Effects of glutaraldehyde and povidone-iodine on apoptosis of grass carp liver and hepatocytes

Since disinfectants are used all over the world to treat illnesses in people and other animals, they pose a major risk to human health. The comprehensive effects of disinfectant treatments on fish liver, especially the impacts on oxidative stress, toxicological effects, transcriptome profiles, and apoptosis, have not yet been fully analyzed. In the current investigation, healthy grass carp were exposed to 80 μg/L glutaraldehyde or 50 μg/L povidone-iodine for 30 days. First, the findings of enzyme activity tests demonstrated that the administration of glutaraldehyde could considerably increase oxidative stress by lowering T-SOD, CAT, and GPx and raising MDA. Furthermore, KEGG research revealed that exposure to glutaraldehyde and povidone-iodine stimulated the PPAR signal pathway. To further elucidate the transcriptome results, the relative expressions of related DEGs in the PPAR signal pathway were verified. Glutaraldehyde induced apoptosis in liver tissue of grass carp; however, it activated cytotoxicity and apoptosis in grass carp hepatocytes when exposed to glutaraldehyde or povidone-iodine. According to the current study, disinfectants can cause the impairment of the immune system, oxidative stress, and attenuation of the PPAR signal pathway in the liver of grass carp, making them detrimental as dietary supplements for grass carp, particularly in the aquaculture sector.

Evaluation of dermal toxicity and toxicokinetics of povidone‑iodine in Göttingen minipigs

BACKGROUND

Povidone‑iodine (PVP-I) is an effective and commonly used broad-spectrum antiseptic; limited information exists around its long-term safety and impact on endocrine disruption. We assessed the dermal toxicity and toxicokinetics following a once-daily application of 7.5% (w/v) and 10% (w/v) PVP-I in Göttingen Minipigs® for up to 39 weeks.

METHODS

An in vivo study was conducted in male (n = 27) and female (n = 27) minipigs. Animals were randomized into untreated control, 7.5% and 10% PVP-I, and matching vehicle treatment groups. Animals were assessed for general in-life measurements, including skin irritation and organ weights. Serum samples were analyzed for PVP, total iodine, triiodothyronine [T3], thyroxine [T4], thyroid stimulating hormone [TSH], and toxicokinetic parameters.

RESULTS

Neither 7.5% nor 10% PVP-I affected general in-life measurements. Increased mean thyroid gland absolute weights were noted with 7.5% and 10% PVP-I. Serum levels of PVP, T3, T4, and TSH in the 7.5% and 10% PVP-I treatment group animals were similar to those in vehicle treatment group animals. Mean total serum iodine concentration was 52- and 13-fold higher with 7.5% and 10% PVP-I, respectively, vs respective vehicle treatments. There was no dose-dependent increase in mean maximum serum concentration and area under the curve from 0 to 24 h for PVP, T3, T4, and TSH, nor accumulation of PVP, T3, T4, or TSH in the study.

CONCLUSION

Once-daily dermal application of 7.5% and 10% PVP-I for up to 39 weeks was safe and well tolerated in Göttingen Minipigs® and was not associated with skin irritation, thyroid dysfunction, or endocrine disruption. As the anatomy and physiology of the minipig skin closely resembles that of human skin, the findings of this study suggest that 7.5% and 10% PVP-I may be translated into antimicrobial benefits for humans without the risk of endocrine disruption.

Chondrotoxic effects of tranexamic acid and povidone-iodine on the articular cartilage of rabbits

PURPOSE

To evaluate the chondrotoxic effects of intra-articular use of TXA 20 mg/kg and/or 0.35% PVPI on knee joint cartilage in an experimental model of rabbits.

METHODS

Forty-four male New Zealand adult rabbits were randomly assigned to four groups (control, tranexamic acid (TXA), povidone-iodine (PVPI), and PVPI + TXA). The knee joint cartilage was accessed through an arthrotomy and exposed to physiological saline SF 0.9% (control group), TXA, PVPI, and PVPI followed by TXA. Sixty days after surgical procedure, the animals were sacrificed and osteochondral specimens of the distal femur were obtained. Histological sections of cartilage from this area were stained with hematoxylin/eosin and toluidine blue. The following cartilage parameters were evaluated by the Mankin histological/histochemical grading system: structure, cellularity, glycosaminoglycan content in the extracellular matrix, and integrity of the tidemark.

RESULTS

The isolated use of PVPI causes statistically significant changes in cartilage cellularity (p-value = 0.005) and decrease glycosaminoglycan content (p = 0.001), whereas the isolated use of TXA decreased significantly the glycosaminoglycan content (p = 0.031). The sequential use of PVPI + TXA causes more pronounced alterations in the structure (p = 0.039) and cellularity (p = 0.002) and decreased content of glycosaminoglycans (p < 0.001) all with statistical significance.

CONCLUSION

Data suggest that intra-articular use of tranexamic acid 20 mg/kg and intraoperative lavage with 0.35% povidone-iodine solution for three min are toxic to the articular cartilage of the knee in an experimental in vivo study in rabbits.

Ex Vivo Toxicity of Commonly Used Topical Antiseptics and Antibiotics on Human Chondrocytes

Topical povidone-iodine, chlorhexidine, bacitracin, and vancomycin are commonly used antiseptic and antimicrobial agents to reduce risk and treat surgical site infections in numerous orthopedic procedures. Chondrocytes potentially may be exposed to these agents during operative procedures. The impact of these topical agents on chondrocyte viability is unclear. The goal of this study is to determine human chondrocyte viability ex vivo after exposure to commonly used concentrations of these topical antiseptic and antimicrobial agents. Human osteochondral plugs were harvested from the knee joint of a human decedent within 36 hours of death. Individual human osteochondral plugs were exposed to normal saline as a control; a range of concentrations of povidone-iodine (0.25%, 0.5%, and 1%), chlorhexidine (0.01% and 0.5%), and bacitracin (10,000 units/L, 50,000 units/L, and 100,000 units/L) for 1-minute lavage; or a 48-hour soak in vancomycin (0.16 mg/mL, 0.4 mg/mL, and 1.0 mg/mL) with nutrient media. Chondrocyte viability was evaluated with a live/dead viability assay at 0, 2, 4, and 6 days after exposure to bacitracin at 0, 3, and 6 days). Control subjects showed greater than 70% viability at all time points. Povidone-iodine, 0.5% chlorhexidine, and vancomycin showed significant cytotoxicity, with viability dropping to less than 40% by day 6. Chondrocytes exposed to 0.01% chlorhexidine maintained viability. Chondrocytes exposed to bacitracin showed viability until day 3, when there was a large drop in viability. Commonly used topical concentrations of povidone-iodine, vancomycin, and bacitracin are toxic to human chondrocytes ex vivo. A low concentration of chlorhexidine appears safe. Caution should be used when articular cartilage may be exposed to these agents during surgery. [Orthopedics. 2022;45(5):e263-e268.].

