Current State-of-the-Art Therapy for Malignant Pleural Mesothelioma and Future Options Centered on Immunotherapy

Malignant pleural mesothelioma (MPM) is a locally aggressive disease related to asbestos exposure with a median survival for untreated patients of 4-8 months. The combination of chemotherapy based on platinum and antifolate is the standard treatment, and the addition of bevacizumab adds two months to median survival. Recently, in first-line treatment, immunotherapy combining nivolumab with ipilimumab has been shown to be superior to chemotherapy in the CheckMate-743 study in terms of overall survival (18.1 months), leading to its approval by the FDA and EMA. The positive results of this study represent a new standard of treatment for patients with MPM; however, not all patients will benefit from immunotherapy treatment. In an effort to improve the selection of patient candidates for immunotherapy for different tumors, biomarkers that have been associated with a greater possibility of response to treatment have been described. MPM is a type of tumor with low mutational load and neo-antigens, making it a relatively non-immunogenic tumor for T cells and possibly less susceptible to responding to immunotherapy. Different retrospective studies have shown that PD-L1 expression occurs in 20-40% of patients and is associated with a poor prognosis; however, the predictive value of PD-L1 in response to immunotherapy has not been confirmed. The purpose of this work is to review the state of the art of MPM treatment in the year 2023, focusing on the efficacy results of first-line or subsequent immunotherapy studies on patients with MPM and possible chemo-immunotherapy combination strategies. Additionally, potential biomarkers of response to immunotherapy will be reviewed, such as histology, PD-L1, lymphocyte populations, and TMB.

Expression of TILs and Patterns of Gene Expression from Paired Samples of Malignant Pleural Mesothelioma (MPM) Patients

MPM is an aggressive disease with an immunosuppressive tumor microenvironment, and interest in exploring immunotherapy in this disease has been increasing. In the first line of treatment, the combination of nivolumab and ipilimumab demonstrated an improvement in survival over chemotherapy. The presence of TILs has been recognized as a marker of antitumor immune response to chemotherapy in solid tumors. The aim of our study is to identify the effect of treatment on immune cells and the immune gene profile in MPM. We investigated the changes in expression of TILs in 10 human MPM paired tumor tissues using immunohistochemistry and gene expression analysis from paired untreated and treated samples. In this small series, we demonstrated that during the evolution of disease without any treatment there was an increase in the inflammatory component in tumor samples. After systemic treatment there was a decrease in the number of TILs. We observed that after systemic treatment or disease progression immune gene signatures were suppressed. Our integrated analysis of paired samples with immune profile and genomic changes on MPM suggested that during the evolution of the disease the immune system tends to switch, turning off with treatment.

Selective HIF2A Inhibitors in the Management of Clear Cell Renal Cancer and Von Hippel-Lindau-Disease-Associated Tumors

Von Hippel-Lindau (VHL) loss is the hallmark event characterizing the clear cell renal cancer subtype (ccRCC). Carriers of germinal VHL mutations have an increased prevalence of kidney cysts and ccRCC as well as hemangioblastoma, pheochromocytoma and pancreatic neuroendocrine tumors. In both sporadic and inherited ccRCC, the primary mechanism of VHL-mediated carcinogenesis is the abnormal stabilization of hypoxia-inducible factors (HIF1A and HIF2A). While HIF1A acts as a tumor suppressor and is frequently lost through inactivating mutations/14q chromosome deletions, HIF2A acts as an oncogene promoting the expression of its target genes (VEGF, PDGF, CAIX Oct4, among others). Selective HIF2a inhibitors block the heterodimerization between HIF2A and ARNT, stopping HIF2A-induced transcription. Several HIF2A inhibitors have entered clinical trials, where they have shown a favorable toxicity profile, characterized by anemia, fatigue and edema and promising activity in heavily pretreated ccRCC patients. Belzutifan, a second-generation HIF2a inhibitor, was the first to receive FDA approval for the treatment of unresectable ccRCC in VHL syndrome. In this review, we recapitulate the rationale for HIF2a blockade in ccRCC, summarize the development of HIF2a inhibitors from preclinical models up to its introduction to the clinic with emphasis on Belzutifan, and discuss their role in VHL disease management.

Antibody-Drug Conjugates for Lung Cancer: Payloads and Progress

Antibody Drug Conjugates (ADCs) are a novel class of therapeutic that structurally comprise an antibody directed at a tumor epitope connected via a linker to a cytotoxic payload that have shown significant antitumor activity across a range of malignancies including lung cancer. In this article we review the pharmacology of ADCs, describe results of trials with ADCs directed at targets in lung cancer including Trophoblast cell-surface antigen 2(TROP2), HER3, MET, Carcinoembryonic antigen-related cell adhesion molecular 5(CECAM-5) and HER2. Trastuzumab Deruxtecan (also known as DS-8201a or T-DXd) an ADC directed at HER2 recently became the first ADC to receive FDA approval in lung cancer, on the basis of its activity in tumors with HER2 mutations, demonstrated in the Destiny-Lung01 and Lung02 trials.

