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[Paraquat poisoning. A study of 29 cases and evaluation of the effectiveness of the "Caribbean scheme"].

BACKGROUND: To study clinical aspects of the oral paraquat intoxication and to assess the effectiveness of both the charcoal haemoperfusion and the so-called "Caribbean scheme" (cyclophosphamide, dexamethasone, furosemide and vitamins B and C) to reduce its mortality. PATIENTS AND METHOD: Retrospective study of 29 consecutive cases admitted to our intensive care unit in 17 years. RESULTS: a) Twenty five men and four women ingested 20% paraquat solution, either accidentally (4 subjects) or deliberately (25 subjects). The suicidal purpose was particularly strong among men aged 50-66 years. Most of patients had vomits and diarrhoea. All patients developed oral and pharyngeal caustic lesions. Hypokalaemia was detected on admission in 9 patients. Increased levels of serum aminotransferases, bilirubin, amylase or creatinkinase were detected in some patients. Twenty two patients developed acute renal failure and 18 patients respiratory failure. Twenty patients died (ten in the first 48 hours and ten between days 3 and 30); b) charcoal haemoperfusion was performed on 16 patients; 4 of the 16 treated patients survived, versus 5 of the 13 non treated (p = NS), and c) the "Caribbean scheme" was applied on 18 patients. All but one of the 11 subjects who ingested >= 45 ml (treated with the "Caribbean scheme" or not) died. Among those who ingested 45 ml, 8 of the 12 treated patients survived, versus none of the 6 non treated ones (p < 0.05). CONCLUSIONS: Charcoal haemoperfusion did not reduce mortality of paraquat. The "Caribbean scheme" was associated with a lesser mortality in the subjects who ingested 45 ml of 20% paraquat solution.

Acute Kidney Injury↗

Perianal condylomata acuminata.

Perianal condylomata, a result of clinical infection with human papillomavirus, are an increasing problem. The warts lead to bleeding, itching, and discomfort in the anal region and also may be associated with anal canal neoplasia. Treatment options are numerous and include chemical caustic agents, surgical ablative methods, and immunotherapy. A high rate of recurrence is encountered despite the best of efforts.

Anus Diseases↗

Non-destructive evaluation of composite materials with ultrasonic waves generated and detected by lasers.

Measurement of the stiffness properties of composite materials with laser generated and detected ultrasound requires proper understanding of waves emanating from a line or point source in anisotropic and viscoelastic media. The paper briefly presents calculation results of waves radiated by such a source through or at the surface of a composite plate. Dispersion is represented as well as the multiple wave arrivals connected with the folded shape of the quasi-shear ray surface. Moreover, internal diffraction at the cusp edges is properly depicted. An identification method with specific signal processing have been used to measure the stiffness coefficients of composite materials. From group velocity data, the stiffness tensor of materials showing an orthorhombic symmetry can be identified. The stiffness tensor changes induced by elevated temperatures in a composite material were then measured. An alternative approach was developed which allows to measure the phase velocities of waves generated with laser line sources. The material characterisation reliability is then improved. Moreover, the method can be used in practical cases where the front side of the structure only is accessible with the experimental devices. Despite reflection at the rear interface of transient divergent waves which ray surfaces may contain caustics, this inverse problem can be solved in a simple and efficient manner.

Journal Article↗

Arsenic removal using a polymeric/inorganic hybrid sorbent.

