Outcomes of complex abdominal wall reconstruction in patients with connective tissue disorders: a single center experience

INTRODUCTION

Individuals diagnosed with connective tissue disorders (CTD) are known to be predisposed to incisional hernia formation. However, there is a scarcity of data on outcomes for these patients undergoing hernia repair. We sought to describe our outcomes in performing abdominal wall reconstructions in these complex patients.

METHODS

Adult patients with CTD undergoing open, elective, posterior component separation with permanent synthetic mesh at our institution from January 2018 to October 2022 were queried from a prospectively collected database in the Abdominal Core Health Quality Collaborative. We evaluated 30-day wound morbidity, perioperative complications, long-term hernia recurrence, and patient-reported quality of life.

RESULTS

Twelve patients were identified. Connective tissue disorders included Marfan's n = 7 (58.3%), Loeys-Dietz syndrome n = 2 (16.7%), Systemic Lupus Erythematosus n = 2 (16.7%), and Scleroderma n = 1 (8.3%). Prior incisions included three midline laparotomies and nine thoracoabdominal, mean hernia width measured 14 cm, and 9 were recurrent hernias. Surgical site occurrences (SSOs) were observed in 25% of cases, and 16.7% necessitated procedural intervention. All twelve patients were available for long-term follow-up, with a mean of 34 (12-62) months. There were no instances of reoperation or mesh excision related to the TAR procedure. One patient developed a recurrence after having his mesh violated for repair of a new visceral aneurysm. Mean HerQLes scores at 1 year were 70 and 89 at ≥ 2 years; Mean scaled PROMIS scores were 30.7 at 1 year and 36.3 at ≥ 2 years.

CONCLUSION

Ventral hernia repair with TAR is feasible in patients with connective tissue disorder and can be a suitable alternative in patients with large complex hernias.

Achievement of Two Cohorts of Immigrants: Cognitive Mapping Changes and the Country of Origin as Moderator

This study compares the achievement of two cohorts of immigrants with ages between 7 and 30 years old. Two sets of participants were assessed in two points in time and in different regions of Portugal. 169 students with similar immigration conditions for this analysis (nationality, length of residence, previous education in the country of origin) were examined in two trials of language and cognitive tasks, through two periods (period 1: 2002-2007; period 2: 2013-2017). These two periods and cohorts were result from two randomized studies, approved in different regions and submitted to ethical board in different times. Regarding age: participants presented a mean age of 14 years (M = 13.8; SD = 4.7); and concerning the nationality. The two cohorts are from the Centre and the South of the country being 61 participants in the first cohort (arrived in the period of 2002-2007) and 108 were the second cohort.The main objective is to ascertain if age and/or nationality characteristics became moderators of significant changes in Second Language achievement considering the two periods of study. The variety of nationalities in the two periods and cohorts are direct implications from the changing of immigrant routes. Then, affecting also the cognitive and linguistic changes over time.Results revealed that the two groups diverge significantly in verbal reasoning and other discrimination tasks explained by the nationality and not by age. These findings shed light on the impact of new routes of immigration for the linguistic and school development of children.

Vermiculite as a potential functional additive for water treatment bioreactors inhibiting toxic action of heavy metal cations upsetting the microbial balance

A new adsorbent that combines mineral vermiculite with the yeast Saccharomyces cerevisiae, was used for Cd²⁺ removal. The influence of vermiculite presence on the toxic effects of Cd²⁺ to Saccharomyces cerevisiae yeast was evaluated as a function of the microorganisms' respiratory activity (CO₂ production). The Cd²⁺ toxicity increased with prolonged exposure time reaching the LC₅₀ value of 857 and 489 mg L^-1 after 30 and 120 min, respectively. The yeast managed to bioaccumulate 25.0 ± 0.6 mg g^-1 of Cd²⁺ at the initial Cd²⁺ concentration of 741.9 mg L^-1; the maximum Cd²⁺ adsorption capacity of vermiculite reached 25 ± 5 mg g^-1. The addition of the mineral decreased the cations toxic effect; the LC₂₀ value in vermiculite absence attained approximately 200 mg L^-1 after 30 min and decreased to 80 mg L^-1 after 2 h, while in the bio-mineral system it was at the level of 435 ± 50 mg L^-1 without a significant change in time. The mineral provided a superior living environment for the yeast by removing part of the cations, releasing essential microelements and providing a protective, clay hutch-like habitat for the cells.

