First reported long-term two- and three-dimensional echocardiographic follow-up with histopathological analysis of a transcatheter pulmonary valve implantation in a pet dog

Transcatheter pulmonary valve implantation (TPVI) is indicated for use in the management of failing pulmonary valves in humans. We report here the long-term follow-up of the first documented transcatheter pulmonary valve implanted in a client-owned dog. A one-year-old Beagle dog with severe congenital type A valvular pulmonic stenosis first underwent percutaneous balloon pulmonary valvuloplasty, leading two years later to severe pulmonary regurgitation. A TPVI using a Melody™ bioprosthetic valve was then successfully performed, with normalization of the right heart cavities. Repeated two- and three-dimensional transthoracic echocardiographic examinations combined with Doppler modes confirmed the appropriate position and function of the valve for four years. Mitral myxomatous valvular degeneration led to refractory left-sided congestive heart failure, and the dog was humanely euthanized. After postmortem examination, X-ray imaging and histopathological evaluation of the stent and the valve were performed. Ex-vivo imaging of the implanted valve using a Faxitron® Path radiography system and microscopic evaluation of the implanted stent and bioprosthetic leaflets did not show any relevant leaflet or stent alterations. This case provides a proof of concept in interventional veterinary cardiology, showing that TPVI can be performed in dogs with subsequent long-term maintaining normal pulmonary valve function.

Impact of a blood return system on mechanical thrombectomy-associated blood loss and hemodynamic outcomes in a pulmonary embolism registry

Background

Mechanical thrombectomy can treat pulmonary embolism (PE) while eliminating the bleeding risks associated with thrombolytic-based therapies. In longer and more complex procedures, however, blood loss from aspiration-based mechanical thrombectomy can potentially limit thrombus removal.

Purpose

Assess a blood return system's ability to reduce mechanical thrombectomy procedure blood loss and characterize hemodynamic outcomes post-procedure.

Methods

This retrospective analysis of a prospective, multicentre, real-world registry enrolling intermediate- and high-risk PE patients treated with mechanical thrombectomy compared all patients enrolled prior to the availability of a blood return system with all patients whose treatment included use of a blood return system. Linear regression was used to model the blood return system's effect on estimated blood loss. The model was adjusted for patient characteristics and disease factors that may have been different between the treatment groups or related to blood loss.

Results

Complete case analysis was used to identify 319 patients prior to the availability of a blood return system (no blood return), and 50 patients who were treated using a blood return system through January 2022 (blood return). As shown in Table 1, the only significant differences in the summary statistics for the blood return group were 160 ml decreased estimated blood loss (292.5 to 132.5 ml; p<0.01) and a 13.1 minute increase in thrombectomy time (47.9 to 61.0 minutes; p<0.01).

Linear regression modeling revealed that use of a blood return system was associated with a 200 ml (69%) reduction (p<0.01) in blood loss for the average patient and thrombectomy time (Figure 1A). Importantly, the addition of an interaction term between thrombectomy time and blood return showed blood loss reduction increased with thrombectomy time (Figure 1B). Post-procedure mean pulmonary arterial pressure decreased by 7.0 mmHg (33.0 to 26.0 mmHg) in the blood return group and 7.9 mmHg (32.1 to 24.2 mmHg) in the no blood return group. In patients with depressed baseline cardiac index (CI) <2, CI improved by 0.3 L/min/m2 (1.8 to 2.1 L/min/m2) in the blood return group and 0.4 L/min/m2 (1.6 to 2.0 L/min/m2) in the no blood return group, demonstrating normalization of depressed CI in both groups. No hemodynamic outcomes differed significantly between groups (p>0.05).

Conclusions

Treatment with aspiration mechanical thrombectomy in combination with a blood return system achieved equivalent hemodynamic outcomes compared with mechanical thrombectomy alone, while reducing 69% of procedure blood loss. The fact that blood return patients had equivalent hemodynamic improvements suggests these improvements are related to thrombus removal rather than aspiration-related blood loss. The association identified between blood loss and thrombectomy time indicates that thrombus removal is not limited by blood loss when a blood return system is used.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Inari Medical

Beneficial effect of oral administration of zinc sulfate on 5-fluorouracil-induced gastrointestinal mucositis in rats

OBJECTIVE

This experimental study explored the potential of oral zinc sulfate to protect the gut mucosa from 5-fluorouracil (5-FU)-induced degenerative lesions in Wistar rats.

MATERIALS AND METHODS

Female Wistar rats were used and divided into 2 interventional groups (Z with 6 animals and F with 5 animals) and one control group (M with 5 rats). After 2 hours of fasting, group Z received via oral gavage 1.5 ml of solution, corresponding to 15 mg zinc sulfate for 9 consecutive days. Groups F and M received only the vehicles. On day 3, 400 mg/kg of 5-FU was administered intraperitoneally to groups Z and F. Tissue samples were collected from the duodenum, jejunum, colon and liver. Histological assessment for each gastrointestinal tract segment was determined semi-quantitatively by rating 11 histological features from normal (0) to severe (3). The independent groups were analyzed using the Kruskal-Wallis test and the Mann-Whitney U-test, with a Bonferroni correction for alpha (p ≤ 0.016).

