• Title/Summary/Keyword: Experimental infection

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Long-term clinical and experimental/surface analytical studies of carbon/carbon maxillofacial implants

  • Szabo, Gyorgy;Barabas, Jozsef;Bogdan, Sandor;Nemeth, Zsolt;Sebok, Bela;Kiss, Gabor
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.37
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    • pp.34.1-34.14
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    • 2015
  • Background: Over the past 30-40 years, various carbon implant materials have become more interesting, because they are well accepted by the biological environment. The traditional carbon-based polymers give rise to many complications. The polymer complication may be eliminated through carbon fibres bound by pyrocarbon (carbon/carbon). The aim of this study is to present the long-term clinical results of carbon/carbon implants, and the results of the scanning electron microscope and energy dispersive spectrometer investigation of an implant retrieved from the human body after 8 years. Methods: Mandibular reconstruction (8-10 years ago) was performed with pure (99.99 %) carbon implants in 16 patients (10 malignant tumours, 4 large cystic lesions and 2 augmentative processes). The long-term effect of the human body on the carbon/carbon implant was investigated by comparing the structure, the surface morphology and the composition of an implant retrieved after 8 years to a sterilized, but not implanted one. Results: Of the 16 patients, the implants had to be removed earlier in 5 patients because of the defect that arose on the oral mucosa above the carbon plates. During the long-term follow-up, plate fracture, loosening of the screws, infection or inflammations around the carbon/carbon implants were not observed. The thickness of the carbon fibres constituting the implants did not change during the 8-year period, the surface of the implant retrieved was covered with a thin surface layer not present on the unimplanted implant. The composition of this layer is identical to the composition of the underlying carbon fibres. Residual soft tissue penetrating the bulk material between the carbon fibre bunches was found on the retrieved implant indicating the importance of the surface morphology in tissue growth and adhering implants. Conclusions: The surface morphology and the structure were not changed after 8 years. The two main components of the implant retrieved from the human body are still carbon and oxygen, but the amount of oxygen is 3-4 times higher than on the surface of the reference implant, which can be attributed to the oxidative effect of the human body, consequently in the integration and biocompatibility of the implant. The clinical conclusion is that if the soft part cover is appropriate, the carbon implants are cosmetically and functionally more suitable than titanium plates.

The Study on Wound Healing in Rabbit Skins by Low-intensity Laser Irradiation (저강도 레이저 조사에 의한 가토 피부의 상처 치유에 관한 연구)

  • 김식현;전진석
    • Biomedical Science Letters
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    • v.6 no.2
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    • pp.119-129
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    • 2000
  • The skin is an organ that has many important roles, including protection against infection, regulation of temperature and fluid loss, and sensory function. Injury to the skin, wound repair normally involves: (1) balanced activity of inflammation, (2) the re-epithelial phase and (3) the matrix formation of remodeling phase. Thus, skin wound healing is a finely controlled biological process involving a series of complex cellular interactions. Laser therapy is being implemented with increasing frequency in medicine. Low intensity laser is one that is capable of producing an energy density so low that any biologic alterations are the result of direct irradiation effect, not thermal events. This study was designed to evaluate the efficacy of low intensity laser therapy on skin wound healing in rabbits. A total of 10 male rabbits (New Zealand White Rabbit), age 8 weeks were used. Skin wound were surgically created dorso-lateral on the flank of 10 rabbits (2$\times$2 cm/damage areas). The experimental animals were treated with 5Hz (830 nm wave length) low-intensity laser (MILTA-01 Model) daily for 10 min (1.6 J/$cm^2$) for 12 days. Control animals were sham treated with the laser head. Laser irradiation animals showed a complete remodeling of the epithelial layer, a positive repair of connective tissues, and enhanced the wound closure rate over time as compared to the control animals. Especially, laser irradiation groups improved fibroblast activity, cellular content, granulation tissue formation, and collagen deposition which is resulted in improving the tensile strength of the wound. These findings suggest that laser photostimulation could accelerate healing of open wound in rabbits, and may be benefit in the treatment of open wound, including decubitis ulcers.