Chlorhexidine ototoxicity in ear surgery part II: survey of preparation solution used by otolaryngologists in Canada: is there a cause for concern?

OBJECTIVE

To conduct a survey of the antiseptic preparations used for ear surgeries among otolaryngologists in Canada.

METHODS

An electronic survey was sent to active members of the Canadian Society of Otolaryngology-Head and Neck Surgery via e-mail. Questions included the use of antiseptic, choice of preparation solution, duration of preparation, use of a barrier method, and compliance with hospital protocol changes.

RESULTS

The e-mail was received by 253 otolaryngologists, and 85 completed the survey. Four of 85 respondents did not perform tympanoplasty surgery and were not included in the analysis. Of those who performed tympanoplasty (n  =  81), 78 of the 81 respondents (96%) used an antiseptic preparation solution at surgery, whereas 3 respondents (4%) did not. Sixty-six of the 77 respondents (86%) used aqueous povidone-iodine, 4 (5%) used a chlorhexidine-based preparation, 3 (4%) used an alcohol-based solution, 3 (4%) used others, and 1 answered "I don't know." Thirty-eight of 75 (29%) respondents used a barrier method, 23 (31%) answered "always," 18 (24%) answered "sometimes," and 5 (7%) answered "I don't know." When asked if they would comply with a hypothetical hospital policy to use chlorhexidine in ear surgery, 15 of 79 (19%) respondents agreed, whereas 64 (81%) disagreed. Among the aqueous povidone-iodine users (n  =  66), 7 (11%) agreed to change to chlorhexidine.

CONCLUSIONS

There is a wide variation in practice in the use of surgical preparation solution among otolaryngologists performing ear surgery. Surgeons must be vigilant to avoid ototoxicity. A national society consensus on appropriate preparation solutions for ear surgery would minimize patients' risk and minimize future medicolegal actions.

The effect of intravitreally injected povidone-iodine on Staphylococcus epidermidis in rabbit eyes

PURPOSE

Firstly, the aim of this study was to determine the maximally tolerated dose of intravitreally injected povidone-iodine (PVP-I). A second aim was to test the efficacy of PVP-I on rabbit eyes infected intravitreally with Staphylococcus epidermidis.

METHODS

Phase I of the study used 16 New Zealand albino rabbits, divided into 4 groups (n=4 each). Animals were anesthetized and intravitreally injected with 0.1 mL of 50, 100, 200, or 400 micrograms (microg) of PVP-I in 1 eye, and with saline in the other. The animals were examined at days 1, 7, and 14, using indirect ophthalmoscopy and slit-lamp biomicroscopy; electroretinography (ERG) was performed before treatment and prior to euthanization. Histological preparations were examined to determine retinal damage. Phase II of the study divided 20 New Zealand albino rabbits into 4 groups (n=5 each). Animals were anesthetized and injected with 0.1 mL of S. epidermidis containing 3030 colony forming units (CFU) in 1 eye and saline in the other. Seven (7) h later, animals were treated with 0.1 mL of 20, 50, and 100 microg of PVP-I, or no treatment. Bacterial concentrations from extracted vitreous were determined 2 days following infection. Results were analyzed for statistical significance, using the Student t test and analysis of variance, and histologic preparations assessed the presence of endophthalmitis.

RESULTS

Phase I of the study observed no retinal damage at any of the concentrations studied, as noted by indirect ophthalmoscopy, slit-lamp biomicroscopy, ERG, and histologic exam. Phase II of the study showed no statistical difference in bacterial counts between treatment and control groups. All infected eyes went on to develop endophthalmitis, as observed by indirect ophthalmoscopy and histologic preparations.

CONCLUSIONS

These results suggest that 400_g of PVP-I can be tolerated intravitreally in rabbit eyes with no noticeable damage over a 14-day period. Results further showed that 100 microg of intravitreally injected PVP-I has no statistically significant effect on rabbit eyes injected intravitreally with 3030 CFU of S. epidermidis.

In vitro comparison of chlorhexidine and povidone-iodine on the long-term proliferation and functional activity of human alveolar bone cells

This work reports the behaviour of osteoblastic human alveolar bone cells (first subculture) in the presence of chlorhexidine (CHX) and povidone-iodine (PI). Short contact (2 min) of 24-h cultures with CHX, at 0.12 and 0.2%, and PI, at 5 and 10%, caused cell death within minutes; contact with 1% PI resulted in loss of the elongated characteristic cell shape. Cell adhesion was adversely affected at concentrations higher than 5 x 10(-5)% CHX or 0.05% PI. Long-term exposure to CHX at 10(-5) and 10(-4)% or PI at 10(-4)% had little effect on cell growth and caused an induction in the synthesis of alkaline phosphatase (ALP). Concentrations of CHX and PI similar and higher than, respectively, 5 x 10(-4)% or 0.05% caused dose-dependent deleterious effects. CHX affected mainly the cell growth, whereas the effects of PI were observed mostly in ALP production and matrix mineralization. Considering the levels of CHX and PI used routinely in the oral cavity, results suggest that CHX has a higher cytotoxicity profile than PI. This observation might have some clinical relevance regarding the potential utility of PI in the prevention of alveolar osteitis.

[Study of the toxicity of povidone-lodine for fibroblast-like cells (BALB-3T3) and primary human chondrocytes]

Povidone-iodine (polyvinyl-pyrrolidone-iodine complex, PVP-iodine, CAS 25655-41-8) is a commonly used antiseptic because of its broad spectrum of antimicrobial effect and its comparatively low allergic risk. It is also used for open joint lavage. Animal and organ culture studies provide controversial results about the risk of cartilage damage due to povidone-iodine. There is a paucity of in vitro study data concerning the effect of povidone-iodine on chondrocyte cultures are still missing. The aim of this study was therefore to investigate the effect of different concentrations and exposition times of povidone-iodine on cell growth and differentiation of human chondrocytes. Using of a vitality test (MTT) and a proliferation assay (BrdU) in the fibroblast-like cell line BALB3T3, suitable concentrations and incubation times were identified to investigate the influence of povidone-iodine on proteoglycan synthesis and DNA synthesis of primary human chondrocytes. Concentrations of up to 1% povidone-iodine had no significant effect on proteoglycan and DNA synthesis of chondrocytes after incubation for 30 min. An incubation time of 24 h did not inhibit DNA- and proteoglycan synthesis, until a concentration of 0.2% povidone-iodine was used. DNA synthesis rate was impaired after 10 min incubation with 0.2% and fully inhibited with 1% povidone iodine. BALB3T3 reacted more sensitively than chondrocytes. Vitality and proliferation rate were fully inhibited at a concentration of 0.5% after the same exposition time. However, cells recovered 24 h after 30 min incubation with 0.5% povidone-iodine. After incubation with 5% povidone iodine cells did not recover. From the results it can be concluded that low concentrations of povidone-iodine (< 1%) and short incubation times (< 30 min) have no damaging influence on chondrocytes. Previous studies have reported the antimicrobial effectiveness of low concentrations of povidone-iodine on the reduction of tissue damage by microorganisms. Data from previus studies and the current findings from this investigation support the clinical use of povidone-iodine at low concentrations and short incubation times for antiseptic treatment of cartilage tissues.