RESULTS

In group F the jejunum was the most affected area with a mean histological score of  27 (25-32). In the Z group, significantly lower histological scores were obtained compared with group F (duodenum Z vs. F: U = 0, p = 0.004; jejunum Z vs. F: U = 0, p = 0.006 and colon: Z vs. F: U = 0, p = 0.005). Graded liver necro-inflammatory lesions were significantly lower in group Z compared with group F (U = 0, p = 0.004), suggesting fewer bacterial intestinal translocation processes.

CONCLUSIONS

Zinc sulfate has a beneficial role, decreasing the severity of gut mucosal injuries induced by 5-FU in Wistar rats.

QSAR models for biocides: The example of the prediction of Daphnia magna acute toxicity

Biocides are multi-component products used to control undesired and harmful organisms able to affect human or animal health or to damage natural and manufactured products. Because of their widespread use, aquatic and terrestrial ecosystems could be contaminated by biocides. The environmental impact of biocides is evaluated through eco-toxicological studies with model organisms of terrestrial and aquatic ecosystems. We focused on the development of in silico models for the evaluation of the acute toxicity (EC₅₀) of a set of biocides collected from different sources on the freshwater crustacean Daphnia magna, one of the most widely used model organisms in aquatic toxicology. Toxicological data specific for biocides are limited, so we developed three models for daphnid toxicity using different strategies (linear regression, random forest, Monte Carlo (CORAL)) to overcome this limitation. All models gave satisfactory results in our datasets: the random forest model showed the best results with a determination coefficient r² = 0.97 and 0.89, respectively, for the training (TS) and the validation sets (VS) while linear regression model and the CORAL model had similar but lower performance (r² = 0.83 and 0.75, respectively, for TS and VS in the linear regression model and r² = 0.74 and 0.75 for the CORAL model).

Therapeutic strategies utilization and resource consumption in patients treated for psoriatic arthritis: findings from a real-world analysis in an Italian setting

PURPOSE

The purpose of this study was to analyze the therapeutic strategies and estimate the health care resource consumption in patients with psoriatic arthritis (PsA).

PATIENTS AND METHODS

An observational retrospective cohort analysis of administrative databases of six Italian Local Health Units was performed. Patients ≥18 years with a hospitalization discharge diagnosis of PsA (International Classification of Diseases, Ninth Revision code: 696.0) or exemption code (045.696.0) for PsA from January 1, 2010 to December 31, 2015 (inclusion period), with at least one prescription of any therapy used for PsA were included. The index date (ID) was the first date matching with at least one of the inclusion criteria during the inclusion period. All patients were followed up after the ID until the end of data availability. Baseline C-reactive protein (CRP) levels (±6 months in relation to the ID) were also analyzed.

RESULTS

A total of 2,408 (prevalence 0.83 per 1,000) patients with PsA (male 52%; median age 54 years) were included in the study; patients were already treated for PsA in 42.4% of cases. At 1 year of follow-up, 73% of the patients received one systemic drug, while 22% of patients received two systemic drugs; in addition, our results show an increase in the number of add-on or switches in a longer follow-up period. The utilization of biologic agents was higher among patients with previous PsA treatment, showing a progression of the pathology. Overall, a medium/high level of CRP at baseline was observed among more than half of the overall sample, with slight changes across subgroups in analysis. The average health care costs were €1,966.4 and €13,914 per year for patients treated with conventional systemic therapy and biological agents, respectively.

CONCLUSION

A better knowledge of prescription therapeutic scheme and economic burden of PsA could stimulate the rational development of health programs aimed at potentiating services for its management.

Endodontic configuration of the lower incisors in a Romanian population: a radiological study

The significant rate of failure of endodontic treatment to lower incisors was attributed to poor knowledge of their endodontic morphology. As emphasized by Tinelli ME et al. (2011), the morphology of the endodontic system is strongly related to ethnicity, making possible the existence of important anatomical variations at different population groups. The present study analyzes, using radiological means, the endodontic anatomy of lower incisors extracted from a Romanian population. Five hundred seventy-five lower central and lateral incisors were radiographed and Weine's classification was used to evaluate their endodontic morphology. After processing the data, it was concluded that 81% of the studied teeth have one canal and the remaining 19% have two canals. In terms of endodontic configuration, 81% of 575 studied teeth are Weine Type I, 17% Type II, 1% Type III and 1% Type IV. Results obtained in this study are within existing international endodontic literature. Type II and IV configurations have a high degree of treatment difficulty. This requires thorough clinical and radiological examination of several incidents, possibly cone beam computed tomography (CBCT) and individualized therapeutic means to ensure treatment success. This study is the first of this magnitude in the Romanian specialty literature.

[Histo-anatomical researches of two subspecies of Lavandula angustifolia Mill]

AIM

The structure of the inflorescences of two subspecies of Lavandula angustifolia sL. angustifolia ssp. angustifolia and. L. angustifolia ssp. pyrenaica (D.C.) Guineaţ was studied to determine the range of variation in certain histo-anatomical characters.

METHODS

The flower and leaf structure has been analysed on cross and superficial section using the usual techniques and methods applied in plant histo-anatomical research.