UALGORITMO, a New Instrument of the University of Algarve for Scientific Outreach

Researchers at Universities generate and convey the knowledge acquired through communications in specialized (inter)national journals and congresses. An effort to share the scientific achievements with the general public is extremely important. For this purpose, we have launched the UALGORITMO, a journal freely accessible online, written in lay Portuguese language by Researchers of the University of the Algarve, to summarize recent communications published in peer reviewed journals. After submission, the manuscripts are revised by High Schools Students of the Algarve, under the guidance of a schoolteacher, for further simplification of the language and general improvement of the manuscript and figures. The revised manuscripts by the authors are edited and published, with an acknowledgment and a presentation of the reviewers at the end of each article. To maximize the outreach, the articles include a summarized biography of the authors, and links to their research centers and teaching courses. We believe that the UALGORITMO is a valuable instrument to promote scientific literacy and culture amongst all communities.

Routes for Specialization in Psychology throughout Europe

The specialization of psychology helps to delineate fields in the practice of psychology. When establishing professional qualification criteria, associations seek to promote, in their members, scientific skills and knowledge considered fundamental for the practice of psychology in a given area. The present study reports on a survey of the member associations of the European Federation of Psychologists Associations (EFPA). The survey inquired about: (a) the initial requisites for entering the profession and (b) additional requisites for specialization. Of the 37 associations contacted, 14 replied and we retrieved the information of 12 associations from their official websites. The results indicate that specialization is widespread throughout Europe and is independent of the regulation of the profession. In almost half of the countries considered, the specialization process is completed in universities—it is frequently associated with the postgraduate level of the EuroPsy—and relies on conventional learning methods. The number of existing specialties in psychology is very high, but the traditional areas (clinical and health, education, and social/organizational) are more prevalent. The results are discussed in light of the advantages, but also the challenges posed by the specialization in psychology. A continuous model of the specialization of psychology is proposed with two stages: broad and advanced psychology areas.

Evaluation of the adsorption potential of biochars prepared from forest and agri-food wastes for the removal of fluoxetine

Twelve biochars from forest and agri-food wastes (pruning of Quercus ilex, Eucalyptus grandis, Pinus pinaster, Quercus suber, Malus pumila, Prunus spinosa, Cydonia oblonga, Eriobotrya japonica, Juglans regia, Actinidia deliciosa, Citrus sinensis and Vitis vinifera) were investigated as potential low-cost and renewable adsorbents for removal of a commonly used pharmaceutical, fluoxetine. Preliminary adsorption experiments allowed to select the most promising adsorbents, Quercus ilex, Cydonia oblonga, Eucalyptus, Juglans regia and Vitis vinifera pruning material. They were characterized by proximate, elemental and mineral analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy, determination of specific surface area and pH at the point of zero charge. Batch and equilibrium studies were performed, and the influence of pH was evaluated. The equilibrium was reached in less than 15 min in all systems. The maximum adsorption capacity obtained was 6.41 mg/g for the Eucalyptus biochar, which also demonstrated a good behavior in continuous mode (packed column).

How useful are hemoglobin concentration and its variations to predict significant hemorrhage in the early phase of trauma? A multicentric cohort study

Background

The diagnostic value of hemoglobin (Hb) for detecting a significant hemorrhage (SH) in the early phase of trauma remains controversial. The present study aimed to assess the abilities of Hb measurements taken at different times throughout trauma management to identify patients with SH.

Methods

All consecutive adult trauma patients directly admitted to six French level-1 trauma centers with at least one prehospital Hb measurement were analyzed. The abilities of the following variables to identify SH (≥ 4 units of red blood cells in the first 6 h and/or death related to uncontrolled bleeding within 24 h) were determined and compared to that of shock index (SI): Hb as measured with a point-of-care (POC) device by the prehospital team on scene (POC-Hb_prehosp) and upon patient’s admission to the hospital (POC-Hb_hosp), the difference between POC-Hb_hosp and POC-Hb_prehosp (DeltaPOC-Hb) and Hb as measured by the hospital laboratory on admission (Hb-Lab_hosp).

