% of the cases. In men in Navarre there has been an increase in the incidence rates of cancer of the prostate, kidney and non-Hodgkin lymphoma. Avoidable cancers such as those related to smoking (lung, oral cavity and pharynx or pancreas) continue to rise, and represent a greater global risk of dying from cancer in the latest period studied than in the decades of the 1970s and 1980s. From 1995 up to the present, mortality due to cancer has moved from occupying the second place to become the first cause of death among men in Navarre. The global risk of death due to cancer in men is now equal to the first period studied, 1975-1977. Amongst women the global risk of death due to cancer fell by 25% between 1975 and 2002, basically at the cost of breast and stomach cancer. Tumours related to smoking increased both in mortality and in incidence and appear as a significant health problem amongst women in Navarre. Breast cancer has increased in incidence, with lower mortality figures than those of the first period 1975-1977. Invasive cancer of the cervix remains at very low rates in comparison with many European countries, including Spain. In both sexes colorectal and skin cancer has increased, while the incidence and mortality of stomach cancer continues to fall.

Lipopolysaccharide profiles from nodules as markers of bradyrhizobium strains nodulating wild legumes

To develop the use of electrophoretic lipopolysaccharide profiles for Bradyrhizobium strain identification, we studied the feasibility of using electrophoresis of whole legume nodule homogenates to obtain distinctive lipopolysaccharide profiles. The electrophoretic patterns were the same whether we used nodule extracts, bacteroids, or cultured bacteria as samples, and there was no evidence of changes in the ladder-like pattern during the nodulation process. To assess the reliability of using lipopolysaccharide profiling performed with individual nodules for studying the diversity and microdistribution of the rhizobia nodulating wild shrub legumes, we used a population of Adenocarpus foliolosus seedlings. We obtained 75 different profiles from the 147 nodules studied. There was no dominant profile in the sample, and a plant with different nodules generally produced different profiles. Electrophoresis of legume root nodules proved to be a fast and discriminating technique for determining the diversity of a bradyrhizobial population, although it did not allow the genetic relationships among the nodulating strains to be studied.

Lentiviral vectors transcriptionally targeted to hematopoietic cells by WASP gene proximal promoter sequences

The development of vectors that express a therapeutic transgene efficiently and specifically in hematopoietic cells (HCs) is an important goal for gene therapy of hematological disorders. In order to achieve this, we used a 500 bp fragment from the proximal WASP gene promoter to drive the expression of the WASP cDNA in the context of a self-inactivating lentiviral vector. Single-round transduction of WASp-deficient herpesvirus saimiri (HVS)-immortalized cells as well as primary allospecific T cells from Wiskott-Aldrich syndrome (WAS) patients with this vector (WW) resulted in expression levels similar to those of control cells. Non-HCs were transduced with similar efficiency, but the levels of WASp were 135-350 times lower than those achieved in HCs. Additionally, transduction of WASp-deficient cells with WW conferred a selective growth advantage in vitro. Therefore, lentiviral vectors incorporating proximal promoter sequences from the WASP gene confer hematopoietic-specific, and physiological protein expression.

Efficient lentiviral transduction of Herpesvirus saimiri immortalized T cells as a model for gene therapy in primary immunodeficiencies

Infection of human T lymphocytes with the Herpesvirus saimiri (HVS) yields immortalized T-cell lines (HVS-T) which retain all the phenotypical and functional characteristics of their parental cells. This represents a new experimental model for studying genetic disorders of T lymphocytes. In spite of the efforts of many laboratories, no satisfactory way has been found so far to modify HVS-T cells genetically. We have analyzed the capacity of oncoretroviral (MLV)- and lentiviral (HIV-1)-based vectors pseudotyped with vesicular stomatitis virus glycoprotein (VSVg) to transduce HVS-T cells. HIV-1-derived vectors efficiently transduced HVS-T cell lines, reaching up to 85% of cells expressing the transgene in a single round of infection. MLV-based vectors, on the other hand, were unable to transduce more than 1% of any of the HVS-T cell lines analyzed. Lentiviral-driven gene expression was maintained constant and stable in HVS-T cells for a minimum of 48 days. We also observed that although the lentiviral transduction efficiency achieved on HVS-T cells is lower than that obtained with tumor or primary endothelial cells, it is nevertheless similar to that found with activated primary T cells.