RESULTS

In cross-section, inflorescence axis has a squared-shape contour, with four proeminent ribs. On the epiderme of inflorescence axis there are present stomata, trichoms and secretory hairs. The trichoms are pluricelullar and T-branched. The secretory hairs have a short pedicel and a uni-or bicellular head.

CONCLUSIONS

The study revealed that there are only quantitative differences, referring to the degree of sclerification and lignification of mechanical elements and the size of the vascular bundles.

Anticancer effects of zoledronic acid against human osteosarcoma cells

Based on neoadjuvant chemotherapy, the prognosis of osteosarcoma patients has improved dramatically. However, due to therapy resistance in patient subgroups, the development of new treatment strategies is still of utmost importance. The aim of our study was to test the effects of the nitrogen-containing bisphosphonate zoledronic acid (ZOL) on osteosarcoma cell lines (N = 9). Exposure to ZOL at low micromolar concentrations induced a dose- and time-dependent block of DNA synthesis and cell cycle progression followed by microfilament breakdown and apoptosis induction. The ZOL-induced cell cycle accumulation in S phase was accompanied by significant changes in the expression of cyclins and cyclin-dependent kinase inhibitors with a prominent loss of cyclin E and D1. ZOL not only inhibited growth but also migration of osteosarcoma cells. The mevalonate pathway intermediary geranyl-geraniol (GGOH) but not farnesol (FOH) significantly inhibited the anticancer effects of ZOL against osteosarcoma cells. Correspondingly, ZOL sensitivity correlated with the blockade of protein geranylgeranylation indicated by unprenylated Rap1. Overexpression of even high levels of P-glycoprotein, as frequently present in therapy-resistant osteosarcomas, did not impair the anticancer activity of ZOL. Summarizing, our data suggest that ZOL, which selectively accumulates in the bone, represents a promising agent to improve osteosarcoma therapy.

Repair of articular cartilage defects treated by microfracture and a three-dimensional collagen matrix

The objective of our study was to evaluate the behavior of ovine chondrocytes and bone marrow stromal cells (BMSC) on a matrix comprising type-I, -II, and -III collagen in vitro, and the healing of chondral defects in an ovine model treated with the matrix, either unseeded or seeded with autologous chondrocytes, combined with microfracture treatment. For in vitro investigation, ovine chondrocytes and BMSC were seeded on the matrix and cultured at different time points. Histological analysis, immunohistochemistry, biochemical assays for glycosaminoglycans, and real-time quantitative PCR for collagens were performed. The animal study described here included 22 chondral defects in 11 sheep, divided into four treatment groups. Group A: microfracture and collagen matrix seeded with chondrocytes; B: microfracture and unseeded matrices; C: microfracture; D: untreated defects. All animals were sacrificed 16 weeks after implantation, and a histomorphometrical and qualitative evaluation of the defects was performed. The in vitro investigation revealed viable cells up to 3 weeks; chondrocytes had a predominantly round morphology, produced glycosaminoglycans, and expressed both collagen markers, whereas BMSC stained positive for antibodies against type-II collagen; however, no mRNA for type-II collagen was amplified. All treatment groups of the animal model showed better defect filling compared to untreated knees. The cell-seeded group had the greatest quantity of repair tissue and the largest quantity of hyaline-like tissue. Although the collagen matrix is an adequate environment for BMSC in vitro, the additionally implanted unseeded collagen matrix did not increase the repair response after microfracture in chondral defects. Only the matrices seeded with autologous cells in combination with microfracture were able to facilitate the regeneration of hyaline-like cartilage.

Development of a novel optical bionanosensor

We have developed a novel optical bionanosensor platform using a supported bilayer lipid membrane (SBLM), which has generic multi-analyte sensing capabilities. The SBLM is produced using a novel combination of ordered nanostructured thin film i.e. Langmuir-Blodgett (LB) and self-assembly deposition methodologies. A heptamer linear RGD (arginine-glycine-aspartate) containing peptide was covalently attached to a BODIPY (donor) lipid dye and utilised as an optical biosensor for integrin alpha(v)beta(3) loaded HUVEC's (sensitivity = 1000 cells ml(-1)). A second BODIPY (acceptor) lipid dye was integrated into the SBLM thus enabling signal amplification via a Forster resonance energy transfer (FRET) mechanism. The fluidity of the bilayer was confirmed via fluorescence recovery after photobleaching (FRAP) techniques and was performed without the need for fusogens.

Drug susceptibility and its genetic basis in epidemic Vibrio cholerae O1 in Vietnam

The drug susceptibility and genes responsible for the drug resistance of Vibrio cholerae O1 isolated in Vietnam in 1995, 2000 and 2002 were studied. The strains isolated in 1995 were resistant to streptomycin and harboured the class I integron which contained the aadA1 gene responsible for streptomycin resistance. The strains isolated in 2000 were devoid of a class I integron but were multiple-drug resistant and harboured SXT constin, with several drug-resistant genes. The genes responsible for streptomycin resistance were strA and strB. The strains isolated in 2002 were sensitive to all drugs examined, and the organisms were devoid of both class I integron and SXT constin. Cholera outbreaks in the three periods examined (1995, 2000 and 2002) were apparently due to different categories of V. cholerae O1.

