Neurological involvement in hospitalized children with SARS-CoV-2 infection: a multinational study.

BACKGROUND AND OBJECTIVES: Neurological involvement associated with SARS-CoV-2 infection is increasingly recognized. However, the specific characteristics and prevalence in pediatric patients remain unclear. The objective of this study was to describe the neurological involvement in a multinational cohort of hospitalized pediatric patients with SARS-CoV-2. METHODS: This was a multicenter observational study of children <18 years of age with confirmed SARS-CoV-2 infection or multisystemic inflammatory syndrome (MIS-C) and laboratory evidence of SARS-CoV-2 infection in children, admitted to 15 tertiary hospitals/healthcare centers in Canada, Costa Rica, and Iran February 2020-May 2021. Descriptive statistical analyses were performed and logistic regression was used to identify factors associated with neurological involvement. RESULTS: One-hundred forty-seven (21%) of 697 hospitalized children with SARS-CoV-2 infection had neurological signs/symptoms. Headache (n = 103), encephalopathy (n = 28), and seizures (n = 30) were the most reported. Neurological signs/symptoms were significantly associated with ICU admission (OR: 1.71, 95% CI: 1.15-2.55; p = 0.008), satisfaction of MIS-C criteria (OR: 3.71, 95% CI: 2.46-5.59; p < 0.001), fever during hospitalization (OR: 2.15, 95% CI: 1.46-3.15; p < 0.001), and gastrointestinal involvement (OR: 2.31, 95% CI: 1.58-3.40; p < 0.001). Non-headache neurological manifestations were significantly associated with ICU admission (OR: 1.92, 95% CI: 1.08-3.42; p = 0.026), underlying neurological disorders (OR: 2.98, 95% CI: 1.49-5.97, p = 0.002), and a history of fever prior to hospital admission (OR: 2.76, 95% CI: 1.58-4.82; p < 0.001). DISCUSSION: In this study, approximately 21% of hospitalized children with SARS-CoV-2 infection had neurological signs/symptoms. Future studies should focus on pathogenesis and long-term outcomes in these children.

SARS-CoV-2 infection in technology-dependent children: a multicenter case series.

PURPOSE: The objective of this study was to describe the clinical course and outcomes in children with technology dependence (TD) hospitalized with SARS-CoV-2 infection. METHODS: Seventeen pediatric hospitals (15 Canadian and one each in Iran and Costa Rica) included children up to 17 years of age admitted February 1, 2020, through May 31, 2021, with detection of SARS-CoV-2. For those with TD, data were collected on demographics, clinical course and outcome. RESULTS: Of 691 children entered in the database, 42 (6%) had TD of which 22 had feeding tube dependence only, 9 were on supplemental oxygen only, 3 had feeding tube dependence and were on supplemental oxygen, 2 had a tracheostomy but were not ventilated, 4 were on non-invasive ventilation, and 2 were on mechanical ventilation prior to admission. Three of 42 had incidental SARS-CoV-2 infection. Two with end-stage underlying conditions were transitioned to comfort care and died. Sixteen (43%) of the remaining 37 cases required increased respiratory support from baseline due to COVID-19 while 21 (57%) did not. All survivors were discharged home. CONCLUSION: Children with TD appear to have an increased risk of COVID-19 hospitalization. However, in the absence of end-stage chronic conditions, all survived to discharge.

Predictors of severe illness in children with multisystem inflammatory syndrome after SARS-CoV-2 infection: a multicentre cohort study.

