Association Between Indication for Descemet Stripping Automated Endothelial Keratoplasty and Rural Residency

PURPOSE

Residing in rural locations can be a barrier to health care access. This study investigated the impact of residing in rural and small town (RST) areas on Descemet stripping automated endothelial keratoplasty (DSAEK) indications and outcomes in Atlantic Canada.

METHODS

A retrospective cohort analysis examined consecutive DSAEKs performed in Nova Scotia between 2017 and 2020. Patient rurality was determined by the Statistical Area Classification system developed by Statistics Canada. Univariate and multivariate logistic regression models were used to assess for factors associated with DSAEK indication, including repeat keratoplasty, RST residence status, and travel time.

RESULTS

Of 271 DSAEKs during the study period, 87 (32.1%) were performed on the eyes of RST residents. The median postoperative follow-up time was 1.6 years. Undergoing DSAEK for a previous failed keratoplasty was not associated with a higher odds of RST residency (odds ratio [OR], 0.50; 95% confidence interval [CI], 0.19-1.16; P = 0.13) but was associated with travel time (OR, 0.78 for each increasing hour of travel; 95% CI, 0.61-0.99; P = 0.044). RST residency was not associated with the occurrence of graft failure (OR, 0.48; 95% CI, 0.17-1.17; P = 0.13).

CONCLUSIONS

Residing in a rural area in Atlantic Canada was not associated with DSAEK graft failure. Repeat endothelial keratoplasty was associated with shorter travel time for corneal surgery but not rural residency status. Further research in this field could inform regional health strategies aimed at improving equity and accessibility to ophthalmology subspecialist care.

Pars Plana Vitrectomy for Vitreomacular Traction Resulting in Persistent Postoperative Loculated Foveal Subretinal Fluid

Purpose: To describe a case of postoperative persistent loculated subretinal fluid (SRF) that developed after pars plana vitrectomy (PPV) for vitreomacular traction (VMT) syndrome. Methods: A case was analyzed and a literature review performed. Results: A healthy 64-year-old man with no significant ocular history presented with persistent, symptomatic VMT. Combined phacoemulsification and PPV, epiretinal membrane and internal limiting membrane peeling, and gas-fluid exchange were performed. Postoperative spectral-domain optical coherence tomography imaging showed loculated foveal SRF. The SRF persisted for 8 months, with minimal change in size and little best-corrected visual acuity improvement. Conclusions: Although persistent loculated SRF has been reported after vitrectomy for rhegmatogenous retinal detachment (RD) in high myopia and tractional RD in diabetes, it has not yet been reported postoperatively after PPV for VMT. Studies of the pathophysiology and long-term course of persistent SRF after PPV for VMT are needed to inform management decisions for this rare complication.

Compliance With Cannabis Act Regulations Regarding Online Promotion Among Canadian Commercial Cannabis-Licensed Firms

IMPORTANCE

As global jurisdictions shift toward cannabis legalization, 2 areas of public health importance relate to exposure to youth and to truthful promotion. Although Canada's Cannabis Act specifies many prohibitions related to cannabis promotion, no systematic monitoring or enforcement among licensed firms exists. Compliance with marketing regulations has effects beyond Canadian citizens because of the global outreach of websites and social media.

OBJECTIVES

To evaluate compliance among licensed firms with the Cannabis Act and analyze trends among violations regarding promotional material.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study evaluated cannabis-licensed firms after cannabis legalization. Data were extracted from online public platforms, including company websites, Facebook, Instagram, and Twitter, from October 1, 2019, to March 31, 2020. Descriptive statistics, Poisson regression, and logistic regression were used to analyze the associations of covariates with promotion violations.

MAIN OUTCOMES AND MEASURES

The primary outcome was characterization of type and prevalence of promotion violations. Secondary outcomes were the role of various covariates (namely, licensed firm characteristics and online platforms) in the frequency and probability of violations. Hypotheses were formulated before data collection.

