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PubMed2002

Nanofiltration for the recovery of caustic cleaning-in-place solutions: robustness towards large variations of composition.

In the dairy industry re-use and multi-use cleaning-in-place (CIP) systems are operated by circulating chemicals and water without taking the equipment apart. The solutions, which become polluted due to the removal of fouling compounds, are drained periodically when they are considered to be too polluted. This work shows the large variations in composition (pollution, surface tension, etc) of the industrial caustic solutions coming from milk standardization and pasteurization plant CIP throughout their life time (7 days) and from 1 week to another. The work is also intended to show how nanofiltration (1 kg mol(-1) molecular weight cut-off) was robust and performed well, with good recovery of caustic solutions, even when faced with large variations of solutions composition: high caustic yield, permeation flux (J) in the range 42-110 l h(-1) m(-2), average chemical oxygen demand (COD) reduction equal to 0.58 and low surface tension change. Equations have been established for the prediction of J as a function of initial membrane hydraulic resistance (Rm) caustic concentration, volume reduction ratio (VRR) and initial soluble COD. When VRR increased, both J and pollution retention decreased despite the increase in irreversible fouling induced by the increase of soluble pollution concentration in retentate. The higher the initial soluble COD, the sharper the decrease in J vs. VRR. Since irreversible fouling was usually small (0.1-3.4 x 10(13) m(-1), that is to say of the same order of magnitude as Rm), the membrane cleaning could be efficiently performed by using single phase sodium hypochlorite alternately with a more expensive acid-base cleaning sequence. The obtained permeate was a clear regenerated cleaning solution with low soluble COD (0.2-3.5 g/l) and surface tension (56-30 mJ m(-2)) which could be successfully exploited owing to its cleaning potential.

Animals↗
PubMedDate not supplied

Inactivation of adenovirus type 5 by caustics.

Adenovirus shows significant promise as a vehicle for transfer of therapeutic genes into humans. Based on the importance of this viral vector, it is critical that adequate decontamination procedures are implemented during its large-scale production in multiproduct manufacturing facilities to prevent cross-product contamination and to reduce the risk of personnel exposure. Liquid decontamination procedures based on caustics are easily implemented in a manufacturing setting and are not corrosive to stainless steel surfaces at the concentrations found to inactivate viral proteins and nucleic acids. In this study, we have conducted small-scale experiments to determine the effectiveness of caustic inactivation procedures on adenovirus type 5 and have evaluated the robustness of the process to different sample matrices and adenovirus constructs. We find that the pH of a sample post-addition of caustic solution is a more accurate indicator of the effectiveness of the caustic than its concentration. We have demonstrated that a greater than 6 log reduction in the potency of adenovirus type 5 may be obtained upon exposure of the sample to sodium hydroxide and CIP-100 at concentrations greater than 0.09 M and 0.9%, respectively, at times greater than 10 min.

Adenoviridae↗
PubMed2003

Analysis of the shadow-sausage effect caustic.

We analyze the optical caustic produced by light refracted at the curved meniscus surrounding a cylindrical rod standing partially out of a liquid-filled container. When the rod is tilted from the vertical or when light is diagonally incident, the caustic is a four-cusped astroid with two of its cusps obscured by the rod's shadow. If a portion of the flat end of the rod is raised above the water level, the caustic evolves into a pattern of five interlocking cusps. The five cusps result from symmetry breaking of a three-cusped surface perturbation caustic.

Journal Article↗
PubMed2001

Dark matter caustics.

The late infall of cold dark matter onto an isolated galaxy such as our own produces flows with definite velocity vectors at any physical point in the galactic halo. It also produces caustics which are places where the dark matter density is very large. The outer caustics are topological spheres whereas the inner caustics are rings. The self-similar model of galactic halo formation predicts that the caustic ring radii a(n) follow the approximate law a(n) approximately 1/n. In a recent study of 32 extended and well-measured galactic rotation curves, we found evidence for this law.

Journal Article↗
PubMed1996

Esophageal motility in patients with esophageal caustic injury.

