Effect of TCDD exposure on CYP1A1 and CYP1B1 expression in explant cultures of human endometrium.

Endometriosis is a debilitating disease estimated to affect 10% of reproductive-age women and characterized by the growth of endometrial tissue outside of the uterus. The present study characterizes a human endometrial explant culture model for studying the direct effects of TCDD exposure by assessing the expression of CYP1A1 and CYP1B1 mRNA (Northern blotting), protein (Western blotting), and activity (7-ethoxyresorufin-O-deethylase; EROD) in explants cultured with and without TCDD. Explants were obtained at laparoscopy or laparotomy from women undergoing surgery for tubal ligation, endometriosis, or pelvic pain unrelated to endometriosis. The explants were cultured with 10 nM estradiol (E(2)) or 1 nM E(2) plus 500 nM progesterone (P(4)) with or without TCDD (first 24 h). The expression of CYP1A1 and CYP1B1 mRNA was greatest with 10 nM TCDD and increased up to 72 h after initial exposure. EROD activity increased up to 120 h. Explants from a secretory phase biopsy became reorganized in culture and formed a new epithelial membrane, while maintaining basic endometrial morphology and viability for up to 120 h. At 24 h, TCDD significantly increased CYP1A1 and CYP1B1 mRNA, and at 72 h, TCDD significantly increased EROD activity and CYP1B1 protein compared to explants cultured without TCDD for similar times. CYP1B1 protein also exhibited substantial constitutive expression that was similar in uncultured biopsies, where CYP1B1 protein was immunolocalized in the cytoplasm of epithelial glands, with only occasional patches of protein in the surface epithelial membrane. In explants cultured with and without TCDD exposure, CYP1B1 protein was localized in the cytoplasm of the new surface epithelial membrane and glands closest to the surface. CYP1A1 protein was not detected in uncultured biopsies or explants. Both younger age (age 30 and under) and proliferative phase were associated with higher TCDD-induced EROD activity in specimens treated with E(2):P(4). No significant endometriosis-related differences were observed for any of the biomarkers, but the detection of disease-specific change was limited by small sample size and variability in tissue-cycle phase. The human endometrial explant culture model will be useful for future studies of the effects of dioxin-like compounds on human endometrium in relationship to cycle phase and hormonal exposure.

Improvement of host response to sepsis by photobiomodulation.

BACKGROUND AND OBJECTIVE: Late sepsis causes immunosuppression and is associated with energy depletion in lymphocytes. Adjuvant treatment with ATP-MgCL2 appears to improve cellular energetics and decrease mortality. Laser irradiation can promote cell proliferation and increase cellular ATP synthesis, which may improve the host immune response in sepsis. The purpose of this study was to determine whether laser irradiation (LI) has a stimulatory effect on the immune response in sepsis using an animal model. STUDY DESIGN/MATERIALS AND METHODS: The cecal ligation and puncture (CLP) rat model was used. Thirty-six SD rats were divided equally among four groups: control (nonoperative), sham operation, CLP treated with laser irradiation, and CLP without laser irradiation. The peritoneal cavity of each animal in CLP/laser group was irradiated immediately after CLP using an Argon-dye laser at a wavelength of 630 nm and at a fluence of 5 J/cm2. Some animals were euthanized 24 hr following CLP and were used to evaluate the immune response (lymphocyte proliferation). In a separate experiment, the survival of septic rats was observed for 60 days. Lymphocytes isolated from normal rat spleens were used to observe for biostimulatory effects in vitro. RESULTS: LI significantly improved ex-vivo lymphocyte proliferation of cells from septic rats (179.7 +/- 17.2 vs. 129.5 +/- 7.8; P < 0.01) and enhanced survival in septic rats (79% vs. 42%; P < 0.001). LI significantly stimulated lymphocyte proliferation in the presence of mitogenic stimuli and enhanced lymphocyte ATP synthesis (P < 0.05). CONCLUSION: LI improves the host immune response and survival rate in sepsis in an animal model. Our studies suggest that LI may be useful as an adjuvant therapy for sepsis.

Impact of prenatal screening and diagnosis on the epidemiology of structural congenital anomalies.