Dynamic changes in circulating tumor DNA assessed by shallow whole-genome sequencing associate with clinical efficacy of checkpoint inhibitors in NSCLC

Immune checkpoint inhibitors (ICIs) targeting the PD-1/PD-L1 axis are the main therapeutic option for patients with advanced non-small cell lung cancer (NSCLC) without a druggable oncogenic alteration. Nevertheless, only a portion of patients benefit from this type of treatment. Here, we assessed the value of shallow whole-genome sequencing (sWGS) on plasma samples to monitor ICI benefit. We applied sWGS on cell-free DNA (cfDNA) extracted from plasma samples of 45 patients with metastatic NSCLC treated with ICIs. Over 150 samples were obtained before ICI treatment initiation and at several time points throughout treatment. From sWGS data, we computed the tumor fraction (TFx) and somatic copy number alteration (SCNA) burden and associated them with ICI benefit and clinical features. TFx at baseline correlated with metastatic lesions at the bone and the liver, and high TFx (≥ 10%) associated with ICI benefit. Moreover, its assessment in on-treatment samples was able to better predict clinical efficacy, regardless of the TFx levels at baseline. Finally, for a subset of patients for whom SCNA burden could be computed, increased burden correlated with diminished benefit following ICI treatment. Thus, our data indicate that the analysis of cfDNA by sWGS enables the monitoring of two potential biomarkers-TFx and SCNA burden-of ICI benefit in a cost-effective manner, facilitating multiple serial-sample analyses. Larger cohorts will be needed to establish its clinical potential.

Update in collecting duct carcinoma: Current aspects of the clinical and molecular characterization of an orphan disease

Collecting duct renal cell carcinoma (cdRCC), which until recently was thought to arise from the collecting ducts of Bellini in the renal medulla, is a rare and aggressive type of non-clear renal cell carcinoma (ncRCC), accounting for 1% of all renal tumors and with nearly 50% of patients being diagnosed with Stage IV disease. The median overall survival in this setting is less than 12 months. Several regimens of chemotherapies had been used based on morphologic and cytogenetic similarities with urothelial cell carcinoma described previously, although the prognosis still remains poor. The use of targeted therapies also did not result in favorable outcomes. Recent works using NGS have highlighted genomic alterations in SETD2, CDKN2A, SMARCB1, and NF2. Moreover, transcriptomic studies have confirmed the differences between urothelial carcinoma and cdRCC, the possible true origin of this disease in the distal convoluted tubule (DCT), differentiating from other RCC (e.g., clear cell and papillary) that derive from the proximal convoluted tubule (PCT), and enrichment in immune cells that may harbor insights in novel treatment strategies with immunotherapy and target agents. In this review, we update the current aspects of the clinical, molecular characterization, and new targeted therapeutic options for Collecting duct carcinoma and highlight the future perspectives of treatment in this setting.

Up-to-date role of aflibercept in the treatment of colorectal cancer

Introduction: Colorectal cancer (CRC) is a major public health problem. Despite major progress understanding the biological basis of this tumor added to the incorporation of optimized diagnostic and therapeutic strategies, prognosis after progression on first-line standard treatment remains poor. Several antiangiogenic treatments have demonstrated improvement in overall survival (OS) in the second-line treatment being aflibercept, a fully humanized recombinant protein, one of them. The results of the VELOUR study showed that the addition of aflibercept to second-line FOLFIRI improved OS and progression-free survival.Areas covered: A literature review of published clinical studies was performed in order to discuss the clinical data on aflibercept in mCRC from early drug development to real-world data.Expert opinion: The combination of aflibercept with FOLFIRI provides a statistical improvement in OS and in all the efficacy endpoints analyzed in the VELOUR trial, showing efficacy independently on time to progression, molecular status, prior biological treatment, or age. Further studies are needed to find new biomarkers and molecular characterization in order to better select patients that could benefit from this treatment.