Expression of CD94 and NKG2 molecules on human CD4(+) T cells in response to CD3-mediated stimulation

We investigated the ability of human peripheral CD4(+) cells to express CD94 and NKG2 molecules as a consequence of CD3-mediated activation. Using highly purified peripheral CD4(+) T cells, we found expression of both CD94 and NKG2A 15 days after CD3-mediated stimulation of cells. We also determined by reverse transcriptase-PCR that all gene members of NKG2 family-namely, NKG2A, -C, -D, and -E-are sequentially expressed on CD4(+) cells. We found that this expression is tightly regulated by cytokines, and we identified transforming growth factor-beta1 and interleukin-10 as the main factors that, on CD3-dependent stimulation, positively contribute to the expression of CD94 and NKG2A on CD4(+) cells. We also investigated the functional role of NKG2A and found that coligation of CD3 and NKG2A by specific monoclonal antibodies results in significant inhibition of interferon gamma and tumor necrosis factor alpha production by stimulated CD4(+) cells. The presence and function of these receptors on CD4(+) lymphocytes support a more general role for NKG2 molecules, whose functions were originally thought to be confined to cytotoxic cells, in the immune system.

Altered expression of CD43-hexasaccharide isoform on peripheral T lymphocytes from HIV-infected individuals

OBJECTIVE

To examine if peripheral T lymphocytes from HIV-infected individuals show abnormalities in the surface expression of CD43, the major sialoglycoprotein of leukocytes.

DESIGN

A series of 86 HIV-positive individuals was studied. The subjects, grouped by their peripheral CD4 cell count, were in different stages of the disease as defined by the Centers for Disease Control and Prevention (CDC).

METHODS

Peripheral leukocytes and isolated lymphocytes were examined by double and triple immunofluorescence flow cytometric and Western blot analyses with monoclonal antibodies, which discriminate between CD43 isoforms.

RESULTS

We found elevated percentages of the surface expression of CD43-hexasaccharide isoform on T lymphocytes from 82 out of 86 individuals tested. Increasing percentages are progressively found in CDC groups 1, 2 and 3 patients. The expression of the molecule is remarkably biased towards the CD8 cell subpopulation. The percentage of cells bearing human leukocyte antigen-DR locus molecules (HLA-DR) is also augmented. Two subsets expressing T305 have been identified: a minor subset that co-expresses HLA-DR and T305; and a second population formed by the majority of T305-positive cells, which lack surface HLA-DR. Finally, we found CD43 bands with altered electrophoretic mobility in lysates from peripheral lymphocytes from all HIV-positive individuals tested.

CONCLUSION

The augmented expression of CD43-hexasaccharides and the observed cellular distribution suggest an important regulatory role for this molecule in HIV-specific responses.

Effects of salinity on protein and lipopolysaccharide pattern in a salt-tolerant strain of Mesorhizobium ciceri

AIMS

To characterize the physiological and metabolic responses of Mesorhizobium ciceri strain ch-191 to salt stress, investigating the changes induced by salinity in protein and lipopolysaccharide profiles, as well as determining the accumulation of amino acids, glutamate and proline.

METHODS AND RESULTS

Strain ch-191 of M. ciceri was grown with different NaCl concentrations. Protein and lipopolysaccharide patterns were determined by electrophoresis. The strain ch-191 tolerated up to 200 mmol l-1 NaCl, although higher salt dosages limited its growth and induced changes in the protein profile. The most noteworthy change in the LPS-I pattern was the decrease in the slowest band and the appearance of an intermediate mobility band. The accumulation of proline in response to salt stress surpassed that of glutamate.