Lack of in vitro Genotoxicity of Povidone-Iodine in Solution, in Ointment or in a Liposomal Formulation (Repithel®)

The in vitro genotoxicity of povidone-iodine in Repithel, Betaisodona ointment and Betaisodona solution was investigated using CHO-K1 cells. The comet assay and chromosome aberration test were used to characterise the genotoxic potency of povidone-iodine within 4 h of contact with test cells. Methyl methanesulphonate without S9 activation and benzo[a]pyrene with S9 activation were used as positive controls. No higher concentrations than 6% Repithel, 5% Betaisodona ointment and 2% Betaisodona solution in culture medium with 10% fetal bovine serum were tested within 4 h of contact with CHO-K1 cells for the comet assay, because higher concentrations will provide >60% cytotoxicity. All tested concentrations of povidone-iodine formulations (4-6% Repithel, 3-5% Betaisodona ointment and 1-2% Betaisodona solution) are not genotoxic in the comet assay. 10% Repithel, 5% Betaisodona ointment and 2.5% Betaisodona solution in culture medium with 10% fetal bovine serum were final concentrations in the chromosome aberration test, which provide <60% cytotoxicity within 4 h of contact with CHO-K1 cells. All tested concentrations of povidone- iodine formulations (5-10% Repithel, 2.5-5% Betaisodona ointment and 1.25-2.5% Betaisodona solution) are not genotoxic in the chromosome aberration test. Using the comet assay and chromosome aberration test to characterise the genotoxic potency of povidone-iodine within 4 h of contact with CHO-K1 cells, there was no chromosome damage detected.

Comparative Study of in vitro Cytotoxicity of Povidone-Iodine in Solution, in Ointment or in a Liposomal Formulation (Repithel®) and Selected Antiseptics

The cytotoxicity of povidone-iodine in Repithel, Betaisodona ointment and Betaisodona solution was investigated using CHO-K1 cells. To estimate the vitality of test cells after 30 min contact time using vital dye neutral red, the following IC(50) were determined: 16-18% Repithel, 8-9% Betaisodona ointment and 1.8-2% Betaisodona solution; using MTT for detecting vitality, the IC(50) were: 5-10% Repithel, 1.3-2.5% Betaisodona ointment and 0.6-1.3% Betaisodona solution. Therefore, the first attack of the antiseptic agent iodine to mammalian cells is carried out on enzymes, perhaps by oxidation, followed by membrane attack. Murine fibroblasts were used to compare the cytotoxic impact of povidone-iodine with those of chlorhexidine digluconate (CHex), octenidine dihydrochloride (Oct) and polyhexamethylene biguanide (PHMB). On the base of molecular concentration, povidone-iodine is more than 20 times better tolerated by L929 cells than CHex, Oct or PHMB. Moreover, after 30 min contact of L929 cells with povidone-iodine, there is a temporarily cytotoxic reaction, which leads after 24 h culture to an unexpected revitalisation of murine fibroblasts. This phenomenon was not detected using CHex, Oct or PHMB. Povidone-iodine seems to be the most tolerated antiseptic in comparison with CHex, Oct or PHMB.

Toxic effects of povidone–iodine on synovial cell and articular cartilage

The objective of this study was to investigate the toxic effects of povidone-iodine (PVI). A series of MTT assay of cultured synovial cells stimulated by PVI have been made. Test for assay of membrane-toxic effect of PVI and lactate dehydrogenase (LDH) has also been carried out. After making intraarticular injection into rats' hind knee joints with 0.1 ml of PVI every day for 1 week, we have extracted the knee joints and blood from rats in four divided groups on the 0, 1st, 3rd, and 7th day. Our microscopic analysis was performed that cartilage and synovium membrane were stained with hematoxylin, toluidine blue, and safranin O. Iodine, glutamic oxaloacetic transminase, creatine phosphokinase (CPK), and LDH in rat sera have been measured. We were able to confirm cytotoxicity in the synovial cells placed in PVI concentration of more than 6.25 x 10(-2)%. In comparison with the positive control, LDH, in this case, was released at the concentration level of 33.3%. Independent of period of stimulation, LDH was released the most in the PVI concentration of 6.25 x 10(-2). The histopathological analysis of articular cartilage has indicated clear morphological alterations in rats' synovium; especially, toluidine blue staining and safranin O staining were seen in the metachromasia of articular cartilage. However, no fissures or erosive changes in the articular cartilage, which were usually observable in the case of osteoarthritis, were observed. In the synovium inflammatory cells, which were mainly plasma cells and lymphoid cells, no neutrophils were infiltrated. The degree of infiltration has increased steadily day by day. Fibrin deposition has been observed even in the synovium of 1-day stimulation. On the 7th day, a serum total iodine concentration has been 544 microg/dl, 4,440 IU/ml for CPK concentration, and 2,049 IU/ml for LDH concentration, while the control concentrations have been 7.1 microg/dl, 491 IU/ml, and 700 IU/ml, respectively. Our experiment has disclosed that PVI preparation is strongly cytotoxic to synovial cell and articular cartilage.

An In Vitro Evaluation of the Cytotoxicity of Various Endodontic Irrigants On Human Gingival Fibroblasts

The purpose of this study was to measure the cytotoxicity of six endodontic irrigants on cultured gingival fibroblasts using the CyQuant assay. Human gingival fibroblasts were grown in Dulbecco's Modified Eagle Medium (DMEM) containing 10% fetal bovine serum at 37 degrees C and 5% CO(2). At confluence, cells were split, plated in 96-well plates and incubated for 24-h to allow attachment. The following irrigants were tested at various concentrations: Sodium hypochlorite (NaOCl); iodine potassium-iodide (IKI); Betadine scrub (BS); calcium hydroxide [Ca(OH)2]; chlorine dioxide (SCD) and DMEM (positive control). Experimental groups were compared by the logarithmic difference between the clinical and LD50 concentrations of a particular irrigant. The results showed that IKI and Ca(OH)2 were significantly less cytotoxic than SCD, NaOCl, and BS. In conclusion, IKI and Ca(OH)2 are well tolerated by human gingival fibroblasts.