Gene analysis of Vibrio cholerae NAGV14 pilus and its distribution

Adhesive pilus of Vibrio cholerae 034, strain NAGV14, was genetically analyzed. The deduced amino acid (aa) sequence of the major pilin structural gene (VcfA) was 67% homologous to the MshA pilin in the N-terminal region, but no homology was found in the C-terminal region which contained the antigenic epitopes. Upstream and downstream flanking regions examined were highly homologous to mshB and mshC of the MSHA (mannose-sensitive hemagglutinin) gene locus. A short leader sequence and a pair of cysteines near the C-terminus which are the characteristics of type 4a pilus family were found. The major pilin structural gene of NAGV14 was compared to that of a strain V10 producing non-adhesive pili. The deduced aa sequences showed 60% homology, and the distance between two cysteines in the C-terminal region was different. A total of 177 V. cholerae strains were investigated for the presence of a type 4 pilus gene locus by PCR, and 95% were positive. The major pilin gene of NAGV14 was detected in 4 of 93 V. cholerae non-O1, non-0139 strains tested, but none of the V. cholerae O1 and O139 (72 and 12 strains, respectively). Our result suggested that a type 4 pilus gene locus similar to the MSHA gene locus is widely distributed among V. cholerae strains. We proposed naming this type 4 pilus gene locus the VCF (for V. cholerae flexible pili) gene locus.

Intercellular transfer of the virally derived precursor form of acid alpha-glucosidase corrects the enzyme deficiency in inherited cardioskeletal myopathy Pompe disease

Pompe disease is a lethal cardioskeletal myopathy in infants and results from genetic deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). Genetic replacement of the cDNA for human GAA (hGAA) is one potential therapeutic approach. Three months after a single intramuscular injection of 10(8) plaque-forming units (PFU) of E1-deleted adenovirus encoding human GAA (Ad-hGAA), the activity in whole muscle lysates of immunodeficient mice is increased to 20 times the native level. Direct transduction of a target muscle, however, may not correct all deficient cells. Therefore, the amount of enzyme that can be transferred to deficient cells from virally transduced cells was studied. Fibroblasts from an affected patient were transduced with AdhGAA, washed, and plated on transwell culture dishes to serve as donors of recombinant enzyme. Deficient fibroblasts were plated as acceptor cells, and were separated from the donor monolayer by a 22-microm pore size filter. Enzymatic and Western analyses demonstrate secretion of the 110-kDa precursor form of hGAA from the donor cells into the culture medium. This recombinant, 110-kDa species reaches the acceptor cells, where it can be taken up by mannose 6-phosphate receptor-mediated endocytosis. It then trafficks to lysosomes, where Western analysis shows proteolytic processing to the 76- and 70-kDa lysosomal forms of the enzyme. Patient fibroblasts receiving recombinant hGAA by this transfer mechanism reach levels of enzyme activity that are comparable to normal human fibroblasts. Skeletal muscle cell cultures from an affected patient were also transduced with Ad-hGAA. Recombinant hGAA is identified in a lysosomal location in these muscle cells by immunocytochemistry, and enzyme activity is transferred to deficient skeletal muscle cells grown in coculture. Transfer of the precursor protein between muscle cells again occurs via mannose 6-phosphate receptors, as evidenced by competitive inhibition with 5 mM mannose 6-phosphate. In vivo studies in GAA-knockout mice demonstrate that hepatic transduction with adenovirus encoding either murine or human GAA can provide a depot of recombinant enzyme that is available to heart and skeletal muscle through this mechanism. Taken together, these data show that the mannose 6-phosphate receptor pathway provides a useful strategy for cell-to-cell distribution of virally derived recombinant GAA.

Ascorbate conversion to oxalate in alkaline milieu and Proteus mirabilis culture

BACKGROUND AND PURPOSE

Ascorbate breakdown reportedly accounts for 30% to 55% of urinary oxalate excreted. Three potential degradation routes can be postulated: bowel, endogenous, and urinary. Because the pH of normal urine ranges from 4.5 to 8.0, the urinary oxalate concentration in the presence of ascorbate may be influenced by urinary pH and environment, so we studied ascorbate conversion to oxalate in standard buffer solution and in urine. About 10% of infection stones associated with Proteus mirabilis are reportedly composed of calcium oxalate, and their pathogenesis is not well explained. Therefore, we studied whether a pH change induced by P. mirabilis contributes to ascorbate conversion to oxalate in vitro.

RESULTS

Oxalate production from ascorbate increased as a function of pH (7.0-10.0) and incubation time (30 minutes-24 hours) in standard and urine specimens. Two-hour exposure to pH 10 in a urinary milieu containing approximately 3 mM ascorbate converted approximately 40% of the ascorbate to oxalate, whereas 24-hour exposure to pH 8 in a urinary milieu that was approximately 3 mM ascorbate converted approximately 20% of the ascorbate to oxalate. The pH in Proteus cultures increased to 9.0 at 24 hours of culture. The ascorbate concentration in the culture medium significantly decreased at 12 hours and 24 hours, and the oxalate concentration increased significantly at 24 hours.

CONCLUSION

Urinary ascorbate, if present at a high concentration in association with Proteus mirabilis infection, appears to be locally degraded to oxalate, potentially leading to calcium oxalate deposition on infection stones.