Young-onset colorectal cancer: A call for action

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Background: Young-onset colorectal cancer (YOCR) is defined as diagnosis below the age of 50. Over the past decades, the incidence of YOCRC has increased at an alarming rate, but causes and pathogenesis still remain unknown. Early detection of colorectal cancer (CRC) has demonstrated to improve survival. Despite these facts, adults < 50 years old are not yet included in screening programs and YOCRC is not well characterized. We aimed to characterize the clinical and molecular characteristics of YOCRC in patients (pts) diagnosed at our institution. Methods: Consecutive pts with a diagnosis of CRC below the age of 50 visited for the first time at Vall d’Hebron University Hospital in Spain between January 2017 and October 2020 were included in the analysis. Data of clinicopathologic features and treatment were collected retrospectively from medical records. Results: 205 pts met the inclusion criteria, 111 (54%) were females, 8 (4%) presented a personal history of cancer at diagnosis and 109 (53%) a family history of cancer. Age at diagnosis was: < 30: 10 (5%), {30 – 40): 52 (25%), {40-45): 51 (25%), {45-50): 92 (45%). Site of primary tumor was: right colon: 50 (24%), left colon: 107 (52%): rectum: 48 (24%). Stage at diagnosis was I: 3 (1%), II: 14 (7%), III: 60 (29%), IV: 128 (63%). 6 of 14 (43%) and 44 of 60 patients (73%) with stage II and III CRC presented disease progression after initial treatment, respectively. Molecular status was: KRAS mutation: 74 (36%), NRAS mutation: 7 (3%), BRAF mutation: 12 (6%), MSI-H: 12 (6%). 43 pts (21%) had documentation of genetic counseling. Median (range) number of lines of treatment for metastatic disease was 3 (1-7), 53 pts (30%) received at least 4 lines of treatment. Median (range) number of metastatic sites was: 2 (1-6). 114 patients (55.6%) had died at the cut-off timepoint. Conclusions: YOCR is usually diagnosed with a more advanced stage than standard-onset CRC, with a poorer course of the disease. Further studies in young adults with CRC should address this phenomenon to understand the underlying causes, and prioritize genetic counseling. Our results support the unmet need of initiating screening programs in adults younger than 50 years, the urgency for a global consensus and a call for action.

Grade I meningioma with disseminated bone disease: a rare clinical phenomenon

Meningioma, the second most common primary tumour of the central nervous system, is classified into three different grades based on their characteristics. Each tumour grade includes different molecular subtype, growth potential, and thus, different prognosis. Grade I meningioma is the most common subtype with a benign course, in which systemic dissemination rarely occurs. We present the case of a 48-year-old male patient with a history of grade I meningioma who was referred 3 years after the initial diagnosis to our centre due to pelvic pain. Computed tomography (CT) images showed new pelvic bone lesions whose histopathological report was compatible with a grade I meningioma. Neither hormonal therapy concomitant with octreotide nor hydroxiurea treatments were effective. Very little is known about this entity's prevalence and treatment when disseminated disease occurs. Thus, we think it is important to increase the positive and negative clinical experiences in this setting.

Thermal stress exposure, bleaching response, and mortality in the threatened coral Acropora palmata

Demographic data for Elkhorn coral, Acropora palmata, and in situ water temperature data from seven upper Florida Keys (USA) reefs revealed three warm thermal stress events between 2010 and 2016. During a mild bleaching event in 2011, up to 59% of colonies bleached, but no mortality resulted. In both 2014 and 2015, severe and unprecedented bleaching was observed with up to 100% of colonies bleached. A. palmata live tissue cover declined by one-third following the 2014-2015 events. Colony mortality of mildly- and non-bleached colonies did not differ but increased significantly with more severe bleaching. Increased bleaching prevalence corresponded to maximum daily average water temperatures above 31.3°C. However, the cumulative days with daily average exceeding 31.0°C provided a better predictor of bleaching response. The bleaching response of surviving colonies in 2015 was not consistent with acclimatization as most individual colonies bleached at least as badly as in 2014.

A prospective, randomised, cross-over trial comparing two standard polyvinyl chloride tracheal tubes. Are all the tubes the same?

BACKGROUND

A randomised study was conducted on the number of attempts made during the conventional endotracheal intubation of a mannequin using two polyvinyl (PVC) tracheal tubes, apparently similar but from different manufactures: INTERSURGICAL (IS; Intersurgical S.L., Madrid, Spain) and Mallinckrodt (ML; Mallinkrodt Medical S.A., Madrid, Spain).

METHODS

A total of 26 anaesthesiologists, in randomly established order (generated by Epidat 3.1) intubated a mannequin twice using a different tube each time. The tubes were masked by painting them to prevent recognition. The main outcome of the study was to compare the number of attempts needed to complete the manoeuvre for each tube. Data on intubation time and failed intubations were also collected.

RESULTS

The number of attempts with the ML tube was significantly lower than with the IS tube. Intubation was completed on the first attempt with the ML tube in 93.3% of cases, while using the IS tube the percentage fell to 30.8% (Fisher exact test, P<.001). The time required to complete the manoeuvre was greater with the IS tube (median 10.8seconds, interquartile range 6-22) than with the ML tube (median 4.4seconds, interquartile range 3.5 to 6.3).

CONCLUSIONS

The PVC tube from the ML manufacturer was superior when compared with the IS, the latter was also associated with a larger number of attempts to complete intubation using a conventional Macintosh blade.