Impact of antiseptics on radical metabolism, antioxidant status and genotoxic stress in blood cells: povidone-iodine versus octenidine dihydrochloride

No sufficient data are available of the of antiseptics' influence on human blood cells. Effects of two antiseptics, povidone-iodine (PVD-I) versus octenidine dihydrochloride (OD), were tested on antioxidant status, radical formation, antioxidant defence enzymes and genotoxic stress in blood cells, in vitro. Human blood was taken by venipuncture, enriched with PVD-I or OD (0.0001-20% final concentration) and incubated at 37 degrees C between 30 and 120 min. alpha-Tocopherol was assessed in erythrocytes and granulocytes. Superoxide-dismutase (SOD) and glutathione (GSH) were determined in erythrocytes, the total anti-oxidative capacity (TAC) and malondialdehyde (MDA) in their ghosts. In granulocytes status of hydrogen peroxide (H(2)O(2)), superoxide anions and MDA was observed. Genotoxic stress was determined by counting sister chromatide exchanges (SCE) in lymphocytes after enrichment within 0.05-0.4% of antiseptics. Based on all biomarker tested, concentrations up to 0.05% incubated for 30 min did not affect cell metabolism. 1% and 10% PVD-I reduced the activity of SOD (-40%), GSH (-62%) and the content of alpha-tocopherol more than OD (p<0.05). No significant differences between the antiseptics were observed for TAC and MDA. H(2)O(2) and superoxide anions were significantly reduced after the 10% addition for both substances independent on the exposure. Without having changes in lipid oxidation, the reduction of antioxidative defence mechanisms must be due to the oxidation caused by the antiseptics, mainly PVD-I. An increased SCE rate was neither observed with PVD-I nor with OD within an enrichment with 0.05-0.4%. Higher concentrations (1% and more) could not be tested on SCE formation because they caused cell bursts. The results presented indicate that concentrations up to 0.05% incubated for 30 min are safe for exposing blood cells of healthy subjects.

[Cytotoxic effect and influence of povidone-iodine on wounds in guinea pig]

Cytotoxicity and effect on guinea pig wounds were compared with three kinds of 10% povidone-iodine solution (isodine, neojodine, J-iodine) and povidone-iodine. It gave the following results: 1. In the Chang conjunctiva cell where remarkable toxicity was observed in the used cell line, the toxicity emphasized was 10 times using povidone-iodine < J-iodine < neojodine < isodine. In addition, a toxic difference was recognized between cells, in the order of Chang conjunctiva > SIRC > FRSK > human fibroblast for isodine and neojodine. 2. As for the influence on cells achromatized in sodium thiosulfate, alteration was not recognized in isodine, J-iodine using half-maximum cytotoxicity concentrations (CC50), and, in neojodine and povidone-iodine, elimination of drug toxicity was recognized in Chang conjunctiva/FRSK cells. 3. Strong toxicity was seen in isodine and neojodine in the toxicity test using colony formation method, however on washing with PBS (-), an easing of the toxicity effect could be seen to 0.01%. 4. Polyoxythylene nonylphenyl ether, NP-10 was the most toxic in the used surfactants in this study, and the toxicity by 100 times when compared with sodium polyoxyethylene lauryl ether sulfate, SBL-2N. Prominent sensitivity was observed in Chang conjunctiva cells with regard to the cell line and subsequently showed toxicity in order of SIRC > FRSK > human fibroblast. Remarkably, the difference between solutions of isodine and J-iodine was made more clear from the 5th culture. 5. In this study, significantly guinea pig wounds, povidone-iodine blocked all examples significantly recognized as dallying by distance between epidermal cells. In addition, isodine was meaningful area. Although their ware not offer the significant differences, the solutions obstructed the sliding of epidermal cells in comparison with povidone-iodine, and a delaying tendency of inflammation was also recognized. The toxic difference between povidone iodine solutions was regarded as the influence of surfactants added to the povidone-iodine. Based on this foundation study, more detailed clinical testing is necessary in determine where sterilization to wounds/mucosa/eyes with solutions containing additive is a suitable panpractice or not.

Virucidal activity and cytotoxicity of the liposomal formulation of povidone-iodine

Two drug formulations of povidone-iodine (PVP-I)--an aqueous PVP-I solution (Betaisodona) and a liposomal PVP-I formulation--were tested for their virucidal activity and cytotoxicity in cell culture. As to the virudical activity against influenza A virus, herpes simplex virus type 1, adenovirus type 8 and human rhinovirus type 14, the liposomal formulation of PVP-I proved to be approximately as active as the aqueous one. Half maximum cytotoxic PVP-I concentrations were 0.01-0.07% for aqueous PVP-I and 0.03-0.27% for the liposomal PVP-I formulation (XTT reduction assay EZ4U). The detection of lactate dehydrogenase (LDH) release, DNA fragmentation (ELISA) and DNA strand breakage (TUNEL assay) after 24 h exposure of human embryonic lung fibroblasts to PVP-I revealed that necrosis predominates in cells treated with aqueous 0.08-0.32% PVP-I solutions, whereas apoptosis was the predominant type of cell death in cells treated with equivalent concentrations of liposomal PVP-I formulation. The favorable virucidal efficiency together with the preferred apoptotic route of cell death makes the liposomal PVP-I formulation a promising candidate for topical use in prevention and treatment of infections of the eye and the upper respiratory tract.

[Caustic sclerosing cholangitis following injection of anthelmintics into rat bile duct. An experimental study]

It is the purpose of the study to assay the effect of intrabiliary injection of scolicide agents most frequently used in clinical practice. Fifty-five albino rats are divided up into 4 groups according to type of solution injected, as follows: control group A--with physiological saline, B--20 per cent natrium chloratum, C--10 per cent povidone iodine, and D--3 per cent hydrogenium hyperoxidatum. Histological assessment of extrahepatic bile ducts and liver parenchyma are conducted at 10 and 90 days of treatment. Lesions along with cholestatic and reparative changes are documented, most markedly expressed after injecting 20 per cent NaCl, rather weakly--after 10 per cent povidone iodine, and least pronpunced after injecting 3 per cent hydrogen peroxide. Periductal sclerosis is noted in three rats only injected with hypertonic saline. The experimental results are analyzed, and clinically relevant inferences reached.