Sequence of the gene encoding an alkaline serine proteinase of Bacillus pumilus TYO-67

The complete nucleotide sequence of the gene encoding an alkaline serine proteinase (aprP) of Bacillus pumilus TYO-67 was determined. The sequence analysis showed an open reading frame of 1,149 bp (383 amino acids) that encoded a signal peptide consisting of 29 residues and a propeptide of 79 residues. The deduced 3 amino acid residues, D32, H64, and S221, were identical with 3 essential amino acids in the catalytic center of subtilases. The sequence around these residues revealed that APRP was a new member of the true subtilisin subgroup of the subtilisin family. The highest homology was found in subtilisin NAT at 64.4% in the DNA sequence. The residue S189 of APRP was different from those of other subtilases.

Cloning, sequencing and expression of the gene encoding the extracellular metalloprotease of Aeromonas caviae

A gene (apk) encoding the extracellular protease of Aeromonas caviae Ae6 has been cloned and sequenced. For cloning the gene, the DNA genomic library was screened using skim milk LB agar. One clone harboring plasmid pKK3 was selected for sequencing. Nucleotide sequencing of the 3.5 kb region of pKK3 revealed a single open reading frame (ORF) of 1,785 bp encoding 595 amino acids. The deduced polypeptide contained a putative 16-amino acid signal peptide followed by a large propeptide. The N-terminal amino acid sequence of purified recombinant protein (APK) was consistent with the DNA sequence. This result suggested a mature protein of 412 amino acids with a molecular mass of 44 kDa. However, the molecular mass of purified recombinant APK revealed 34 kDa by SDS-PAGE, suggesting that further processing at the C-terminal region took place. The 2 motifs of zinc binding sites deduced are highly conserved in the APK as well as in other zinc metalloproteases including Vibrio proteolyticus neutral protease, Emp V from Vibrio vulnificus, HA/P from Vibrio cholerae, and Pseudomonas aeruginosa elastase. Proteolytic activity was inhibited by EDTA, Zincov, 1,10-phenanthroline and tetraethylenepentamine while unaffected by the other inhibitors tested. The protease showed maximum activity at pH 7.0 and was inactivated by heating at 80 C for 15 min. These results together suggest that APK belongs to the thermolysin family of metalloendopeptidases.

Oxalate-degrading Enterococcus faecalis

An oxalate-degrading Enterococcus faecalis was isolated from human stools under anaerobic conditions. The bacteria required a poor nutritional environment and repeated subculturing to maintain their oxalate-degrading ability. The E. faecalis produced 3 proteins (65, 48, and 40 kDa) that were not produced by non-oxalate-degrading E. faecalis as examined by SDS-PAGE. Antibodies against oxalyl-coenzyme A decarboxylase (65 kDa) and formyl-coenzyme A transferase (48 kDa) obtained from Oxalobacter formigenes (an oxalate-degrading anaerobic bacterium in the human intestine) reacted with 2 of the proteins (65 and 48 kDa) from the E. faecalis as examined by Western blottings. This is the first report on the isolation of oxalate-degrading facultative anaerobic bacteria from humans.

Evaluation of the contribution of environmental factors

For the simulated data of GAW11, the roles of two environmental factors, E1 and E2, were investigated. Logistic regression analyses measuring the association between outcome (either mild or severe disease versus no disease) and E1 and E2 exposure indicated that E1 was a risk factor for disease (either mild or severe) but that E2 was not associated with outcome. Linkage analyses were performed for strata defined by E1 and E2 exposure. A specific disease locus was identified in these stratified analyses where this locus would not have been identified with an unstratified linkage analysis. Finally, stratified generalized transmission disequilibrium test analyses yielded several false positive results.

Disease-marker associations: power and heterogeneity in independent population samples

We applied generalized transmission disequilibrium testing (TDT) models in combined replicates 1 through 5 from each of four simulated population samples. All analyses were conducted without knowledge of the generating models. To assess power and consistency of results within and between samples, analyses were repeated in all 25 replicates combined and in each replicate. With the exception of sample-specific findings for locus D, power was generally low to detect linkage in a genome scan or to confirm linkages detected by allele sharing in affected relatives, due to lack of linkage disequilibrium. We proposed likelihood ratio and Wald tests to detect heterogeneity among samples in disease-marker associations. Pooling data across heterogeneous populations may not improve power of the TDT method.

Detection of Clostridium difficile toxin A by reversed passive latex agglutination

A reversed passive latex agglutination (RPLA) assay for detecting Clostridium difficile toxin A is presented. Purified monoclonal antibody (mAb 37B5) was used for latex sensitization. The culture supernatants of 93 strains of C. difficile were tested by RPLA assay and the results compared with those of a commercially available latex agglutination test, PCR and cytotoxin assay with Vero cells. There was agreement between RPLA, cytotoxicity and PCR assays, but 29 strains were positive in the RPLA assay while 35 were positive in the cytotoxicity test and PCR using primer pair NK3-NK2 directed to the nonrepeating portion of the C. difficile toxin A gene. The 6 cytotoxic but RPLA-negative strains were demonstrated to be toxin A-negative/toxin B-positive strains in the PCR assay by using primer pair NK11-NK9 directed to the repeating portion of the C. difficile toxin A gene. There were no cross-reactions with culture supernatants of the other clostridial strains except for two strains of C. sordelli that produced hemorrhagic toxin (which is immunologically related to C. difficile toxin A).

