A safer disposal of hazardous phosphate coating sludge by formation of an amorphous calcium phosphate matrix.

Phosphate coating hazardous wastes originated from the automotive industry were efficiently encapsulated by an acid-base reaction between phosphates present in the sludge and calcium aluminate cement, yielding very inert and stable monolithic blocks of amorphous calcium phosphate (ACP). Two different compositions of industrial sludge were characterized and loaded in ratios ranging from 10 to 50 wt.%. Setting times and compressive strengths were recorded to establish the feasibility of this method to achieve a good handling and a safe landfilling of these samples. Short solidification periods were found and leaching tests showed an excellent retention for toxic metals (Zn, Ni, Cu, Cr and Mn) and for organic matter. Retentions over 99.9% for Zn and Mn were observed even for loadings as high as 50 wt.% of the wastes. The formation of ACP phase of low porosity and high stability accounted for the effective immobilization of the hazardous components of the wastes.

Treatment of toxic metal aqueous solutions: encapsulation in a phosphate-calcium aluminate matrix.

Polyphosphate-modified calcium aluminate cement matrices were prepared by using aqueous solutions polluted with toxic metals as mixing water to obtain waste-containing solid blocks with improved management and disposal. Synthetically contaminated waters containing either Pb or Cu or Zn were incorporated into phosphoaluminate cement mortars and the effects of the metal's presence on setting time and mechanical performance were assessed. Sorption and leaching tests were also executed and both retention and release patterns were investigated. For all three metals, high uptake capacities as well as percentages of retention larger than 99.9% were measured. Both Pb and Cu were seen to be largely compatible with this cementitious matrix, rendering the obtained blocks suitable for landfilling or for building purposes. However, Zn spoilt the compressive strength values because of its reaction with hydrogen phosphate anions, hindering the development of the binding matrix.

Review: leucocyte-endothelial cell crosstalk at the blood-brain barrier: a prerequisite for successful immune cell entry to the brain.

Leucocyte migration into the central nervous system is a key stage in the development of multiple sclerosis. While much has been learnt regarding the sequential steps of leucocyte capture, adhesion and migration across the vasculature, the molecular basis of leucocyte extravasation is only just being unravelled. It is now recognized that bidirectional crosstalk between the immune cell and endothelium is an essential element in mediating diapedesis during both normal immune surveillance and under inflammatory conditions. The induction of various signalling networks, through engagement of cell surface molecules such as integrins on the leucocyte and immunoglobulin superfamily cell adhesion molecules on the endothelial cell, play a major role in determining the pattern and route of leucocyte emigration. In this review we discuss the extent of our knowledge regarding leucocyte migration across the blood-brain barrier and in particular the endothelial cell signalling pathways contributing to this process.

Screening of extracts of algae from Baja California sur, Mexico as reversers of the antibiotic resistance of some pathogenic bacteria.

BACKGROUND AND OBJECTIVES: Sixty ethanol extracts of marine flora of Baja California Sur (Mexico) were screened to evaluate the reversing effect of the bacterial resistance to antibiotics in combination with a sublethal concentration of ampicillin or erythromycin. MATERIALS AND METHODS: The activity was assayed by using a modification of the classical agar-diffusion method against 3 resistant, pathogenic bacteria; Escherichia coil (ATCC BAA196), Staphylococcus aureus (ATCC BAA42), and Streptococcus pyogenes (ATCC BAA946). RESULTS: From the 60 ethanolic extracts, 12 (20%) of them in combination with ampicillin were able to reverse the resistance of Staphylococcus aureus and 8 (13%) with erythromycin yielded the same reversal with Streptococcus pyogenes. An extract from Sargassum horridum was the only one that reversed the resistance to antibiotics against both Staphylococcus aureus and Streptococcus pyogenes. CONCLUSIONS: Our findings suggest that some algae may be source of compounds with the potential to reverse the antibiotic resistance of some bacteria. In addition, of the assayed extracts, 35 (57%) showed inhibitory activity against Staphylococcus aureus, 48 (78%) were active against Streptococcus pyogenes, but none was active against Escherichia coil. The most active extracts were from Laurencia spp., Gelidium robustum, Chnoospora implexa, Padina mexicana, Gracilaria subsecundata, and Dictyopteris undulata.