A fixed-bed sorption process can be very effective in removing trace concentrations of arsenic from contaminated groundwater provided: the sorbent is very selective toward both As(III) and As(V) species; the influent and treated water do not warrant any additional pre- or post- treatment; pH and composition of the raw water with respect to other electrolytes remain unchanged besides arsenic removal, and the sorbent is durable with excellent attrition resistance properties. In addition, the sorbent should be amenable to efficient regeneration for multiple reuse. This study reports the results of an extensive investigation pertaining to arsenic removal properties of a polymeric/inorganic hybrid sorbent. Each hybrid sorbent particle is essentially a spherical macroporous cation exchanger bead within which agglomerates of nanoscale hydrated Fe oxide (HFO) particles have been uniformly and irreversibly dispersed using a simple chemical-thermal treatment. The new sorbent, referred to as hybrid ion exchanger or HIX, combines excellent mechanical and hydraulic properties of spherical polymeric beads with selective As(III) and As(V) sorption properties of HFO nanoparticles at circum-neutral pH. Comparison of the results of fixed-bed column runs between the new sorbent and the polymeric anion exchanger confirmed that both As(V) and As(III) were removed very selectively with HIX. Equally important, no pH adjustment, pre- or post-treatment was warranted. Besides the absence of arsenic, the treated water composition was identical to that of influent water. HIX was amenable to efficient in situ regeneration with caustic soda and could subsequently be brought into service following a short rinse with carbon dioxide sparged water. During fixed-bed column runs, intraparticle diffusion was identified as the primary rate-limiting step for both As(III) and As(V) sorption. Repeated use of the same HIX particles during various laboratory investigations provided strong evidence that the new sorbent possesses excellent attrition resistance properties and retains its arsenic removal capacity over cycles.

Adsorption↗

History of direct vision internal urethrotomy.

Throughout medical history, the treatment of urethral strictures ranged from catheterization, the insertion of bougies, and the application of caustics to different methods of dilation, blind internal urethrotomy, and open surgery. The rise of endoscopy in the 19th century added the possibility of direct vision internal urethrotomy to this therapeutic spectrum. The development of this endourologic method is recapitulated from the first report in 1865 to the gold standard of cold knife urethrotomy in 1971 and later modifications (eg, advanced laser techniques).

Cryosurgery↗

Porcelain adherence to dental cast CP titanium: effects of surface modifications.

OBJECTIVES: A reaction layer forms on cast titanium surfaces due to the reaction of the molten titanium with the investment material. Such a layer prevents strong adhesion between titanium and porcelain. This study characterized the effects of surface modifications on cast titanium surfaces and titanium-ceramic adhesion. METHODS: ASTM grade II CP titanium was cast into an MgO-based mold. Castings were devested by sandblasting with alumina particles, and subjected to surface modification by immersion in one of the following solutions: (1) 35% HNO3-5% HF at room temperature for 1min; (2) 50% NaOH-10% CuSO4 x 5H2O at 105 degreesC for 10min; (3) the NaOH-CuSO4 solution followed by the HNO3-HF solution; (4) 50% NaOH-10% NaSO4 at 105 degreesC for 10 min; (5) the NaOH-NaSO4 solution followed by the HNO3-HF solution; and (6) 50% NaOH solution at 105 degreesC for 10min. Surfaces only sandblasted with alumina were used as controls. Specimen surfaces were characterized by XRD and SEM/EDS, and hardness-depth profiles were determined. All specimens were sandblasted with 110 microm alumina particles before porcelain firing. An ultra-low-fusing porcelain (Vita Titankeramik) was fused on the titanium surfaces. The titanium-ceramic adhesion was characterized by a biaxial flexure test, and area fraction of adherent porcelain (AFAP) was determined by X-ray spectroscopy. RESULTS: EDS analyses revealed a substantial amount (13-17 wt%) of Al on the control, and specimens modified with Methods 2, 4, and 6. XRD revealed residual stress in the titanium surfaces and corundum on the control, and Methods 2, 4, and 6 specimens. A new Ti(Cu, Al)2 phase was identified on the titanium surfaces modified by immersion in 50% NaOH-10% CuSO4 x 5H2O aqueous solution. Reduced residual stress was observed on Method 1, 3, and 5 specimens. No corundum peaks were detected on these specimens. Compared to the control, significantly lower (P < 0.05) hardness values were found for Methods 1-3 and Method 5 specimens at 20 microm below the surfaces and for Method 1-5 specimens at 50 microm below the surfaces. Significantly higher (P < 0.05) AFAP values were found for surfaces modified with Methods 2-6 compared to the control and Method 1, and no significant differences were found among Methods 1-6, and between control and Method 1. SIGNIFICANCE: Based on the results from the present study, porcelain adherence to cast CP titanium can be improved by the caustic baths used in the study.