Palladin promotes invasion of pancreatic cancer cells by enhancing invadopodia formation in cancer-associated fibroblasts

The stromal compartment surrounding epithelial-derived pancreatic tumors is thought to have a key role in the aggressive phenotype of this malignancy. Emerging evidence suggests that cancer-associated fibroblasts (CAFs), the most abundant cells in the stroma of pancreatic tumors, contribute to the tumor's invasion, metastasis and resistance to therapy, but the precise molecular mechanisms that regulate CAFs behavior are poorly understood. In this study, we utilized immortalized human pancreatic CAFs to investigate molecular pathways that control the matrix-remodeling and invasion-promoting activity of CAFs. We showed previously that palladin, an actin-associated protein, is expressed at high levels in CAFs of pancreatic tumors and other solid tumors, and also in an immortalized line of human CAFs. In this study, we found that short-term exposure of CAFs to phorbol esters reduced the number of stress fibers and triggered the appearance of individual invadopodia and invadopodial rosettes in CAFs. Molecular analysis of invadopodia revealed that their composition resembled that of similar structures (that is, invadopodia and podosomes) described in other cell types. Pharmacological inhibition and small interfering RNA knockdown experiments demonstrated that protein kinase C, the small GTPase Cdc42 and palladin were necessary for the efficient assembly of invadopodia by CAFs. In addition, GTPase activity assays showed that palladin contributes to the activation of Cdc42. In mouse xenograft experiments using a mixture of CAFs and tumor cells, palladin expression in CAFs promoted the rapid growth and metastasis of human pancreatic tumor cells. Overall, these results indicate that high levels of palladin expression in CAFs enhance their ability to remodel the extracellular matrix by regulating the activity of Cdc42, which in turn promotes the assembly of matrix-degrading invadopodia in CAFs and tumor cell invasion. Together, these results identify a novel molecular signaling pathway that may provide new molecular targets for the inhibition of pancreatic cancer metastasis.

Regulation of human sperm motility by opioid receptors

The endogenous opioid system has been reported to have important functions in human reproduction. Practically all the components of this peptide system have been discovered in human sperm cells, but their functions in these cells are far from being well understood. In the present work, we report the effects of opioid agonism and antagonism on human sperm motility, a parameter which is crucially associated with male fertility. Morphine (10(-7) M), a μ- opioid receptor agonist, decreased both the percentage of motile progressive sperm and three measured velocities without altering the linearity, straightness or vigour of sperm cells. This effect was reversed by naloxone. Higher doses of morphine did not have further effects on the measured parameters. The incubation of sperm cells with the δ-opioid receptor agonist D-penicillamine (2,5)-enkephalin did not affect sperm cell motility. However, naltrindole, a specific δ-receptor antagonist, reduced the linear and curvilinear velocities, as well as linearity, straightness and the amplitude of head displacement, and beat frequency. In summary, our results indicate that the endogenous opioid system may regulate opioid motility in vitro. These finding suggest that the endogenous opioid system could be useful as a biochemical tool for the diagnosis and treatment of male infertility.

[Treatment of wet age-related macular degeneration with ranibizumab in clinical practice: results and prognostic factors]

OBJECTIVES

To evaluate the efficacy of ranibizumab in wet age-related macular degeneration (ARMD), and to identify prognostic factors.

METHODS

A retrospective longitudinal study of 79 eyes treated with intravitreal Ranibizumab in our hospital due to wet ARMD, with an initial regimen of three consecutive monthly injections, followed by injections on demand based on the exploratory findings. We conducted a descriptive study of the baseline examination (n=79), and 3 (n=79), 6 (n=67) and 12 months (n=49) after starting treatment. The characteristics of the baseline examination and annual examination results were compared using univariate and multivariate analysis.

RESULTS

After the three initial injections, the 93.67% of patients lost fewer than 15 letters, and 19% gained 15 points or more. This result remained similar at 1 year (83.67% and 20.40%, respectively). After 1 year of treatment 40.82% had a VA ≥ 0.3 and 22'45% had a VA ≤ 0.1. We used a median of 5 injections per year. The increased AV at the beginning and the persistence of large intraretinal cysts at 3 months (P=.0013), as well as the development of fibrosis during evolution (P=.0005), are associated with visual deterioration.

CONCLUSIONS

The guidelines used here stabilised or improved visual acuity in most patients. The most favourable cases are those with initially lower VA or large intraretinal cysts resolved after the loading phase. The appearance of fibrosis implies a poor long-term visual prognosis.

Monitoring influenza activity in Europe with Google Flu Trends: comparison with the findings of sentinel physician networks - results for 2009-10

The number of Internet searches has recently been used by Google to estimate the influenza incidence in the United States. We examined the correlation between the Google Flu Trends tool and sentinel networks estimates in several European countries during the 2009 influenza A(H1N1) pandemic and found a good correlation between estimates and peak incidence timing, with the highest peaks in countries where Internet is most frequently used for health-related searching. Although somehow limited, Google could be a valuable tool for syndromic surveillance.