BACKGROUND: SARS-CoV-2 infection can lead to multisystem inflammatory syndrome in children (MIS-C). We sought to investigate risk factors for admission to the intensive care unit (ICU) and explored changes in disease severity over time. METHODS: We obtained data from chart reviews of children younger than 18 years with confirmed or probable MIS-C who were admitted to 15 hospitals in Canada, Iran and Costa Rica between Mar. 1, 2020, and Mar. 7, 2021. Using multivariable analyses, we evaluated whether admission date and other characteristics were associated with ICU admission or cardiac involvement. RESULTS: Of 232 children with MIS-C (median age 5.8 yr), 130 (56.0%) were male and 50 (21.6%) had comorbidities. Seventy-three (31.5%) patients were admitted to the ICU but none died. We observed an increased risk of ICU admission among children aged 13-17 years (adjusted risk difference 27.7%, 95% confidence interval [CI] 8.3% to 47.2%), those aged 6-12 years (adjusted risk difference 25.2%, 95% CI 13.6% to 36.9%) or those with initial ferritin levels greater than 500 µg/L (adjusted risk difference 18.4%, 95% CI 5.6% to 31.3%). Children admitted to hospital after Oct. 31, 2020, had numerically higher rates of ICU admission (adjusted risk difference 12.3%, 95% CI -0.3% to 25.0%) and significantly higher rates of cardiac involvement (adjusted risk difference 30.9%, 95% CI 17.3% to 44.4%). At Canadian sites, the risk of ICU admission was significantly higher for children admitted to hospital between December 2020 and March 2021 than those admitted between March and May 2020 (adjusted risk difference 25.3%, 95% CI 6.5% to 44.0%). INTERPRETATION: We observed that age and higher ferritin levels were associated with more severe MIS-C. We observed greater severity of MIS-C later in the study period. Whether emerging SARS-CoV-2 variants pose different risks of severe MIS-C needs to be determined.

Infants hospitalized for acute COVID-19: disease severity in a multicenter cohort study.

Age is the most important determinant of COVID-19 severity. Infectious disease severity by age is typically J-shaped, with infants and the elderly carrying a high burden of disease. We report on the comparative disease severity between infants and older children in a multicenter retrospective cohort study of children 0 to 17 years old admitted for acute COVID-19 from February 2020 through May 2021 in 17 pediatric hospitals. We compare clinical and laboratory characteristics and estimate the association between age group and disease severity using ordinal logistic regression. We found that infants comprised one-third of cases, but were admitted for a shorter period (median 3 days IQR 2-5 versus 4 days IQR 2-7), had a lower likelihood to have an increased C-reactive protein, and had half the odds of older children of having severe or critical disease (OR 0.50 (95% confidence interval 0.32-0.78)).    Conclusion: When compared to older children, there appeared to be a lower threshold to admit infants but their length of stay was shorter and they had lower odds than older children of progressing to severe or critical disease. What is Known: • A small proportion of children infected with SARS-CoV-2 require hospitalization for acute COVID-19 with a subgroup needing specialized intensive care to treat more severe disease. • For most infectious diseases including viral respiratory tract infections, disease severity by age is J-shaped, with infants having more severe disease compared to older children. What is New: • One-third of admitted children for acute COVID-19 during the first 14 months of the pandemic were infants. • Infants had half the odds of older children of having severe or critical disease.

Custom nasal stent and columellar reconstruction after a rhinoplasty complication: A clinical report.

Nostril stenosis is typically caused by retraction and contraction after trauma or infection, although loss of nasal tissue is not common during rhinoplasty. This clinical report describes the fabrication of a nasal stent to replace the lost columella and a columella prosthesis for a patient who had had reconstructive surgery for nasal valve collapse and a missing columella. The stent established a comfortable means of nasal air exchange that was also esthetically acceptable. The stent also provided the necessary support for the nasal tissue before further nasal reconstructive surgeries.

Global trends of hand and wrist trauma: a systematic analysis of fracture and digit amputation using the Global Burden of Disease 2017 Study.