OBJECTIVE: There are few studies of esophageal function subsequent to the ingestion of lye. We investigated the esophageal motility of patients who had ingested liquid sodium hydroxide. METHODS: Esophageal manometry was performed on 21 patients who [1-53 yr before the manometric examination (median: 13 yr)] had drunk 10-30 g of sodium hydroxide diluted in water. The results were compared with those obtained for a control group of 22 healthy volunteers. RESULTS: The lower esophageal sphincter (LES) pressure of the caustic group (14.9 +/- 1.7 mm Hg, mean +/- SE) did not differ (p > 0.05) from that of the control group (17.4 +/- 1.1 mm Hg). LES pressure in eight patients was below 10 mm Hg. The amplitude of contraction was lower (p < 0.01) in the caustic group than in the control group. In the proximal part of the esophageal body, the duration of contraction was longer (p < 0.01) in the caustic group (2.3 +/- 0.1 s) than in controls (1.8 +/- 0.1 s). Nonperistaltic contraction was a finding in 14 patients, repetitive in five of them. The velocity of peristaltic contractions was higher (p < 0.05) in the caustic group (distal: 3.2 +/- 0.2 cm/s) than in the control group (2.2 +/- 0.2 cm/s). Although there was some impairment of esophageal motor function in 71% of the patients, they were asymptomatic when we performed esophageal manometry. CONCLUSIONS: Esophageal motility impairment was present in most of the patients who ingested sodium hydroxide. Nonperistaltic contractions of low amplitude were found most frequently.

Accidents↗
PubMed1984

Caustic ingestions. Symptoms as predictors of esophageal injury.

The ingestion of a caustic substance can lead to severe damage to the esophagus. Currently, esophagoscopy is recommended for all patients with a history of caustic substance ingestion because clinical criteria have not proved to be reliable predictors of esophageal injury. The records of 79 consecutive patients younger than 20 years who were first seen with a history of corrosive ingestion were reviewed. The presence or absence of three serious signs and symptoms--vomiting, drooling, and stridor--as well as the presence and location of oropharyngeal burns were compared with the findings on subsequent esophagoscopy. Fifty percent (7/14) of the patients with two or more of these serious signs and symptoms (vomiting, drooling, and stridor) had serious esophageal injury as compared with no positive endoscopic results in the group with none or only one of these clinical findings. The presence of oropharyngeal burns did not identify patients with serious esophageal injury. These results suggest that the presence of two or more signs or symptoms in patients with a history of caustic substance ingestion may be a reliable predictor of esophageal injury.

Adolescent↗
PubMed1990

Experimental studies on caustic burns of the stomach by aggressive chemicals.

The treatment of caustic burns of the stomach in childhood by acids, alkalis and especially soldering fluids has remained without any clear concept so far. Surgical treatment consists of therapy of acute complications or late sequelae. Early endoscopy enables one to decide between conservative treatment and early laparotomy. Animal experiments were performed in albino rats for the development of a therapeutic concept. Because of its amphoteric and aggressive nature, soldering fluid zinc dissolved in 33-50 M saline) was used as the caustic substance. Clear demarcation and tissue changes can be recognized after 6-8 h, at the earliest. Laparotomy aiming at protective plication or atypical gastric resection should be performed at that time, if endoscopy reveals a third-degree caustic burn of the stomach.

Animals↗
PubMed2003

[Gastric conservation in severe caustic lesions of the digestive tract: is it legitimate?].

OBJECTIVE: To evaluate advantages and drawbacks of a controlled conservative management of patients with severe gastric caustic injuries. METHODS: Among 40 patients with severe caustic gastric burns (> IIb), 28 with stade III lesions (mosaic necrosis: n = 10, extensive or circumferential necrosis: n = 18) were managed prospectively from 1990 to 1998. Twenty-two patients had associated stage III oesophageal lesions and 6 had stage III duodenal lesions. All patients were followed up by daily surgical examination. Total gastrectomy with esophageal exclusion or stripping was performed in case of perforation. RESULTS: Five immediate and 7 secondary total gastrectomies, two associated esophagectomies and two jejunal resections were performed. Mortality rate was 18% (5/28). Sixteen gastric preservations (60%) were achieved, including 7 complete and 9 partial because of gastric stricture. Eighteen esophagoplasties for oesophageal strictures or after gastrectomy were performed without mortality. CONCLUSION: Stage III caustic injuries of the stomach, when they are not immediately life-threatening, do not systematically require total gastrectomy. A strict conservative attitude can be done with significant morbidity and acceptable mortality and significantly raises the numbers of preserved stomach.