Dental Casting Investment↗

Recurrent conjunctivitis as a presentation of munchausen syndrome by proxy.

PURPOSE: To report a case of Munchausen syndrome by proxy, which manifested as recurrent bilateral keratoconjunctivitis in an infant. DESIGN: Interventional case report. INTERVENTION: The patient underwent numerous diagnostic studies, including two endoscopies, skin biopsy, conjunctival pH measurement, and a skeletal survey. She underwent daily eye examinations until the corneal and conjunctival epithelial defects resolved. MAIN OUTCOME MEASURE: Resolution of cutaneous, mucosal, corneal, and conjunctival epithelial defects. RESULTS: A punch biopsy of the right postauricular area was performed, and pathology subsequently determined that the findings seemed to be the result of an exogenous injury. The conjunctival pH was 8.0, consistent with exposure to an exogenous, caustic agent. The acute ocular lesions resolved. CONCLUSIONS: Munchausen syndrome by proxy can be seen with ophthalmic manifestations and should be considered in the differential diagnosis when ocular abnormalities cannot be explained after a thorough and methodical evaluation.

Conjunctivitis↗

Granular myringitis in children.

BACKGROUND: Granular myringitis (GM), described mainly in adults, is considered a rare infection of the tympanic membrane (TM) with possible involvement of the external ear canal. The study was aimed to evaluate the clinical characteristics of the disease in children. MATERIAL: A 2-year prospective study on all children with GM in a primary otolaryngology practice affiliated to a tertiary academic medical center. GM was defined by de-epithelization of the TM, granulation-tissue formation and discharge. Children with otitis media were excluded. Treatment included topical application of ear drops, caustic solution in unresponsive cases and mechanical removal of polypoidal granulations. RESULTS: Nine children, five boys and four girls, aged 3--16 (mean=11.5 years) were diagnosed as GM. Mainly plugged ear (6) and aural discharge (5) presented GM. Only a circumscribed area of the pars tensa was involved. GM was expressed either by a tiny shallow lesion (6) or by raised polypoidal masses (3). All children recovered within 2--11 weeks (mean 3.6). Recurrent infection was noted twice in one child. Small dry perforation of the TM was noted in two children. Histopathological studies revealed non specific acute and chronic inflammatory reaction. CONCLUSIONS: Granular myringitis must be recognized in children. GM has a benign course responding to topical treatment. It may be misidentified as persistent chronic suppurative otitis media with polyps protruding through the TM. Although perforation of the TM may develop in the course of the disease, the middle ear remained intact.

Child↗

The changing indications for paediatric tracheostomy.

OBJECTIVE: To investigate whether the incidence and indications for paediatric tracheostomy in this unit have changed over recent years. METHODS: All paediatric tracheostomies performed between 1993 and 2001 were identified from our departmental database. The indications for these were ascertained by retrospective case note review. RESULTS: Over the 9-year period studied 362 tracheostomies were performed, the number increased slightly between the first and second half of the period, with peaks in 1997 and 1999. The commonest indication was prolonged ventilation due to neuromuscular or respiratory problems. CONCLUSIONS: This large series shows that the increase in frequency of paediatric tracheostomy performed in this unit over the past decade has been due to conditions such as subglottic and tracheal stenosis, respiratory papillomatosis, caustic alkali ingestion and craniofacial syndromes. Conditions in which tracheostomy are now less common are subglottic haemangioma and laryngeal clefts. Prolonged ventilation remains the commonest indication overall.

Catchment Area, Health↗

Accidental ingestion of liquid zinc chloride: local and systemic effects.