BACKGROUND: As global rates of mortality decrease, rates of non-fatal injury have increased, particularly in low Socio-demographic Index (SDI) nations. We hypothesised this global pattern of non-fatal injury would be demonstrated in regard to bony hand and wrist trauma over the 27-year study period. METHODS: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 was used to estimate prevalence, age-standardised incidence and years lived with disability for hand trauma in 195 countries from 1990 to 2017. Individual injuries included hand and wrist fractures, thumb amputations and non-thumb digit amputations. RESULTS: The global incidence of hand trauma has only modestly decreased since 1990. In 2017, the age-standardised incidence of hand and wrist fractures was 179 per 100 000 (95% uncertainty interval (UI) 146 to 217), whereas the less common injuries of thumb and non-thumb digit amputation were 24 (95% UI 17 to 34) and 56 (95% UI 43 to 74) per 100 000, respectively. Rates of injury vary greatly by region, and improvements have not been equally distributed. The highest burden of hand trauma is currently reported in high SDI countries. However, low-middle and middle SDI countries have increasing rates of hand trauma by as much at 25%. CONCLUSIONS: Certain regions are noted to have high rates of hand trauma over the study period. Low-middle and middle SDI countries, however, have demonstrated increasing rates of fracture and amputation over the last 27 years. This trend is concerning as access to quality and subspecialised surgical hand care is often limiting in these resource-limited regions.

Epidemiology of facial fractures: incidence, prevalence and years lived with disability estimates from the Global Burden of Disease 2017 study.

BACKGROUND: The Global Burden of Disease Study (GBD) has historically produced estimates of causes of injury such as falls but not the resulting types of injuries that occur. The objective of this study was to estimate the global incidence, prevalence and years lived with disability (YLDs) due to facial fractures and to estimate the leading injurious causes of facial fracture. METHODS: We obtained results from GBD 2017. First, the study estimated the incidence from each injury cause (eg, falls), and then the proportion of each cause that would result in facial fracture being the most disabling injury. Incidence, prevalence and YLDs of facial fractures are then calculated across causes. RESULTS: Globally, in 2017, there were 7 538 663 (95% uncertainty interval 6 116 489 to 9 493 113) new cases, 1 819 732 (1 609 419 to 2 091 618) prevalent cases, and 117 402 (73 266 to 169 689) YLDs due to facial fractures. In terms of age-standardised incidence, prevalence and YLDs, the global rates were 98 (80 to 123) per 100 000, 23 (20 to 27) per 100 000, and 2 (1 to 2) per 100 000, respectively. Facial fractures were most concentrated in Central Europe. Falls were the predominant cause in most regions. CONCLUSIONS: Facial fractures are predominantly caused by falls and occur worldwide. Healthcare systems and public health agencies should investigate methods of all injury prevention. It is important for healthcare systems in every part of the world to ensure access to treatment resources.

Concomitant Overlap Steal Tip-plasty: A Versatile Technique to Simultaneously Adjust the Rotation, Definition, Projection, and Symmetry of the Nasal Tip.

BACKGROUND: Tip-plasty is a particularly challenging stage of aesthetic nose surgery. The diversity of nasal tip deformities has necessitated the development of numerous surgical techniques that can be difficult to master and may yield unpredictable surgical results when combined. OBJECTIVES: The authors describe how concomitant overlap steal tip-plasty (COST) can enable surgeons to address all of the aesthetic characteristics of the nasal tip simultaneously. COST involves lateral crural steal followed by medial crural overlap. METHODS: The medical records of 1617 patients who underwent primary open septorhinoplasty with COST were evaluated in a retrospective study. Pre- and postoperative patient photographs were compared for nasal length, nasolabial angle, tip projection, and deviation of the nasal axis. RESULTS: Pre- and postoperative mean nasal lengths were 5.66 cm and 5.17 cm, respectively (P < .05). The mean nasolabial angle was 86.95° preoperatively and 101.8° postoperatively (P < .05). The projection of the nasal tip was reduced from 3.09 cm to 2.53 cm, and tip symmetry was achieved by decreasing the nasal axis deviation from 7.76° to 1.71° (both P < .05). CONCLUSIONS: COST does not obviate all other tip-plasty techniques for specific situations. Once mastered, however, COST can become the only procedure needed to achieve all of the aesthetic goals of the nasal tip in most cases. LEVEL OF EVIDENCE 4: Therapeutic.

