What impact can hospitalization environment produce on the ANS functioning in patients with Unresponsive Wakefulness Syndrome? - 24-hour monitoring.

Objectives: Studies showed that the recovery of patients with Unresponsive Wakefulness Syndrome (UWS) is also correlated to the recovery of circadian rhythms. In this study, we observed the correlations between patients with UWS biometrical and ambient parameters. Methods: A dedicated monitoring system was realized to record and correlate the level of noise and luminosity with biometric Heart Rate (HR), Heart Rate Variability (HRV) and Breath Rate (BR) parameters. Eleven patients with UWS were recruited and monitored for 13 ± 7 days. Correlation of ambient and biometric parameters was analyzed by Spearman's test. Wilcoxon's test was used to compare the biometric parameters in two different moments of daily activity in the rehabilitation unit (night and day). Patients showed a moderate negative or positive correlation between biometric and ambient parameters. Results: Significant differences between night and morning (0.0001 < p ≤ 0.001) were found for HR, HRV and BR in seven, five and four patients, respectively, at Wilcoxon's test. HR and BR were higher during the night while HRV was lower. Conclusion: In patients with UWS, lower HRV and higher HR and BR during the night might be indicative of interference in sleep/wake cycles. The modifications of the environment surrounding the patient due to the unit procedures of the staff and/or some interaction modalities of the relatives may have an effect on residual endogenous mechanisms of self-regulation. However, differences between night and day in the biometrical parameters are not necessarily linked to the changes in the environment care unit.

Coma recovery scale-r: variability in the disorder of consciousness.

BACKGROUND: Despite evidence from neuroimaging research, diagnosis and early prognosis in the vegetative (VS/UWS) and minimally conscious (MCS) states still depend on the observation of clinical signs of responsiveness. Multiple testing has documented a systematic variability during the day in the incidence of established signs of responsiveness. Spontaneous fluctuations of the Coma Recovery Scale-revised (CRS-r) scores are conceivable. METHODS: We retrospectively analyzed the CRS-r repeatedly administered to 7 VS/UWS and 12 MCS subjects undergoing systematic observation during a conventional 13 weeks. rehabilitation plan. RESULTS: The CRS-r global, visual and auditory scores were found higher in the morning than at the afternoon administration in both VS/UWS and MCS subgroups over the entire period of observation. The probability for a VS/UWS subject of being classified as MCS at the morning testing at least once during the 13 weeks. observation was as high as 30%, i.e., compatible with the reported misdiagnosis rate between the two clinical conditions. CONCLUSIONS: Multiple CRS-r testing is advisable to minimize the risk of misclassification; estimates of spontaneous variability could be used to characterize with greater accuracy patients with disorder of consciousness and possibly help optimize the rehabilitation plan.

A study of the reliability of the Nociception Coma Scale.

OBJECTIVE: In this study, we investigated the reliability of the Nociception Coma Scale which has recently been developed to assess nociception in non-communicative, severely brain-injured patients. DESIGN: Prospective cross-sequential study. SETTING: Semi-intensive care unit and long-term brain injury care. SUBJECTS: Forty-four patients diagnosed as being in a vegetative state (n=26) or in a minimally conscious state (n=18). INTERVENTIONS: Patients were assessed by two experts (rater A and rater B) on two consecutive weeks to measure inter-rater agreement and test-retest reliability. MAIN MEASURES: Total scores and subscores of the Nociception Coma Scale. RESULTS: We performed a total of 176 assessments. The inter-rater agreement was moderate for the total scores (k = 0.57) and fair to substantial for the subscores (0.33 ≤ k ≤ 0.62) on week 2. The test-retest reliability was substantial for the total scores (k = 0.66) and moderate to almost perfect for the subscores (0.53 ≤ k ≤ 0.96) for rater A. The inter-rater agreement was weaker on week 1, whereas the test-retest reliability was lower for the least experienced rater (rater B). CONCLUSIONS: This study provides further evidence of the psychometric qualities of the Nociception Coma Scale. Future studies should assess the impact of practical experience and background on administration and scoring of the scale.

Perioperative pain management after scapular tip free flap harvesting for head and neck reconstruction using mini-catheters to inject the local anesthetic.