RESULTS

Among 261 licensed firms, 211 (80.8%) had an online platform, including 204 (96.7%) with websites, 128 (60.7%) with Facebook, 123 (58.3%) with Instagram, and 123 (58.3%) with Twitter. Of all licensed firms with an online platform, 182 (86.3%) had at least 1 violation. Compared with websites, the risk of violations was significantly higher on Facebook (rate ratio [RR], 1.24; 95% CI, 1.11-1.39) and Instagram (RR, 1.19; 95% CI, 1.05-1.34). The most common violations included lack of age restrictions, brand glamorization, and omission of risk information. With websites as the reference group, lack of age restrictions was approximately 15 times more likely to occur on Facebook (odds ratio [OR], 14.76; 95% CI, 8.06-27.05); the odds of an age restriction violation were also higher on Instagram (OR, 2.48; 95% CI, 1.43-4.32) and Twitter (OR, 4.03; 95% CI, 2.29-7.09). For unsubstantiated claims, the odds of violations were significantly decreased on Facebook (OR, 0.23; 95% CI, 0.11-0.48) and Instagram (OR, 0.28; 95% CI, 0.14-0.57). The odds of glamorization were associated with an increase on Instagram (OR, 2.90; 95% CI, 1.72-4.88).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, widespread violations were observed in online Canadian cannabis promotion. To protect public health and safety amid legalization, decision-makers should make explicit federal regulation and enforcement regarding promotional activities of cannabis retailers. These results suggest that policy and enforcement of cannabis promotion in Canada would have an international impact, from ease of access to online media and downstream consequences of unregulated promotion.

Non-collagen genes role in digenic Alport syndrome

Background

Alport syndrome is a clinically heterogeneous nephropathy characterized by severe symptomatology at kidney level due to ultrastructural lesions of the glomerular basement membrane (GBM) as consequence of mutations in COL4 genes. The disease has been linked to COL4A3/COL4A4/COL4A5 mutations, which impair GBM functionality and can be inherited in a dominant, recessive or X-linked transmission. Although a targeted Next Generation Sequencing approach has allowed identifying families with pathogenic mutations in more than one COL4 α3-α4-α5 heterotrimer encoding genes, leading to conclude for a digenic pattern of inheritance, the role of non-collagen genes in digenic Alport syndrome has not yet been established.

Methods

We employed a whole-exome sequencing approach on three families in whom a digenic pattern of transmission could be suspected because of a likely biparental contribution or an unexplained phenotype in the proband.

Results

We identified in the three probands hypomorphic LAMA5 mutations co-inherited with pathogenic COL4 α4-α5 chains mutations. Segregation analysis revealed that the combination of LAMA5/COL4 variants co-segregate with a fully penetrant phenotype in line with a digenic inheritance.

In one of the three probands an hypomorphic variant in NPHS2 was also found, suggesting that role of other kidney disease related-genes as modifiers.

Conclusion

These findings validate the impact of LAMA5 mutations in digenic ATS and highlight the role of extracellular matrix’s genes, basement membrane, slit diaphragm and podocyte cytoskeleton in ATS. This underline the need for a more extensive panel approach in the presence of a digenic ATS, in order to better define clinical severity and recurrence risk for family members.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1258-5) contains supplementary material, which is available to authorized users.

Alport syndrome: impact of digenic inheritance in patients management

Alport syndrome (ATS) is a genetically heterogeneous nephropathy with considerable phenotypic variability and different transmission patterns, including monogenic (X-linked/autosomal) and digenic inheritance (DI). Here we present a new series of families with DI and we discuss the consequences for genetic counseling and risk assessment. Out of five families harboring variants in more than one COL4 gene detected by next generation sequencing (NGS), minigene-splicing assay allowed us to identify four as true digenic. Two families showed COL4A3/A4 mutations in cis, mimicking an autosomal dominant inheritance with a more severe phenotype and one showed COL4A3/A4 mutations in trans, mimicking an autosomal recessive inheritance with a less severe phenotype. In a fourth family, a de novo mutation (COL4A5) combined with an inherited mutation (COL4A3) triggered a more severe phenotype. A fifth family, predicted digenic on the basis of silico tools, rather showed monogenic X-linked inheritance due to a hypomorphic mutation, in accordance with a milder phenotype. In conclusion, this study highlights the impact of DI in ATS and explains the associated atypical presentations. More complex inheritance should be therefore considered when reviewing prognosis and recurrence risks. On the other side, these findings emphasize the importance to accompany NGS with splicing assays in order to avoid erroneous identification of at risk members.