In vitro and in silico evaluation of fucosterol from Sargassum horridum as potential human acetylcholinesterase inhibitor.

The fucosterol has been reported numerous biological activities. In this study, the activity in vitro of the fucosterol from Sargassum horridum as potential human acetylcholinesterase inhibitor was evaluated. The structural identification was obtained by nuclear magnetic resonance (NMR) spectroscopy and based on experimental data, we combined docking and molecular dynamics simulations coupled to the molecular-mechanics-generalized-born-surface-area approach to evaluating the structural and energetic basis for the molecular recognition of fucosterol and neostigmine at the binding site of acetylcholinesterase (AChE). In addition, the Lineweaver-Burk plot showed the nature of a non-competitive inhibition. The maximum velocity (Vmax) and the constant of Michaelis-Menten (Km) estimated for fucosterol (0.006 µM) were 0.015 1/Vo (ΔA/h and 6.399 1/[ACh] mM-1, respectively. While, for neostigmine (0.14 µM), the Vmax was 0.022 1/Vo (ΔA/h) and Km of 6.726 1/[ACh] mM-1, these results showed a more effective inhibition by fucosterol respect to neostigmine. Structural analysis revealed that neostigmine reaches the AChE binding site reported elsewhere, whereas fucosterol can act as a no-competitive and competitive acetylcholinesterase inhibitor, in agree with kinetic enzymatic experiments. Binding free energy calculations revealed that fucosterol reaches the acetylcholinesterase binding site with higher affinity than neostigmine, which is according to experimental results. Whereas the per-residue decomposition free energy analysis let us identify crucial residues involved in the molecular recognition of ligands by AChE. Results corroborate the ability of theoretical methods to provide crucial information at the atomic level about energetic and structural differences in the binding interaction and affinity from fucosterol with AChE. Communicated by Ramaswamy H. Sarma.

Second isolated anastomotic recurrence after curative surgery for colorectal cancer.

Introduction The two mechanisms postulated for cancer recurrence at the anastomosis site ('anastomotic recurrence' (AR)) after curative surgery for colorectal cancer are: (i) intraluminal dissemination of viable cancer cells; (ii) metachronous carcinogenesis related with changes in the local milieu provoked by the materials employed to carry out the anastomosis. Case History We describe a 79-year-old female who underwent a left hemicolectomy due to a stenotic lesion shown on colonoscopy: an adenocarcinoma (pT3NO, G2). One year after surgery, control colonoscopy revealed an AR, so a new resection was carried out. Pathology showed it to be a recurrent adenocarcinoma over the staple line (pT3N0, G2). One year after the second surgical procedure, control colonoscopy evinced a new AR, resulting in a new resection. Pathology revealed a new AR. Conclusions This is only the second time that a second isolated AR after curative resection for colorectal cancer has been reported.

Incarcerated umbilical Littre's hernia at the trocar site of a previous laparoscopic surgical procedure.

INTRODUCTION: Prevalence of Littre's hernia (protrusion of a Meckel´s diverticulum through an opening in the abdominal wall) is very low, and Littre's hernias found in an umbilical site are uncommon. Even rarer are cases of an incarcerated hernia resulting in a surgical emergency. Trocar-site hernias are a relatively common complication after laparoscopic cholecystectomy that develop in association with insertion of wide trocars (usually at the umbilical port). CASE HISTORY: A 63-year-old female with a history of obesity, diabetes mellitus, hypertension, laparoscopic cholecystectomy and open hysterectomy arrived at hospital complaining of acute umbilical pain but with no other symptoms or fever. A painful mass observed was believed to be an incarcerated umbilical hernia at a trocar site used in previous laparoscopic surgery. Emergency surgery was undertaken: the opening of the hernia sac revealed a Meckel's diverticulum within it. The Meckel's diverticulum was resected using a stapler, followed by herniorrhaphy and hernioplasty. Postoperative recovery was uneventful. CONCLUSION: An incarcerated umbilical Littre's hernia at a laparoscopic trocar site has not been reported before. To avoid this complication, we agree with the numerous authors who recommend closure of trocar sites of width ≥10mm.

Generation of avian cells resembling osteoclasts from mononuclear phagocytes.