Results

A total of 6402 patients were included, 755 with SH and 5647 controls (CL). POC-Hb_prehosp significantly predicted SH with an area under ROC curve (AUC) of 0.72 and best cutoff values of 12 g/dl for women and 13 g/dl for men. POC-Hb_prehosp < 12 g/dl had 90% specificity to predict of SH. POC-Hb_hosp and Hb-Lab_hosp (AUCs of 0.92 and 0.89, respectively) predicted SH better than SI (AUC = 0.77, p < 0.001); best cutoff values of POC-Hb_hosp were 10 g/dl for women and 12 g/dl for men. DeltaPOC-Hb also predicted SH with an AUC of 0.77, a best cutoff value of − 2 g/dl irrespective of the gender. For a same prehospital fluid volume infused, DeltaPOC-Hb was significantly larger in patients with significant hemorrhage than in controls.

Conclusions

Challenging the classical idea that early Hb measurement is not meaningful in predicting SH, POC-Hb_prehosp was able, albeit modestly, to predict significant hemorrhage. POC-Hb_hosp had a greater ability to predict SH when compared to shock index. For a given prehospital fluid volume infused, the magnitude of the Hb drop was significantly higher in patients with significant hemorrhage than in controls.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0420-8) contains supplementary material, which is available to authorized users.

Application of vermiculite-derived sustainable adsorbents for removal of venlafaxine

Removal of emerging pollutants, such as pharmaceuticals, from wastewater is a challenge. Adsorption is a simple and efficient process that can be applied. Clays, which are natural and low-cost materials, have been investigated as adsorbent. In this work, raw vermiculite and its three modified forms (expanded, base, and acid/base treated) were tested for removal of a widely used antidepressant, venlafaxine. Adsorption kinetics followed Elovich's model for raw vermiculite while the pseudo-2nd order model was a better fit in the case of other materials. Equilibrium followed Langmuir's model for the raw and the acid/base-treated vermiculite, while Redlich-Peterson's model fitted better the expanded and the base-treated materials. The adsorption capacity of vermiculite was significantly influenced by the changes in the physical and chemical properties of the materials caused by the treatments. The base-treated, raw, and expanded vermiculites showed lower maximum adsorption capacities (i.e., 6.3 ± 0.5, 5.8 ± 0.7, 3.9 ± 0.2 mg g^-1, respectively) than the acid/base-treated material (33 ± 4 mg g^-1). The acid/base-treated vermiculite exhibited good properties as a potential adsorbent for tertiary treatment of wastewater in treatment plants, in particular for cationic species as venlafaxine due to facilitation of diffusion of the species to the interlayer gallery upon such treatment. Graphical abstract ᅟ.

High level of venous thromboembolism in critically ill trauma patients despite early and well-driven thromboprophylaxis protocol

Background

Venous thromboembolism (VTE) is one of the most common preventable causes of in-hospital death in trauma patients surviving their injuries. We assessed the prevalence, incidence and risk factors for deep venous thrombosis (DVT) and pulmonary embolism (PE) in critically ill trauma patients, in the setting of a mature and early mechanical and pharmacological thromboprophylaxis protocol.

Methods

This was a prospective observational study on a cohort of patients from a surgical intensive care unit of a university level 1 trauma centre. We enrolled consecutive primary trauma patients expected to be in intensive care for ≥48 h. Thromboprophylaxis was protocol driven. DVT screening was performed by duplex ultrasound of upper and lower extremities within the first 48 h, between 5 and 7 days and then weekly until discharge. We recorded VTE risk factors at baseline and on each examination day. Independent risk factors were analysed using a multivariate logistic regression.

Results

In 153 patients with a mean Injury Severity Score of 23 ± 12, the prevalence of VTE was 30.7%, 95 CI [23.7–38.8] (29.4% DVT and 4.6% PE). The incidence was 18%, 95 CI [14–24] patients-week. The median time of apparition of DVT was 6 days [1; 4]. The global protocol compliance was 77.8% with a median time of introduction of the pharmacological prophylaxis of 1 day [1; 2]. We identified four independent risk factors for VTE: central venous catheter (OR 4.39, 95 CI [1.1–29]), medullar injury (OR 5.59, 95 CI [1.7–12.9]), initial systolic arterial pressure <80 mmHg (OR 3.64, 95 CI [1.3–10.8]), and pelvic fracture (OR 3.04, 95 CI [1.2–7.9]).