The case of a 24-year-old man who accidentally ingested liquid zinc chloride is presented. Local caustic effects included erosive pharyngitis and esophagitis. Nausea, vomiting and abdominal pain, as well as hypocalcemia and hyperamylasemia, suggested acute pancreatitis. Microhematuria occurred, but renal function did not deteriorate. Lethargy and confusion, noted previously in another case of hyperzincemia, were present. Chelation therapy was instituted, with reversal of the clinical and biochemical effects of zinc poisoning.

Acute Disease↗

Metabolic abnormalities associated with phosphoric acid ingestion.

A 64-year-old man ingested a phosphoric acid solution in a suicide attempt. He subsequently developed hyperphosphatemia, hypocalcemia, and systemic metabolic acidosis. Local caustic effects of the acid were mild. The patient recovered and was lost to follow-up.

Aluminum Hydroxide↗

Copper deficiency with pancytopenia due to enteral nutrition through jejunostomy.

Copper deficiency is a rare complication of enteral nutrition. Haematologic abnormalities such as neutropenia and anaemia, but not pancytopenia, have been described associated to copper deficiency. We report the case of a patient requiring long term enteral nutrition through jejunostomy who developed copper deficiency and pancytopenia. In 1991, a 47-year-old woman was admitted with severe gastroesophageal mucositis after an attempted suicide with caustic intake. Enteral nutrition with a commercial, polymeric, fiber-containing formula was started. Twenty-eight months later, the patient developed anemia and neutropenia that did not respond to combined iron and parenteral vitamin B(12) supplementation. In 1996 the patient showed pancytopenia and low serum levels of copper and ceruloplasmin. Pancytopenia improved after copper supplementation. Possible mechanism causing copper deficiency and pancytopenia are discussed. We conclude that assessment of copper status is advisable in patients receiving long-term enteral nutrition by jejunostomy.

Journal Article↗

Evaluation of modified methods for determining skin irritation.

The premarket testing of household cleaning products for dermal irritancy is best achieved via human testing. Animal dermal irritation testing is generally limited to screening for possible dermal hazard of totally new or unique products or ingredients prior to human testing or to meeting regulatory requirements of government bodies. Alternatives to animal tests are being sought; however, until such time that these alternatives are identified, validated, and accepted by government bodies, the judicious use of animal testing remains a necessity. Modifications to standard animal skin irritation test procedures have been evaluated against human skin irritation results with the objective of defining one method that could be used in place of current standard procedures that differ slightly from one another, and thereby avoid excessive and redundant use of animals. Hill Top Chambers (19 mm) and standard gauze patches (U.S. Department of Transportation procedure) were used to obtain comparative irritation responses for 24 cleaning products, common caustics, and acids in rabbits and humans. Exposure times were 1 or 4 hr, and responses were graded over a 72-hr period. Results indicate that use of the Chamber offers the potential to (1) reduce the number of animals used for skin irritation screening (smaller group size and up to eight test substances/concentrations per animal); (2) eliminate the need for conducting multiple tests to satisfy different governmental requirements; and (3) reduce animal stress by reducing exposure times without compromising the value of the irritancy patch test as a screening tool. When animal data are required, it is suggested that the use of a Chamber and other modifications of traditional test procedures offers advantages that could result in using fewer animals and/or have less potential for producing unnecessarily severe responses in animals.

Animals↗

Oxidation of nitric oxide in a two-stage chemical scrubber using dc corona discharge.

The dc corona was studied as an alternative for NO oxidation in a two-stage chemical scrubber. The dc corona plasma reactor completely oxidized 150ppm of NO to NO2 in an air stream. The NO2 was further oxidized at a higher voltage. For some cases, the NO2 in the effluents of the plasma reactor was absorbed quantitatively by a caustic sodium sulfite aqueous solution in a 2l bubble column gas absorber. The outlet concentrations of both NO and NO2 from the plasma-scrubber combination system (corona-induced chemical scrubber) were below the detection limit of the chemiluminescent NOx analyzer.