CONCLUSION

The protein profile showed major alterations at salinity levels which inhibited growth. However, the alterations in the LPS profile and accumulation of compatible solutes were evident from the lowest levels, suggesting that these changes may constitute adaptative responses to salt, allowing normal growth.

SIGNIFICANCE AND IMPACT OF THE STUDY

The selection and characterization of salt-tolerant strains, which also show efficient symbiotic performance under salinity, may constitute a strategy for improving Cicer arietinum-Mesorhizobium ciceri symbiosis in adverse environments.

Functional expression of CD43 on human natural killer cells

CD43 is the major leukocyte sialoglyco-protein that plays important functional roles in neutrophils and lymphocytes. However, the expression of CD43 on human natural killer (NK) cells and its participation in the regulation of NK activity has not been studied. We have therefore investigated the expression of CD43 isoforms on human NK cell subpopulations as well as the role of this molecule in NK cell activation and cytotoxicity. We found that CD56bright and CD56dim NK cells express different sialylated forms of CD43, observing that activation of the CD56bright NK cells induces the change of tetrasaccharide O-glycans to hexasaccharide O-glycans on CD43. Cross-linking of the molecule with mAbs results in a metalloprotease-dependent loss of CD43 from the NK cell surface, whereas soluble anti-CD43 mAbs induce a vigorous NK cell proliferation. This property is distinct from T cells, which proliferate after CD43 cross-linking only in the presence of monocytes. Occupancy of the CD43 receptor on NK cells transduces specific signals, leading to enhanced killing activity and tyrosine phosphorylation and de-phosphorylation of several substrates. We therefore propose that CD43 significantly contributes to the regulation of the NK cell function by participating in the control of effector/target interactions and, if pertinent, by transducing activation signals.

Studies on the structure and the solution conformation of an acidic extracellular polysaccharide isolated from Bradyrhizobium

The structure of an acidic extracellular polysaccharide isolated from Bradyrhizobium (Chamaecytisus proliferus) has been elucidated by hydrolysis, methylation analysis, and 1D and 2D 1H- and 13C-NMR spectroscopy of the complete polysaccharide. The NMR spectrum showed that microheterogeneity was present due to the minor existence of a variety of O-acetyl groups. Thus, a deacetylated sample was prepared by alkaline treatment which was then fully analysed. The deacetylated polysaccharide has the following sequence: -->3)-[alpha-D-Galp-(1-->6)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)- alpha-D-GalpA-(1-->3)-alpha-D-Manp-(1--> The sample is partially O-methylated at position 4 of the alpha-D-Galp-(1-->6) unit. In addition, the same moiety of the native sample is also partially and heterogeneously O-acetylated. The conformational features of the deacetylated sample have been evaluated by molecular mechanics and dynamics calculations and NOE spectroscopy. The results indicate that the polysaccharide may adopt a variety of three dimensional shapes, and that there is a fair agreement between the NMR-derived distances and those provided by the calculations

Solution conformation and dynamics of an extracellular polysaccharide isolated from Bradyrhyzobium as deduced from 1H-NMR off resonance ROESY and 13C-NMR relaxation measurements

The conformational and dynamical features of an extracellular branched deacetylated polysaccharide isolated from Bradyrhizobium (Chamaecytisus proliferus) have been investigated by homo and heteronuclear NMR methods. 1H-NMR cross relaxation rates have been obtained for this polysaccharide through regular NOESY and ROESY spectra as well as by modern off resonance ROESY techniques. Local proton-proton correlation times as well as interproton distances have been obtained. 13C-NMR relaxation parameters (T1, T2, NOE) have also been measured at two different magnetic fields and interpreted using different approximations based on the Lipari and Szabo model free approach. The analysis of the data indicates the existence of important flexibility for the different linkages of the polysaccharide. Motions in the range of several ns contribute to the relaxation of the macromolecule, although faster internal motions in the 600-800 ps time scales are also present. These time scales indicate that segmental motions as well as internal motions around the glycosidic linkages are the major sources of relaxation for this molecule at 299 K.