Conclusion

Despite a rigorous, protocol-driven thromboprophylaxis, critically ill trauma patients showed a high incidence of VTE. Further research is needed to tailor pharmacological prophylaxis and balance the risks and benefits.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0315-0) contains supplementary material, which is available to authorized users.

Acid-base treated vermiculite as high performance adsorbent: Insights into the mechanism of cationic dyes adsorption, regeneration, recyclability and stability studies

Additional treatment with NaOH of acid activated vermiculite results in even higher increase in the adsorption capacity in comparison to samples modified only in acidic solution (first step of activation) with respect to raw material. Optimization of treatment conditions and adsorption capacity for two cationic dyes (methylene blue (MB) and astrazon red (AR)), also as binary mixture, was evaluated. The capacity, based on column studies, increased from 48 ± 2 to 203 ± 4 mg g^-1 in the case of methylene blue and from 51 ± 1 to 127 ± 2 mg g^-1 in the case of astrazon red on starting and acid-base treated material, respectively. It was shown that adsorption mechanism changes for both cationic dyes after NaOH treatment and it results in decrease of adsorption rate. In binary mixtures methylene blue is bound stronger by adsorbent and astrazon red may be removed in initial stage of adsorption. Extensive studies on desorption/regeneration process proved high efficiency in recyclable use of all materials. Although cation exchange capacity decreases due to acid treatment, after base treatment exchange properties are used more efficiently. On the other hand, increased specific surface area has less significant contribution into the adsorption potential of studied materials. Obtained adsorbents worked efficiently in 7 adsorption-regeneration cycles and loss of adsorption capacity was observed only in two first cycles.

Simultaneous removal of dyes and metal cations using an acid, acid-base and base modified vermiculite as a sustainable and recyclable adsorbent

The aim of this work was the modification of vermiculite in order to produce a low cost, efficient and sustainable adsorbent for dyes and metals. Three activation methods consisting of acid, base and combined acid/base treatment were applied to improve the of vermiculite's adsorption properties. Adsorbents were tested in single, bi- and tricomponent solutions containing cationic dyes and Cu²⁺ cations. The raw material showed low adsorption capacity for dyes and metal. The acid/base treated vermiculite had very good adsorption capacity toward dyes while the maximum adsorption capacity for Cu²⁺ did not change comparing to the starting material. The alkaline treated vermiculite was a good adsorbent for metals, while still being able to remove dyes on the level of the not treated material. Moreover, it was shown that the materials may be regenerated and used in several adsorption-desorption cycles. Furthermore, it was possible to separate adsorbed dyes from metals that were desorbed, using as eluents ethanol/NaCl and 0.05M HNO₃, respectively. This opens a possibility for sustainable disposal and neutralization of both of the pollutants or for their further applications in other processes.

Physicians versus surgeons. A pilot study on hand dexterity within a controlled population

INTRODUCTION

Hand dexterity is defined as the innate or acquired capacity of performing any given procedure with one's hands. This study seeks the role of regular hand training on hand dexterity over time. Materials and Methods : Pilot study composed by two independent groups with 28 subjects each (surgeons and physicians), stratified according to gender and age. Measurement of hand dexterity using Lafayette's Purdue Pegboard through the sum of the first three exercises as well as the assembly exercise. No difference was found between groups in regards of gender, age, time of practice and hand size (p = 0.415 ; p = 0.225 ; p = 0.267 ; p = 0.937). Statistical significance was assumed when p < 0.050.

RESULTS

Surgeons performed better but a statistically significant difference was not observed both on the -assembly score (p = 0.560) and three tests sum score (p = 0.244). The decay of dexterity over time happened in a homogeneous fashion in the surgeons' arm (p < 0.001 and p = 0.043) but not in the physicians' arm (p = 0.157 and p = 0.098).

DISCUSSION

Surgeons seem to perform better than physicians in regards of hand dexterity, although no definitive conclusion was possible given our small sample. It is well known that aging worsens hand -dexterity, but our study suggests it happens much more homogeneously within surgeons.