PURPOSE: Although functional and esthetic results after the use of a scapular tip free flap (STFF) in head and neck reconstruction, and the related donor-site morbidity, have been extensively described, data regarding acute postoperative donor-site pain management are lacking. Purpose of this study is to explore the use of mini-catheters to administer local anesthetics for donor-site pain management after reconstruction using STFF. METHODS: Patients who underwent head and neck reconstruction using a STFF were prospectively enrolled and, through a perineural catheter placed in the donor site during the surgical procedure, a bolus of chirochaine was injected before the patient regained consciousness and at 8, 16, and 24 h postoperatively. Before and 40 min after each dose administration, donor-site pain on a numerical rating scale (NRS; 0-10) was evaluated. RESULTS: Study population consisted of 20 patients (40-88 years). At 8 h, the pain scores before and after the injection were 0-10 (mean 3.35) and 0-5 (mean 1.25), respectively. At 16 h, the pain scores before and after the injection were 0-8 (mean 2.55) and 0-4 (mean 0.55), respectively. At 24 h, the pain scores before and after the injection were 0-8 (mean 1.30) and 0-4 (mean 0.30), respectively. CONCLUSION: Statistical analysis confirmed a significant difference between the pain scores before and after administration at 8, 16, and 24 h (p < 0.001, p < 0.001, and p = 0.003, respectively). Mini-catheters for local anesthetic administration represent an effective strategy for pain control after STFF harvesting for head and neck reconstruction.

Orthognathic surgery for juvenile idiopathic arthritis of the temporomandibular joint: a critical reappraisal based on surgical experience.

Juvenile idiopathic arthritis (JIA) involving the temporomandibular joint (TMJ) can result in significant dentofacial deformities that may require orthognathic surgical correction. The aim of this study was to assess the functional and aesthetic results relative to stability after bimaxillary surgery with counterclockwise rotation of the occlusal plane in patients with JIA. A retrospective chart review was conducted of all patients affected by JIA who underwent orthognathic surgery between January 2000 and December 2019 at the Face Surgery Centre (Parma, Italy). Patient records were evaluated for surgical indications, complications, and outcomes. The final study sample included 13 patients (12 female, one male). The mean age of the patients was 18.6 years (range 17-26 years) at the time of surgery; 12 patients had bilateral TMJ disease. At the 1-year follow-up, all patients except one had a stable occlusion with a natural, well-balanced morphology of the face and adequate dynamic excursion of the mandible. The 1-year postoperative cone beam computed tomography (CBCT) scan revealed complete ossification at all osteotomy sites. Bilateral sagittal split osteotomy with mandibular advancement is an effective procedure with a low rate of complications for patients with JIA with stable disease confirmed by preoperative CBCT or magnetic resonance imaging.

Microvascular reconstruction of the mandible with medial femoral condylar flap for treatment of mandibular non-union.

Mandibular non-union occurs in 2-9% after open reduction and internal fixation of a mandibular fracture (trauma surgery, orthognathic cases, access osteotomy for oncological purposes). The medial femoral condyle (MFC) has emerged more recently as one of the most versatile donor sites in the treatment of challenging bone reconstruction. This is the first description of MFC for treatment of mandibular non-union. A retrospective chart review was conducted for all patients who underwent reconstruction with a microvascular MFC flap for bone defects of the head and neck area between January 2015 and December 2018 at Careggi Hospital of Florence. Inclusion criteria were patients where the FMC was used for mandibular defects arising due to non-union. Seven patients presented mandibular defects reconstructed by MFC flap and were included in this investigation (two cases of segmental mandible defect due to post-traumatic non-union; two patients of pathological mandibular fracture after prolonged bisphosphonate therapy for osteoporosis; three patients with mandibular continuity loss after failed orthognathic surgeries). At one-year follow-up, all patients had satisfactory occlusion. One-year postoperative CTs revealed full osteointegration of the flaps. In conclusion, the MFC free flap is an attractive option for mandibular reconstruction. Small defects (3-5 cm) in poorly vascularized beds are the ideal target.

Closed reduction of the isolated anterior frontal sinus fracture via percutaneous screw placement.