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Incidence of Vesicoureteral Reflux in Asymptomatic Siblings of Patients with Reflux (방광요관역류 환아의 무증상 형제 자매의 역류 빈도 조사)

  • Kim, Jong Shik;Koo, Ja Wook
    • Clinical and Experimental Pediatrics
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    • v.45 no.12
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    • pp.1540-1545
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    • 2002
  • Purpose : Vesicoureteral reflux(VUR) is defined as a retrograde flow of urine from the bladder into the upper urinary tract. It has been shown to predispose patients to hypertension, renal scarring, and end-stage renal failure if not recognized and treated. The observation that VUR occurs in siblings of children with reflux at a significantly higher rate than the general pediatric population has been recognized for many years and VUR was detected in 26% to 51% of siblings of patients with VUR. The purpose of this study is to determine the incidence of VUR in asymptomatic siblings of children with VUR and to see if this form of screening would be practical. Methods : We retrospectively reviewed the records of 28 patients with VUR and their siblings. The total number of asymptomatic siblings investigating VUR were 28 persons. All patients and siblings were evaluated for VUR by a voiding cystourethrography and all patients and siblings with VUR were performed $^{99m}Tc$ 2,3-dimercaptosuccinic acid renal scan. Results : A total of 28 patients(14 boys, 14 girls) with VUR were studied; the mean patient age was 2.7 years(range 1 month to 8.4 years). The total number of asymptomatic siblings investigating VUR were 28 persons(17 boys, 11 girls) and the mean age was 3.3 years(range 2 months to 7.4 years). Renal scar was detected in 20 of 28(71.4%) patients with VUR. VUR was noted in three of 28(10.7%) siblings and renal scar was detected in one of three siblings with VUR. Conclusion : In this study, the predictive value of a positive family history alone in identifying VUR was 10.7%. This incidence suggests more investigation of asymptomatic siblings and continued study of this group of patients at risk is needed for clarifying the family screening of patients with VUR.

Clinical features and results of recent neonatal cardiac surgery - A review of 82 cases in one hospital (최근 신생아 심장 수술의 특징과 결과 - 단일 병원에서의 82례 고찰)

  • Oh, Ki Won;Kim, Jung Ok;Cho, Joon Yong;Hyun, Myung Chul;Lee, Sang Bum
    • Clinical and Experimental Pediatrics
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    • v.50 no.7
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    • pp.665-671
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    • 2007
  • Purpose : The purpose of this study was to investigate the clinical features and outcome in newborns undergoing cardiac surgery. Methods : Eighty two neonates underwent heart surgery for congenital heart defect at Kyungpook National University Hospital between March 2000 and February 2006. Patient characteristics (sex, age, diagnosis), pre-operative conditions, operation type, postoperative complications and mortality were reviewed retrospectively. Results : In 82 patients, 41 (50%) were male. The mean age and weight at operation were 12 days and 3.2 kg, respectively. The common cardiac anomalies were complete transposition of the great arteries (TGA), Tetralogy of Fallot (TOF), pulmonary atresia with intact ventricular septum, and single ventricle variants. Fifty seven operations were performed with cardiopulmonary bypass and corrective surgery was done on 54 patients. Arterial switch operation and modified Blalock-Taussig shunt were most frequently performed as corrective and palliative operations, respectively. The early hospital mortality rate was 7%; the late mortality was 3.9%. Complications were acute renal insufficiency, delayed sternal closure, wound infection, arrhythmia, and brain hemorrhage. Conclusion : During the last 6 years, the outcomes of cardiac surgery for congenital heart defects in neonates improved by progress in perioperative, anaesthetic, surgical, and postoperative care.