Purification and characterization of an Aeromonas caviae metalloprotease that is related to the Vibrio cholerae hemagglutinin/protease

A zinc metalloprotease (AP34) from Aeromonas caviae was purified by ammonium sulfate precipitation and subsequent gel filtration through Sephadex G-100 and Sephadex G-50 Superfine. The molecular mass was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 34 kDa. The protease showed maximum activity at pH 7.0 and was stable at 60 degrees C. AP34 was completely inactivated by EDTA and Zincov. The N-terminal amino acid sequence of AP34 showed a high degree of homology with a range of proteases within the family Vibrionaceae, including the hemagglutinin/protease (HA/P) of Vibrio cholerae. Immunologic relatedness of AP34 and HA/P was demonstrated by Western blotting. AP34-like protease was widely distributed among the aeromonad strains.

[Importance of a multidisciplinary approach to metastatic cancer of the rectum]

Management of rectal cancers with synchronous metastasis is difficult. We evaluated in 23 patients a combination of pelvic radiotherapy at the dose of 45 Gy in 5 weeks and 25 fractions with chemotherapy by 5-fluorouracil (350 mg/m2/day) and folinic acid (20 mg/m2/day) for 5 days at the time of the first and the fifth week of the irradiation. Surgery was indicated firstly in cases of stricture or secondarily for resection of the primary location and, when possible, of the metastasis. General state of health of the patients improved in 35%, symptomatology in 86% and comfort in 72% of the cases. Response rates for the primary tumor were 41% of partial response and 50% of stable disease. For the metastatic lesions, they were 9% and 59% respectively. Sixty-one per cent of patients were secondarily operated with resection of the primary tumor in 12 cases and of hepatic metastases in 2 cases. The median survival and the median survival without progression were respectively 13 and 9 months. Radiochemotherapy combination as the first treatment was beneficial in 4/5 of the patients presenting a rectal cancer with synchronous metastasis and allowed us to select those that would secondarily benefit from a surgical resection.

Filamentous phage fs1 of Vibrio cholerae O139

Filamentous phage, fs1, was obtained from Vibrio cholerae O139. The lysogenized strains produced a large amount of fs1 phage in the culture supernatant. This phage was previously reported as novel fimbriae of that organism. The genome of the phage was a 6.5 kb single-stranded DNA. The capsid of fsl consists of a small molecule peptide (about 2.5 kDa).

[The prognostic factors for survival in advanced forms of non-small-cell lung cancer]

This study attempted to determinate the prognostic value for survival of various clinical, biological and therapeutical prognostic factors in patients with non-resectable non-small cell lung cancer (NSCLC).

METHOD

We performed a retrospective study on 236 patients with histologically proved unresectable NSCLC. We collected 36 variable and analysed them by univariate and multivariate methods in order to establish their influence on survival.

RESULTS

The global estimated median survival time was 10 month. In univariate analysis were significantly related to survival: age (> 60 years), weight loss (> 5%), local extend of of disease, Karnofsky performance index (< 70%), stage of disease (stage IIIA vs. IIIB, IV), hemoglobinemia (< 10 g%), calcemia, platelet count, radiotherapy total dose (< 50 Gy), Cisplatin chemotherapy. In a Cox regression model, the explanatory variables were: age > 60 years, Karnofsy performance index 70%, stage IIIB and IV, thoracic total radiotherapy dose < 50 Gy. These results led to a classification of the patients into three subgroups (prognostic index).

CONCLUSION

We confirm by our analysis the role of independent factors for survival and we obtained three prognostic groups, the best one needs a radio-chemotherapy association.

Role of intracellular calcium for noradrenaline-induced depolarization in rat mesenteric small arteries

We have investigated the effect of intracellular calcium levels for membrane potential during noradrenaline application in isolated small arteries. Rat mesenteric small arteries were mounted for isometric tension measurement. Smooth muscle membrane potentials were measured by conventional intracellular electrodes, and intracellular calcium concentration was measured using Fura-2 fluorescence. Under control conditions, noradrenaline caused contraction and depolarization from -55.5 to -29.3 mV. In intact arteries, depleting intracellular calcium stores with thapsigargin caused smooth muscle hyperpolarization and inhibited contraction to noradrenaline. In de-endothelialized vessels, thapsigargin still depleted calcium stores, but did not affect either the depolarization or contraction caused by noradrenaline. In noradrenaline-activated vessels, inhibition of calcium influx by amlodipine caused tension and calcium levels to fall to near-baseline levels, but membrane potential returned by only 55%. Treatment with a combination of thapsigargin, D-600 and BAPTA-AM inhibited the tension and calcium responses to noradrenaline, but the membrane potential response was reduced by only 34%. Acute reduction of extracellular chloride concentration caused similar, small depolarization at rest and during noradrenaline exposure. It is concluded that an elevation of intracellular calcium concentration is not essential for noradrenaline depolarization, although part of the depolarization is associated with the raised intracellular calcium level.