Biological nitrogen removal with three different SBBR

In order to compare the performance of biofilms growing on different support media, three reactors were fed with municipal wastewater from the city of Garching, Germany, and operated under the sequencing batch procedure. The support media tested have the commercial names of Kaldnes, polyethylene special support for moving bed reactors with approximate diameter of 12 mm; Liapor, ceramic spheres with diameters between 4 and 6 mm; Linpor, plastic foam cut in cubes of 15 mm. The bench-top reactors were tested for COD, TSS and ammonia nitrogen removal. During 452 days runs with organic loads between 0.5 and 8.0 gCOD/m2 x d were tested. Thin biofilms (Kaldnes and Liapor) perform better for COD and ammonia removal under lower organic loading values (< 2.5 gCOD/m2 x d). For organic loads over 3.0 gCOD/m2 x d, the reactor packed with Linpor (thick biofilm) showed a better COD and ammonia nitrogen removal than the other two. Linpor achieved the highest NOx-N production reaching values between 15 and 20 mg/l. For low organic loading rates Linpor and Liapor present similar average NOx-N concentrations. Kaldnes shows the lowest concentrations throughout the whole experimental period. The difference between ammonia nitrogen removal and NOx-N generation is simultaneous denitrification inside the deep biofilms. The average mean cellular retention times were 5.4 days for Liapor, 10.0 days for Kaldnes and 22.9 days for Linpor. This is the reason why Linpor achieved complete nitrification even with higher organic loads.

Epistatic interaction between FCRL3 and NFkappaB1 genes in Spanish patients with rheumatoid arthritis

BACKGROUND

A Japanese study has described a strong association between rheumatoid arthritis and several polymorphisms located in the Fc receptor-like 3 (FCRL3) gene, a member of a family of genes related to Fc receptors located on chromosome 1q21-23.

OBJECTIVES

To evaluate the association between rheumatoid arthritis and FCLR3 polymorphisms in a large cohort of Caucasian patients with rheumatoid arthritis and healthy controls of Spanish origin. Owing to the described functional link between the FCRL3 polymorphisms and the transcription factor nuclear factor kappaB (NFkappaB), a functional polymorphism located in the NFkappaB1 gene was included.

METHODS

734 patients with rheumatoid arthritis from Madrid and Granada, Spain, were included in the study, along with 736 healthy controls. Polymorphisms in the FCRL3 gene were studied by TaqMan technology. The -94ins/delATTG NFkappaB1 promoter polymorphism was analysed by fragment analysis after polymerase chain reaction with labelled primers. Genotypes were compared using 3x2 contingency tables and chi2 values.

RESULTS

No overall differences were found in any of the FCRL3 polymorphisms and in the NFkappaB1 promoter polymorphism when patients were compared with controls. However, when stratified according to NFkappaB1 genotypes, a susceptibility effect of FCRL3 polymorphisms was observed in patients who were heterozygotes for NFkappaB1 (pc = 0.003).

CONCLUSIONS

The FCRL3 polymorphisms associated with rheumatoid arthritis in a Japanese population are not associated per se with rheumatoid arthritis in a Spanish population. A genetic interaction was found between NFkappaB1 and FCRL3 in Spanish patients with rheumatoid arthritis. These findings may provide a general rationale for divergent genetic association results in different populations.

Helicobacter pylori vacA s1a and s1b alleles from clinical isolates from different regions of Chile show a distinct geographic distribution

AIM

To establish the most common vacA alleles in Helicobacter pylori (H pylori) strains isolated from Chilean patients and its relationship with gastritis and gastroduodenal ulcers.

METHODS

Two hundred and forty five H pylori clinical isolates were obtained from 79 biopsies from Chilean infected patients suffering from gastrointestinal diseases. An average of 2-3 strains per patient was isolated and the vacA genotype was analyzed by PCR and 3% agarose electrophoresis. Some genotypes were checked by DNA sequencing.

RESULTS

The most prevalent vacA genotype in Chilean patients was s1b m1 (76%), followed by s1a m1 (21%). In contrast, the s2 m2 genotype was scarcely represented (3%). The s1b m1 genotype was found most frequently linked to gastropathies (P<0.05) rather than ulcers. Ulcers were found more commonly in male and older patients. Curiously, patients living in cities located North and far South of Santiago, the capital and largest Chilean city, carried almost exclusively strains with the s1b m1 genotype. In contrast, patients from Santiago and cities located South of Santiago carried strains with either one or both s1a m1 and s1b m1 genotypes. Regarding the s2 m2 genotype, comparison with GenBank sequences revealed that Chilean s2 sequence was identical to those of Australian, American, and Colombian strains but quite different from those of Alaska and India.

CONCLUSION

Differences in geographic distribution of the s and m vacA alleles in Chile and a relationship of s1b m1 genotype with gastritis were found. Sequence data in part support a hispanic origin for the vacA genotype. Asymmetric distribution of genotypes s1b m1 and s2 m2 recedes H Pylori strain distribution in Spain and Portugal.

PADI4 polymorphisms are not associated with rheumatoid arthritis in the Spanish population

OBJECTIVES

The presence of anti-citrullinated peptide antibodies is the most specific serological marker known of rheumatoid arthritis (RA). The PADI4 gene, encoding a haematopoietic isoform of the peptidylarginine deiminase citrullinating enzyme, has recently been associated with susceptibility to RA in the Japanese population. A subsequent UK report could not confirm this association, and a later French study also yielded a negative result. Given this discrepancy and the importance of antibodies against citrullinated peptides in the early course of the disease, we performed a replication study.