Psychometric properties of the Revised Fibromyalgia Impact Questionnaire (FIQR) - a contribution to the Portuguese validation of the scale

BACKGROUND

Fibromyalgia (FM) remains a relatively misunderstood and clinically challenging condition that impact significantly in the individual´s life, impairing global functioning and diminishing quality of life. Management is complex and frequently unsatisfactory, requiring personal tailoring and adaptation of interventions according to the fluctuations of the disease manifestations and their response to therapy. The use of comprehensive and quantified assessment tools constitutes, therefore, an essential component of the management of patients with FM. The Revised Fibromyalgia Impact Questionnaire (FIQR) is currently one of the most used and well validated instruments to assess functional (in)capacity and global impact of FM and associated symptoms.

OBJECTIVES

To translate to Portuguese the FIQR and to study its psychometric properties.

MATERIAL AND METHODS

The total sample comprised 103 women with fibromyalgia, defined according to the established criteria for FM. A self-report battery composed by the Revised Fibromyalgia Impact Questionnaire (FIQR), the Portuguese version of Beck Depression Inventory-II (BDI-II) and the Profile of Mood States (PoMS) was administered. The FIQR was re-administered to twenty-four participants, six weeks after the first evaluation. Internal reliability was assessed through Cronbach's alpha, corrected item-total score correlations and alpha if item deleted. Spearman and Pearson correlations along with repeated measures tests were computed to assess the temporal stability of the scale. Convergent and divergent validity were assessed via Spearman and Pearson correlations.

RESULTS

The FIQR demonstrated a good to very good internal consistency (from α = 0.87 to α = 0.94). All items correlated to a good degree (above 0.30) to the total score and contributed significantly to the overall reliability. Moreover, FIQR presented a good temporal stability (from r = .617 to r = .886, p ≤ .001) and favorable convergent and discriminant validity with depressive symptoms (r > .289, p ≤ .01) and positive (r > -.186, p > .05) and negative affect (r > .206, p ≤ .05).

CONCLUSIONS

The Portuguese version of the FIQR demonstrated good psychometric properties, which renders it a proper and valuable tool to be used in different settings.

Discordances in the application of different criteria for quantification of paediatric abdominal obesity: an analysis of two Swiss studies

Several definitions of paediatric abdominal obesity have been proposed but it is unclear whether they lead to similar results. We assessed the prevalence of abdominal obesity using five different waist circumference-based definitions and their agreement with total body fat (TBF) and abdominal fat (AF). Data from 190 girls and 162 boys (Ballabeina), and from 134 girls and 113 boys (Kinder-Sportstudie, KISS) aged 5–11 years were used. TBF was assessed by bioimpedance (Ballabeina) or dual energy X-ray absorption (KISS). On the basis of the definition used, the prevalence of abdominal obesity varied between 3.1 and 49.4% in boys, and 4.7 and 55.5% in girls (Ballabeina), and between 1.8 and 36.3% in boys and 4.5 and 37.3% in girls (KISS). Among children considered as abdominally obese by at least one definition, 32.0 (Ballabeina) and 44.7% (KISS) were considered as such by at least two (out of five possible) definitions. Using excess TBF or AF as reference, the areas under the receiver operating curve varied between 0.577 and 0.762 (Ballabeina), and 0.583 and 0.818 (KISS). We conclude that current definitions of abdominal obesity in children lead to wide prevalence estimates and should not be used until a standard definition can be proposed.

Effect of Artificial Aging and Surface Treatment on Bond Strengths to Dental Zirconia