In vitro cytotoxicity of chlorhexidine gluconate, benzydamine-HCl and povidone iodine mouthrinses on human gingival fibroblasts

Mouthrinses are frequently prescribed for the treatment of ulcerative diseases of the oral mucosa. In this study the in vitro cytotoxic effect of 0.2% chlorhexidine gluconate in water, 0.15% benzydamine-HCl in 8.5% ethanol and 1% povidone iodine in 10% ethanol were determined. Results of photographs and cell counts revealed that all the cells exposed to chlorhexidine gluconate, benzydamine-HCl and povidone iodine were immediately fixated onto the tissue culture surfaces. The three agents were then diluted in phosphate buffered saline to concentrations varying between 10% and 90% and fibroblasts were once again exposed to the dilutions of the test agents. Photographs were taken and cell concentrations in the wells were determined immediately after exposure and after 2, 4 and 24 hours. Results indicated that cells were immediately fixated by 10% chlorhexidine gluconate in water, 20% povidone iodine and 70% benzydamine-HCl. Fibroblasts survived and recovered from the exposure to 8.5% and 10% ethanol, which indicated that the fixation effect is not the result of the ethanol, but should be ascribed to the activity of the active ingredients in the mouthrinses.

Corneal endothelial cytotoxicity of diluted povidone--iodine

PURPOSE

To assess corneal endothelial toxicity of diluted povidone-iodine (PI) in vivo and in vitro.

SETTING

Cell Biology Laboratory and the Laboratory for Intraocular Microsurgery and Implants, Goldschleger Eye Research Institute, Sackler School of Medicine, Tel-Aviv University, Chaim Sheba Medical Center, Tel-Hashomer, Israel.

METHODS

In an in vitro study, cultured bovine corneal endothelial cells were exposed to diluted PI. The degree of cell damage was determined by staining with trypan blue and by comparing the results to those in a control group. In an in vivo study, a single dose of diluted PI was injected into the anterior chamber of rabbit eyes, completely replacing the aqueous humor. The eyes were evaluated by clinical examination, specular microscopy, pachymetry, pneumotonometry, and histopathology and compared to a control group injected with a balanced salt solution.

RESULTS

In vitro, PI concentrations of 0.05% or less did not induce endothelial cell damage. Significant damage was observed with a PI concentration of 0.1%. Calf serum concentrations of 1% and higher in the culture media protected the endothelial cell monolayer from cytotoxic damage by PI. Aqueous humor did not have a similar effect. In vivo, PI concentrations of 0.1% or less did not induce changes in corneal endothelium morphology or function as assessed by specular microscopy and pachymetry. A PI concentration of 1% served as a positive control, causing corneal edema and endothelial cell loss as demonstrated by pachymetry, histopathology, and elevated intraocular pressure.

CONCLUSIONS

The concentrations of PI tolerated by animal endothelium in vitro and in vivo were higher than the reported bactericidal levels. These findings justify further investigation of the safety and efficacy of PI for intracameral prophylaxis during surgery.

The effect of povidone iodine on the corneal endothelium

PURPOSE

Povidone iodine has been proven to be a valuable antiseptic solution in preparing the eye for surgery and is an alternative to postoperative topical antibiotics. No study has addressed the intraocular toxicity of povidone iodine after injection into the anterior chamber. We investigated the potential toxicity of povidone iodine on the corneal endothelium after injections into the anterior chamber in a rabbit model.

METHODS

In this study we used 24 eyes of 12 albino rabbits. The eyes were divided into the following three groups according to the drugs tested: group A, 5% povidone iodine; group B, 10% povidone iodine; group C, balanced salt solution. The injected eyes were evaluated by biomicroscopy, specular microscopy, corneal pachymetry, and transmission and scanning electron microscopy.

RESULTS

Corneal edema was observed in all eyes of groups A and B. In groups A and C, the endothelial cell morphology was not significantly changed and the mean endothelial cell count of the eyes did not change significantly (p = 0.5054). There was no significant difference in corneal thickness between groups A and C (p = 0.3823), but there was a significant difference between groups B and C ( = 0.0002). Transmission and scanning electron microscopy results were normal in group C but not in groups A and B.

CONCLUSION

Povidone iodine in both 5% and 10% concentrations demonstrates severe toxicity when one drop of either concentration is placed directly in the anterior chamber. When povidone iodine is used in preparing the eye for intraocular surgery and as an alternative to postoperative antibiotics, the inadvertent leakage of povidone iodine into the anterior chamber must definitely be prevented.

Microbial decontamination of human donor eyes with povidone-iodine: penetration, toxicity, and effectiveness

BACKGROUND/AIMS

Povidone-iodine (PVP -I) is applied for microbial decontamination of human eyes donated for transplantation. Concentrations and immersion times vary greatly. The effectiveness and toxicity of PVP-I were assessed for different decontamination protocols.

METHODS

Human donor eyes and corneas were immersed in different concentrations (5-100 mg/ml) of PVP-I for different times (2-30 minutes). The penetration of iodine into the corneal tissue was assessed by x ray microanalysis. Microbial contamination was determined by taking cultures of the limbal areas and storage solutions and by incubation of the corneoscleral buttons in antibiotic-free culture medium. Cytotoxicity of PVP-I for corneal fibroblasts in culture was assessed using the MTT assay.

RESULTS

Depending on concentration and immersion time iodine was found to penetrate into the epithelium, Bowman's layer, and stroma in amounts equivalent to 2-40 mg/ml PVP-I. The MTT assay demonstrated that 2.5 mg/ml PVP-I caused total damage to fibroblasts in vitro. Rinsing eyes with tap water and subsequent immersion in PVP-I reduced the rate of contamination from 82 out of 106 to 69 out of 106 and 37 out of 106, respectively. Antibiotics in the storage medium further reduced contamination from about 40% to 3%. Microbial contamination was not reduced by increasing the concentration and immersion times beyond 5 mg/ml PVP-I for 2 minutes.

CONCLUSION

Immersion of human donor eyes in 5 mg/ml PVP-I solution for 2 minutes significantly reduces microbial contamination of donor corneas without relevant penetration of iodine into the corneal layers. Higher PVP-I concentrations and longer immersion times do not further reduce contamination, whereas the amount of iodine penetrating the corneal layers is elevated above the level cytotoxic for corneal fibroblasts. In view of this, concentrations above 5 mg/ml of PVP-I and immersion periods over 2 minutes are not recommended for reduction of the contamination rate of donor eyes.