In vitro differentiation of adipose-tissue-derived mesenchymal stem cells into neural retinal cells through expression of human PAX6 (5a) gene.

The neural retina is subjected to various degenerative conditions. Regenerative stem-cell-based therapy holds great promise for treating severe retinal degeneration diseases, although many drawbacks remain to be overcome. One important problem is to gain authentically differentiated cells for replacement. Paired box 6 protein (5a) (PAX6 (5a)) is a highly conserved master control gene that has an essential role in the development of the vertebrate visual system. Human adipose-tissue-derived stem cell (hADSC) isolation was performed by using fat tissues and was confirmed by the differentiation potential of the cells into adipocytes and osteocytes and by their surface marker profile. The coding region of the human PAX6 (5a) gene isoform was cloned and lentiviral particles were propagated in HEK293T. The differentiation of hADSCs into retinal cells was characterized by morphological characteristics, quantitative real-time reverse transcription plus the polymerase chain reaction (qPCR) and immunocytochemistry (ICC) for some retinal cell-specific and retinal pigmented epithelial (RPE) cell-specific markers. hADSCs were successfully isolated. Flow cytometric analysis of surface markers indicated the high purity (~97 %) of isolated hADSCs. After 30 h of post-transduction, cells gradually showed the characteristic morphology of neuronal cells and small axon-like processes emerged. qPCR and ICC confirmed the differentiation of some neural retinal cells and RPE cells. Thus, PAX6 (5a) transcription factor expression, together with medium supplemented with fibronectin, is able to induce the differentiation of hADSCs into retinal progenitors, RPE cells and photoreceptors.

The Road Less Traveled: The Marham National Health Institute's Journey on Cleft Lip and Palate Surgery Missions.

Congenital cleft lip and palate represent the prevailing craniofacial birth anomalies on a global scale. Notably, a substantial proportion of patients within remote regions of Iran defer corrective surgery until later stages of life, often in childhood or adulthood, primarily due to intricate financial and cultural constraints. In response to this pressing healthcare challenge, a dedicated collective of volunteer plastic surgeons was established in 2009 with the explicit aim of providing medical care to these underserved patients. Over the subsequent years, this compassionate team embarked on 31 meticulously planned missions to underprivileged areas scattered across the country. Through these organized endeavors, a remarkable total of 20,579 medical visits were conducted, coupled with the performance of 2,303 essential surgeries, thus offering a lifeline of healthcare to these disadvantaged individuals.

Assessment of Maxillary Sinus Variations Post-LeFort: A Systematic Review.

Background: The purpose of this article was to systematically review maxillary sinus changes after LeFort. We examined and analyzed the anatomical abnormalities that occurred following LeFort I osteotomy, as well as the abnormalities of maxillary sinus volume (MSV) before and after the operation. Methods: A systematic search was conducted on various databases, such as Google Scholar, PubMed, and Scopus. The articles used were in English and original. This study was conducted until September 2023, and after reviewing the articles, several keywords, such as "Maxillary sinus" and "LeFort I osteotomy", were employed. The obtained data were evaluated based on the PICO framework. Results: Findings from 15 studies showed that the amount of MSV decreased before and after the operation (considering the three dimensions of the sinus, the measurement was performed linearly). These reduction values differed between men and women, with men having a greater reduction. As is the case with other operations, there were some side effects associated with this type of operation that some patients experienced postoperatively. Conclusion: In both male and female patients, the MSV was reduced after one-piece and multi-segment osteotomies. Nonetheless, one-piece LeFort I osteotomy showed a higher reduction in MSV than the multi-segment osteotomy method, according to this systematic review and meta-analysis.

The Causes and Prevalence of Maxillofacial Fractures in Iran: A Systematic Review.