Air Pollutants↗

Prolonged intermittent hydrotherapy and early tangential excision in the treatment of an extensive strong alkali burn.

It is well known that the first step in the treatment of cutaneous strong alkali burn is very early and persistent washing of the site of injury with large volumes of water. However, ideal duration and the technique of hydrotherapy has not yet been established. Besides hydrotherapy, tangential excision of the injured skin might prevent further tissue damage if it is performed early enough. We report the treatment of a 36-year-old male who sustained 53% body surface area (BSA) cutaneous burn due to caustic soda (NaOH). Prolonged intermittent hydrotherapy, early tangential excision and autografting of the injured skin are the keys for the proper management of extensive strong alkali burn.

Accidents, Occupational↗

Epidemiology of hospitalized burns patients in Taiwan.

Previous studies based on either single hospital data or sampling of specific groups of hospitalized burns victims in Taiwan have provided only minimal epidemiological information. The study is designed to provide additional data on the epidemiology of hospitalized burns patients in Taiwan. Data were obtained from the Burn Injury Information System (BIIS), which brings together information supplied by 34 contracted hospitals. The study time course spanned a 2-year period from July 1997 to June 1999. Patient characteristics (age, sex, education level, etc.), causes and severity of injuries, and medical care measures were explored. A total of 4741 patients were registered with BIIS over the study period. The majority of hospitalized patients (67%) were male. The age distribution of burns patients showed peaks occurring at the age groups of 0-5 and 35-44 years. Over the time course of a day, burn injuries occurred more frequently from 10:00 to 12:00 h and 16:00 to 18:00 h. Injuries suspected as the result of suicide, homicide or child abuse accounted for 4.8% of hospitalized cases. More than 48% of the burns occurred in the home. The leading type of burn injury was scalding, followed by naked flame, explosion, electrical burns, and chemical burns due to caustic or corrosive substances. The mean percent total body surface area (%TBSA) for adults was 19%, and for young children was 12%. The average length of hospital stay was 18 days. In conclusion, children under 5 years and adults between 35 and 44 years of age are two high-risk groups for burn injuries. Corresponding to meal preparation time, hot substances such as boiling water, hot soup, etc. are the most common agents responsible for scalds. Prevention programs for reducing the risk of burn injuries during cooking and eating are required, especially for parents with young children.

Accidents, Home↗

Simple alkaline treatment induces intestinal metaplasia in the stomach of rats.

By infusing caustic soda (NaOH) into the stomach of rats, the gastric mucosa fell off and regeneration could be induced. In 18 of 26 rats, intestinal metaplasia associated with goblet cells was observed in the regenerative epithelium. Recently, induction of intestinal metaplasia by weak carcinogenic agents are reported with some emphasis on its precancerous meaning. However, our results suggest that, as intestinal metaplasia can be induced by a benign process of regeneration, it is not directly related with carcinogenesis.

Animals↗

Functional and corrective claw trimming.

Foot care and claw trimming require proper systems for restraint, sharp knives and trimming equipment, and an understanding of the biomechanics of weight bearing and hoof overgrowth in cattle. The objective of functional claw trimming is to correct hoof overgrowth, thereby re-establishing appropriate weight bearing within and between the claws of each foot. Traditional trimming methods fail to achieve these objectives. Corrective trimming procedures are applied to horn lesions affecting the claw capsule. Primary objectives of corrective trimming are to adjust weight bearing to provide rest for diseased claws and to remove loose horn and hard ridges that may cause further injury to the corium. The application of a foot block to the healthy claw is a valuable aid in foot care when corrective trimming alone is insufficient to provide needed relief from weight bearing. Finally, the use of topical treatments under a bandage is controversial. It is recommended that caustic treatments be avoided and that the use of a bandage be limited to conditions requiring hemostasis or when operators are committed to their removal within a period of 2 to 5 days depending on the level of environmental contamination.

Animal Husbandry↗