Adolescent↗
PubMed1989

Caustic esophageal lesions in childhood: prevention of stricture formation.

Accidental caustic ingestion, a problem of childhood, can lead to esophageal stricture formation. We studied 132 children less than 19 years of age who were admitted to our hospital for suspected caustic ingestion. Forty-nine had burns in the esophagus, 11 of whom had deep and circular burns and were therefore prone to developing esophageal strictures. Only these 11 children were treated for prevention of stricture formation with a special nasogastric tube, functioning as intraluminal stent; this was their sole treatment. No corticosteroids were used. Only one of the 11 developed mild stenosis. In none of the other untreated children was stricture formation observed. Therefore, we believe that this approach spares many children unnecessary treatment and hospitalization, that our nasogastric tube effectively prevents stricture formation, and that there is no need for the use of corticosteroids in the treatment of caustic esophageal lesions in childhood.

Adolescent↗
PubMed1999

Reactive oxygen radical levels in caustic esophageal burns.

PURPOSE: This study was designed to determine the tissue levels of reactive oxygen radicals in caustic esophageal burns in a rat model. METHODS: Forty rats were divided into four groups of 10 animals each. The control rats were uninjured in group A, and the others were injured rats in groups B, C, and D. Through a median laparatomy incision, a 1.5-cm abdominal esophageal segment was isolated and tied with 2-0 chromic sutures in all groups as described by Gehanno. One milliliter of 10% sodium hydroxide solution in groups B, C, and D and 0.9% saline solution in group A were instilled through the isolated segment via a no. 24 cannula for 3 minutes, then the esophagus was rinsed for 1 minute with distilled water. The studied 1.5 cm of the abdominal esophagus was removed from each animal 24 hours after caustic injury in group B, 48 hours after in group C, and 72 hours after in group D. In group A, studied uninjured segments were removed for biochemical investigation. Tissue malondialdehyde (MDA) and glutathione (GSH) levels were determined for each group. RESULTS: The mean MDA levels in esophageal tissue were significantly higher in groups B, C, and D than in group A (P < .05). Moreover, the mean GSH levels in the same esophageal tissues were significantly lower in groups C and D than in groups A and B (P < .05). CONCLUSION: The reactive oxygen radicals may be play an important role in early phase of caustic esophageal burns by increasing the tissue damage.

Animals↗
PubMed2003

Effects of caustic lye injury to the esophageal smooth muscle reactivity: in vitro study.

PURPOSE: We investigated late effects of caustic lye injury on esophageal smooth muscle reactivity in the rat model. MATERIALS AND METHODS: Male Sprague-Dawley rats were divided into two groups. Through a median laparatomy incision, abdominal esophageal segment was isolated. Orogastric and gastric (via gastrotomy) catheters were placed and tied over the isolated esophageal segment. Saline (0.9%) or 50% sodium hydroxide (1 ml) solution were instilled via orogastric catheter to the isolated segment in the control and caustic esophagus (CE group) groups, respectively. Then, the esophagus was rinsed with 0.9% saline via gastric catheter. The esophagus was removed and studied in organ chambers 28 days after the operation. RESULTS: Carbachol- and KCl-induced contractile responses of esophageal smooth muscle were significantly reduced in the CE group with decreased E(max) value compared with the control group. Relaxant responses to serotonin were significantly reduced in the CE group with decreased E(max) value compared with the control group. No significant differences were found in E(max) and pD(2) values for papaverine acting on esophageal strips from the two groups. CONCLUSION: The results provide evidence that, a surgically created caustic injury causes impaired smooth muscle reactivity that may contribute to esophageal motor dysfunction.

Animals↗
PubMed2001

[Pneumatic dilatation of caustic esophageal stenosis in children. Report of five cases].