Defective actin reorganization and polymerization of Wiskott-Aldrich T cells in response to CD3-mediated stimulation

The Wiskott-Aldrich syndrome (WAS) is a severe immunodeficiency and platelet deficiency disease arising from mutation(s) in the WASP gene, which in normal cells encodes an intracellular protein able to interact with other proteins relevant to the control of cytoskeleton organization. Immunodeficiency is mainly due to T-cell progressive malfunction. Salient defects of WAS T cells are a CD3-restricted impairment in proliferative responses and cytoskeletal abnormalities, including the frequent appearance of T cells with atypical morphology. We have investigated the possibility that the CD3-restricted defect and some of the cytoskeletal defects of WAS T cells are linked. For this purpose, we immortalized by means of infection with Herpesvirus Saimiri a number of previously described allospecific WAS T-cell lines. The resulting cells preserve the surface, molecular, and functional phenotypes of their parental lines, including a negligible WASP mRNA expression as well as the CD3-restricted defect and cytoskeleton abnormalities. Results show that, in CD3-stimulated WAS T cells, the pattern of temporal changes in cell shape and F-actin distribution is substantially different from that of control cells. Furthermore, polymerization of actin, a critical step in the CD3-mediated cytoskeleton reorganization, does not occur in WAS T-cell lines in response to OKT3 stimulation. In conclusion, our data link both CD3 and cytoskeletal defects in WAS T cells, strongly suggesting that cytoskeleton abnormalities are an underlying cause for WAS immunodeficiency.

[Study of meniscal regeneration following total meniscectomy and the replacement of meniscus by different autologous plasties]

In order to study meniscal regeneration, and the behaviour of different autologous plasties used as meniscal substitutes, the knees of 45 adult White New Zealand rabbits were operated on. The 45 knees were divided into three groups with fifteen knees in each group. The meniscectomy group was given the letter M, the patellar group R, and the cartilage group C. In group M a total medial meniscectomy was performed; in group R, after the total medial meniscectomy, a strip of the patellar tendon, harvested from the same rabbit, was implanted on the site of the original meniscus; in group C, after the total medial meniscectomy, a fragment of cartilage, also harvested from the same animal, was implanted on the site of the original meniscus. We reviewed 5 knees from each group 6, 12 and 24 weeks after surgery, and the newly formed menisci were histologically studied. Twenty-four weeks after surgery we found fibrocartilaginous menisci in the three groups; the metaplasiant sequence from fibrous tissue to fibrocartilage was similar in the three groups. We therefore conclude that: 1. Meniscal regeneration occurs. 2. The autografts we have used could be valid meniscal substitutes.

Specific monoclonal antibodies against leukocyte-restricted cell surface molecule CD43 react with nonhematopoietic tumor cells

CD43 is the major sialoglycoprotein found on the surface of cells of hemopoietic origin. Because CD43 is a typical member of the surface mucins, molecules that play a relevant role in tumor progression, we have addressed the expression of CD43 in nonhematopoietic tumor cells. For this purpose, we have tested a broad panel of anti-CD43 antibodies on tumors of different embryonic origins. Of the 17 anti-CD43 mAbs used, 9 reacted with leukocytes in paraffin-fixed formalin-embedded lymph node tissues. Two mAbs, BS1 and L10, stained 24 out of 31 (78%) nonhematopoietic tumors analyzed; ie., some tumors were positive for both antibodies, and others were positive for either L10 or BSL We have also found reactivity of these two anti-CD43 mAbs in 13 out of 20 metastases studied.