Clinical characteristics of acute renal failure of rhabdomyolysis in children (소아에서 횡문근융해증을 동반한 급성신부전의 임상양상)

  • Kim, Jae Hui;Goo, Min Ji;Yeom, Jung Sook;Park, Eun Sil;Seo, Ji Hyun;Lim, Jae Young;Park, Chan Hoo;Woo, Hyang Ok;Youn, Hee Shang
    • Clinical and Experimental Pediatrics
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    • v.50 no.3
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    • pp.277-283
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    • 2007
  • Purpose : Acute renal failure (ARF) is an important complication of rhabdomyolysis. The purpose of this study was to identify the major causes of rhabdomyolysis in children and to identify the factors associated with the developmet of ARF. Methods : A retrospective chart review between January 1997 to June 2005 was conducted of 60 patients with a diagnosis of rhabdomyolysis. Rhabdomyolysis was defined by an elevation of serum creatine phosphokinase (CK) greater than 1,000 IU/L with a MM fraction more than 95% or serum myoglobin>300 mg/dL or positive urine myoglobin. Patients were excluded if they had evidence of myocardial ischemia, or cerebrovascular insufficiency. Results : Sixty patients (37 males, 23 females) were enrolled, with the median age of 4.25 year. The most common causes of rhabdomyolysis were repiratory tract infection (9), seizure (7), hypoxia or asphyxia (6). Fifteen patients (25.0%) developed ARF and ten of them (66.0%) died. The initial serum creatinine, uric acid, potassium, pH and peak serum creatinine, initial systolic blood pressure, and mental status were statistically correlated with the development of ARF. The peak serum CK was associated with mortality of rhabdomyolysis. Conclusion : Acute renal failure was significant complication of rhabdomyolysis in children. Several clinical and laboratory factors were statistically associated with the development of ARF and death.

Investigating Organ Toxicity Profile of Tenofovir and Tenofovir Nanoparticle on the Liver and Kidney: Experimental Animal Study

  • Peter, Aniekan Imo;Naidu, Edwin CS;Akang, Edidiong;Ogedengbe, Oluwatosin O;Offor, Ugochukwu;Rambharose, Sanjeev;Kalhapure, Rahul;Chuturgoon, Anil;Govender, Thirumala;Azu, Onyemaechi O
    • Toxicological Research
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    • v.34 no.3
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    • pp.221-229
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    • 2018
  • Tenofovir nanoparticles are novel therapeutic intervention in human immunodeficiency virus (HIV) infection reaching the virus in their sanctuary sites. However, there has been no systemic toxicity testing of this formulation despite global concerns on the safety of nano drugs. Therefore, this study was designed to investigate the toxicity of Tenofovir nanoparticle (NTDF) on the liver and kidney using an animal model. Fifteen adult male Sprague-Dawley (SD) rats maintained at the animal house of the biomedical resources unit of the University of KwaZulu-Natal were weighed and divided into three groups. Control animals (A) were administered with normal saline (NS). The therapeutic doses of Tenofovir (TDF) and nanoparticles of Tenofovir (NTDF) were administered to group B and C and observed for signs of stress for four weeks after which animals were weighed and sacrificed. Liver and kidney were removed and fixed in formal saline, processed and stained using H/E, PAS and MT stains for light microscopy. Serum was obtained for renal function test (RFT) and liver function test (LFT). Cellular measurements and capturing were done using ImageJ and Leica software 2.0. Data were analysed using graph pad 6, p values < 0.05 were significant. We observed no signs of behavioural toxicity and no mortality during this study, however, in the kidneys, we reported mild morphological perturbations widening of Bowman's space, and vacuolations in glomerulus and tubules of TDF and NTDF animals. Also, there was a significant elevation of glycogen deposition in NTDF and TDF animals when compared with control. In the liver, there were mild histological changes with widening of sinusoidal spaces, vacuolations in hepatocytes and elevation of glycogen deposition in TDF and NTDF administered animals. In addition to this, there were no significant differences in stereological measurements and cell count, LFT, RFT, weight changes and organo-somatic index between treatment groups and control. In conclusion, NTDF and TDF in therapeutic doses can lead to mild hepatic and renal histological damage. Further studies are needed to understand the precise genetic mechanism.