METHODS

Three hundred and fifty-four Spanish RA patients and 498 Spanish controls were recruited from two Madrid hospitals. The padi4_104 and padi4_94 single-nucleotide polymorphisms (SNP) were analysed by TaqMan assays.

RESULTS

Similarly to what was described in the British and French population, the less frequent allele of this SNP was not associated with the disease (genotype TT, 16.1% in RA patients vs 14.3% in controls; P = 0.46, odds ratio 1.15, 95% confidence interval 0.78-1.71). A confirmatory negative result was obtained on analysing another SNP in the same gene, padi4_94, in 248 RA patients and 394 controls.

CONCLUSIONS

The results of our group and from the British and French studies strongly suggest that polymorphisms of the PADI4 gene do not play a role in susceptibility to RA in European populations.

Effects of changes in hydromineral balance on rat brain aspartyl, arginyl, and alanyl aminopeptidase activities

In order to examine the possible relationship between the processing and inactivation roles of aminopeptidases and the disruption of water-electrolyte balance, we measured the activities of aspartyl aminopeptidase (Asp-Ap), arginyl aminopeptidase (Arg-Ap) and alanyl aminopeptidase (Ala-Ap) in certain brain areas (hypothalamus, hippocampus, thalamus and brain cortices) and in the pituitary gland in several models of hydrosaline change. The activity of hypothalamic membrane-bound Asp-Ap significantly decreased (more than 50%) following treatments which induced a hypovolemic state. Aminopeptidase M activity (membrane-bound Ala-Ap activity with low sensitivity to puromycin) was also significantly decreased by 53 % in the thalamus of rats under conditions of hypovolemia plus hyperosmolality in comparison to the control group. These results indicate that aminopeptidases in the central nervous system may be involved in the physiological regulation of hydromineral balance.

Isolation and identification of adenovirus in hospitalized children, under five years, with acute respiratory disease, in Havana, Cuba

Nine Adenovirus (Ad) strains isolated in Cuba, from 128 nasopharingeal swab specimens of children below five years old, with acute respiratory diseases, during 1996 and 1997, were studied by restriction enzyme analysis of genomic DNA with two endonucleases BamH I and Sma I. All different fragment patterns were compared with the respective prototypes. The identified adenoviruses were Ad 1 (n=4), Ad 2 (n=1) and Ad 6 (n=4). Males were more frequently infected than females. The analysis of the occurrence of these Adenovirus strains of subgenus C revealed that Ad 1 and Ad 6 were the predominant serotypes in 1996 and in 1997, respectively.

Subcellular distribution of pyroglutamyl-peptidase I activity in the developing rat cerebellum

In this work we analyzed the activity of pyroglutamyl (pGlu)-peptidase I in several subcellular fractions of the rat cerebellum during its development. The aim of this study is to determine if there is a developmental redistribution of this enzyme activity and if this fact could indicate changes in the role of the enzyme as age progresses. Results show that pGlu-peptidase I is widely distributed, but not homogeneously, in all the subcellular fractions that were studied, in both soluble and particulate forms. Significantly the distribution of the enzyme changes with development. Thus, in the soluble synaptosomal fraction, the pGlu-peptidase I activity is low until PD9 and the activity increases significantly from PD9 to PD15, when it reaches adult levels. In contrast, in the cytosolic fraction, the pGlu-peptidase I activity is high from fetal day 22 to postnatal day 6, and then decreases significantly until postnatal day 90.

Detection of respiratory syncytial virus in nasopharyngeal secretions by 24-well plate precentrifugation assay using a monoclonal antibody against F protein

BACKGROUND

Respiratory syncytial virus (RSV) is responsible for 50% of all bronchiolitis and 25% of pneumonia cases during the first month of life. Detection of the RSV antigen by immunofluorescence in exfoliated nasal epithelium or by other methods in nasopharyngeal swabs is useful in the potentially infected patient because results are available within a few hours. In contrast, RSV antigen detection in cell culture may require as much as 3 weeks.

METHODS

Three methods for detection of respiratory syncytial virus in 131 clinical respiratory specimens from patients with acute respiratory disease and bronchiolitis were compared utilizing the following: a precentrifugation immunofluorescence assay using Hep-2 cells, indirect immunofluorescence assay, and conventional tube cell culture using Hep-2 cells.

RESULTS

Respiratory syncytial virus was identified in 36 specimens by the three methods previously described. The virus was recovered in 41 (31.3%) samples by precentrifugation immunofluorescence assay, 40 (30.5%) were identified by the immunofluorescence technique, and 38 (29.0%) cases were positive by conventional cell culture. The sensitivity of the precentrifugation assay in relation to the immunofluorescence technique was 90%, the specificity 94.5%, and the agreement, 96.2%. A positive predictive value of 90.2% was obtained. Sensitivity, specificity, agreement, and positive predictive values obtained by the precentrifugation assay variant compared to the conventional cell were 90.8%, 94.5%, 93.1%, and 87.8%, respectively.