The ingestion of caustic substances is a frequent accident in the child. The treatment of caustic strictures of the esophagus, which constitute the most frightening complication, varies from conservative treatment to esophageal replacement. We report the preliminary results of a prospective work established since July 1998 and aimed at evaluating the role of pneumatic dilatation in the treatment of these injuries. STUDIED POPULATION: The series included five boys with an average age of six years. Two children were neurologically handicapped. RESULTS: The caustic product was soda (three cases), a dishwasher solution (one case) and bleach (one case). Dysphagia was constant and concerned the semi-fluids in four cases. The stricture was extended over an average length of 4 cm. The total number of dilatations was 36, with an average of seven sessions/patient. No complication was noted. The result was good in four cases. The only failure was noted in a child who presented a gastroesophageal reflux secondary to the scarring phenomena. CONCLUSION: Pneumatic dilatation constitute a therapeutic mean whose results are attested. The best treatment remains, however, preventive: it is the setting out of reach of the child the dangerous products.

Burns, Chemical↗
PubMed1996

Caustic injury of the oesophagus. Sixteen years experience, and introduction of a new model oesophageal stent.

Caustic ingestion can lead to oesophageal stenosis. We studied 251 patients, 205 of whom were children, in a sixteen-year period. Seventeen patients, of whom one was an adult, acquired deep burns in the oesophagus which had to be treated, to prevent the development of oesophageal strictures. These patients were treated with long-term stenting of the oesophagus with specially designed, silicone rubber stents, impregnated with silicone oil 20 cS, designed by one of us (R.N.P.B.) as the only treatment. Of all models, the twin-tube dilator was the most satisfactory. No corticosteroids were administered. Only one patient developed a mild stenosis. It is therefore our opinion that, when life-saving operations are not indicated, twin-tube stenting of the oesophagus is helpful in treating caustic lesions of the oesophagus and will prevent stricture formation. Corticosteroids were not given in this series, and should be abandoned in the treatment of caustic lesions.

Adolescent↗
PubMed2005

Prevention of esophageal strictures in a caustic burn model using halofuginone, an inhibitor of collagen type I synthesis.

OBJECTIVE: Esophageal strictures caused by caustic injury continue to be a plaguing problem. Halofuginone (HF) has been proven to inhibit the formation of fibrosis in various animal models and human diseases. Its mechanism appears to be through the suppression of the production of collagen alpha1(I) and transforming growth factor-beta signaling pathway. We tried to assess whether HF would have an effect on the formation of strictures after inducing caustic esophageal. MATERIALS AND METHODS: Esophageal injury was caused by injecting 25% NaOH to an isolated esophageal segment. Study group rats were treated with HF orally for 3 consecutive days before the injury and afterward. Control group rats received regular chow. The results were evaluated by upper gastrointestinal series (UGI) and through pathologic studies. RESULTS: HF treatment resulted in marked improvement in the esophageal strictures. The UGI series showed esophageal patency of 73% (45%-100%) in the treated animals (n = 7) as compared with almost no patency, 11% (5-16%), in the controls (n = 4) (P = .018). The histologic examination showed significantly less stricture and scarring in the treated group. Whereas the ratio between the esophageal wall thickness to mucosal thickness was 2.34 +/- 0.23 in the study group, the control group had a ratio of 9.56 +/- 0.69 (P = .0044). Finally, whereas 86% of the study group survived, all the rats in the control group died by day 20. CONCLUSIONS: HF modulated the wound healing reaction caused by caustic injury of the esophagus in a rat model, resulting in increased esophageal patency, reduction in esophageal wall thickness, and increased survival.

Animals↗
PubMed2006

Effects of time of contact and concentration of caustic agent on generation of injuries.

