The Genotoxic Effect of Nasal Steroids on Human Nasal Septal Mucosa and Cartilage Cells In Vitro.

OBJECTIVE: To determine whether budesonide (Bud) and triamcinolone acetate (TA) cause DNA fractures in the nasal mucosa and septal cartilage cells through examinations using the comet assay technique. STUDY DESIGN: Prospective, controlled experimental study. SETTING: University hospital. METHODS: Septal mucosal epithelial and cartilage tissue samples were taken from 9 patients. Cell cultures were prepared from these samples. Then, budesonide and triamcinolone acetate active ingredients at 2 different doses of 0.2 and 10 µM were separately applied to the cell cultures formed from both tissues of each patient, except the control cell culture, for 7 days in one group and 14 days in one group. After the applications, genotoxic damage was scored with the comet assay technique and the groups were compared. RESULTS: In both the budesonide and triamcinolone acetate groups, the comet scores at low and high doses, on the 7th and 14th days were found to be significantly higher in both cartilage and epithelial tissue than in the control group. CONCLUSION: The study results showed that budesonide and triamcinolone acetate lead to a significantly high rate of genotoxic damage in both epithelial tissue and cartilage tissue.

Cell Toxicity in Fibroblasts, Tenocytes, and Human Mesenchymal Stem Cells-A Comparison of Necrosis and Apoptosis-Inducing Ability in Ropivacaine, Bupivacaine, and Triamcinolone.

PURPOSE: To analyze the ability of ropivacaine, bupivacaine, and triamcinolone to induce apoptosis and necrosis in fibroblasts, tenocytes, and human mesenchymal stem cells. METHODS: Human dermal fibroblasts, adipose-derived human mesenchymal stem cells (hMSCs), and tenocytes gained from the rotator cuff tendon were seeded with a cell density of 0.5 × 104/cm2. One specimen of ropivacaine, bupivacaine, and triamcinolone was tested separately on the cells with separate concentrations of 0.5%, 0.25%, and 0.125% for each specimen. The negative control received no agent, only a change of medium. The incubation period for each agent was 30 minutes. After a change of medium and 1 hour, 24 hours, and 7 days of incubation, 104 cells were harvested and analyzed via fluorescence-activated cell sorting with double-staining with annexin V and propidium iodide. Statistical analysis to determine significant difference (P < .05) between the groups with SPSS statistics 23 through one-way analysis of variance with a univariate general linear model was performed. RESULTS: Bupivacaine showed necrosis-inducing effects on fibroblasts and tenocytes, with the necrotic effect peaking at 0.5% and 0.25%. Ropivacaine and triamcinolone caused no significant necrosis. Compared with fibroblasts and tenocytes, hMSCs did not show significant necrotic or apoptotic effects after exposure to bupivacaine. Overall, no significant differences in apoptosis were detected between different cell lines, varying concentrations, or time measurements. CONCLUSIONS: Bupivacaine 0.5% and 0.25% have the most necrosis-inducing effects on fibroblasts and tenocytes. Ropivacaine caused less necrosis than bupivaine. Compared with fibroblasts and tenocytes, hMSCs were not affected by necrosis using any of the tested agents. A significant apoptosis-inducing effect could not be detected for the different cell lines. CLINICAL RELEVANCE: Possible cell toxicity raises questions of concern for intra-articular injections using local anesthetics and corticosteroids. The present study demonstrates the necrotic and apoptotic effects of ropivacaine, bupivacaine, and triamcinolone and may give recommendations for intra-articular use of local anesthetics and corticosteroids.

The retinal biocompatibility of dyes in the ex vivo model of the isolated superfused vertebrate retina.