CONCLUSIONS

The precentrifugation immunofluorescence assay method was as sensitive as the remainder of the methods used in our study and represents a valid alternative for rapid detection of respiratory syncytial virus in clinical samples.

Antigenic and genetic characterization of twenty-six strains of human respiratory syncytial virus (subgroup A) isolated during three consecutive outbreaks in Havana city, Cuba

Twenty-six human respiratory syncytial virus strains (subgroup A) isolated from three outbreaks in Havana City during the period 1994/95, 1995/96 and 1996/97 were analyzed to determine their antigenic and genetic relationships. Analyses were performed by monoclonal antibodies and restriction mapping (N gene) following amplification of the select region of the virus genome by polymerase chain reaction. All isolated strains were classified as subgroup A by monoclonal antibodies and they showed a restriction pattern NP4 that belonged to subgroup A. Thus the results obtained in this work, showed a close relation (100%) between antigenic and genetic characterization of the isolated strains in our laboratory. These methods permit the examination of large numbers of isolates by molecular techniques, simplifying the researchs into the molecular epidemiology of the virus.

[Follicular conjunctivitis caused by an adenovirus. The characterization of its strains by restriction endonucleases]

A study of conjunctivitis cases with a possible viral cause was carried out in Havana City during June and August, 1993. Thirty seven cases from "Ramón Pando Ferrer" Ophthalmological Hospital were studied, of whom 13 isolations (35.1%) in cell culture of Hela cells were obtained. Isolations showed a cytopathic effect characteristic of Adenovirus. A direct immunofluorescence with conjugated serum of rabbit specific to Adenovirus was performed and results were positive in 100% of cases. A DNA restriction analysis of each isolated was performed for their classification. Restriction endonucleases SmaI and Hind III were used and 2 isolates were classified as Adenovirus type 3, and 6 as Adenovirus type 7b, 4 out of 13 isolates were not classified because of the degradation of the genetic material.

[The standardization of an ultramicro ELISA assay for the detection of IgG antibodies to the respiratory syncytial virus]

An ultramicro ELISA assay of double antibody for the detection of IgG antibodies to the respiratory syncytial virus (RSV) was standardized. It was used a RVS antiprotein F monoclonal antibody produced by the Genetic Engineering and Biotechnology Center (GEBC) in Havana. The use of this antibody allowed to include crude antigenic preparations instead of purified fractions, which caused a significant reduction of the reactivity obtained with the antigen control. The assay conditions were determined by crossed titration. It was obtained a sensitivity of 97.2%, a coincidence of 91%, and a specificity of 83.3% of the UMELISA as regards the complement fixation. The results may be qualitatively expressed or by antibody titres using only one serum dilution (1:40) and a pattern curve.

[Diagnosis of cytomegalovirus infections in patients with HIV infection. Comparison of the indirect immunofluorescence and viral isolation techniques]

The technique for the detection of fluorescent early antigen was compared to the classical method of viral isolation in cells from the human lung. The study was performed with the use of 85 urine samples from 64 patients presenting with HIV infection. The technique for the detection of fluorescent early antigens showed a sensitivity of 91%, an specificity of 97%, and a coincidence of 94% with respect to viral isolation. The main advantage of the technique for the detection of fluorescent early antigens with respect to viral isolation is that the former provides a quicker diagnosis of cytomegalovirus infection within 48-72 hours, besides being easy to perform.

[Determination of complement-fixing antibodies to respiratory syncytial virus. Longitudinal study in a population of less than 1 year of age in the City of Havana]

Respiratory syncytial viruses (RSV) are considered among the most important agents causing acute respiratory infections in infants below 1 year of age. A 10-year longitudinal study of monosera from children under 15 years was carried out; 1,069 monosera from children under 1 year were studied using the RSV antigen complement-fixing technique. It was observed that there were short or longer periods between the peaks of positive sera and when they were compared with medical care reports, they showed correspondence with increased numbers of medical care reports. A typical seasonal pattern in the distribution of antibodies was determined and this corresponded to the month of February, suggesting that this is probably due to the circulation of the virus and not to maternal antibodies. The results attained give grounds for considering the possible circulation of RSV in our country.

[Detection of cytomegalovirus in urine using DNA-DNA hybridization]

A discussion is conducted on the results of the application of the technique for hybridizing nucleic acids to the detection of cytomegalovirus (CMV) in urine samples. For this purpose, 2 probes from 2 different regions of the genome of the AD169 strain of CMV were used. The results were compared with those obtained by the technique for the detection of early fluorescent antigens (DEFA) in 2 groups of patients at risk of suffering from CMV infections. After assessing the usefulness of the two probes in detecting CMV in urine samples, it was shown that probe B from the region which codes the synthesis of early viral proteins had a coincidence and specificity levels regarding the reference test (DEFA) significantly superior to that of probe A. The results of hybridization may be ready within 48 and 72 hours. The qualification of the technique fo its application to virological diagnosis is discussed.