OBJECTIVES: Solid caustic soda (CS) ingestion levels continue high in Brazil. The aggressiveness of a caustic agent depends, among other factors, on its concentration and time of contact with mucosa. However, the interdependence of these factors in the production of caustic lesion in the esophageal mucosa is not known, especially regarding CS as the strongest corrosive agent. We analyze the effects of concentration and time of contact on the aggressiveness of CS to the esophagus of live animals. STUDY DESIGN/METHODS: One milliliter of CS at concentrations between 1.83% and 73.33% was applied to rats. The solution was kept in contact with the mucosa for 10 to 120 minutes. Internal and external organ aspects were analyzed and the epithelium, submucosa, muscle layer, and adventitia were analyzed microscopically RESULTS: Epithelial necrosis was observed at all concentrations. Among the necrotic layers, the submucosa was observed starting at the 7.33% concentration, and the muscular layer and adventitia were observed at 14.66% concentration. Damage to the pulmonary parenchyma and trachea occurred at 33.66% after 10 minutes, and perforation of the esophagus was observed only after 120 minutes. After 10 minutes, important corrosive lesions installed in the esophageal layers, expanding in depth and superficial extension. The use of heparin had no effect on the production of lesions. CONCLUSIONS: Ten minutes were sufficient to provoke necrosis, and longer contact increased the area of necrosis. Solution concentration levels were more important in damage production: 1.83% was sufficient for epithelial necrosis, 7.33% caused submucosal necrosis, and 14.66% muscle and adventitia necrosis; 33.66% solutions caused lung and trachea damage after 10 minutes and esophageal perforation after 120 minutes.

Animals↗
PubMed2003

Endoscopic treatment of upper airway and digestive tract lesions caused by caustic agents.

We present our experience in the endoscopic management of upper aerodigestive tract lesions caused by caustic agents. Between 1985 and 2000, 112 patients with upper airway and digestive tract lesions due to caustic agents were treated at the Airways Endoscopic Surgery Unit of Padua Hospital: 44 were male and 68 were female, and the median age was 42.6 years. A retrospective statistical analysis of our case series was made to evaluate the factors that most influenced the severity of injuries and the outcome of treatment. All of the patients underwent videoendoscopic assessment. In 79 cases, the patients came under our observation in the acute phase, whereas 33 presented a picture of chronic lesions. Acute lesions were classified into 3 grades. All acute grade 1 lesions healed spontaneously. In the 32 patients with grade 2 lesions, endoscopic treatment based on removal of necrotic tissue, dilations, and cleansing of abnormal fibrin adhesions resolved the disease in 30 cases (94%). Nine patients (43%) with acute grade 3 lesions developed severe chronic lesions that required subsequent treatments. Rigid endoscopy with diode laser-assisted radial lysis was performed in 32 patients with chronic cicatricial lesions and was successful in 30 cases (94%). We reiterate the need for a standardized multidisciplinary protocol for treating lesions caused by caustic agents and emphasize the essential role of airway and digestive canal videoendoscopy in the diagnosis and treatment of both the acute lesions and chronic cicatricial sequelae.

Adolescent↗
PubMedDate not supplied

Foreign body and caustic ingestion: management 1979.

Most physicians involved in the diagnosis and management of foreign body aspiration and caustic ingestion assume that the numbers of these cases are decreasing. A sizeable number of patients die of caustic ingestion and poisoning annually, and deaths from foreign body ingestion have more than doubled since 1950. Increasing the significance of these needless tragedies is the fact that the most frequent victim is a young, healthy child. Physicians should encourage educational campaigns to alert parents to the dangers of caustic agents and small items capable of being aspirated. They should be conversant with the treatment of both. This paper reviews current opinions regarding management.

Airway Obstruction↗
PubMed1992

Caustic ingestion injuries of the upper aerodigestive tract.

Few reports have described in detail the injuries that occur to the oral cavity, pharynx, and larynx following caustic ingestion. The role of dynamic radiographic studies to delineate the extent of damage has been minimized. In-depth radiographic analysis of such cases has not, to our knowledge, been previously reported. In order to examine the injuries and functional abnormalities of these sites following caustic ingestion, the records of The Johns Hopkins Swallowing Center were reviewed. Five patients were identified as having significant upper aerodigestive tract caustic injuries. All patients had dysphagia, epiglottis injuries, and incomplete laryngeal protection with aspiration. Four of five had sustained some degree of esophageal stenosis. Also noted were pharyngeal muscle dysfunction, nasopharyngeal regurgitation, tongue fixation, and hypopharyngeal stenosis. Roentgenographic findings are described and illustrated. The multidisciplinary approach to the management and rehabilitation of these patients is discussed.

Adult↗