The objective of this project was to study the influence of artificial aging and surface treatment on the microtensile bond strengths (μTBS) between zirconia and a phosphate monomer–based self-adhesive cement. Thirty zirconia disks (IPS e.max ZirCAD, Ivoclar Vivadent) were randomly assigned to two aging regimens: AR, used as received, which served as a control, and AG, artificial aging to simulate low-temperature degradation. Subsequently, the disks of each aging regimen were assigned to three surface treatments: NT, no surface treatment; CO, surface silicatization with CoJet sand (3M ESPE); and ZP, zirconia surface treated with Z-Prime Plus (Bisco Inc). Thirty discs were made of Filtek Z250 (3M ESPE) composite resin and luted to the zirconia discs using RelyX Unicem (3M ESPE). The specimens were sectioned with a diamond blade in X and Y directions to obtain bonded beams with a cross-section of 1.0 ± 0.2 mm. The beams were tested in tensile mode in a universal testing machine at a speed of 0.5 mm/min to measure μTBS. Selected beams were selected for fractographic analysis under the SEM. Statistical analysis was carried out with two-way analysis of variance and Dunnett T3 post hoc test at a significance level of 95%. The mean μTBS for the three AR subgroups (AR-NT, AR-CO, and AR-ZP) were significantly higher than those of the corresponding AG groups (p<0.0001). Both AR-CO and AR-ZP resulted in statistically significant higher mean bond strengths than the group AR-NT (p<0.006 and p<0.0001, respectively). Both AG-CO and AG-ZP resulted in statistically significant higher mean bond strengths than the group AG-NT (both at p<0.0001). Overall, AG decreased mean μTBS. Under the SEM, mixed failures showed residual cement attached to the zirconia side of the beams. CO resulted in a characteristic roughness of the zirconia surface. AR-ZP was the only group for which the amount of residual cement occupied at least 50% of the interface in mixed failures.

Specific recommendations for PROs and HRQoL assessment in allergic rhinitis and/or asthma: a GA(2)LEN taskforce position paper

The GA(2)LEN taskforce on Patient-Reported Outcomes (PROs) and Health-Related Quality of Life (HRQoL) published in 2009 a position paper concerning PROS and HRQoL assessment in clinical trials on allergy. Because of the specificity of this topic in asthma and rhinitis, specific recommendations are needed. The aim of this position paper is to define PROs and their meaning in asthma and rhinitis research, explore the available tools to provide criteria for a proper choice, identify patient-related factor which could influence PROs assessment, define specific recommendations for assessment, analysis and results spreading, underline the unexplored areas and unmet needs. PROs assessment is gaining increasing importance, and it must be performed with a rigorous methodological procedure and using validated tools. This approach enables to better understand patient-related factors influencing clinical trials and real-life management outcomes, identify patients subgroups that can benefit from specific treatment and management plan and tailor treatment to address PROs (not only physician-defined targets) to improve asthma and rhinitis management.

Recommendations for assessing patient-reported outcomes and health-related quality of life in clinical trials on allergy: a GA(2)LEN taskforce position paper

The aim of this Global Allergy and Asthma European Network (GA(2)LEN) consensus report is to provide recommendations for patient-reported outcomes (PROs) evaluation in clinical trials for allergic diseases, which constitute a global health problem in terms of physical, psychological economic and social impact. During the last 40 years, PROs have gained large consideration and use in the scientific community, to gain a better understanding of patients' subjective assessment with respect to elements concerning their health condition. They include all health-related reports coming from the patient, without involvement or interpretation by physician or others. PROs assessment should be performed by validated tools (disease-specific tools when available or generic ones) selected taking into account the aim of the study, the expected intervention effects and the determinant and confounding factors or patient-related factors which could influence PROs. Moreover, each tool should be used exclusively in the patient population following the authors' indications without modification and performing a cross-cultural validation if the tool must be used in a language that differs from the original. The result analysis also suggests that the relevance of PROs results in any interventional study should include a pre-post assessment providing information concerning statistical differences within or among groups, rates of response for the PROs and a minimal important difference for the population. The report underlines the importance of further investigation on some topics, such as the quality assessment of existing PROs tools, the definition of inclusion and exclusion criteria and a more extensive evaluation of the correlation between PROs, besides health-related quality of life, and clinical data.

Chlorophyll-a determination via continuous measurement of plankton fluorescence: methodology development

A methodology is presented for the continuous measurement of chlorophyll-a concentration due to plankton, in surface water environments. A Turner 10-AU fluorometer equipped with the F4T5.B2/BP lamp (blue lamp), a Cs 5-60 equivalent excitation path filter, and a 680 nm emission filter, has been used. This configuration allows the in vivo, in situ determination of chlorophyll-a by measuring the fluorescence due to the pigments. In field work the fluorometer, data logging and positioning equipment were placed aboard a manageable boat which navigated following a scheme of regularly spaced crossings. Some water samples were collected during the measurement for laboratory chlorophyll-a measurements by the spectrophotometric method, thus providing for calibration and comparison. Spatial chlorophyll-a concentration distributions can be easily defined in large volumes, such as reservoirs, etc. Two distinct environments have been monitored: in the Vargem das Flores reservoir chlorophyll-a concentrations varied between 0.7 and 2.6 mg/m3, whereas in the Lagoa Santa lake these values lied in the 12 to 18 mg/m3 range. The simplicity, versatility and economy of the method, added to the large amount of data that can be gathered in a single run, clearly justify its use in field environmental studies.