Defective B7 expression on antigen-presenting cells underlying T cell activation abnormalities in systemic lupus erythematosus (SLE) patients

Defective T cell functions, including IL-2 production and proliferation, have been shown in SLE patients. After T cell stimulation (first signal), a costimulatory signal (second signal) is required to achieve complete T cell activation. Main costimulatory signals are provided to T cells by B7 antigens (CD80 and CD86, expressed on antigen-presenting cells (APC)) upon interaction with its receptor, the CD28 molecule expressed on T cells. The aim of this study was to investigate the role of CD28/B7 interactions in the impaired T cell responses of SLE patients. We show that stimulation of T cells with phytohaemagglutinin (PHA) in the presence, but not in the absence, of anti-CD28 MoAb or B7+ cells results in tyrosine phosphorylation of specific substrates, transcription of mRNA and production of IL-2 that is indistinguishable in SLE patients and healthy controls. Moreover, proliferation of costimulated T cells from SLE and controls was specifically abrogated by blocking the CD28/B7 interactions by means of addition to the culture of the CTLA4-Ig fusion protein. However, in most patients activated APC failed to up-regulate B7 molecules, giving rise to ineffective costimulatory signalling to T cells. These results indicate that the CD28/B7 costimulatory pathway is defective in SLE patients.

Fine needle aspiration biopsy in urothelial carcinoma of the renal pelvis

Ten of 73 kidney neoplasms (14%) collected from the files of the Hospital de Navarra over a five-year period were urothelial carcinomas of the renal pelvis (UCRP). In 54 of 73 kidney neoplasms fine needle aspiration biopsy (FNAB) was performed. In seven cases a cytologic diagnosis of urothelial carcinoma was made. The majority of patients presented with pain and hematuria of short duration. In three cases a renal mass was detected by roentgenography. A filling defect in the collector system, with no conclusive roentgenographic diagnosis, was observed in the remaining cases. Computed tomography-guided FNAB was performed in all cases. Voided urine was collected for microscopic study in six cases. The cytologic pattern of all cases was similar to that of bladder urothelial carcinoma. This feature was particularly frequent in well-differentiated papillary carcinomas. The differential diagnosis with other kidney lesions based on cytologic findings was established. FNAB is useful not only in the preoperative diagnosis of UCRP but also in follow-up.

[Anticardiolipin antibodies in parenteral drug addicts: relationship with HIV]

The IgG isotype of anticardiolipin antibodies (aCL) and its possible relationship with the immunodeficiency virus (HIV) were studied in 65 parenteral drug addicts (PDA). Thirty-seven patients were infected in the present study. Nineteen (51%) fulfilled diagnostic criteria of AIDS. Thirty-two of these 37 HIV-positive patients (86%) were IgG-aCL positive. Fourteen (50%) of the 28 HIV-negative patients were IgG-aCL positive. Our study reveals a lack of correlation between aCL and thrombocytopenia. None of the patients had thromboembolic complications. In AIDS patients no relationship was found between IgG-aCL levels and the presence of Pneumocystis carinii, other infections by opportunist microorganism, and clinical deterioration. Highly increased levels of IgG-aCL (> 80 GPL) were observed in three patients with AIDS and infectious endocarditis. In conclusion, given the non-specificity of aCL en PDA, it is our opinion that its measurement is of little help in daily clinical praxis.

[Leukocytoclastic vasculitis associated with tumors]

We report 6 patients with the diagnosis of leukocyclastic vasculitis, with a neoplasia as the only clinical manifestation associated. Evolution of vasculitis was chronic or recidivant; rapid erythrocyte sedimentation rate, positivity for rheumatoid factor, and hypocomplementemia were frequent in our cases. The clinical course of vasculitis and tumour was discordant. The authors believe that there are not sufficient data to demonstrate an association between leukocytoclastic vasculitis and tumours.