Molecular analysis of a filamentous phage (fsl) of Vibrio cholerae O139

A filamentous bacteriophage from Vibrio cholerae O139 strain A1-4450 was isolated (fsl). The phage fsl had a ssDNA genome and dsDNA as a replicative form (RF) in lysogenic host cell. The DNA sequence of fsl RF was determined. It consisted of 6340 bp and had a G + C content of 43.5%. Fifteen possible ORFs were found in fsl. One of them, ORF384, was estimated to encode 384 amino acid residues (44.6 kDa) and had homologous regions with the zot gene of V. cholerae and gene I of the coliphage group. ORF104, located upstream of ORF384, was homologous to gene 93 protein of Pf3 (filamentous phage of Pseudomonas sp.) corresponding to gene VI of coliphage. Other than ORF384 and ORF104, the ORF81, ORF44, ORF29, and ORF193 were speculated to correspond to gene V, gene VII, gene IX, and gene III, respectively, in the order as reported on f1 phage.

Reversed passive latex agglutination assay for detection of toxigenic Corynebacterium diphtheriae

A reversed passive latex agglutination (RPLA) assay for determining the toxigenicity of Corynebacterium diphtheriae is presented. Rabbit antitoxin antiserum was raised by using commercially available diphtheria toxoid. This antiserum reacted with the diphtheria toxin when the culture supernatant was assayed by Western blotting, and it did not cross-react with other extracellular antigens. Affinity-purified antibodies for latex sensitization were obtained by using a Hi Trap N-hydroxysuccinimide-activated column. Demonstration of toxin in five of seven clinical isolates was in accordance with the PCR assay and the Vero cell cytotoxicity test. Culture of the bacteria for 6 h was sufficient for toxin production, and an additional 6 h was needed to observe latex agglutination. Therefore, diphtheria toxin can be detected in 12 h by this method. The lowest concentration of diphtheria toxin detectable by the RPLA assay was about 5 ng/ml. The RPLA assay can provide a convenient and reliable method for laboratories involved in the identification of toxinogenic corynebacteria.

[The use of echography in the diagnosis of autoimmune thyropathies]

Ultrasonography is a first line method in thyroid imaging. The aim of this study was to evaluate the usefulness of thyroid ultrasonography in the diagnosis of thyroid autoimmune diseases (TAD): Graves' disease (GD) and autoimmune thyroiditis (AT)--Hashimoto's and atrophic thyroiditis. Ultrasonography was performed with a 7.5 MHz transducer in 1033 consecutive patients. The excluding criteria was nodular goiter, irrespective of its function. Thyroid volume was calculated using the formula of a rotating ellipsoid. Hypoechogenicity was appreciated using a qualitative scale: 1 = absent, 2 = mild, 3 = moderate, 4 = marked. In patients with TAD thyroid hypoechogenicity was significantly higher than in normal subjects (2.5 +/- 1 in GD and 2.7 +/- 1 in AT, vs. 1.2 +/- 0.6 in normal subjects, p < 0.0001). The specificity of the test in identifying TAD was 91.4%, the sensitivity was 68.6% for GD and 80.8% for AT, positive predictive value was 91.5%, and negative predictive value 91.5%. Ultrasonography is useful in identifying patients with probable autoimmune thyroid diseases, being useful in epidemiological studies and having an important contribution in confirmation of the diagnosis.

Cloning and genetic analysis of the Vibrio cholerae aminopeptidase gene

The structural gene for the Vibrio cholerae leucine aminopeptidase (lap) was cloned and sequenced. The cloned DNA fragment contained a 1,503-bp open reading frame potentially encoding a 501-amino-acid polypeptide with a calculated molecular mass of 54,442 Da. The deduced amino acid sequence of the entire protein showed high homology with the sequence of Vibrio proteolyticus leucine aminopeptidase. The residues potentially involved in binding the zinc ions were completely conserved in the V. cholerae aminopeptidase as well as in the V. proteolyticus aminopeptidase. The recombinant protein was partially purified and characterized. The molecular mass was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 34 kDa, suggesting a processing of the protein to acquire the mature form. The protease showed maximum activity at pH 9.0 and was thermostable at 70 degrees C. The substrate leucyl-p-nitroanilide was cleaved by the protease, and its activity was inhibited by EDTA and bestatin. These results suggested that the protein was a leucine aminopeptidase. The PCR analysis of lap gene distribution showed that it was widely distributed among the V. cholerae strains. It was not present in the other species examined.

[An analysis of the articles published in Revista Medico-Chirurgicală over the last 7 years]

INTRODUCTION

As the number of medical journals is continuously increasing, their quality becomes a very reliable tool used by the editors in order to increase readership. As a consequence, the structure and the content of submitted papers are carefully revised before publication.

OBJECTIVES

The purpose of our study is to describe structural aspects and the use of descriptive and inferential statistics methods in papers published by the Medical-Surgical Journal between 1990 and 1997.

METHODS

Fifteen items were collected for each paper. Ten of them were related to the general structure: type of paper, number of authors, town of authors, professional environment, medical topic covered by the paper, pluridisciplinarity, the existence of a bibliography, the number of titles in the bibliography, language of publication, presence of abstract. The other five were related to data analysis and reporting: description of statistical methods, the existence of significant results without method description, presence of tables and graphics, use of descriptive and inferential statistics.