Preparation and characteristics of antibacterial sepiolite containing povidone-iodine as a useful pharmaceutical product for patient care

Povidone-iodine (PVP-I), an antibacterial medicine, was infiltrated in sepiolite (SPL). The available iodine content in this new pharmaceutical product, a sepiolite preparation containing povidone-iodine (PVP-I-SPL), was retained at 98.9 and 98.3% during storage at 40 degrees C for 3 and 6 months, respectively. The effective removal of various gasses, including ammonia, hydrogen sulfide, ethylmercaptan and acetaldehyde, was achieved by use of PVP-I-SPL. Especially, the concentration of ammonia gas was reduced more than half after 30 min of exposure, suggesting that PVP-I-SPL has excellent ability to adsorb ammonia gas. The satisfactory antibacterial effect of PVP-I-SPL was also obtained by testing its minimum bactericidal concentration (MBC). No irritation reactions to the rabbit auricle or ophthalmic mucosa or to human skin were observed by the skin irritation test. The PVP-I-SPL preparation has bactericidal activity and gas-adsorbing ability; therefore, this pharmaceutical product should be useful for the prevention of infections and deodorization in hospital rooms and houses, as well as in nursing homes for elderly people.

Toxic effects of wound irrigation solutions on cultured tibiae and osteoblasts

Irrigating wounds with solutions of antiseptic or antibiotic agents is routinely performed in orthopaedic surgery to reduce the incidence of microbial infection. The effects of these agents on healthy bone tissue is unknown. Three commonly employed antiseptic agents (hydrogen peroxide, Betadine solution, Betadine scrub) and one antibiotic solution (bacitracin) were tested on tibiae and osteoblasts isolated from embryonic chicks. Osteoblast function was evaluated by glycolytic energy metabolism (lactate production), cell number (DNA content), and collagen synthesis ([3H]proline hydroxylation). Two series of experiments were performed. To study concentration-related effects, tibiae or cells were exposed to a range of concentrations of the agents (diluted in saline, 0.9% NaCl) for 2 min, rinsed with saline, and incubated for 24 h in medium containing [3H]proline. For the recovery study, the cells were exposed to an effective, but nonlethal, concentration of the antiseptic agents for 2 min, rinsed with saline, and the incubation was continued in complete culture medium for 6, 12, 24, 48, or 72 h with [3H]proline added for the final 6 h. Solutions containing the antiseptic agents were cytotoxic to both bones and cells at concentrations well below those used clinically in irrigation solutions. In contrast, bacitracin at the concentrations tested was safe for osteoblasts and tibiae. These results suggest that the use of irrigation solutions containing H2O2, Betadine solution, or Betadine scrub on exposed bone tissue should be considered with caution.

[Evaluation of the cytotoxicity of antiseptics used in current practice on cultures of fibroblasts and keratinocytes]

Infection is the greatest problem in burn patients and topical antiseptics must be chosen with great care especially when cultured skin is grafted. We examined the cytotoxicity of 6 antiseptics commonly used on cultured human fibroblasts and keratinocytes. Cultured cells were exposed for 15 min to Hibitane (chlorhexidine), Biseptine (chlorhexidine + benzalkonium chloride + benzylic alcool), dermic Betadine (polvidone iodine + nonoxinol), scrub Betadine (polyvidone iodine + quaternary ammonium) and gynecologic Betadine (polyvidone iodine). The cell viability was determined using the MTT test. At therapeutic concentration all the antiseptics were cytotoxic for fibroblasts and keratinocytes. The data suggest that the antiseptics must be used in function of the time of the grafting of the cultured epithelium.

Preservative-free artificial tear preparations. Assessment of corneal epithelial toxic effects

Scanning electron microscopy was used to evaluate the corneal epithelium of rabbit eyes after administration of two preservative-free ocular lubricants, preservative-free artificial tear-1 (Hypotears PF) and preservative-free artificial tear-2 (Refresh), and 0.02% benzalkonium chloride. Animals were randomly assigned to either mild or exaggerated use regimens. A quantitative rating system was used to assess epithelial damage. With mild use, scanning electron microscopy revealed normal epithelial morphologic characteristics for both preservative-free artificial tear solutions (mean relative damage score, solution 1, 0.75 +/- 0.16; solution 2, 1.02 +/- 0.23), which were not significantly different from eyes treated with phosphate-buffered saline (1.38 +/- 0.38) or a mild dosage regimen of 0.02% benzalkonium chloride (1.20 +/- 0.12). Exaggerated use with preservative-free artificial tear solutions (solution 1, 1.31 +/- 0.21; solution 2, 1.35 +/- 0.08) induced minimal damage that was not different from control eyes treated with phosphate-buffered saline (1.26 +/- 0.13). Compared with an exaggerated use of 0.02% benzalkonium chloride (4.0 +/- 0.16), both preservative-free artificial tear solutions induced significantly less epithelial damage (P = .0001). These results suggest that with frequent-dosage regimens, preservation-free artificial tear solutions-1 and -2 are free of the toxic effects associated with preserved solutions.

The cytotoxic effects of commonly used topical antimicrobial agents on human fibroblasts and keratinocytes

This study evaluated the cytotoxicity of commonly used topical agents to human dermal fibroblasts and epidermal keratinocytes, which play a prominent role in wound healing. The effects of these topical agents were assessed using two separate assays for the fibroblasts--tritiated thymidine incorporation and the uptake of a vital dye (neutral red). Keratinocytes were evaluated with the neutral red assay. Serial dilutions of each of 10 commonly used topical agents produced decreases in both the uptake of neutral red and the incorporation of thymidine at clinically relevant doses. Only Neosporin G.U. irrigant showed no significant difference compared with controls in the assays for both the fibroblasts and the keratinocytes. Careful attention must be paid to which agent is used in the clinical setting, since many of these can have profound effects on cells that influence wound healing.

Non-toxic antiseptic irrigation with chlorhexidine in experimental revascularization in the rat

The effect of different wound irrigation fluids upon femoral arteries and veins was investigated in the rat, using microsurgical techniques. Toxicity was evaluated by microscopical observation after selective staining of histological slides. Povidone-iodine, 10%, proved to be a very irritant solution, provoking an attack on the vascular endothelium and secondary thrombosis. Chlorhexidine at 0.05%, 0.02% and 0.001% was found by contrast to have a very low toxicity which was comparable to physiological saline. Experimental investigation of antiseptic solutions should not only include the determination of the antibacterial effect, but also the potential for cell toxicity, using an irrigation technique.