Iron mobilization by succinylacetone methyl ester in rats. A model study for hereditary tyrosinemia and porphyrias characterized by 5-aminolevulinic acid overload

Accumulation of 5-aminolevulinic acid (ALA) is an event characteristic of porphyrias that may contribute to their pathological manifestations. To investigate effects of ALA independent of porphyrin accumulation we treated rats with the methyl ester of succinylacetone, an inhibitor of 5-aminolevulinic acid dehydratase that accumulates in the porphyric-like syndrome hereditary tyrosinemia. Acute 2-day treatment of fasted rats with succinylacetone methyl ester (SAME) promoted a 27% increase in plasma ALA. This increase in plasma ALA was accompanied by augmentation of the level of total nonheme iron in liver (37%) and brain (20%). Mobilization of iron was also indicated by 49% increase in plasma iron and a 77% increase in plasma transferrin saturation. Liver responded with a mild (12%) increase in ferritin. Under these acute conditions, some indications of oxidative stress were evident: a 15% increase in liver reactive protein carbonyls, and a 42% increase in brain subcellular membrane TBARS. Brain also showed a 44% increase in CuZnSOD activity, consistent with observations in treatment with ALA. Overall, the data indicate that SAME promotes ALA-driven changes in iron metabolism that could lead to increased production of free radicals. The findings support other evidence that accumulation of ALA in porphyrias and hereditary tyrosinemia may induce iron-dependent biological damage that contributes to neuropathy and hepatoma.

Detection of focal myeloma lesions by technetium-99m-sestaMIBI scintigraphy

BACKGROUND AND OBJECTIVE

The tracer tachnetium-99m-2-methoxy-isobutyl-isonitrile (Tc99m-sestaMIBI) has recently been shown to concentrate in some neoplastic tissues, including myeloma. We investigated the diagnostic capacity and limits of this procedure in tracing focal myeloma lesions, and compared them with those of conventional radiological procedures (Xr).

DESIGN AND METHODS

We studied 55 patients suffering from multiple myeloma (MM) or solitary plasmacytoma in different stages and clinical conditions, or from monoclonal gammopathy of undefined significance (MGUS), by whole body scans obtained 10 minutes after injection of 555 MBq of Tc99m-sestaMIBI. Scans were defined as normal (physiological uptake only), diffuse (presence of bone marrow uptake), or focal (localized areas of uptake), and were compared to conventional skeletal Xr.

RESULTS

Thirty patients showed no focal areas of Tc99m-sestaMIBI uptake; this group consisted of 5 patients with MGUS, 6 with MM in stage IA and 2 in stage IIA, 11 patients studied after effective chemotherapy and 6 in early relapse. Twenty-five patients showed one or more spots of focal uptake: all of them had active disease (untreated, resistant or relapsing MM). In the setting of tracing focal lesions, Tc99m-sestaMIBI scans were concordant with the radiological examination in 38 patients and discordant in 17. Among the latter, in 4 cases Tc99m-sestaMIBI revealed focal lesions not detected by Xr, and in 13 cases lytic areas detected by Xr did not show Tc99m-sestaMIBI uptake.

INTERPRETATION AND CONCLUSIONS

In untreated patients, the number of lesions revealed by Tc99m-sestaMIBI was comparable to that shown by Xr, while in pretreated patients Tc99m-sestaMIBI traced a number of lesions lower than that detected by Xr. The reason for this discrepancy is that Tc99m-sestaMIBI traces only active lesions. Tc99m-sestaMIBI limitations in identifying focal lesions may derive from the dimension of the smallest traceable lesion (about one centimeter), and from the possibility that focal plasma cell localizations in collapsed bone may not be visualized due to inadequate vascularization. Tc99m-sestaMIBI scintigraphy is an interesting tool for diagnosing, staging and following up focal myeloma lesions, in the bone as well as in soft tissues. It is more specific than conventional Xr in identifying sites of active disease.