RESULTS

A number of 477 papers were analysed. Original papers represented 57.4%, 71.5% of the authors were involved in medical/non-medical teaching, 58.3% of papers were related to clinical sciences, 29.8% were related to basic medical sciences; pluridisciplinarity was present in 26.8% of papers (significantly increasing trend, p < 0.01), the bibliography was not present in 27.3% of papers (significantly decreasing trend, p < 0.001), romanian was the language of publication in 83% of papers, followed by english (10.9%), french (4.6%) and german (1.5%). Papers without abstract represented 29.9%, the median number of authors is 3(range 1-15) and the mean number of titles in reference list 14.7(SD = 12). Eighteen papers (3.8%) reported significant results without description of methods, 51.4% used tables and graphics, 13.4% used descriptive statistics methods and only 6.9% of the papers have used inferential statistics methods.

CONCLUSION

The structural problems of papers published in Medical Surgical Journal should be avoided using a more restrictive editorial policy. The use of such a policy shows positive results for the last 2 years (1995 and 1996). Statistical methods are poorly used in this Romanian medical journal and much progress is to be made before speaking about statistical assessment of submitted papers.

Disseminated Langerhans cell histiocytosis: a case report with a light microscopic and ultrastructural study

A case of disseminated Langerhans cell histiocytosis (L.C.H.) in a 9 month-old boy is reported. The clinical picture was characterized by severe multivisceral involvement with cutaneous and bone lesions. Histological examination of the skin biopsy revealed diffuse infiltration of large mononucleated histiocytes admixed with a small number of inflammatory cells. Ultrastructural examination confirmed the Langerhans cell (L.C.) phenotype by showing intracytoplasmic Birbeck granules in the proliferating histiocytes. We report the histological and ultrastructural characteristics of our case and review the diagnostic features of L.C.H. in the light of the criteria established by the Writing Group of the Histiocytic Society in 1987.

Activation of potassium currents by inhibitors of calcium-activated chloride conductance in rabbit portal vein smooth muscle cells

1. The conventional whole-cell recording technique was used to study the effects of the chloride channel inhibitors ethacrynic acid, anthracene-9-carboxylic acid (A-9-C) and indanyloxyacetic acid (IAA) on membrane currents in rabbit portal vein smooth muscle cells at a holding potential of 0 mV. 2. Using a pipette solution that contained 1 x 10(-4) M 1,2-bis (2-aminophenoxy)-ethane-N,N,N,N,-tetraacetic acid (BAPTA) and a normal bathing solution the addition of ethacrynic acid (2 x 10(-4) M to 1 x 10(-3) M) inhibited spontaneous transient outward currents (STOCs) and evoked a concentration-dependent current at a holding potential of 0 mV. A similar current was activated by IAA (5 x 10(-4) M to 1 x 10(-3) M) but not by A-9-C (1-5 x 10(-3) M) at a holding potential of 0 mV. 3. The amplitude of the current evoked by ethacrynic acid and IAA was linearly related to potential between -30 and 0 mV and displayed outward rectification at positive potentials. The current induced by A-9-C was evident only at potentials positive to +20 mV. 4. Glibenclamide (1 x 10(-5) M) abolished the current evoked by ethacrynic acid and IAA at potentials negative to +10 mV and partially inhibited the current positive to +10 mV. The glibenclamide-insensitive current at positive potentials was completely inhibited by 1 x 10(-3) M TEA. The A-9-C-evoked current was insensitive to glibenclamide and abolished by 1 x 10(-3) M TEA. 5. The glibenclamide-sensitive current activated by ethacrynic acid was not sustained and declined to control levels in the continued presence of ethacrynic acid. However, the outwardly rectifying current recorded at +50 mV was well maintained over the same period. 6. Outwardly rectifying currents evoked by ethacrynic acid and A-9-C were observed with a pipette solution containing 1 x 10(-2) M BAPTA in cells bathed in Ca-free extracellular solution containing 5 x 10(-4) M BAPTA and 1 x 10(-5) M cyclopiazonic acid. 7. It is concluded that all three chloride-channel blockers activated an outwardly rectifying, TEA-sensitive current. Moreover, ethacrynic acid and IAA evoked an additional glibenclamide-sensitive current which was present at all potentials between -30 and +50 mV.

Effect of Vibrio cholerae non-O1 protease on lysozyme, lactoferrin and secretory immunoglobulin A

The effect of Vibrio cholerae non-O1 protease on host defense proteins (lysozyme, secretory immunoglobulin A and lactoferrin) was studied in relation to its virulence mechanism. The proteins treated with the protease were analysed by SDS-PAGE. There was no influence of the protease on lysozyme. The protease cleaved lactoferrin into two fragments of 50 kDa and 34 kDa. N-terminal amino acid sequencing of these fragments revealed that the cleavage site was near the hinge region, between serine 420 and serine 421. This cleavage could affect the transition from open to closed configuration which is involved in iron binding and release. The anti-bacterial activity of lactoferrin was not affected by protease treatment. Secretory immunoglobulin A yielded a 42-kDa protein as the cleavage product. The susceptibility of secretory immunoglobulin A to V. cholerae non-O1 protease suggests a mechanism by which bacteria might evade the effect of this immunoglobulin.