BACKGROUND: Peeling of the internal limiting membrane or epiretinal membranes is a successful principle in macular surgery to achieve a functional benefit. Different dyes are used to facilitate the identification of intraocular tissues. The aim of our work was to investigate the retinal tolerance to the different dyes and their solvent carriers to provide valuable data for surgeons in handling for an optimal intraoperative use. METHODS: Using the ex vivo model of the isolated superfused vertebrate retina technique, the effects of the dyes were tested on human and bovine retinal function. The retinas were perfused with an oxygen preequilibrated standard solution. The electroretinogram (ERG) was recorded using Ag/AgCl electrodes. After recording stable ERG amplitudes, the dyes brilliant blue G, indocyanine green, trypan blue, patent blue, triamcinolone and their solvent carriers were investigated. RESULTS: Reductions of the ERG amplitudes were found for each tested dye. The effects after application of the dyes were dependent on time and concentration of the applied dyes, which were different for each dye. CONCLUSION: In part, the ERG has shown strong effects already after a short period of dye application. Surgeons who rely on the intraocular use of the dyes should keep in mind our findings, and the use of some dyes should be limited to selected cases. The well-considered use of the dyes by the surgeons could lead to a better functional outcome and avoid a possible harmful outcome of the surgery after mishandling.

The chondrotoxicity of single-dose corticosteroids.

PURPOSE: Corticosteroids are commonly injected into the joint space. However, studies have not examined the chondrotoxicity of one-time injection doses. The purpose of this study is to evaluate the effect of dexamethasone sodium phosphate (Decadron), methylprednisolone acetate (Depo-Medrol), betamethasone sodium phosphate and betamethasone acetate (Celestone Soluspan), and triamcinolone acetonide (Kenalog) on human chondrocyte viability in vitro. METHODS: Single-injection doses of each of the corticosteroids were separately delivered to human chondrocytes for their respective average duration of action and compared to controls using a bioreactor containing a continuous infusion pump constructed to mimic joint fluid metabolism. A 14-day time-controlled trial was also performed. A live/dead reduced biohazard viability/cytotoxicity assay was used to quantify chondrocyte viability. RESULTS: Over their average duration of action, betamethasone sodium phosphate/acetate solution and triamcinolone acetonide caused significant decreases in chondrocyte viability compared to control media (19.8 ± 2.9% vs. 5.2 ± 2.1%, P = 0.0025 and 10.2 ± 1.3% vs. 4.8 ± 0.9%, P = 0.0049, respectively). In the 14-day trial, only betamethasone sodium phosphate/acetate solution caused a significant decrease in chondrocyte viability compared to control media (21.5% vs. 4.6%, P < 0.001). CONCLUSIONS: A single-injection dose of betamethasone sodium phosphate and betamethasone acetate solution illustrated consistent and significant chondrotoxicity using a physiologically relevant in vitro model and should be used with caution. Given the observed chondrotoxicity of triamcinolone acetonide in a single trial, there may be some evidence that this medication is chondrotoxic. However, at 14 days, betamethasone sodium phosphate and betamethasone acetate was the only condition that caused significant cell death.

Toxicological considerations for intravitreal drugs.

INTRODUCTION: Intravitreal injections are a very common procedure and are the most effective route of drug delivery to the retina. There are currently several drugs available and even more are in development; therefore, safety is a very important concern. AREAS COVERED: The toxicological considerations of the most common drugs used for intravitreal pharmacotherapy such as anti-VEGFs, corticosteroids and antibiotics. Emerging agents such as anti-TNFs, VEGF-trap and kinase inhibitors are also discussed. An assessment of the efficacy and safety issues of the most relevant drugs including bevacizumab, ranibizumab and triamcinolone is presented. EXPERT OPINION: The toxicology and safety profiles are available for several drugs that are either in use or will be available for intravitreal injections. Retinal pharmacotherapy is very effective for different retinal diseases; however safety is a very important issue when intravitreal injections are applied and the possibility of retinal toxicity should always be kept in mind. Bevacizumab and ranibizumab are effective for the therapy of wet-age-related macular degeneration and macular edema, while triamcinolone remains an alternative agent to treat secondary macular edema. It is important, as some of these drugs will be used for extended periods of time, that their long-term toxicological effects are better understood.

The effects of commercially available preservative-free FDA-approved triamcinolone (Triesence®) on retinal cells in culture.