Several lines of indirect evidence suggest that a monocyte family precursor gives rise to the osteoclast, although this hypothesis is controversial. Starting with a uniform population of nonspecific esterase positive, tartrate-sensitive, acid phosphatase-producing, mannose receptor-bearing mononuclear cells, prepared from dispersed marrow of calcium-deprived laying hens by cell density separation and selective cellular adherence, we generated multinucleated cells in vitro. When cultured with devitalized bone, these cells show, by electron microscopy, the characteristic osteoclast morphology in that they are mitochondria-rich, multinucleated, and, most importantly, develop characteristic ruffled membranes at the matrix attachment site. Moreover, as documented by scanning electron microscopy, these cells pit bone slices in a manner identical to freshly isolated osteoclasts. In addition, isoenzymes of acid phosphatase from generated osteoclasts, separated by 7.5% polyacrylamide gel electrophoresis at pH 4, are identical to those of mature osteoclasts in migration pattern and tartrate resistance, although the precursor cells from which the osteoclasts are generated produce an entirely different isoenzyme, which is tartrate-sensitive and migrates less rapidly at pH 4. The fused cells also exhibit a cAMP response to prostaglandin E2. Therefore, osteoclast-like cells can be derived by in vitro culture of a marrow-derived monocyte cell population.

The human nervous tissue in proximity to granulomatous lesions induced by Taenia solium metacestodes displays an active response.

In neurocysticercosis, the nervous tissue surrounding the brain lesion is affected as a consequence of the local immune response induced by a Taenia solium metacestode. In this study, a histological and immunohistochemical analysis of five brain specimens from patients with neurocysticercosis revealed a proinflammatory activity reflected by an apparently altered blood-brain barrier permeability, secretion of pro-inflammatory cytokines, and up-regulation of molecules associated with antigen presentation. There were also anti-inflammatory cytokines, as well as an active wound-healing process reflected by angiogenesis, collagen deposition and glial scar formation. This immune response displayed by the nervous tissue adjacent to chronic neurocysticercosis lesions appeared to be contributing to the local tissue damage, and hence, may be fundamental in the pathology of NCC.

Prenatal dexamethasone rescues heart hypoplasia in fetal rats with congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Patients and rats with congenital diaphragmatic hernia (CDH) have lung and heart hypoplasia. Prenatal steroids improve lung hypoplasia in CDH rats. The current study tests the hypothesis that prenatal dexamethasone could rescue heart hypoplasia in rats with CDH. METHODS: Timed pregnant rats received intragastrically either 100 mg nitrofen or oil on day 9.5, and other animals had the same treatment with, in addition, either 0.25 mg/kg dexamethasone intraperitoneally or no treatment on days 19 and 20. Fetuses were recovered on day 21, and heart weight to body weight ratios, heart DNA, protein, and glycogen were measured in fresh specimens. Left-to-right ventricular diameter and aortic-to-pulmonary diameter ratios were measured after formalin fixation. RESULTS: Wet heart weight to body weight, left-to-right ventricular diameter, and aortic-to-pulmonary root diameter ratios, which were lower in fetuses exposed only to nitrofen than in their oil controls, were similar in those exposed to nitrofen plus dexamethasone than in their corresponding oil plus dexamethasone controls. Total heart DNA, which was decreased in fetuses exposed to nitrofen with CDH in comparison with their controls, was increased in those receiving nitrofen and dexamethasone in comparison with theirs. Protein to DNA ratio was decreased in all rats with CDH irrespective of their exposure or not to dexamethasone. Glycogen to DNA ratio was higher in all dexamethasone-treated fetuses than in those without this treatment. No gross histologic differences were seen among groups. CONCLUSIONS: Heart hypoplasia in rats with CDH is in part rescued by prenatal dexamethasone treatment as expressed by increased number of smaller myocytes with higher glycogen content. Prenatal steroids could modify heart involvement in human fetuses with CDH as well.