Background: Maxillofacial fractures are a common type of injury that can result in significant morbidity and mortality. We aimed to systematically review the literature on the prevalence and causes of maxillofacial fractures in Iran to estimate the overall prevalence of maxillofacial fractures and the most common causes. Methods: A systematic search of PubMed, Cochrane Library, Web of Science (WS) and Google Scholar (GS) electronic databases was conducted to identify relevant articles published up to January 2023. Studies reporting the prevalence and causes of maxillofacial fractures in Iran were included in the analysis. MOOSE guidelines were adopted for the current systematic review. No data or language restriction were applied. Risk of bias across the articles was assessed. Results: A total of 32 studies comprising 35,720 patients were included in the analysis. The most common cause of maxillofacial fractures was road traffic accidents (RTAs), accounting for 68.97% of all cases, followed by falls (12.62%) and interpersonal violence (9.03%). The prevalence of maxillofacial fractures was higher in males (81.04%) and in the age group of 21-30 years (43.23%). Risk of bias across studies was considered low. Conclusion: Maxillofacial fractures are a significant public health problem in Iran, with a high prevalence and RTAs being the leading cause. These results highlight the need for increased efforts to prevent maxillofacial fractures in Iran, especially through measures to reduce the incidence of RTAs.

The Effect of Covid-19-Related Social Distancing Restrictions on Maxillofacial Fractures Epidemiology.

Background: The purpose of the present study was to evaluate the changes in maxillofacial fracture epidemiology and etiology regarding Covid-19-related social distancing restrictions in an Iranian population. Methods: A retrospective cross-sectional study was undertaken in six major trauma center hospitals in Iran in a period of two years (March 2018 until March 2020). The primary outcome variable was the maxillofacial fractures incidence. Patients' demographic data, date of injury as well as fracture characteristics, fracture etiology, type, and site were all recorded, compared, and analyzed in the control and experimental groups. Results: The patients consisted of 520 (83.6%) males and 102 (16.4%) females. Patients sustaining maxillofacial fractures over this two-year period displayed a mean age of 31.24±14.44, with an age range of 2 to 88 years. The incidence of maxillofacial fractures significantly decreased in all age groups (p<0.001). After social distancing restrictions were placed; there was a significant drop in the number of subjects attending due to motorcycle collisions and road traffic accidents, whereas the number of fractures caused by assaults and domestic violence significantly increased (p<0.001 for each). Conclusion: The investigators realized that social distancing restrictions were able to change the trends and patterns in maxillofacial fracture incidence and etiology.

Treatment Options of Maxillofacial Fractures in Iran: A Comprehensive Systematic Review.

Background: The aim of this study was to systematically review the literature on the treatment options of maxillofacial fractures in Iran, complementing a previous article regarding causes and the overall prevalence. Methods: A systematic search of PubMed, Cochrane Library, Web of Science (WS) and Google Scholar (GS) electronic databases was conducted to identify the relevant articles published up to January 2023. Studies reporting the treatment option of maxillofacial fractures in Iran were included in the analysis. MOOSE guidelines were adopted for the current systematic review. No data or language restriction were applied. Risk of bias across the articles was assessed. Results: This systematic review included 13 articles with a total of 19,147 treated patients for maxillofacial fractures. ORIF was the most common type of treatment, but complications occurred in approximately 5% of cases. Mandible fractures were not statistically more treated by ORIF than closed reduction or conservative treatment, and no type of treatment was considered statistically preferable depending on the anatomical region affected by Iranian maxillofacial surgeons. The included studies were considered to have a low risk of bias, but many were not clear in reporting cross-referenced data regarding the type of treatment, which could be considered a major flaw. Conclusion: Overall, this study provides valuable insights into the types of treatment used for maxillofacial fractures by Iranian surgeons and highlights the importance of clear reporting of data in research articles.

A mechanistic study on the effect of ethanol and importance of water on permeation of drugs through human third-degree burn eschar.