PURPOSE: To evaluate the effects of Triesence® (TRI), a new preservative-free triamcinolone approved by the U.S. Food and Drug Administration (FDA) for intraocular use, on human retina pigment epithelial (ARPE-19) and rat neurosensory (R28) cells in culture. METHODS: ARPE-19 and R28 cell cultures were treated 24 h with 1,000, 500, 200, or 100 µg/mL of crystalline (cTRI) or 1,000, 500, or 200 µg/mL of solubilized (sTRI). TRI was solubilized by centrifuging the drug, discarding the supernatant containing the vehicle and then resuspending the drug pellet in an equivalent amount of Dimethyl sulfoxide to achieve the same concentration as the commercial preparation. Percentage of cell viability (CV) was evaluated by a trypan blue dye-exclusion assay. The mitochondrial membrane potential (ΔΨm) was analyzed with the JC-1 assay. The caspase-3/7 activity was measured by a fluorochrome assay. RESULTS: In the ARPE-19 cultures, the cTRI caused a decrease in CV at 1,000 µg/mL (13.03±6.51; P<0.001), 500 µg/mL (28.87±9.3; P<0.001), 200 µg/mL (54.93±5.61; P<0.001), and 100 µg/mL (82.53±0.65; P<0.005) compared with the untreated controls (96.98±0.16). In R28 cultures, the cTRI treatment also reduced CV values significantly (P<0.001) for the 1,000 µg/mL (22.73±2.44), 500 µg/mL (34.63±1.91), 200 µg/mL (58.70±1.39), and 100 µg/m (75.33±2.47) compared with the untreated controls (86.08±3.54). Once the TRI was solubilized (sTRI), the CV and ΔΨm remained similar to the untreated controls for both ARPE-19 and R28 cells. The sTRI treatment with 1,000, 500, and 200 µg/mL increased in caspase-3/7 activity in ARPE-19 cells (P<0.01) and in R28 cells (P<0.05) compared with dimethyl sulfoxide equivalent controls. CONCLUSION: The crystalline form of TRI (cTRI) can cause a significant decrease in CV to cultured retinal cells. Once the TRI is solubilized (sTRI), at the same concentrations, the cells remain viable with no decrease in CV or ΔΨm. The sTRI can, however, increase caspase-3/7 activity, thus suggesting some degree of apoptosis.

Bupivacaine and triamcinolone may be toxic to human chondrocytes: a pilot study.

BACKGROUND: Intraarticular injections of corticosteroids combined with local anesthetics are commonly used for management of chronic pain symptoms associated with degenerative joint diseases and after arthroscopic procedures. Several studies suggest chondrotoxicity of local anesthetics whereas others report chondroprotective and cytotoxic effects of corticosteroids on cartilage. Given the frequency of use of these agents, it is important to know whether they are in fact toxic. QUESTIONS/PURPOSES: We asked whether (1) bupivacaine and triamcinolone acetonide, alone and combined, were chondrotoxic to chondrocytes in culture; (2) buffering of the reagents diminished toxicity of the bupivacaine and triamcinolone; and (3) the presence of the superficial layer of articular cartilage protects against toxicity. MATERIALS AND METHODS: We obtained cartilage from three patients undergoing arthroplasty. To address triamcinolone acetonide, bupivacaine, and combinatorial toxicity to human chondrocytes, we set up monolayer chondrocyte cultures (n = 8 wells per condition). The question of buffering was addressed by performing the same assays as above, but the reagents were buffered. An MTT assay was used to assess chondrocyte survival in the monolayer. We harvested 21 articular plugs from each of three patients (total 63 plugs) and exposed them to the same reagents as above, including the buffered reagents. A Live/Dead assay was used to determine chondrocyte survival. RESULTS: Triamcinolone acetonide, bupivacaine, and their combination were toxic to human chondrocytes in the monolayer comparisons. The addition of buffering did not mitigate chondrocyte death. With the intact superficial layer in the plug group, bupivacaine was not toxic as compared with for the control group; all the other reagents (triamcinolone, combination bupivacaine/triamcinolone, buffered bupivacaine, buffered triamcinolone, and buffered combination) produced chondrotoxicity. CONCLUSIONS: Triamcinolone induced chondrotoxicity in the articular plug and monolayer culture, whereas bupivacaine induced chondrotoxicity only in monolayer culture. The combined used of triamcinolone and bupivacaine did not show additive chondrocyte death in any arm. Buffering of bupivacaine increased its chondrotoxicity. CLINICAL RELEVANCE: Although not necessarily reflecting in vivo conditions, our data suggest physicians should be cognizant of the potential in vitro chondrotoxicity of bupivacaine and triamcinolone when contemplating intraarticular administration.