Fractures of the frontal sinus are a common maxillofacial trauma and constitute 5-15% of all maxillofacial fractures. Conventional surgical approaches include the coronal flap, direct cutaneous incision, and endoscopic techniques. Minimally invasive techniques have recently been described for the reduction of the isolated anterior frontal sinus fracture via a closed approach. The medical records and radiological findings of all patients who underwent surgical treatment for anterior frontal sinus fractures from January 2009 to December 2013 at the study hospital in Florence, Italy, were reviewed. The final study sample consisted of 15 patients (13 males and two females) with isolated anterior frontal sinus fractures who were treated with closed reduction using percutaneous screws. The mean age was 32.1 years. The skin incisions healed without any visible scarring, and no depressions of the frontal sinuses were evident in the postoperative period. Computed tomography scans performed at 6 months postoperatively showed adequate reduction of the displaced fragments. This closed technique is a good option for displaced isolated fractures of the anterior frontal sinus. However, the technique is not adequate for complex fractures of the frontal sinus.

Surgical approach to isolated bilateral orbital floor fractures.

Isolated bilateral orbital floor fractures are uncommon and are rarely described in the scientific literature. They are usually seen in association with naso-ethmoidal fractures, zygomatic fractures, or fractures of the middle third. We report our experience in the management of a patient presenting bilateral isolated orbital floor fracture. The difficulties in management of these fractures are due to the lack of an uninjured contralateral side for intraoperative comparison.

Expression of 11 beta-hydroxysteroid dehydrogenase during decidualization of human endometrial stromal cells.

This study evaluated the expression of the corticosteroid-metabolizing enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) during in vitro decidualization of human endometrial stromal cells. The cultured stromal cells displayed both NADP(+)-dependent (type 1) and NAD(+)-dependent (type 2) 11 beta HSD activities under basal conditions. Although the cells did not respond to estradiol (E2) added alone, catalytic levels of both isoforms were enhanced by medroxyprogesterone acetate (MPA) and further enhanced by E2 plus MPA. Type I messenger RNA (mRNA) was undetected by Northern analysis of total RNA, but was evident as a 1.5-kilobase band in polyadenylated selected RNA from E2- plus MPA-treated cultures. Use of RT-PCR to augment the sensitivity of mRNA detection revealed the presence of type I mRNA as a faint band in the MPA-treated cultures and as an intense band in the E2- plus MPA-treated cultures. Thus, type I mRNA is present as a low abundance message in the cultured stromal cells whose steady state levels parallel progestin-enhanced enzyme activity. As the expression of several progestin-regulated decidualization markers is also augmented by E2, the results of the present study reveal a correlation between enhanced 11 beta HSD expression and the decidualization reaction. Time-course measurements indicated that elevated 11 beta HSD expression is an early event in the decidualization response, which precedes E2- plus MPA-enhanced PRL production by several days. Clear dose-response effects on both type 1 and type 2 11 beta HSD activities were obtained in cells incubated with 10(-8) mol/liter E2 added together with MPA at concentrations that approximated circulating progesterone levels from the luteal phase (10(-9) mol/liter) through pregnancy (10(-7) mol/liter). Corticosteroids are thought to exert toxic and teratogenic effects on the implanting embryo and could influence trophoblast invasion by regulating extracellular matrix turnover. Therefore, the novel finding that decidualization involves marked enhancement of the corticosteroid-metabolizing capacity of stromal cells suggests a mechanism by which decidual cells could affect the health and invasiveness of implanting trophoblastic cells.

Relationship between the concentrations of estriol sulfate and estrone sulfate in human breast cyst fluid.

Estriol-3-sulfate (E3S) is present in human breast cyst fluid (BCF) in median levels of 8.7-10.4 nmol/L, yet is barely detectable in the serum (less than 0.034 nmol/L). The source of this huge concentration of E3S is unknown. It may accumulate from blood by active transport or be synthesized and concentrated within the cyst. Since estrone sulfate (E1S) and its possible precursor, dehydroepiandrosterone sulfate (DHEAS) are elevated in BCF, E3S may originate via 16 alpha-hydroxylation of E1S. The present study examined the correlations between the levels of DHEAS and E1S with those of E3S in BCF. The sodium and potassium ions were also quantified and related to the steroid concentrations. By linear regression analysis of log-normalized data there was a highly significant correlation between the concentrations of E1S and E3S (n = 355, r = 0.690, P less than 0.001) and between DHEAS and E3S (n = 361, r = 0.577, P less than 0.001). The BCF were classified according to their K/Na ion ratios: type 1, greater than 1.0, type II, less than 0.25, and type III, 0.25-1.0. By Student's t test, the concentrations of E3S differed between each BCF Type (P less than 0.002). This was also true for E1S and DHEAS. Type 1 cysts were associated with the highest estrogen sulfate levels and type II with the lowest levels. The possible physiological importance of this observation resides in reports that the BCF type expressing the highest steroid concentrations has been related to an aporcine-like epithelial lining of the cyst wall and a somewhat higher risk for developing breast cancer. The results suggest that E3S in BCF may originate from E1S, but alternate mechanisms are not precluded.