Tc-99m sestamibi scintigraphy in multiple myeloma

Tc-99m sestamibi imaging was performed in two patients with multiple myeloma. Focal areas of increased uptake in one patient and diffuse skeletal uptake in the second patient were found. Tc-99m sestamibi appears to identify bone marrow and osteolytic involvement in multiple myeloma.

Expression of adhesion molecules in chronic B-cell lymphoproliferative disorders

BACKGROUND AND OBJECTIVE

Abnormalities in the expression of cell adhesion molecules (CAM) are thought to influence the patterns of intranodal growth and hematogeneous spread of malignant cells in chronic lymphoproliferative disorders (LPD). Therefore, the characterization of CAM phenotypic profiles of the neoplastic clones in LPD may help to identify distinct subtypes with prognostic implications. In this work we sought to investigate whether the expression of CAM by circulating malignant cells in patients with B-cell LPD differed from that of normal peripheral blood B-lymphocytes (PBL) and whether the observed phenotypic patterns could be correlated to other biological and clinical parameters of known clinical relevance.

DESIGN AND METHODS

Peripheral blood mononuclear cells were obtained from 148 patients with B-cell chronic lymphocytic leukemia (B-CLL), 52 with B-cell non-Hodgkin lymphomas (NHL) and 10 with hairy cell leukemia (HCL). The expression of CAM was analyzed by flow cytometry using monoclonal antibodies against CD49d, CD29, CD11a, CD11b, CD11c, CD18, CD62L, CD54 and CD44.

RESULTS

All CAM were detected in normal peripheral blood B-lymphocytes, except CD11c and CD54, which were present in only a minority of cells. Fluorescence mean channel values (FMC) showed that all molecules, with the exception of CD44, were expressed with dim intensity. Emerging patterns of CAM expression, as assessed by FMC values, were observed in different LPD: thus, B-CLL is characterized by a very low expression of CD49d/CD29 and beta 2 integrins. In this disorder, CD49d/CD29, CD11a, and CD54 increase with tumor burden; NHL show high expression of CD29 and CD54; strong expression of all molecules (except CD11a) was found in HCL, particularly CD11c (FMC values 60 times higher than normal). CD62L was faintly expressed in all diagnostic groups, whereas CD11c showed consistently high FMC values.

INTERPRETATION AND CONCLUSIONS

The data shows that the phenotypic characterization of LPD can be further refined by the analysis of their patterns of CAM expression which may help to identify distinct subsets within each nosological group.

Correlation between plasma 5-aminolevulinic acid concentrations and indicators of oxidative stress in lead-exposed workers

5-Aminolevulinic acid (ALA), a heme precursor accumulated in acute intermittent porphyria and lead poisoning, undergoes metal-catalyzed aerobic oxidation at physiological pH to yield reactive free radical species (O2., HO., and ALA.). We analyzed the relationships between plasma ALA concentrations, blood concentrations of lead, protoporphyrin IX (PP-IX), superoxide dismutase (SOD), and methemoglobin (metHb), and urine chemiluminescence (CL) in samples collected from lead-exposed workers. All variables measured were substantially (P < 0.01) higher (2-8-fold) in the lead-exposed workers (n = 60). Plasma ALA concentrations were, on average, 6-fold higher in lead-exposed workers. We observed positive linear relationships between ALA and lead (r = 0.992), ALA and PP-IX (r = 0.891), ALA and metHb (r = 0.984), lead and SOD (r = 0.948), ALA and urine CL (r = 0.987), and lead and PP-IX (r = 0.993). These data are consistent with our free radical hypothesis for lead poisoning, where ALA distribution to and accumulation in several organs may trigger oxidative stress responses.

Retinal complications after bungee jumping

Bungee jumping is becoming a popular sport in the Western world with some cases of ophthalmic complications being reported in recent literature. The authors reported a case of a 23-year-old healthy female who presented retinal complications following a bungee jumping. Her fundi showed superficial retinal hemorrhages in the right eye and a sub-internal limiting membrane hemorrhage affecting the left eye. A general examination, including a full neurological examination, was normal and laboratorial investigations were all within normal values. More studies are necessary to identify risk factors and the true incidence of related ocular lesions, but until then, we think this sport activity should be desencouraged, especially to those that are not psychological and physically fit.