Intravitreal micronized triamcinolone versus triamcinolone acetonide: a clinical and morphological comparative study.

Nowadays many authors suggest the use of intravitreal triamcinolone acetonide (TA) for the treatment of vitreoretinal diseases, although it can be associated with a high risk of local toxicity. In order to develop a safer injection for clinical use, the purpose of our study is to evaluate the in situ safety of two different triamcinolone preparations, a commercially available TA and a micronized triamcinolone. The experiments were performed on 18 adult male age-matched New Zealand rabbits. The clinical examination included funduscopy with an indirect ophthalmoscope and intraocular pressure (IOP) measurement. At the end of the clinical observations, the animals were sacrificed and the eyes enucleated and processed for the morphological evaluation. In our study the main side effect observed was the IOP elevation in the group injected with triamcinolone acetonide. In addition, in the TA-injected group, one eye was enucleated following an endophthalmitis. Our study highlights that doses as low as 4 mg of triamcinolone acetonide injected into the rabbit vitreous may have a local toxic effect in terms of IOP elevation, endophthalmitis occurrence and changes in the retinal morphology. In contrast, the micronized triamcinolone injection shows a less toxic effect in situ, thus suggesting the alternative use of this more reliable preparation which seems to be safer for a clinical use.

[Optic atrophy subsequent to epiretinal triamcinolone deposits in an eye following inner limiting membrane peeling]. / Optikusatrophie nach epiretinalen Triamcinolon-Ablagerungen in einem Auge mit entfernter Membrana limitans interna.

BACKGROUND: Although current in vitro studies show local cytotoxicity of triamcinolone (TA) crystals if they are in direct contact with cells, a toxic effect of epiretinal TA deposits has not been reported yet clinically. For the first time, we present a case of potential cytotoxicity of epiretinal TA deposits in vivo. CASE REPORT: A 68-year old patient underwent a re-vitrectomy with peeling of a macular pucker and the internal limiting membrane (ILM) combined with an intravitreal injection of 25 mg TA due to a secondary macular pucker with cystoid macular edema. Postoperatively, pronounced epiretinal deposits of TA crystals were identified in the area of the posterior pole. Two months after the injection a consecutive optic atrophy with central visual field defect and severe reduction of the visual acuity to hand movements was apparent. CONCLUSION: Our case report indicates possible in-vivo toxicity of TA deposits in eyes subsequent to vitrectomy and peeling of the ILM. This is in accordance with previous in-vitro studies showing ILM and vitreous to be protective biological factors, but demonstrate pronounced cytotoxicity if TA crystals are allowed to directly adhering to denuded ganglion cells. Hence, we consider that TA injection should be carefully weighed in those patients with prior ILM removal.

Potentiation of triamcinolone-induced cleft palate in mice by maternal high dietary fat.

This study investigated whether the current range in dietary fat levels, which has arisen partly in response to some major health concerns, would affect frequency of congenital anomalies if continued into the period of early pregnancy. The effect of 5.6%, or 48% of calories from fat in the maternal diet, was tested on pregnant strain CD-1 mice injected with triamcinolone in doses of 0.01 mg, 0.02 mg, 0.04 mg, or 0.06 mg per day on days 11 through 14 of gestation. Frequency of cleft palate increased with increasing doses of triamcinolone, with clefts of the palate being rare at the two lower doses. No clefts appeared without triamcinolone on either diet. In combination with triamcinolone treatment, 226 fetuses exposed to a maternal low fat diet had normal palates and 86 had cleft palates. With exposure to high fat, 186 fetuses had normal palates and 101 had cleft palates, which was a significant increase in clefting (p < 0.05). Also, the latter group showed a greater degree of retardation in palate development (p < 0.05). Thus both a greater frequency and a more severe form of clefting support the conclusion that high dietary fat potentiated the cleft palate-producing effects of triamcinolone in mice.