Relevance of the inoculum effect of antibiotics in the outcome of experimental infections caused by Escherichia coli

The minimum dosage of antibiotics that reduced mortality in bacteraemic rats inoculated with two different Escherichia coli isolates was determined in an attempt to study the therapeutic importance of the inoculum effect. Low mortality rates (0-5%) at 48 h were obtained when antibiotics with minimal or no inoculum effect (ampicillin, cefuroxime, cefoxitin and gentamicin) were administered to yield serum levels 5 to 14 times the MIC, while antibiotics with a pronounced inoculum effect (piperacillin, cefotaxime and aztreonam) had to be administered to yield serum levels 57 to more than 1000 times the MIC determined with a standard (low) inoculum. All of the antibiotics with inoculum effect studied here are administered empirically in clinical practice at a higher dose than the microbiological and pharmacokinetic data would indicate (in order to reach peak serum concentrations exceeding the MICs of the pathogens by 4-10 times). Our experiment suggests that such high and empirical doses of antibiotics with inoculum effect may be justified.

Immunomodulation of HLA class I and II expression on a human tumor derived cell line by 5-azacytidine, bacterial lipopolysaccharide, gamma interferon and a phorbol ester

The modulation of histocompatibility antigens (HLA) expression by four different agents (gamma-IFN, LPS, PMA and 5-azaC) was investigated on a human tumor derived cell line that did not constitutively express HLA class I and class II molecules on its surface. Demethylating drug 5-azaC induced HLA class I but not HLA class II antigen expression. Gamma interferon and LPS induced HLA-DR and HLA-DP, but not HLA-DQ class II nor HLA class I antigens, while phorbol ester was unable to induce either class I or II molecule expression of the HLA system. These results suggest that HLA class I expression is constitutively inhibited by methylation of its coding genes. Treatment with 5-azaC leads to the HLA class I molecule expression, while HLA class II genes, DR and DP, seem to be under a different inhibitory mechanism as it was induced by LPS and gamma-interferon but not by 5-azaC. HLA-DQ class II antigens were not detected in response to any of the immunomodulators used.

Effect of Bacteroides fragilis on mortality induced by Escherichia coli in an experimental infection treated with cefotaxime, aztreonam or gentamicin

The possibility that beta-lactamase-producing strains of Bacteroides fragilis can protect Escherichia coli from cefotaxime was studied in an in-vivo model of peritoneal infection in rats. The protective effect of cefotaxime, aztreonam and gentamicin in peritonitis induced by E. coli alone or combined with B. fragilis was evaluated by analysing mortality at 24 and 48 h after bacterial inoculation and treating the animals with two doses of each antibiotic. Comparisons, by drugs, at 24 and 48 h revealed that a statistically significant high mortality rate was obtained at 48 h when mixed infections were treated with cefotaxime, a drug very active in the infection caused by E. coli alone. Infections by mixed flora or E. coli alone treated with aztreonam or gentamicin did not show any significant difference in mortality rate analysed at 24 or 48 h. These in-vivo results confirm previous in-vitro studies and suggest that cefotaxime could be inactivated in mixed infections if a beta-lactamase-producing strain, such as B. fragilis, is involved in a clinical infection.

Determination of cell membrane bound IgE in allergic patients and healthy controls. A new technology

Cell membrane bound IgE was determined in 44 allergic patients and 34 healthy controls with a radiobinding technique using I-125 labeled anti-IgE as a marker. The technique possesses an intraassay variability of 10% and an interassay variability of 20%. Owing to the possibility that anti-IgE may bind to the cell membrane via the Fc receptor, IgE was detached from the membrane by gradually reducing pH to 4 and quantitating bound anti-IgE. This procedure led to an 83 +/- 14.23% drop in I-125 anti-IgE uptake. However, other cell markers tested (OKT-3, OKT-4, IgG) as well as cell viability remained unchanged, thus demonstrating the high degree of specific labeled anti-IgE uptake by IgE molecules on the cell membrane. The results presented to date support the usefulness of the technique described. Hence, bound IgE was determined in allergic subjects and controls, and correlated to the free serum levels of IgE. The results show that greater quantities of IgE are found on the cell membranes of allergic patients in comparison to the control population. In 81% of the former, uptake surpassed 3% of the total amount of isotope added, whereas 85% of the control subjects showed less than 3% uptake. No statistically significant correlation was obtained between serum IgE (UI/ml) and bound IgE levels in allergic subjects. Double immunofluorescence assays demonstrated the presence of cells with surface-bound IgE (s IgE +) which also expressed HLA class II (DR) molecules. Protein synthesis blocking studies showed IgE on the cell membrane to have a predominantly carrier role.