Hemagglutinating and sialidase activities of subpopulations of influenza A viruses

The present study was conducted to investigate the characteristics of two samples of influenza A/England/42/72 (H3N2) virus, one of them selected by an adsorption-elution technique, to determine the possible existence of virus variants or subpopulations. Based on specificity of virulence-related cell receptor-binding and sialidase activities, this selection technique using human O group erythrocytes revealed the presence of variants within a standard virus sample with diversity for their hemagglutinating and sialidase activities. The standard-like (E1) sample exhibited titers of 4 and 32 HAU (hemagglutinating units in 25 microliters) with human O group and chicken erythrocytes, respectively, while the sample obtained by the adsorption-elution process (E2) exhibited titers of 32 and 4 HAU, respectively, with these same types of erythrocytes. The E2 sample showed higher sialidase activity at pH values between 5.4 and 6.6 with human erythrocytes (128-256 HAU), but the E1 sample did not exhibit significant sialidase activity with either human or chicken erythrocytes. The different pH optima for hemolysis (5.2) and sialidase (5.4-6.6) activities and the higher hemolysis indexes present in samples with sialidase activity inhibited by heating (at 56 degrees C for 30 min) or by treatment with EDTA (dilution in buffer containing 2 mM EDTA, a chelating agent on calcium-dependent sialidase activity) demonstrate the independence of these activities in the selected sample: native E2 (absorbance = 0.18), EDTA-treated native E2 (absorbance = 0.28), heated E2 (absorbance = 0.26), EDTA-treated heated E2 (absorbance = 0.41).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative evaluation of a simple and sensitive assay for detection of orthomyxo and paramyxoviruses

Studies were done to evaluate comparatively the traditional HA assay and a more recently introduced lectin-neuraminidase (LN) methodology in search of a simple and sensitive assay for virus detection during laboratorial diagnosis. The results proved the value of LN assay as a sensitive methodology for detection of virus particles, presenting results at least equal to those obtained by HA (hemagglutination) assay, with significant values of accumulated frequencies for LN/HA factors (ratios between LN and HA titers) higher than two. The accumulated values of frequencies for LN/HA factors as high as four were very significant, 72.7% for influenzavirus and 60.7% for Newcastle disease virus (NDV), moreover accumulated frequencies for LN/HA factors even as high as 32 were due to influenzavirus (45.4%) and NDV (7.2%) samples. After the storage period, most of those concentraded samples that even did not present HA titers could be detected through LN assay, demonstrating a lower threshold for virus detection.

[Mitral valve replacement with porcine bioprosthesis in children. Evaluation of 29 patients during 12 years]

PURPOSE

To analyze the clinical result of the mitral valve substitution for the porcine bioprostheses, the incidence of dysfunction caused by calcification and its importance related to the durability of bioprostheses and also the patients' survival.

METHODS

Twenty-nine children of about seven to sixteen years old were operated on from November 1977 to August 1982 and all of them received porcine bioprostheses of low profile.

RESULTS

There were three (10.34%) hospital deaths and nine other late mortalities. The follow-up period varied from 4 to 128 months with average of 58.17 months and with the loss of nine patients. An actuarial survival rate of 46.08% has been observed at 11 years after surgery. Calcification of 21 bioprostheses occurred in 14 out of 17 follow-up patients; 47.6% of them happened until the third year of pos-operative and 85.7% until the fifth year. Eleven patients were reoperated on with 9.09% of hospital mortality. There were no cases of thromboembolism.

CONCLUSION

Porcine bioprostheses works well with an evident clinical improvement of patients, with no thromboembolic accidents. However, its durability has been affected by the high incidence of calcification, which is responsible for an increase in late morbidity and mortality. Mitral valve disease treatment in children must be conservative, in an attempt to solve the problem with the different available plastic technics and leave the valve substitution to be a last option. In that case, the preference is given to the homologous bioprostheses.

[Experimental venous thrombosis in guinea pigs: effect of heparin and drugs affecting platelet function (author's transl)]

Thrombosis was induced in the jugular vein of guinea pigs by damage of the epithelium with a sclerosing solution. The effect of heparin, Dextran 70, acetylsalicylic acid, dypriridamole and phenilbutazone in preventing the development of the thrombus was investigated. Only heparin in high doses showed this effect.