Heart hypoplasia in experimental congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Heart hypoplasia is associated with congenital diaphragmatic hernia (CDH) and decisively influences survival rate. This study examines whether nitrofen-exposed fetal rats have heart hypoplasia. METHODS: Pregnant rats received either 100 mg nitrofen or vehicle on gestational day 9.5. The hearts recovered near full term were either formalin fixed for anatomic studies or snap-frozen for biochemical studies. Heart weight, ventricular chamber diameters and aortic-to-pulmonary root diameter ratios were measured in fixed hearts. Protein and DNA were determined in frozen hearts. Analysis of variance (ANOVA) and correlation-regression studies were used for statistical assessment. RESULTS: All control fetuses were normal, whereas 61% of those exposed to nitrofen had CDH. Cardiovascular malformations were found in 73% of CDH and in 50% of non-CDH animals. Wet and fixed heart weights in percent of fetal weight, left-to-right ventricular diameter ratio, and aortic-to-pulmonary root diameter ratio were significantly decreased in fetuses with CDH in comparison with controls. Only wet heart was significantly decreased in nitrofen-treated fetuses without CDH, although all other variables showed a trend in the same direction. Protein to DNA ratios were similar in the three groups. The structure of the myocytes was histologically similar in all groups. CONCLUSIONS: The spectrum of lesions in the nitrofen model of CDH encompasses heart hypoplasia, further validating its use for research on this condition. Heart hypoplasia is related to cardiopulmonary compression, but its presence in treated animals without CDH demonstrates that the teratogen itself participate directly in its pathogenesis, and this finding invites further research on this line.

Granuloma formation and parasite disintegration in porcine cysticercosis: comparison with human neurocysticercosis.

Taenia solium cysticerci infect human beings and pigs, causing cysticercosis. In this study the pig was used as a model to characterize the immune response against cysticerci, given the difficulties in analysing the developing immune response in infected human brains. Metacestodes in different stages of viability or degeneration were isolated from the brain, heart and skeletal muscle of naturally infected swine, and the adjacent tissue was examined histologically. The immune response elicited by the cysticerci was classified into four separate stages. In stage I the parasites were surrounded by a thin layer of collagen type I, and by stage II there was a sparse inflammatory infiltrate. In stage III, granuloma formation was evident, and by stage IV the parasite was surrounded by an eosinophil-rich infiltrate and its vesicular membrane had begun to degenerate. The final stage, IV, was detected mainly in the heart but not in the brain. The granulomatous reaction in swine resembled that described previously in human patients, but differed in the abundance of eosinophils, the relative paucity of plasma cells, and the discrete deposition of collagen. These differences were probably due to the fact that in pigs the immune response can be examined earlier than in human patients, in whom sampling is inevitably made at a more chronic stage.

Intragastric migration of laparoscopic adjustable gastric band (Lap-Band) for morbid obesity.

The appearance of fistulas and the posterior intragastric inclusion of the adjustable silicone Lap-Band prothesis have been described, representing a severe complication of the Lap-Band procedure. A 45-year-old patient with severe obesity, weighing 115 kg, and having BMI (body max index) of 45 kg/m2 was assigned to a protocol to place a Lab-Band in her. An infection in the reservoir after 9 months indicated the beginning of the appearance of fistulas. The entire adjustable silicone gastric band device eroded inside the stomach between months 9 and 14 after its placement, resulting in reoperation. The gastric inclusion of the Lap-Band device represents a severe complication that requires reoperation, and raises concerns about the safety of this new alternative weight reduction operation.

Laparoscopic appendectomy by ultrasonically activated scalpel in acute appendicitis: preliminary report.

BACKGROUND AND PURPOSE: Laparoscopic appendectomy (LA) is increasingly being used in treating acute appendicitis. New instruments such as the ultrasonically activated scalpel (UAS) have been introduced for most laparoscopic procedures. We evaluated the use of UAS in the performance of LA, as the potential of this instrument in this type of surgery remains to be defined. PATIENTS AND METHODS: Three patients with acute right lower abdominal pain were managed by the laparoscopic approach. Once the diagnosis of acute appendicitis was established, laparoscopic appendectomy was performed with the UAS. RESULTS: The mean operative time was 42.3 minutes (range 32-49 minutes). There were no complications related to the treatment with UAS of either the vascular pedicle or the appendicecal stump. No electrosurgical coagulation, clips, loops, or endostapler was used in any patient. CONCLUSIONS: Total LA performed with UAS is feasible. Use of the UAS may make dissection and resection of the appendix easier, helping to reduce the mean operative time.

Decrease in plasma levels of vasoactive intestinal polypeptide in short bowel syndrome: experimental study.