The influence of acid treatments over vermiculite based material as adsorbent for cationic textile dyestuffs

The influence of different acid treatments over vermiculite was evaluated. Equilibrium, kinetic and column studies have been conducted. The results showed that vermiculite first treated with nitric acid and then with citric acid has higher adsorption capacity, presenting maximum adsorption capacities in column experiments: for Astrazon Red (AR), 100.8 ± 0.8 mg g(-1) and 54 ± 1 mg g(-1) for modified and raw material, respectively; for Methylene Blue (MB) 150 ± 4 mg g(-1) and 55 ± 2 mg g(-1) for modified and raw material, respectively. Materials characterization by X-ray diffraction, UV-vis-diffuse reflectance spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, X-ray fluorescence, N2 adsorption and CEC determination, has been performed. The results suggest the existence of exchange of interlayer cations, leaching of metals from vermiculite's sheets and formation of an amorphous phase in the material. Adsorption follows pseudo 2(nd) order model kinetics for both dyestuffs and equilibrium occurs accordingly to Langmuir's model for AR and Freundlich's model for MB. In column systems Yan's model is the best fit. The enhanced properties of acid treated vermiculite offer new perspectives for the use of this adsorbent in wastewater treatment.

Identification of the naturally occurring genes encoding carbapenem-hydrolysing oxacillinases from Acinetobacter haemolyticus, Acinetobacter johnsonii, and Acinetobacter calcoaceticus

Carbapenem resistance is increasingly being reported among Acinetobacter species, and results mostly from the expression of acquired carbapenem-hydrolysing oxacillinases (CHDLs). Several Acinetobacter species intrinsically possess chromosomal CHDL genes: Acinetobacter baumannii (bla(OXA-51) ), Acinetobacter radioresistens (bla(OXA-23) ), and Acinetobacter lwoffii (bla(OXA-134) ). We aimed to identify the progenitors of novel CHDL-encoding genes for identification of potential reservoirs. We performed PCR screening using degenerated internal primers designed from a sequence alignment of the known CHDLs (OXA-23, OXA-40, OXA-51, OXA-58, OXA-134, and OXA-143) applied to a collection of 50 Acinetobacter strains belonging to 23 different species. Two strains of Acinetobacter johnsonii, one strain of Acinetobacter calcoaceticus and two strains of Acinetobacter haemolyticus were found to harbour, respectively, the totally novel bla(OXA-211) -like, bla(OXA-213) -like and bla(OXA-214) -like genes. In addition, the complete genomes of those three species available in GenBank, i.e. one A. johnsonii genome, four A. calcoaceticus genomes, and one A. haemolyticus genome, were analysed and found to be positive for the presence of bla(OXA211) -like, bla(OXA-213) -like and bla(OXA-214) -like genes, respectively. The β-lactamases OXA-211, OXA-213 and OXA-214 are diverse, with amino acid identities ranging from 53% to 76%, as compared with the naturally occurring OXA-51-like CHDL from A. baumannii. These β-lactamases showed a peculiar hydrolysis profile, including mostly penicillins and carbapenems. Regarding bla(OXA-23) in A. radioresistens and bla(OXA-134) in A. lwoffii, these genes were not expressed (or expressed at a non-significant level) in their host. Detection of these β-lactamase genes might be used as a useful tool for accurate identification of these Acinetobacter species.

Tetra-pyridinium μ-oxido-di-μ-sulfato-bis-[chloridodioxidomolybdate(VI)]

The title salt, (C(5)H(6)N)(4)[Mo(2)Cl(2)O(5)(SO(4))(2)], comprises four pyridinium cations for each [(MoClO(2))(2)(μ-O)(μ-SO(4))(2)](4-) anionic unit. The asymmetric unit consists of three aggregates of the empirical formula. The tetra-anionic bimetallic molybdenum(VI) cluster is unprecedented and contains two sulfate and one oxide bridges. This structure constitutes the first example of a non-polymeric compound with terminal oxide, sulfate and halide ligands bonded to the same metal. The hydrogen bonds connecting the pyridinium cations to the molybdenum clusters are diverse, varying from strong and directional interactions to bifurcated bonds with a subsequent loss of directionality.

4,4'-Di-tert-butyl-2,2'-bipyridine

In the title compound, C₁₈H₂₄N₂, the mol­ecular unit adopts a trans conformation around the central C—C bond [N—C—C—N torsion angle of 179.2 (3)°], with the two aromatic rings almost coplanar [dihedral angle of only 0.70 (4)°]. The crystal packing is driven by co-operative contacts involving weak C—H⋯N and C—H⋯π inter­actions, and also the need to fill effectively the available space.