Ethanol that affects hydration of skin and used in wound treatment formulations was studied here for its effect on permeation of drugs through burn eschar and to investigate the presence of a porous pathway in this barrier. In this study, permeations of clindamycin phosphate (CP, hydrophilic) and diazepam (lipophilic) through human burn eschar were investigated in the presence and absence of ethanol. Permeability coefficients (K(p) ) of CP and diazepam through hydrated eschar were calculated to be 13·1 × 10(-3) and 17·4 × 10(-3) cm/h respectively. These K(p) values were decreased by about 1·5-5·3 and 2-10·7 times respectively upon the addition of 20-70% ethanol. Increased amount of ethanol decreased permeation flux of CP (2-20 times) and increased that of diazepam (3-80 times) from saturated solutions. Thermal analysis showed that ethanol dehydrates eschar and also changes its internal proteineous structure. Such changes were concluded to be the main reasons behind decreased K(p) of both drugs. Comparison of K(p) data suggests the possibility and importance of a pore pathway in permeation of both drugs through the hydrated burn eschar. Present results show that ethanol, and possibly other dehydrating agents, can decrease the permeability of eschar and that this effect should be considered in formulation developments.

Risk factors for severe PCR-positive SARS-CoV-2 infection in hospitalised children.

OBJECTIVE: To identify risk factors for severe disease in children hospitalised for SARS-CoV-2 infection. DESIGN: Multicentre retrospective cohort study. SETTING: 18 hospitals in Canada, Iran and Costa Rica from 1 February 2020 to 31 May 2021. PATIENTS: Children<18 years of age hospitalised for symptomatic PCR-positive SARS-CoV-2 infection, including PCR-positive multisystem inflammatory syndrome in children (MIS-C). MAIN OUTCOME MEASURE: Severity on the WHO COVID-19 Clinical Progression Scale was used for ordinal logistic regression analyses. RESULTS: We identified 403 hospitalisations. Median age was 3.78 years (IQR 0.53-10.77). At least one comorbidity was present in 46.4% (187/403) and multiple comorbidities in 18.6% (75/403). Eighty-one children (20.1%) met WHO criteria for PCR-positive MIS-C. Progression to WHO clinical scale score ≥6 occurred in 25.3% (102/403). In multivariable ordinal logistic regression analyses adjusted for age, chest imaging findings, laboratory-confirmed bacterial and/or viral coinfection, and MIS-C diagnosis, presence of a single (adjusted OR (aOR) 1.90, 95% CI 1.13 to 3.20) or multiple chronic comorbidities (aOR 2.12, 95% CI 1.19 to 3.79), obesity (aOR 3.42, 95% CI 1.76 to 6.66) and chromosomal disorders (aOR 4.47, 95% CI 1.25 to 16.01) were independent risk factors for severity. Age was not an independent risk factor, but different age-specific comorbidities were associated with more severe disease in age-stratified adjusted analyses: cardiac (aOR 2.90, 95% CI 1.11 to 7.56) and non-asthma pulmonary disorders (aOR 3.07, 95% CI 1.26 to 7.49) in children<12 years old and obesity (aOR 3.69, 1.45-9.40) in adolescents≥12 years old. Among infants<1 year old, neurological (aOR 10.72, 95% CI 1.01 to 113.35) and cardiac disorders (aOR 10.13, 95% CI 1.69 to 60.54) were independent predictors of severe disease. CONCLUSION: We identified risk factors for disease severity among children hospitalised for PCR-positive SARS-CoV-2 infection. Comorbidities predisposing children to more severe disease may vary by age. These findings can potentially guide vaccination programmes and treatment approaches in children.

Unacceptable results with an accepted soft tissue filler: polyacrylamide hydrogel.