Reversible effects of triamcinolone and lack of effects with aspirin or L-656,224 on external genitalia of male Sprague-Dawley rats exposed in utero.

Inhibitors of the arachidonic acid cascade were given to pregnant rats during the critical period for morphogenesis of the external genitalia. Groups treated subcutaneously (s.c.) with 0.1 or 0.25 mg/kg/day of triamcinolone acetonide (TA) on gestational days (GD) 14-19 had male fetuses on GD 20 with moderate decreases in absolute anogenital distance (AGD), but gross and histological examinations revealed no alterations to the genital tubercle (i.e., no hypospadias). The s.c. coadministration of arachidonic acid at 100 mg/kg/day had minimal to no effect on AGD in the TA-exposed groups. No effect on AGD was observed in male fetuses from groups administered aspirin orally at 150 mg/kg/day, and only a 6% decrease was observed in the 300-mg/kg/day group. Neither TA nor aspirin adversely affected AGD of female fetuses. In another study, TA was administered on GD 11-19 at dose levels of 0.05 and 0.1 mg/kg/day, and dams were allowed to deliver. High-dose male offspring examined on postcoitum day (PCD) 23, had moderate decreases in AGD. In both studies with TA, there were also significant decreases in offspring weights. The contribution of the decreased weight to the decrease in absolute AGD was examined by a variety of methods (ratio of AGD to cube root of weight or biparietal distance, comparison to weight-matched controls, and covariance analysis). We conclude that TA caused a specific decrease in AGD on GD 20 that was largely reversed by PCD 23. When examined as adults (8 weeks old), the external genitalia of TA-exposed offspring were normal. Thus, the TA-induced decreases in AGD on GD 20 did not predict irreversible malformation. TA also caused other effects, which included a somewhat flattened genital tubercle and apparently thinned and glossy skin between the tubercle and the anus in both sexes on GD 20 and PCD 23, but not as adults. In addition, there were high pup mortality and high incidences of micrognathia and omphalocele (in the 0.25-mg/kg/day group only). Aspirin at 75 or 150 mg/kg/day and a specific lipoxygenase inhibitor (L-656,224) at 1,000 or 2,000 mg/kg/day were also administered from GD 14 to 19, and no offspring effects were observed. Thus, of the three agents that potentially inhibit the arachidonic acid cascade, only triamcinolone produced moderate effects on rat external genitalia that were largely reversible.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of ototopic application of a corticosteroid preparation on cochlear function.

The ototoxicity of the corticosteroid triamcinolone diacetate was investigated using the compound action potential (CAP) of the auditory nerve as a parameter when the drug was applied to the middle ear cavity of the chinchilla. Comparison with the contralateral ear, instilled with Ringer's solution, demonstrated no significant difference in the threshold, amplitude, and latency of the CAP responses at the overall frequencies tested. In addition, the side difference of the CAP threshold in individual animals showed that this corticosteroid did not induce cochlear dysfunction in any case.

Pathologic changes and contractile properties of the diaphragm in corticosteroid myopathy in hamsters: comparison to peripheral muscle.