[Extra-anatomic aortic bypass for repair of aortic arch diseases in adults]

Surgical management of aortic arch diseases in the adult are challenging. Use of extra-anatomic conduits are a well established form of treatment. We report a retrospective study of four patients operated on in our institution between 2000 and 2006, using this technique. Two patients had a median sternotomy, one a left thoracotomy and one a right thoracotomy. There were no perioperative mortality and all patients were alive and doing well after a mean follow-up of 19 months. In this subset of patients, surgical treatment should be individualized. In our experience, extra-anatomic bypass is a valuable, effective and safe surgical option.

Cardiovascular manifestations in Marfan syndrome

INTRODUCTION

Cardiovascular complications are the major cause of morbidity and mortality in Marfan syndrome (MS), a common connective tissue disorder. Currently it is considered that the prognosis and morphologic characteristics in infantile Marfan syndrome may be quite different from those reported in older patients. The objective of this study was to analyze the cardiovascular manifestations and evolution of the patients with Marfan syndrome followed at our pediatric cardiac unit.

METHODS

The authors reviewed the clinical files of all the patients that fulfilled the diagnostic criteria for MS according to De Paepe et al. (1996). We analyzed the following parameters: gender, age at referral, race, family history, clinical examination, diagnostic exams, therapy and evolution. The patients were divided into two groups according to the age at diagnosis: infants (group 1) and older patients (group 2).

RESULTS

Group 1 included 3 infants, two boys and one girl, sporadic cases, presenting congestive heart failure. The major cardiac diagnoses were aortic dilatation (1/3) and mitral valve prolapse with severe mitral regurgitation (2/3). Congenital heart disease was associated in two cases (patent ductus arteriosus and atrial septal defect). Two needed cardiac surgery at an early age and one was recently proposed for surgery. There were no deaths. Group 2 included 20 patients, 14 boys and 6 girls, first seen at a mean age of 8 years. Ten had a positive family history and none presented cardiac symptoms. The major cardiac manifestations were mitral valve prolapse (18/20) and aortic dilatation (17/20). There was no significant progression of the cardiac lesions, except for one case, during the 12 years of follow-up.

CONCLUSION

Infantile MS presented high morbidity; mitral regurgitation was severe in two cases. All patients presented heart failure, two needing early operations. In classic MS evolution was favorable, and the commonest cardiac lesions were mitral valve prolapse and aortic dilatation. We emphasize the need for beta-blockers to prevent progression of aortic dilatation. The decision for surgery rests upon the severity of valve regurgitation and the rate of progression of aortic dilatation. It is important to inform patients and family about physical exercise, prevention of endocarditis, risks associated with pregnancy and genetic counseling.

[Dysgenetic male pseudohermaphroditism]

Dysgenetic male pseudohermaphroditism is the result of a defect of testis development that encompasses a large clinical heterogeneity. It is characterized by bilateral dysgenetic testis, absence of mullerian regression, ambiguous genitalia and/or stigmata of Turner's syndrome in the majority of the cases. Typically, these individuals have either a 46,XY or 45,X/46,XY karyotype. The authors present four cases of dysgenetic male psudohermaphroditism, with ages of diagnosis between 1 month and 17 years old. The first had a male phenotype with stigmata of Turner's syndrome and the others ambiguous genitalia. Two patients were 45,X/46,XY and 45X/47,XYY mosaics and the other two were 46,XY. Gonadal karyotyping showed mosaicism (45,X/46,XY) in all four cases. In the first case was programed orquidectomy; all the others assigned a male gender, with regular follow-up until the puberty.

Isolation of a proteinase with plasminogen-activating activity from Lachesis muta muta (bushmaster) snake venom