Identification of urocortin mRNA and peptide in the human endometrium.

Urocortin is a 40-amino acid peptide belonging to the corticotropin-releasing factor (CRF) family. In human reproductive tissues, urocortin expression has been previously demonstrated in the ovary, in the placenta and fetal membranes and in pregnant uterine tissues, while no data are available on the expression of the peptide in the nonpregnant uterus. In this study, urocortin expression was evaluated by both immunohistochemistry and reverse transcription-polymerase chain reaction, in human uterine tissues and cells at different phases of the menstrual cycle. Urocortin was immunolocalized in endometrial epithelial and stromal cells, as well as in the myometrium, and in vascular smooth muscle cells. No differences between proliferative and secretory phase were observed. These results were confirmed by reverse transcription-polymerase chain reaction analysis of isolated endometrial epithelial and stromal cells, and myometrial specimens. These findings open new questions on the roles played by urocortin in the human uterus.

Effect of serum albumin on estrogen metabolism in human cancer cell lines.

The observation that charcoal-treated fetal bovine serum (ctFBS) was able to modify one of main pathways of estrogens in cancer cells in culture, prompted us to initiate the present study. The active component of serum was isolated using native preparative polyacrylamide gel electrophoresis (PAGE). Under analysis with SDS-PAGE, a M(W) of 68 kDa and mobility of authentic bovine serum albumin (BSA) was observed. The addition of BSA to the serum free culture medium of HEC 1A human endometrial cancer cell line, resulted in an alteration of estradiol (E2) metabolism similar to that observed in the presence of ctFBS. BSA in fact, much enhanced 16 alpha-hydroxylation and significantly reduced 2-hydroxylation of E2 in HEC 1A cells. Comparable results were obtained with different endometrial (Ishikawa) and mammary (MCF-7) tumor cell lines having a different metabolic conversion rate of E2. Several albumin preparations from either bovine or human serum had the same effect; besides, BSA activity was unaffected by treatment with dextran-charcoal or heat. In the light of the present results, the inclusion of serum albumin (SA) in the formulation of media for studies evaluating steroid metabolism in cultured cells should be carefully considered.

11Beta-hydroxysteroid dehydrogenase expression in first trimester human trophoblasts.

This study evaluated the levels and the enzymatic characteristics of 11beta-hydroxysteroid dehydrogenase activity (11beta-HSD) of chorionic villi isolated from first trimester human placenta. The results demonstrated a predominant expression of the NAD-dependent dehydrogenase isoform (11beta-HSD2) over the NADP-dependent oxoreductase (11beta-HSD1). Thus, in tissue homogenates exogenous NAD increased the conversion of corticosterone to 11-dehydrocorticosterone of about 14-fold while NADP was ineffective. There was no conversion of 11-dehydrocorticosterone to corticosterone either with NADH or NADPH demonstrating the lack of reductase activity. In keeping with these results, RT-PCR analysis indicated a mRNA for 11beta-HSD2 in villous tissue while 11beta-HSD1 mRNA levels were undetectable. In addition, immunohistochemical staining localized the 11beta-HSD2 protein to syncytiotrophoblasts and cell columns of the chorionic villi. These results suggest roles for the trophoblast-associated 11beta-HSD2 oxidative activity in modulating the exposure of the embryo to active glucocorticoids in the early gestation and in regulating trophoblasts invasion of the uterine wall.

Gonadal malignant germ cell tumors express immunoreactive inhibin/activin subunits.