To investigate the behaviour of the vasoactive intestinal polypeptide (VIP) in short bowel syndrome (SBS), an experimental model of massive intestinal resection (MIR) was developed. For this purpose, 20 'minipigs' were divided into two experimental groups: A (control) and B (MIR). The parameters determined were the mean plasma levels of VIP and the degree of steatorrhea at four different times: T1 (basal), T2 (one week after surgery), T3 (two weeks after surgery), and T4 (24 weeks after surgery). The results indicated that, after MIR, a progressive decrease in the mean plasma levels of VIP takes place, with statistical significance in T3 (p < 0.05) and T4 (p < 0.01). This situation seems to be a direct result of the massive loss of intestinal tissue, and could lead to the use of this peptide to mark the evolution of the intestinal adaptation process.

[Anisakiasis as a cause of acute appendicitis and rheumatologic picture: the first case in medical literature]. / Anisakiasis como causa de apendicitis aguda y cuadro reumatológico: primer caso en la literatura médica.

We report a case of acute abdomen due to appendicular lumen occlusion by anisakis larvae. This is the first case of human anisakiasis known in Spain, and the first case of acute appendicitis, in the medical World literature, produced by this nemathode. The association of myalgias and arthralgias stands out, being in this aspect the second case found the in medical litterature.

[Appendicular invagination]. / Invaginación apendicular.

Two cases of intussusception of the appendix are reported. The first case stands out for its rarity, corresponding exclusively to intussusception of appendicular mucosa. The second case was due to cystoadenoma of the appendix. Both cases were treated by right hemicolectomy due to the difficulty of diagnosing the condition.

[Digestive hemorrhage caused by vascular malformation (Rendu-Osler-Weber). A diagnostic and therapeutic challenge]. / Hemorragia digestiva por malformación vascular (Rendu-Osler-Weber). Un reto diagnóstico y terapéutico.

We present a case of gastrointestinal bleeding due to vascular malformation (Osler-Weber-Rendu disease), without cutaneous manifestations but with mucous manifestations and familiar and personal history of epistaxis. Until diagnosis, the patient underwent multiple radiologic and endoscopic tests and two surgical procedures. We would underline the diagnostic and therapeutic difficulty of recurrent gastrointestinal bleeding secondary to vascular malformation.

Acute diverticulitis and diverticular disease of the colon: a safe indication for laparoscopic surgery.

AIM: We analyzed our experience with a laparoscopic method for the treatment of acute diverticular disease. METHODS: Between January 1994 and October 1999 a group of 52 patients who fulfilled the criteria for symptomatic diverticular disease in the descending and sigmoid colon underwent laparoscopy with resection of an average of 40 cm of the bowel. Intraabdominal mechanical anastomosis completed the procedure. RESULTS: The use of ultrasonic scissors made the laparoscopic technique easier and shortened operative time. Operative morbidity was 15%. Two patients with acute diverticulitis and associated sepsis were reconverted to open surgery, and 4 patients presented postoperative rectal bleeding which ceased spontaneously. No long-term complications were found except in 1 patient who developed an incisional hernia through an entry port. Oral intake began between the second and third day. Postoperative hospitalization was 3-8 days (mean: 5.5 days) and mean operative time was 130 min (range: 70-240 min). CONCLUSIONS: Despite the steep learning curve for this type of surgery, the good morbidity and mortality rates with the laparoscopic method, especially with high-risk groups of patients (age > 65 years, high blood pressure, etc.) suggest that this surgical option can be used efficiently and safely, and that it achieves better results than with open surgery. However, we feel that the treatment of patients with acute complications of diverticular colon disease requires extensive experience with laparoscopic colorectal surgery.

Surgical treatment of the acute cholecystitis in the laparoscopic age. A comparative study: laparoscopy against laparatomy.

OBJECTIVE: The aim of this study was to assess the complications and results of the laparoscopic opposite to open treatment of the acute cholecystitis. METHODS: A retrospective randomized study with two groups of 30 patients each one. The parameters tested were age, sex, risk factors, surgical time, hospital stay, cholecystitis type, and early or late complications. RESULTS: In the two groups there were no significant differences in age, sex, risk factors, type of cholecystitis and surgical time. The average of hospital stay was significantly longer for open cholecystectomy (9.5) than for laparoscopic technique (2.30) (p < 0.001). The complication rate was higher (7.30%) in open cholecystectomy. CONCLUSIONS: The laparoscopic cholecystectomy should be the standard procedure for the treatment of the acute cholecystitis.