[Indirect ultramicroELISA for the detection of total adenovirus antibodies in human serum]

An indirect ultramicroELISA method was normalized for the detection of total antibodies to Adenovirus (AD) (UMELISA AD). The optimum concentration of surface antigen determined was 30 micrograms/mL; serum dilution was of 1:40; and conjugate dilution, of 1:1,000. The UMELISA AD was compared with the complement fixing and indirect immunofluorescence techniques. Results showed accordance by 88% and 96.6%, respectively. The method is valid for the screening of antibodies in seroepidemiological studies as well as for the diagnosis of the infection by paired serum samples.

[Subgroups classification of strains of the respiratory syncytial virus isolated in an outbreak in Ciudad de La Havana]

A high number of acute respiratory diseases was detected among children under one year admitted in a hospital of Havana City. 25 respiratory syncytial virus strains were obtained from 93 patients studied. Viral isolations were multiplied in HEP-2 cells and after observing a cytopathic effect of 80%, they were classified into subgroups by the indirect immunofluorescence technique, using anti-protein G antibodies from the respiratory syncytial virus. All the samples studied were classified within subgroup A. It is the first time a study like this is conducted in our country, which allowed us to deepen into the viral cause of these diseases and to know that the subgroup A of the respiratory syncytial virus circulated during the outbreak.

Unusual antigenic and genetic characteristics of human respiratory syncytial viruses isolated in Cuba

The G protein of 23 strains of human respiratory syncytial virus isolated in Havana, Cuba, between October 1994 and January 1995 was analyzed at the antigenic and genetic level. All viruses reacted with 10 of 11 antibodies specific for the Long strain. Moreover, the G protein gene of the Cuban isolates had only five nucleotide differences from the sequence of the Long gene. The homogeneity of the Cuban isolates and their resemblance to an ancient strain, such as Long, are at odds with previous findings for viruses isolated in countries with a temperate climate and different socioeconomic status. The G proteins of three of four other viruses isolated in Havana 2 years later (1996) were also identical to those of the 1994-to-1995 isolates, and the fourth virus had a single extra nucleotide difference. This, again, is unusual, since no identical viruses had been isolated in different epidemics previously. The singular characteristics of the Cuban isolates reported here are discussed in terms of the epidemiological, climatic, and socioeconomic characteristics of Cuba.

[Application of the polymerase chain reaction for detecting respiratory syncytial virus]

The polymerase chain reaction (PCR) was developed in order to identify the respiratory syncytial virus by using the reference strain. The high sensitivity and specificity obtained show the PCR utility for detecting the RSV genoma and its application on the diagnosis.

Molecular characterization of an outbreak of respiratory syncytial virus (subgroup A) in Havana, Cuba, by monoclonal antibodies and restriction mapping (N gene)

Twenty-one respiratory syncytial virus (RSV) strains isolated from one outbreak in Havana, Cuba (1994 to 1995), were analyzed to determine their relatedness. All isolated strains were classified as subgroup A by monoclonal antibodies. Of 21 RSV strains examined, 20 were classified as having restriction pattern NP4 and only 1 was classified as having restriction pattern NP5.

Analysis of respiratory syncytial virus in clinical samples by reverse transcriptase-polymerase chain reaction restriction mapping

The aim of this study was to develop a polymerase chain reaction (PCR) for the detection of respiratory syncytial virus (RSV) genomes. The primers were designed from published sequences and selected from conserved regions of the genome encoding for the N protein of subgroups A and B of RSV. PCR was applied to 20 specimens from children admitted to the respiratory ward of "William Soler" Pediatric Hospital in Havana City with a clinical diagnosis of bronchiolitis. The PCR was compared with viral isolation and with an indirect immunofluorescence technique that employs monoclonal antibodies of subgroups A and B. Of 20 nasopharyngeal exudates, 10 were found positive by the three assayed methods. In only two cases, samples that yielded positive RNA-PCR were found negative by indirect immunofluorescence and cell culture. Considering viral isolation as the "gold standard" technique, RNA-PCR had 100% sensitivity and 80% specificity. RNA-PCR is a specific and sensitive technique for the detection of the RSV genome. Technical advantages are discussed.

Detection of cytomegalovirus in urine of HIV-infected patients by DNA-DNA hybridization comparison with virus isolation, immunofluorescence and immunoperoxidase

Immunofluorescence and immunoperoxidase test directed against early viral antigens, and DNA-DNA hybridization were compared with viral isolation for their abilities to detect Cytomegalovirus (CMV) in the urine of 89 HIV infected patients. From the 100 urine samples collected, 70 were found positive by at least one method. Considering viral isolation as the "gold standard" technique, immunofluorescence and immunoperoxidase had a sensitivity of 92.3% and 88% respectively, with a specificity in both cases of 95%. DNA-DNA hybridization showed a sensitivity of 90% but with lower (60%) specificity. All of the three assays were effective in detecting CMV from urine and the technical advantage of each is discussed.