OBJECTIVE: Inhibin and activin are proteins produced by ovarian granulosa cells and testicular Sertoli cells and are members of the transforming growth factor-beta superfamily. Since increased circulating levels of immunoreactive inhibin were detected in women with malignant ovarian tumors, they were proposed as tumor markers for ovarian carcinoma. Immunohistochemical studies later confirmed the presence of inhibin and activin subunits in granulosa cell tumors and epithelial ovarian cancer, as well as in Sertoli and Leydig cell testicular cancer. However, there is discrepant information on the detection of inhibin and activin in malignant germ cell tumors (MGCT). The aim of the present study was to evaluate the immunohistochemical expression of the inhibin/activin alpha, betaA and betaB subunits in ovarian and testicular MGCT specimens using polyclonal antisera. METHODS: The ovarian tissue samples were composed of 19 MGCT, including dysgerminoma (n=18) and yolk sac tumor (n=1). The testis specimens included classic seminomas (n=20), embryonal carcinomas (n=7), choriocarcinomas (n=2), and yolk sac tumor (n=1). RESULTS: Ovarian and testicular malignant germ cell tumors expressed positive staining for inhibin/activin alpha, betaA and betaB subunits, with some variations between and within individual tumors: while ovarian dysgerminomas were diffusely positive for alpha, betaA and betaB, testicular tumors expressed alpha and betaB subunits, whereas betaA staining was weak. CONCLUSIONS: The present results show positive staining for inhibin/activin subunits in ovarian and testicular MGCT, suggesting a possible role in tumorigenesis with the resultant clinical implication.

Progestin regulation of 11beta-hydroxysteroid dehydrogenase expression in T-47D human breast cancer cells.

This study examined the enzymatic characteristics and steroid regulation of the glucocorticoid-metabolizing enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD) in the human breast cancer cell line T-47D. In cell homogenates, exogenous NAD significantly increased the conversion of corticosterone to 11-dehydrocorticosterone, while NADP was ineffective. There was no conversion of 11-dehydrocorticosterone to corticosterone either with NADH or NADPH demonstrating the lack of reductase activity. In keeping with these results, RT-PCR analysis indicated a mRNA for 11beta-HSD2 in T-47D cells, while 11beta-HSD1 mRNA levels were undetectable. In T-47D cells treated for 24 h with medroxyprogesterone acetate (MPA), 11beta-HSD catalytic activity was elevated 11-fold, while estrone (E(1)), estradiol (E(2)) and the synthetic glucocorticoid dexamethasone (DEX) were ineffective. The antiprogestin mifepristone (RU486) acted as a pure antagonist of the progestin-enhanced 11beta-HSD activity, but did not exert any agonistic effects of its own. In addition, RT-PCR analysis demonstrated that MPA was a potent inducer of 11beta-HSD2 gene expression, increasing the steady-state levels of 11beta-HSD2 mRNA. Taken together, these results demonstrate that 11beta-HSD2 is the 11beta-HSD isoform expressed by T-47D cells under steady-state conditions and suggest the existence of a previously undocumented mechanism of action of progestins in breast cancer cells.

Steroid patterns of benign breast disease.

We briefly review some biochemical aspects of benign breast disease (BBD), mainly focusing on free and conjugate estrogen content of breast cyst fluid (BCF), also in relation to cyst type. Evidence is reported that high K(+)-type I-cysts clearly associate with low Cl- levels and accumulate significantly higher quantities of dehydroepiandrosterone sulfate (DHAS) and estrone-3-sulfate (E1S). In spite of the limited number of cases, both increasing DHAS and E1S levels correlate with the increment of K+ to Na+ ratio. A positive correlation was also found between DHAS and E1S. Using electrochemical detection (ECD) on-line to high performance liquid chromatography (HPLC) in the reverse phase mode, we also studied the free estrogen profile. We observed that in type I BCF there are significantly increased amounts of free estrone (E1). The E1S to E1 ratio was significantly different in the two cyst subpopulations; again, a positive correlation was found between free and sulfated E1 (r = 0.820, p less than 10(-6). This last, together with other experimental observations, allows us to hypothesize that in BCF a main pathway of steroids should be E1S----E1. Besides, high specific activity of sulfatase, as well as beta-glucuronidase enzymes, has been demonstrated for BBD. Preliminary information is also reported concerning the BCF pattern of free estrogens, including the highly polar ones, i.e., catecholestrogens (CCE) and the parent methoxy (MeO) conjugates, which represent, in BCF, a predominant portion of all free estrogens. Both CCE levels and ratios appear unevenly distributed in the two different cyst types. In addition, some BCFs show very high concentrations of 16 alpha-OH-E1. Further studies are needed to answer the main question: whether estrogen patterns could represent additive parameters to further categorize breast cystic disease (BCD) or whether they are of minor interest to determine patients' risk of developing breast cancer.