Corticosteroids have been shown to produce a myopathy of peripheral skeletal muscle, characterized predominantly by Type II fiber atrophy. To determine if similar histologic and histochemical changes occur in the diaphragm and whether the in vitro contractile properties of this muscle are adversely affected by steroids, we studied two groups of hamsters. The experimental group received triamcinolone while a control group received saline, both given daily for 3 wk as i.m. injections. Soleus (Sol) and extensor digitorum longus (EDL) muscles and costal diaphragm muscle sections were stained for histologic (hematoxylin and eosin, modified Gomori trichrome) and histochemical (myosin ATPase, succinate dehydrogenase [SDH]) analysis. Muscle fiber proportions and cross-sectional areas (CSA) were measured from myosin ATPase sections. In vitro studies of isometric contractions were carried out on small strips of costal diaphragm, measuring maximal isometric twitch (Pt) and tetanus (Po) tensions, time to peak tension (TTP), half relaxation time (1/2 RT), force-frequency relationship, and fatigue characteristics (60 Hz tetani; duty cycle, 0.5). Triamcinolone treatment resulted in no change in muscle fiber proportions. There was no effect on Type I fiber CSA; however, there was Type IIa (Sol, EDL) and Type IIb (diaphragm, EDL) fiber atrophy in triamcinolone-treated animals. Pt and Po (normalized for weight) of diaphragm strips were not different. There was a prolongation in TTP and 1/2 RT, a left shift in the force-frequency curve, and a reduced fatiguability of triamcinolone-treated diaphragm (P less than 0.05). We conclude that a steroid myopathy could be explained by a loss of muscle mass (Type IIb fiber atrophy) rather than an intrinsic impairment in contractile function.(ABSTRACT TRUNCATED AT 250 WORDS)

[Development and regression of dermal corticosteroid atrophy. 3. Results of discontinuous topical corticosteroid administration]. / Untersuchungen über Entstehung und Rückbildung der dermalen Kortikosteroid-Atrophie. 3. Mitt.: Ergebnisse einer diskontinuierlichen topischen Kortikosteroid-Applikation.

It was shown in two earlier communications that a reduction in skin thickness owing to daily topical corticosteroid application (under occlusion) for about 12 h was measurable within a few days. Dermal atrophy remitted within one week. In this study, an open mode of topical application with a 0.1% triamcinolone ointment (Tri) once a day was tested. A decrease in thickness was also registered in the first week under this treatment. The following non-continuous modes of application were tested in 5 test subjects: 7 d Tri, 7 d free of treatment (7:) and 3 d Tri, 4 d free of treatment (3:4). In the 7:7 mode of application, there was a marked decrease of skin thickness during Tri application which remitted in the treatment-free interval. In the 3:4 application, almost no dependence on the individual phases could be discerned. Skin thickness decreased for nearly 16 d and began to normalize despite continued interval administration. At the end of the investigation (6 weeks), the skin had almost regained its original thickness.

A comparison of hydrocortisone and triamcinolone inhibition of scale and feather development.

Hydrocortisone (30-40 micrograms on day 10) and triamcinolone (10-20 ng on day 7-8) both inhibit or alter morphogenesis of scales and feathers. However, there are marked temporal and region-specific differences in the effects induced by these two glucocorticoids. Triamcinolone (TAC) is most teratogenic on day 7 or 8, inhibiting formation of spurs and feathers and inducing club feather formation. Hydrocortisone is most teratogenic later in development, on day 10. Unique hydrocortisone-induced responses are complete inhibition of scutellate scale formation, bent feathers, and apteria around the external auditory meatus. Altered synthesis of keratin polypeptides follows inhibition of scale morphogenesis by hydrocortisone and TAC. These in vivo data suggest that heterogeneity of glucocorticoid binding occurs in embryonic chick metatarsal skin. Survival data indicate that TAC is 2,000 times more embryotoxic than hydrocortisone.

Strain differences between C57BL/6 and SWV mice in time of palate closure and induction of palatal slit and cleft palate.

Palatal slit, which occurs spontaneously in C57BL/6 (C57BL) mice, is increased in frequency among C57BL fetuses from dams treated with triamcinolone acetonide, but is not induced in SWV fetuses. On the other hand, C57BL is more resistant than SWV to cleft palate induction by triamcinolone. Using these C57BL and SWV mice, the relation of palate stage and chronological age was examined from 1 P.M. on day 14 to 9 A.M. on day 16 in untreated embryos, and the condition of the palate after triamcinolone treatment on day 12 was examined at 9 A.M. on day 16. In untreated embryos, horizontalization and fusion of the palatal shelves occurred earlier in C57BL than in SWV embryos, but fusion of the primary palate with the secondary palate occurred later. After triamcinolone treatment, the development of the palate was delayed in both C57BL and SWV embryos. These results suggest that the times of normal palate closure are related to the differences between C57BL and SWV mice in their susceptibilities to palatal slit and cleft palate induction and that triamcinolone produces palatal slit and cleft palate by delaying palate closure.