Skin colonization by Corynebacterium groups D2 and JK in hospitalized patients

To determine the prevalence of Corynebacterium group D2 and JK organisms on the skin of different types of patients, 200 hospitalized subjects, half of them admitted to a university hospital and the others in a chronic care institution, were surveyed. Samples were taken from the axilla, groin, and abdominal wall. Corynebacterium group D2 and JK organisms were isolated from at least one of the three skin sites in both groups of patients. Only five patients harbored groups D2 and JK at the same time but a different skin sites. The rate of colonization by group D2 organisms was higher in females (43.3%) than in males (17.7%); on the contrary, group JK organisms were isolated more frequently from males (32.1%) than from females (13.5%). All these differences were statistically significant. Corynebacterium group D2 and JK organisms are widely distributed on the skin of hospitalized patients, and the prevalence is sex related.

In vivo significance of the inoculum effect of antibiotics on Escherichia coli

The minimum dosage of antibiotics which reduced mortality in rats intraperitoneally inoculated with an Escherichia coli isolate was determined. Low mortality rates (0-10%) were obtained when antibiotics with minimal or no inoculum effect (cefoxitin, cefmetazole and gentamicin) were administered to yield serum levels 3 to 20 times the MIC, while antibiotics with a pronounced inoculum effect (cefotaxime and aztreonam) had to be administered to yield serum levels 200 to 1,000 times the MIC determined with a standard (low) inoculum. Thus, it seems that the inoculum effect observed in vitro with some antibiotics for Escherichia coli may have clinical significance.

Susceptibility of urinary isolates of Corynebacterium group D2 to fifteen antimicrobials and acetohydroxamic acid

The susceptibility in vitro of 28 Corynebacterium group D2 strains, mainly isolated from urine, to fifteen antimicrobial agents and acetohydroxamic acid (AHA) was determined at two pH values. The bactericidal activity of four antimicrobials and AHA was studied in three reference strains in broth at two pHs and with two inoculum sizes. The activity of norfloxacin and AHA, against one selected strain, in broth and human urine, was also determined. Vancomycin, ofloxacin and norfloxacin were the most active agents tested. Norfloxacin acted bactericidally in broth and in human urine but was not synergic with AHA.

Activity of nine antimicrobial agents against Corynebacterium group D2 strains isolated from clinical specimens and skin

The in vitro activities of nine antimicrobial agents against Corynebacterium group D2 strains isolated from clinical specimens and from healthy skin of hospitalized patients were studied. Ciprofloxacin, ofloxacin, norfloxacin, vancomycin, and teicoplanin were very active against these microorganisms. There were no significant differences in susceptibility between clinical and colonizing isolates.

Struvite crystal formation by Corynebacterium group D2 in human urine and its prevention by acetohydroxamic acid

After 24 h incubation of human urine experimentally inoculated with Corynebacterium group D2, struvite crystals appeared with an increase in pH and ammonium concentration as well as a decrease in the urea concentration. These changes were prevented by the addition of variable concentrations of acetohydroxamic acid. From these results it seems that the prevention of such crystal formation by Corynebacterium group D2 could be due to the inhibition of its urease activity besides acetohydroxamic acid having a significant antimicrobial activity, principally when tested in human urine. These effects were dose-related.

In vitro and in vivo study of stone formation by Corynebacterium group D2 (Corynebacterium urealyticum)

Corynebacterium group D2 inoculated into normal human urine formed struvite crystals and an increase in pH and ammonium concentration after 24 h of incubation. Zinc disks dipped into a broth culture of this microorganism and inserted into the bladders of rats produced stones with a mean weight of 12.5 mg (ranging from 1 to 57.7 mg) after 12 days. Analysis of the infrared spectrum determined the stones to be composed of struvite. From these results its seems that stone formation by Corynebacterium group D2 may be possible both in vitro and in vivo, which may confirm a previous report involving these bacteria in human clinical encrusted cystitis.