A plasminogen activator enzyme (LV-PA) from Lachesis muta muta venom was purified to homogeneity using gel filtration and anion exchange chromatography. SDS-PAGE under reducing conditions showed a single protein band with an Mr of 33,000 Da. It is an acidic glycoprotein which activates plasminogen to plasmin indirectly, functioning via prior formation of a molecular complex, known as plasminogen activator. The purified preparation catalyzes the hydrolysis of several p-nitroanilide peptide substrates containing Lys at the scissile bond. In contrast, no hydrolysis was detected on the synthetic substrates TAME and BAPNA, which contain arginine. By the use of the plasmin-specific chromogenic substrate Tos-Gly-Pro-Lys-pNA, the preparation had a plasmin-like activity of 0.68 U/mg, which was 35.8-fold higher than that of the crude venom from which it was prepared. In vitro, fibrin hydrolysis using LV-PA as plasminogen activator displayed more similarity with the effect produced by streptokinase (SK). SDS-PAGE (10%) analysis showed a 115-kDa complex formation after incubation of plasminogen with either LV-PA or SK. At a molar ratio of 50:1 (fibrinogen:enzyme), the preparation exhibited weakly fibrinogenolytic activity. However, LV-PA is distinguished from thrombin in that it does not clot fibrinogen. After incubation of LV-PA with platelet-rich plasma, the enzyme (2 microM) showed no effect on platelet aggregation induced by ADP, epinephrine, or collagen. Comparison of the N-terminal sequence of LV-PA with other snake venom plasminogen activators revealed that LV-PA exhibits a high degree of sequence identity with the TsVPA from Trimeresurus stejnegeri (90%) and with the Haly-PA from Agkistrodon halys (85%). LV-PA also has homology with other snake venom serine proteinases such as the thrombin-like/gyroxin analogue (38%) from bushmaster venom and with other coagulation serine proteases. The proteinase was readily inhibited by treatment with p-nitrophenyl p-guanidinebenzoate, p-aminobenzamidine, and phenylmethanesulfonyl fluoride but was not affected by metal chelators.

Membrane-bound Fas (Apo-1/CD95) ligand on leukemic cells: A mechanism of tumor immune escape in leukemia patients

There is evidence from bone marrow transplantation that T cells may be involved in the immunologic control of leukemia. But many patients relapse despite a potent graft-versus-leukemia effect mediated by allogeneic T cells. The expression of the FasL protein has been suggested as a mechanism of tumor immune escape. We, therefore, evaluated the capacity of leukemic cells from patients with acute or chronic myelogenous leukemia to escape the allogeneic or autologous immune response by bearing the FasL molecule. Although almost all leukemic cells express the 37-kD form of FasL, only 54% of acute myeloblastic leukemia and 27% of chronic myeloid leukemia (CML) cells bore a FasL with killing properties, as assessed by the ability of leukemic cells to cause the apoptosis of a Fas-sensitive target cell line or autologous activated T cells in 3 tested leukemic cases. Experiments with a recombinant Fas-Fc molecule confirmed the role of Fas/FasL in leukemic-mediated cell death. Only CML leukemic cells from certain individuals contained the 26-kD truncated form of FasL. Thus, myeloid leukemic cells from some, but not all patients can set up a mechanism of immune escape involving the Fas/FasL pathway. This leukemic escape may have implications for patients eligible for adoptive cellular immunotherapy.

[Case report of tuberous sclerosis and congenital heart disease]

The cardiac manifestation usually associated with Tuberous Sclerosis is rhabdomyoma. The authors present a clinical case of Tuberous Sclerosis with the particular coexistence of congenital heart disease (mitral anomaly and pulmonary stenosis) and a single intracardiac rhabdomyoma that appeared at the age of four years.

[Bacterial translocation in acute pancreatitis. Experimental study in rats]

Ninety Wistar rats were studied to confirm if the intestinal tract is a source of infection in acute pancreatitis. Bacterial translocation to the mesenteric lymph nodes, pancreas, peritoneal cavity, and blood was determined at 6 h, 24 h, 48 h and 96 hours after induction of non lethal acute pancreatitis. Bacterial growing was present in 60% (6 h), 90% (24 h), 70% (48 h) and 40% (96 h) (p < 0.05) of the mesenteric lymph nodes. Live bacteria were recovered from 67% (6 h), 90% (24 h), 50% (48 h) and 40% (96 h) (p < 0.05) of the pancreas. Gram-positive bacteria translocate more frequently than Gram-negative bacteria in the early period (6 h). Lately (24-96 h), Gram-negative bacteria were much more frequently isolated (p < 0.05). The most common organism isolated was Escherichia coli. No overgrowth of cecal Gram-negative bacteria was found. It is concluded that bacterial translocation in acute pancreatitis is an early phenomena, initially caused by Gram-positive bacteria and lately by Gram-negative bacteria, and associated with the severity of pancreatic lesions.