Prostate long-term epithelial cell lines. Biological and biochemical features.

This review reports studies on long-term prostate cell lines using multiple experimental approaches. The main goal was to investigate the metabolism of testosterone (T) through in vitro conversion rates. Extensive studies were also carried out on growth curves, tritiated thymidine incorporation, and morphometry by either hormone-responsive or hormone-unresponsive, normal and neoplastic human (PC3 and DU-145) and canine (CAPE and CPA) cell lines. All of them were characterized for their content of both soluble and nuclear androgen receptors. Receptor studies at site I binding in both soluble and nuclear fractions were carried out to establish the hormone sensitivity status of cells. In two prostate epithelial cells, steroid metabolic conversions in vitro show predominantly an oxidative metabolism of T, forming mainly androstenedione. Conversion rates were greater than 50% in the first 24 hours and still higher after 72 hours. At the same time and under exactly the same experimental conditions, the other cells showed metabolic pathways in which reductive metabolism prevails, dihydrotestosterone (DHT) being the prevalent metabolite. Different metabolic patterns of steroids of several cell lines relate to the hormone sensitivity status of the cells; steroid receptor-endowed cells are maintaining higher levels of unconverted precursor than are receptor-empty cells. In fact, hormone-sensitive cells, such as cancer canine CPA and human DU-145, produced DHT early through slowly converting T. On the contrary, unresponsive cells such as human cancer cells PC3 and normal canine CAPE quickly metabolize T, but DHT formation was not observed. These significant differences between cells are highly reproducible provided the proportion between cell number and molar concentration of precursors is constant. Differences we observe cannot be attributed to different experimental conditions. Cell viability, extraction efficiency, and all other parameters used for monitoring cell growth kinetics do not substantiate these reported significant differences in metabolic abilities of cells. The divergent steroid metabolic pathway we observe in different prostate long-term cells appears to be an intrinsic, consistent, highly reproducible property of each cell line.

Cellular kinetics and expression of bcl-2 and p53 in ductal carcinoma of the breast.

In this study, the expression of p53 (wild-type and mutated form) and bcl-2 in ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDC) of the breast was evaluated by immunohistochemistry and PCR-SSCP and correlated with cellular kinetic parameters, i.e., mitotic index (MI) and apoptotic index (AI). The results showed a significant inverse correlation between p53 and bcl-2 expression in all cases of DCIS and IDC. In the DCIS group, two subgroups with different kinetic characteristics were identified. The first group was characterized by p53 positivity, bcl-2 negativity and high values of MI and AI; the other group was characterized by p53 negativity, bcl-2 positivity and low values of MI and AI. Conversely, in IDC some cases were p53 negative, bcl-2 positive and with high values of AI and MI, other cases were p53 positive, bcl-2 negative and with low AI and MI. Molecular biological analysis showed that p53 was wild-type in DCIS, while it was in the mutated form in IDC. These results suggest that in IDC mutated p53 contributes to a change in cellular kinetics and the selection of genetically aberrant cells, thereby favouring neoplastic progression. The coexistence of bcl-2 positivity and high AI could be explained by the presence of of apoptosis that work independently of bcl-2.

Accelerated stability studies on 16-methylene-17 alpha-acetoxy-19-nor-pregn- 4-ene-3,20-dione (Nestorone).

The stability of the contraceptive steroid, Nestorone (16-methylene-17 alpha-acetoxy-19-nor-pregn-4-ene-3,20-dione) in the solid state and in aqueous solutions, was investigated using reverse-phase high-performance liquid chromatography. In the solid state, whether as a powder or when it is incorporated into Silastic implants, the steroid does not undergo detectable degradation even under severe experimental conditions. In solution, the drug undergoes slow degradation that is dependent on temperature and pH of the medium. The decomposition is defined by first-order mechanism. As expected, the reaction rate increases with increasing storage temperature. The linearity of the Arrhenius plot indicates that there is no change in the reaction mechanism within the temperature range studied. In alkaline media, the drug degrades at a faster rate through hydrolytic rather than an oxidative mechanism. The major hydrolytic degradation product, 16-methylene-17 alpha-hydroxy-19-nor-pregn-4-ene-3,20-dione, was separated and identified by mass spectrometry.