Antimicrobial susceptibility of Corynebacterium group D2

The in vitro susceptibility of 30 Corynebacterium group D2 strains to nine antimicrobial agents was determined. Vancomycin and norfloxacin were the most active agents tested. All strains were resistant to ampicillin and cephalothin, all except one were resistant to gentamicin, and the activity of erythromycin, novobiocin, tetracycline, and rifampin varied.

T-lymphocyte behaviour modification in vitro by cancer patient sera

Cell mediated immune response blocking factor(s) in the serum of colon adenocarcinoma patients inhibit blast transformation of lymphocytes from normal individuals. The blocking capacity of the sera has been shown to correlate with the infiltration of the tumor. This correlation suggests that these phenomena may be mediated by identical serum factors and through a common cell receptor present in the lymphocytes of normal individuals.

Activity of cefotaxime and metronidazole against bacteroides and Escherichia coli alone and in mixed culture

The activity of cefotaxime and metronidazole against one strain of Escherichia coli and three of Bacteroides has been studied. A fixed cefotaxime concentration (8 mg/l) did not kill E. coli in presence of Bacteroides due to degradation of the drug by the anaerobe. However, the presence of metronidazole in the same system killed Bacteroides strains very effectively and prevented the degradation of cefotaxime which killed E. coli.

Requirement of macrophage metabolic activity for T-lymphocyte activation

It has been recently demonstrated that macrophages are necessary accessory cells for T-lymphocyte activation by antigens, mitogens and allogenic cells. This paper shows the function of metabolically inactive macrophages in the activation of T-lymphocytes by phytohemagglutinin (PHA). Macrophages inactivated by mitomycin C are unable to collaborate with T-lymphocytes in the development of the proliferative response to PHA indicating that the role of the macrophage in T-lymphocyte activation by mitogens goes beyond insolubilizing it or rendering it more stimulatory by another passive mechanism.

Impaired capacity of the macrophages of newborn mice for T-lymphocyte activation by phytohemagglutinin

The level of collaboration in phytohemagglutinin (PHA) induced lymphoblastic response by the macrophage of neonatal mice was studied. The results show a diminished response to the mitogen (PHA) when lymphocytes from the spleen of syngeneic adult mice were incubated in the presence of macrophages from neonatal mice as compared to those obtained from cultures performed in the presence of macrophages from adult mice. In both cases the highest response corresponded to the lowest dose of PHA and the lowest amount of macrophages used.

Eosinophil inflammatory reaction in isolated organs

Twenty-nine cases of eosinophilic infiltration of isolated organs or tissues, not associated with allergic history, were revised. Sixteen were men and 13 women, the mean age was 39.3 years. The presenting symptoms were related with an inflammation of the target organ or tissue in 25 cases. Nineteen cases had histories of acute or chronic inflammation of the same organ or tissue. Blood eosinophilia was marked in 3 cases of Loeffler's syndrome. Morphologically, eosinophilic infiltration of isolated organs or tissues can be diffuse, focal or polyp-nodular. Charcot-leyden crystals were found in macrophages or between the eosinophilic infiltrate. The present authors believe that some of these lesions are due to a local allergic reaction to any of the different substances liberated in old foci of inflammation of the target organ or tissue. This is based on: 1) Many cases have no allergic history. 2) Blood eosinophilia is unusual in all cases but Loeffler's syndrome. 3) Many patients had personal history of inflammation of the target organ. 4) The eosinophil has a short life span, and 5) Eosinophilic infiltration is more frequent in organs where inflammation is usual. The performance of appropriate sensibility allergic tests in all patients with eosinophilic infiltration of isolated organs is emphasized, in order to probe the validity of our hypothesis.