Secretions of the biliary mucosa in experimental clonorchiasis (간흡충에 감염된 토끼 및 흰쥐 담관상피의 분비기능)

  • 이순형;이종인
    • Parasites, Hosts and Diseases
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    • v.31 no.1
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    • pp.13-20
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    • 1993
  • The histological change of the billary mucosa in clonorchiasis is characterized as adenomatous hyperplasia, and cross-sectioned mucosa looks like intestinal mucosa. In addition to the glandular hyperplasla, the metaplasia of mucin secreting cells is also known. The present study investigated the presence of intestinal secretion from the biliary mucosal cells of rabbits and rats with Clonorchis sinensis infection. The rabbit was infected with 300 and the rat was infected with 100 metacercariae of C. sinensif. A part of the animals were followed up after praziquantel treatment. The rabbit livers were prepared for histochemistry to observe any endocrine secretion and the bile duct mucosa of the mice was processed far the activity of brush border membrane (BBM)-bound enzymes of the small intestine. Immunohistochemistry with the polyclonal antibodies and biotin-streptavidin-peroxidase staining kit showed no positive cells for gastrin and secretin, but a few cells were positive for serotonin. The proliferated billiw mucosa of the mice revealed no activity of dissaccharidases and aminopeptidase. Only alkaline phosphatase activity was found both in the control and the infected. The hyperplastic billary mucosal cells showed no gastrointestinal secretory functions. The serotonin secreting cells may be one of the inflammatory cells.

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Disseminated Intravascular Coagulation in Experimental Fowl Cholera of Chickens (닭의 가금(家禽) 콜레라 감염시(感染時)의 파종성(播種性) 혈관내(血管內) 응고증(凝固症))

  • Park, Nam-Yong
    • Korean Journal of Veterinary Research
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    • v.22 no.2
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    • pp.211-219
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    • 1982
  • Chickens from 10 to 32 weeks of age were inoculated with P. multocida via seven routs(intravenous, intramuscular, intraperitoneal, subcutaneous, into ear, intranasal, per oral). The development or distribution of disseminated intravascular coagulation (DIC) in multiple organs and the role of P. multocida endotoxins in disease process of fowl cholera were studied. The histological diagnosis of DIC was made by demonstration of fibrinous in arterioles, capillaries, venules and medium-sized blood vessels. The presence of fibrinous thrombi in blood vessels of multiple organs was observed in chickens which died within approximately 3 days post inoculation. Fibrinous thrombi were observed most frequently in the lung(90% of all cases with DIC) followed by liver (70%), kidney (60%), heart(20%), spleen, brain, pancreas, thymus and thyroid gland. The density of fibrinous thrombi (i.e. the number of thrombi per section) was greatest in the lung, followed by spleen, kidney, liver and heart. It is thought that the widespread hemorrhage of acute fowl cholera is also caused by P. multocida endotoxin which initiates DIC in variety of organs. The cause of death for the chickens after infection with acute fowl cholera is probably due to an endotoxin (septic) shock accompanied with DIC in multiple organs.