Tolerance of intravitreal povidone-iodine in rabbit eyes

Povidone-iodine is frequently instilled on to the conjunctival surface prior to intraocular surgery in order to prevent septic endophthalmitis. A small amount of povidone-iodine is inevitably introduced into the eye when it is used in this manner. The toxicity of intravitreal povidone-iodine was assessed in rabbit eyes by injecting 0.1 ml of povidone-iodine in concentrations of 0.05%, 0.5% and 5% into the vitreous cavity. The injected eyes were evaluated by clinical examination, anterior segment and fundus photography, endothelial cell counts, electroretinography and histopathology. Compared to control eyes, no changes were observed in all 6 eyes injected with 0.1 ml of 0.05% povidone-iodine solution. 9 of 10 eyes tolerated a concentration of 0.5% with no detectable adverse changes. One eye developed a temporary mild iritis and mild suppression of the ERG. Intra-retinal hemorrhages, edema, arteriolar narrowing and retinal edema were seen one week following injection. Mild retinal necrosis of the same area was seen on histology. All 4 eyes injected with 5% povidone-iodine developed temporary hypotony and iridocyclitis. A dense cataract developed in all eyes. Full thickness retinal necrosis and a profound lasting reduction in the ERG was produced in all of these eyes. No corneal epithelial or endothelial changes were observed in any eye in this series. Low concentrations of intravitreal povidone-iodine likely to be produced by instillation prior to surgery are tolerated by rabbit eyes. The concentrations tolerated by the studied eyes are near reported bactericidal levels.

[Cytotoxicity of povidone-iodine on cultured mammalian cells]

Cytotoxicity of povidone-iodine on cultured mammalian cells was studied using cultured Chinese hamster lung cells (V 79 cells). Treatment of V 79 cells with povidone-iodine at 100-500 micrograms/ml for 24 to 72 hr induced a growth inhibition of the cells in a dose-dependent manner. Although minimum inhibition of survival of V 79 cells was elicited in cultures treated with povidone-iodine at 100-300 micrograms/ml for 2 to 24 hr, treatment at 500 micrograms/ml for 6 to 24 hr resulted in decrease in cell survival in a treatment time-dependent fasion. Exposure of cells to povidone-iodine at 100-500 micrograms/ml for 2 hr caused inhibition of DNA, RNA or protein synthesis of cells up to 13.9% of untreated cells. These results indicate that cytotoxicity of povidone-iodine occurs in dose- and treatment time-dependent manners and that povidone-iodine induces inhibition of DNA, RNA and protein syntheses of cells, even by the treatment which causes no reduction of cell survival.

Chlorhexidine diacetate and povidone-iodine cytotoxicity to canine embryonic fibroblasts and Staphylococcus aureus

Chlorhexidine diacetate and povidone-iodine were evaluated for fibroblast toxicity on a primary line of canine embryonic fibroblasts, and for bactericidal efficacy against Staphylococcus aureus. The cultured fibroblasts or S. aureus were exposed for 30 minutes to incremental dilutions of 0.5 and 0.0005% chlorhexidine diacetate, 5.0 to 0.05% povidone-iodine, or physiologic buffered saline as a control. To determine survival, fibroblasts were trypsinized and counted; S. aureus colonies were counted on brain-heart infusion agar. Survival for both groups was expressed by calculating the number of living cells in test dilutions as a percentage of the number in control cultures. Fibroblast survival occurred at chlorhexidine concentrations less than 0.013% and at povidone-iodine concentrations less than 0.5% (p less than 0.05). Significant S. aureus survival (p less than 0.05) was noted at chlorhexidine concentrations less than 0.05% and povidone-iodine concentrations less than 1.0%. These data showed that all bactericidal concentrations of chlorhexidine diacetate and povidone-iodine were lethal to canine embryonic fibroblasts in vitro, whereas non-lethal concentrations allowed significant bacterial survival.

Polyvinylpyrrolidone iodine: corneal toxicology and epithelial healing in a rabbit model

Polyvinylpyrrolidone-iodine (PVP-I) is a biocompatible broad spectrum antimicrobial that is widely used as an ophthalmic pre-operative prepping agent. In order to determine if PVP-I is safe for treating corneal ulcers and conjunctivitis, we evaluated the ocular toxicity of frequent dosing in a rabbit model. We evaluated ocular irritation in 18 rabbits according to the McDonald-Shadduck method. Concentrations of 0.5% PVP-I or less were practically non-irritating when administered six times per day. We evaluated corneal epithelial wound healing in 16 rabbits with standardized abrasions. Concentrations of 0.33% PVP-I showed epithelial healing comparable to gentamicin treated eyes and untreated controls. Concentrations of 0.5% PVP-I delayed epithelial healing by one day. Because of its broad spectrum and apparently low toxicity, PVP-I may be a useful treatment for corneal ulcers, keratitis and conjunctivitis.

Haematology and serum biochemistry in the racing greyhound following intraperitoneal povidone-iodine

Povidone-iodine caused peritonitis with neutrophilic leukocytosis and a minimal left shift at the dosage rate of 3.5 ml/kg body weight. A dosage rate of 2 ml/kg only caused slight neutrophilic leukocytosis. There was a significant increase in the levels of creatinine (p = 0.049) and BUN (p = 0.020) in dogs that received the higher dose rate. Two dogs died from povidone-iodine toxicity with a marked increase in ALT, AP, SDH and conjugated bilirubin. It is concluded that povidone-iodine is unsafe for use in the peritoneal cavity of dogs.

The use of povidone iodine in neonatal bowel surgery

The ostomy sites of four premature infants undergoing bowel reanastomosis were lavaged with a 10% solution of povidone iodine to reduce local bacterial contamination and the risk of anastomosis dehiscence. There was a significant decrease in serum thyroxin from 112 (+/- 11) mumol/L to 90 (+/- 33) mumol/L 24 hours following surgery (P less than .05), but no change in serum thyroid stimulating hormone (TSH). The total serum iodine rose from 1.5 (+/- 0.05) mumol/L before surgery to 61.6 (+/- 46.4) mumol/L 24 hours later and urinary iodine excretion was 60 times the preoperative value in the second 24 hours following surgery. Both the hormonal and biochemical indices returned to normal 2 weeks following surgery except for total serum iodine, which remained slightly elevated. Povidone iodine is a safe and effective antiseptic agent. However, as it may cause transient suppression of thyroid function in neonates, thyroid status should be tested in all such infants at approximately 2 weeks following repeated or widespread use.

[Teratologic studies on a low-molecular polyvinylpyrrolidone-iodine complex in rabbits]

In investigations on rabbits a low-molecular polyvinylpyrrolidone-iodine complex was tested upon its facultative teratological effects after intramuscular application. The dams showed a dose dependent loss of weight increase. The average embryo- and placenta weights of test animals were lower than those of the control animals. Some malformations in kidneys were realised, but they did not show any relation to dosage. Concerning the applied doses no teratological effect was observed.