BACKGROUND: Polyacrylamide hydrogel, considered a safe and biocompatible soft tissue filler, is widely used in cosmetic procedures. Its use for facial contouring and breast augmentation in Iran has increased dramatically in recent years. Most patients and many doctors are unaware of possible and reported adverse effects related to its administration. METHODS: This study enrolled 98 patients experiencing unsatisfactory results and complications of polyacrylamide hydrogel. Adverse effects related to gel administration were documented for all the patients. Lab values were requested together with related medical care and surgical treatments, and gel was extracted by incision, milking, and irrigation. RESULTS: The most common findings at the time of presentation were inflammation (n = 51), asymmetry (n = 31), irregularity (n = 18), infection and abscess formation (n = 11), and gel migration (n = 8). In one patient, severe anaphylactoid reaction was observed 1 week after gel injection, which led to significant complications for the patient. Histologic findings showed granuloma formation (n = 17), fat necrosis (n = 9), and fibrosis (n = 17). Macroscopic gel-related complications resolved after extraction of the injected material, except for skin necrosis and hyperpigmentation, which remained unchanged. For eight patients, the gel could not be extracted by squeezing and irrigation entirely. Three patients experienced gel reaccumulation after seemingly complete removal of the gel. CONCLUSIONS: A wide range of complications seen among our patients showed that polyacrylamide hydrogel may not be as safe and biocompatible as it was thought previously. Both patients and physicians must be aware of the potential side effects of polyacrylamide hydrogel before gel administration.

Active immunization using exotoxin A confers protection against Pseudomonas aeruginosa infection in a mouse burn model.

BACKGROUND: Pseudomonas aeruginosa is an important cause of nosocomial infection and may lead to septicemia and death. We evaluated the immunogenicity of semi-purified exotoxin A from the bacterium in a mouse burn model. METHODS: The toxoid was prepared from exotoxin A taken from toxigenic strains of P. aeruginosa (PA 103). 50 mice were immunized with the toxoid, burned with hot metal and infected with 1 x 10(8) CFU of toxigenic strains of P. aeruginosa (experimental group); 25 non-immunized mice were also burned and infected (control group). The mortality rate and presence of any exotoxin and P. aeruginosa in the sera, liver and spleen were determined. RESULTS: In the experimental group, 2 mice died before the burns were administered and were excluded from the study. The remainder (48 mice) were challenged with a lethal dose of P. aeruginosa and followed for 70 days. 3 of these mice died. Neither P. aeruginosa nor exotoxin A was not detected in the liver, spleen or sera of the surviving mice. The protective efficacy of toxoid vaccination was therefore 93.8%. In the control group, all mice died from bacteremia and septicemia, most (80%) within 6 days, and P. aeruginosa and exotoxin A were isolated from sera, spleen and liver. CONCLUSION: Active immunization of mice using a semi-purified exotoxin A derived from P. aeruginosa was 93.8% effective at protecting mice from subsequent P. aeruginosa infections in a mouse burn model.

Enhancing drugs absorption through third-degree burn wound eschar.

Antimicrobial therapy remains the most important method of wound infection treatment. Systemically administered antimicrobials may not achieve therapeutic levels in wound. On the other hand, some topically applied antimicrobials cannot penetrate eschar well enough. Therefore, an attempt has been made here to increase permeation of topically applied drugs through eschar using the so-called skin penetration enhancers. To perform this investigation, effects of different potential penetration enhancers on permeation of chlorhexidine, silver sulfadiazine and nitroglycerin through human third-degree burn eschar was evaluated. Results showed that water, glycerin, saline, sodium lauryl sulphate (SDS) and ethanol tend to reduce permeation of chlorhexidine through burn eschar. But, water, glycerin, hexane:ethanol and ethyl acetate:ethanol were able to increase permeation of silver sulfadiazine significantly by about 1.2-1.8 times, while saline, SDS and dimethyl sulfoxide were not able to change its permeation. Glycine showed 2.7 times enhancement toward permeation of nitroglycerin, followed by water, hexane:ethanol mixture, saline and SDS with enhancement ratios of 1.8-2.3. Urea, ethanol and citral were not able to increase permeation of nitroglycerin through eschar. This study shows that permeation of drugs through burn eschar can be improved by penetration enhancement including hydration; the effect depends on the nature of the penetrant.