Allergic contact dermatitis from amcinonide.

Allergic contact dermatitis from topical corticosteroids has been regarded as rare. However, it should be considered in long-standing, resistant or worsening eczema in spite of topical steroid therapy. Cases of allergic dermatitis from amcinonide have been reported previously. We report an additional case.

Comparative teratogenicity of triamcinolone acetonide, triamcinolone, and cortisol in the rat.

Pregnant rats were injected im with 0.5 mg/kg triamcinolone acetonide (TAC) on day 12, 13, or 14 of gestation and the fetuses were examined for cleft palate on day 20. All three TAC-treated groups showed an increased proportion of fetuses with cleft palate compared to an untreated control group. Only the group treated on day 13 showed a significant increase in the proportion of litters affected. This indicates that day 13 of gestation is the most sensitive day for cleft palate induction by TAC in the rat. Pregnant rats were then treated on day 13 of gestation with either TAC, triamcinolone (TA), or cortisol. TAC was 59 times as potent as TA in inducing cleft palate, with ED50 values of 1.1 mg/kg and 65 mg/kg respectively. Cortisol induced a significant increase in cleft palates at 500 mg/kg, but the efficacy of this compound was too low to calculate an ED50 and relative teratogenic potency value. Other developmental abnormalities including umbilical hernias, resorption, and fetal death resulted from TAC treatment. Fetal growth retardation was produced by all three compounds. The rank order of teratogenic potency was determined to be TAC greater than TA greater than cortisol.

Triamcinolone-induced alteration of the notochordal-basichondrocranial relationship in the rhesus monkey.

Triamcinolone-induced alteration of the notochordal-basichondrocranial relationship in the rhesus monkey. Timed-mated pregnant rhesus monkeys received triamcinolone acetonide (10 mg/kg, IM) during early organogenesis. Treated and control embryos and fetuses were removed by hysterotomy on days 35, 42, 50, 60, and 70. All treated cases 42 days or older exhibited craniofacial and brain defects. Microscopic examination showed abnormal notochordal folding and a shortened cranial base in the 35-day embryos prior to any observed CNS involvement. Bends, deviations, focal proliferation, and persistence of the notochord and altered cranial base were observed in older cases. This study supports the hypothesis that encephalocele and related CNS disorders could be secondary to a primary paraxial mesodermal insufficiency.

Retardative effects of a corticosteroid hormone upon chondrocyte growth in the mandibular condyle of neonatal mice.

This study examined the influence of triamcinolone hexacetonide, a long-acting synthetic analog of cortisol on the proliferative activity and subsequent development of chondroprogenitor cells in condylar cartilage of neonatal mice. It became evident that a single injection of relatively low doses of the hormone significantly reduced the uptake and incorporation of [3H]thymidine followed by a significant decrease in the number of young cartilage cells. A unique feature was the fact that at the same time condyles of triamcinolone-treated mice revealed an increase in the number of mesenchyme-like cells within the condylar chondroprogenitor zone. High values of correlation were noted between the inhibitory effects of the hormone upon the incorporation of [3H]thymidine, the number of mitotic figures (within the chondroprogenitor zone), and the dimension of the chondroblastic zone. This study indicates that in young animals fluorinated corticosteroid hormones possess a significant bivalent inhibitory effect upon both the proliferative activity of chondroprogenitor cells as well as upon capacity of the latter cells to differentiate into chondroblasts. In so doing, corticosteroids adversely affect the normal process of endochondral bone formation in one of the prominent growth centers within the craniofacial skeleton. Thus, in the developing animal, corticosteroids impair the growing mandible from expressing its inherent morphogenetic pattern.