Topical antimicrobial toxicity

Three topical antibiotics and four antiseptics (1% povidone-iodine, 0.25% acetic acid, 3% hydrogen peroxide, and 0.5% sodium hypochlorite) were directly applied to cultured human fibroblasts to quantitatively assess their cytotoxicity. The four antiseptics were found to be cytotoxic; all of the cytotoxic agents except hydrogen peroxide were subsequently found to adversely affect wound healing in an animal model. Comparison of bactericidal and cytotoxic effects of serial dilutions of these four topical agents indicated the cellular toxicity of hydrogen peroxide and acetic acid exceeded their bactericidal potency. Bactericidal noncytotoxic dilutions of povidone-iodine and sodium hypochlorite were identified. These experiments provide evidence that 1% povidone-iodine, 3% hydrogen peroxide, 0.5% sodium hypochlorite, and 0.25% acetic acid are unsuitable for use in wound care. This sequence of experiments could be used to identify bactericidal, noncytotoxic agents prior to their clinical use.

Pericardial injury by antibacterial irrigants

We injected antibacterial solutions into rabbit pericardium to investigate tissue injury. Povidone-iodine was the only irrigant found to cause substantial damage. These data lend experimental support to recent clinical observations that suggest a causal relation between pericardial irrigation with povidone-iodine and the later development of constrictive pericarditis.

Povidone-iodine bladder injury in rats and protection with heparin

Povidone-iodine (Betadine) has been proposed for clinical use in controlling bacterial infections by intravesical instillation in concentrations ranging from 0.1 to 1 per cent. The effects, however, of povidone-iodine on the urothelium of the bladder have not been well studied. We performed experiments to see if injury to the urothelium occurred from intravesical instillation in female rats. Injury was indeed found with concentrations of 0.3 per cent and 1 per cent povidone-iodine, as judged by the observations of increased bladder weight due to edema, histological examination, in vivo bladder staining, crystal adhesion and bacterial adhesion upon the bladder mucosa after povidone-iodine injury. Further study showed that the urothelium recovered in 6 to 7 days after povidone-iodine injury, while a 3rd experiment demonstrated at least partial protection from bacterial and crystal adhesion to povidone-iodine injured urothelium by immediate treatment with heparin instillation in the bladder.

Rat bladder irrigation with PVP-I2

Despite technical advances, Foley catheter associated urinary tract infections continue to be the leading cause of nosocomial infections. PVP-I2 has been shown to be nonirritating to abraded tissue and we have shown that dilute solutions are bactericidal for organisms causing Foley catheter associated urinary tract infections. The purpose of this study was to ascertain the toxicity of PVP-I2 on the catheterized rat bladder and to measure the systemic absorption of I2. Bladder catheters were surgically placed into each of 3 groups of rats: group 1, catheters only; group 2, irrigation with PBS q.8h; and group 3, irrigation with a 1:3 dilution of a 10 per cent PVP-1 per cent I2 solution q-8h. One-half of each group was sacrificed at 1 and 2 weeks respectively. Photographs of mounted bladders and histologic sections were then graded by 3 independent observers. Blood for protein bound iodine (PBI), T3 and T4 levels was obtained before the study and at sacrifice. No difference in ulcerations, erythema or inflammation was noted. PBI was higher in group 3 rats at conclusion than group 1 and 2 (6.88 mg./dl. versus 3.42 mg./dl.) (p less than 0.05). There was no difference in T3 or T4 levels. In this study, PVP-I2 was no more toxic to the bladder than catheterization alone or irrigation with PBS.

Assessment of somatogenotoxicity of povidone-iodine using two in vitro assays

The mutagenic potential of povidone-iodine (PVP-I) and some related compounds were studied using the L5178Y mouse (TK+/-) lymphoma assay. The established mutagens ethyl methanesulfonate (EMS) and dimethylnitrosamine (DMN) were highly active in this assay, whereas PVP-I, polyvinyl pyrolidone (PVP), potassium iodide (KI), and iodine (I2) were inactive. Furthermore, in the presence of a rat liver microsomal activating fraction (S-9), PVP-I and I2 had only marginal activity as mutagens. Using the Balb/c 3T3 transformation assay we assessed the transformational capacities of these same agents and the positive mutagen N-methyl-N-nitro-N-nitrosoguanidine (MNNG). All concentrations of the compounds tested were inactive in this assay except for PVP-I (5 mg/ml) and MNNG (5 micrograms/ml). However, the response with PVP-I was only marginal. We concluded from these studies that PVP, PVP-I, KI, and I2 did not possess any biologically significant mutagenic or cell transforming ability.

Intraperitoneal povidone-iodine in experimental peritonitis

Two experimental models were utilized to study the efficacy of intraperitoneal povidone-iodine in an established peritonitis. In both models, there was a 100% mortality in the povidone-iodine treated group. In laboratories which have reported favorable results, the animals were treated before peritonitis was allowed to develop. Clinical studies with povidone-iodine lavage have used dilute solutions which did not remain in the infected space. The effectiveness of this method was probably due to mechanical continuous irrigation. Our toxicity studies showed povidone-iodine to be fatal in normal animals in dosages exceeding 4.0 ml/kg. However, a dose of 2.0 ml/kg, which was nontoxic in normal animals, was fatal in animals with peritonitis. This study strongly suggests that the intraperitoneal administration of povidone-iodine can be fatal when the animal is compromised by peritonitis. The mechanism of this effect is unclear. On the basis of these studies, the intraperitoneal administration of povidone-iodine cannot be recommended for therapy of peritonitis.

Tissue toxicity of antiseptic solutions. A study of rabbit articular and periarticular tissues

The gross, histologic, and biochemical effects of four commercially available antiseptic solutions on rabbit knee articular and periarticular connective tissues were investigated. Rabbit knee joints were injected with 2.0 cc of either Betadine prep solution, Betadine scrub solution, pHisohex or 3% hexachlorophene. The opposite knees were injected with sterile saline. All animals were injected three times at 48-hour intervals and sacrificed 10 days after the last injection. The solutions containing detergents, Betadine scrub, and pHisohex caused severe gross and histologic damage to articular cartilage, synovia, and muscle. The hexachlorophene loss solution caused moderate histologic damage, but caused articular cartilage ground substance. Betadine prep solution caused only minimal gross and histologic damage, without any biochemical evidence of articular cartilage damage. If antiseptic solutions are to be used in irrigating or packing joint injuries, the use of Betadine prep is recommended.

Further studies on effects of irrigation solutions on rat bladders

Further studies on the effects of certain irrigating fluids on the rat bladder for 18 hours are reported. The results have shown that the degradation product p-choloroaniline is not a significant factor in chlorhexidine-digluconate associated erosive cystitis. A high percentage of kanamycin-colistin and povidone-iodine irrigations were associated with erosive cystitis and suggested a possible complication with human usage. Picloxydine irrigations appeared to have a lower incidence of erosive cystitis but further studies would have to be performed before it could be recommended for use in urological procedures.