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The research trends of papers in the journal of korean society of dental hygiene (한국치위생학회지 게재논문의 연구동향 분석)

  • Kang, Boo-Wol;Ahn, Se-Youn;Kim, Sun-Kyung;Yoo, Young-Suk;Yoo, En-Mi;Lee, Sun-Mi
    • Journal of Korean society of Dental Hygiene
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    • v.10 no.6
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    • pp.991-1000
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    • 2010
  • Objectives : The purpose of this study was to analyze 356 papers included in the Journal of the Korean Society of Dental Hygiene between 2000 when the initial number was issued and April, 2010. The papers involved articles, treatises, theses and dissertations. Methods : According to existing literature related to paper analysis, all the journals were analyzed by year to find out the subjects of the studies, places for data gathering, the presence or absence of research funds supplied, the number of researchers, research methods, methods of data collection, themes and data analysis methods. Results : As for subjects, the largest group of the papers that numbered 69(20.7%) examined dental hygienists, and the second biggest group that numbered 65(19.5%) examined dental hygienists and students. The third greatest group that numbered 47(14.2%) examined patients at dental hospitals and clinics. Concerning places of data gathering, schools(37.1%) were the most common places where data were collected, followed by dental hospitals/clinics(31.6%) and laboratories(7.4%). In terms of research design, research studies accounted for 88.5%, and experimental studies accounted for 11.5%. Research studies were far more prevalent. Concerning themes, there were 76 kinds of concepts that the studies dealt with, and the most dominant concepts were oral health awareness and behavior, which 34 studies focused on(9.6%). 10 studies or more were concerned with dental service, oral health status, dental hygiene education, infection control, oral health education, job satisfaction and stress. As to data analysis methods, frequency analysis was most dominant, followed by Chi-square test, t-test, analysis of variance, descriptive statistics, correlation analysis and regression analysis. Most of the studies made use of quantitative research methods. Conclusions : The effort by this study to analyze the papers included in the Journal of the Korean Society of Dental Hygiene to grasp research trends in the field of dental hygiene is expected to be of some use for the determination of the right directions of dental hygiene research in the future.

AGAR-ALGINATE COMBINED IMPRESSION TECHNIQUE AND DIMENSIONAL CHANGE RESULTING FROM IDOPHOR DISINFECTION (아기-알지네이트 연합 인상체의 보관방법 및 idophor 침적소독에 의한 체적 변화에 관한 연구)

  • Oh Nam-Sik;Seo Joung-Min;Kim Sun-Hee;Youn Young-Ah;Shim Joon-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.42 no.1
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    • pp.21-29
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    • 2004
  • Statement of problem : Because dental impression can be a cross-infection source, disinfection, such as immersion disinfection is nessecary. However, the disinfection process may change the volume of the impression cast. Purpose : The purpose of this study is to find out the effects on dimensional change of different storage times and methods, of agar-alginate impression when immersed in a 5% idophor disinfectant. Material and Methods : An agar-alginate impression was made from a mandible model and then was disinfected and stored according the experimental conditions and a stone model was produced. Measurements were taken between reference points on the original mandible model and they were compared to measurements taken between reference points on the stone model. The study was divided into 4 groups. In group 1, the impression was stored in a 100% humidor for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours and 24 hours and stone models were made at each time. In group 2, the impression was immersed in 5% idophor disinfectant and then stored in a 100% humidor for the same length of times as group 1, and stone models were made at each time. In group 3, the impression was stored in extend-A-pourR, a special storage solution for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours, 24 hours 3 days, and 7 days and stone models were made at each time. In group 4, the impression was immersed in 5% idophor disinfectant and then stored in stored in extend-A-pourR, a special storage solution for the same length of times as group 3, and stone models were made at each time. 5 impressions and stone models were made at each time to make a total of 180. The Student-t test (P < .05) was used to do a statistical analysis of the measurements of the mandible model and stone models. The repeated-measure 2-way analysis of variance (P < .05) was used to do a statistical analysis of the difference in the 4 groups. Results : The percent liner dimensional change was from $0.25{\pm}0.03%$ (group 1, 30 minutes) to $0.34{\pm}0.06%$ (group 4, 7 days). No significant change was noticed between the 4 groups. Conclusion : According to the above study, in both methods, least dimensional change was recorded when the storage times were short and in both methods, immersion in 5% idophor disinfectant did not effect dimensional change in the agar-alginate impression.