OBJECTIVE: To assess the impact of prenatal screening on the birth prevalence of three categories of structural congenital anomaly: abdominal wall defects (omphalocele and gastroschisis), renal agenesis/dysgenesis, and limb reduction defects. SETTING: Glasgow, Scotland, United Kingdom. METHODS: Data on the selected defects were obtained retrospectively from the population based Glasgow Register of Congenital Anomalies for the period 1980-91 inclusive. The register records all clinical or laboratory diagnoses of congenital anomaly in live births, stillbirths, and induced abortions occurring in women resident within the boundaries of the Greater Glasgow Health Board. The secular trends in the proportions of the defects diagnosed prenatally and terminated after screening, and in their prevalence at birth and during pregnancy, were examined. A total of 154,845 births were surveyed: 309 cases were identified in the selected anomaly categories. RESULTS: 83 cases of omphalocele/gastroschisis (5.4/10,000 births), 92 cases of renal agenesis/dysgenesis (5.9/10,000 births), and 134 cases of limb reduction defects (8.7/10,000 births) were found. Marked increases occurred over the study period in the proportions of cases diagnosed prenatally but not in the proportions terminated. The greatest difference between the prevalence at birth and during pregnancy was found for omphalocele. There were no significant secular trends in the prevalence of the selected defects. CONCLUSIONS: Prenatal screening has made a limited epidemiological impact on the prevalence of these defects. It has been moderately (but inconsistently) effective in the avoidance of births of infants with omphalocele/gastroschisis and renal agenesis/dysgenesis but not of limb reduction defects. Future efforts should be directed towards improving the technical aspects of the ultrasonographic detection of fetal abnormalities and exploring in detail, locally, the reasons for the varying pattern of decision making about termination of pregnancy among prospective parents.

Gastric cancer invading the lamina muscularis propria.

BACKGROUND: Gastric cancer invading the lamina muscularis propria is considered to be an intermediate stage between early and far advanced gastric cancer. This study evaluated the clinicopathological pictures of muscularis propria gastric cancer. METHODS: In the past 5 years, 407 patients with adenocarcinoma of stomach underwent radical gastrectomy in Department of Surgery, Veterans General Hospital-Taipei. Of them, 46 patients (11.3%) with gastric cancer invading the muscularis propria were studied. Their clinicopathologic features were further analyzed with special reference to the gross appearance of the tumor. RESULTS: Most muscularis propria gastric cancers occurred at lower stomach. Nodal spread accounted for 32.6% and was largely confined to n2 with limited involvement of n3. Borrmann type cancer comprised 63% (29/46) of cases and early-like type cancer comprised 37%. Early-like type cancer was smaller in size than Borrmann type cancer (p < 0.001). Nodal spread was more extent in Borrmann type cancer than in early-like type cancer. Other clinicopathologic features and survival were identical in both types of muscularis propria gastric cancer. CONCLUSIONS: Most muscularis propria gastric cancers were Borrmann type cancer grossly. Compared with the early-like type, the Borrmann type cancer was larger and had more extensive nodal spread.

Drug-excipient incompatibility studies of the dipeptide angiotensin-converting enzyme inhibitor, moexipril hydrochloride: dry powder vs wet granulation.

The drug-excipient incompatibility screen for moexipril hydrochloride (1) using various isothermal stress methods is reported herein. It was found that most of the commonly used filters, disintegrants, lubricants, glidants, and coating agents were incompatible with 1 in dry powder mixtures; moisture and basic (or alkalizing) agents were determined to be the dominant destabilizing factors. In wet granulations, basic agents, however, were found to suppress drug degradation even in the presence of moisture. Supported by the product distribution studies, the stabilization is proposed to involve the neutralization of the acidic drug by the basic excipients.

Drug-excipient interactions resulting from powder mixing. IV: Role of lubricants and their effect on in vitro dissolution.

Two lubricants, magnesium stearate and sodium stearyl fumarate, were compared under identical mixing conditions to study their roles in drug-excipient interactions. After prolonged mixing, sodium stearyl fumarate did not interact with the drug or excipients; as a result, the disintegration time and drug dissolution rate from hand-filled, uncompacted capsules were not adversely affected. In contrast, magnesium stearate did exhibit drug-excipient interactions which resulted in lamination and subsequent adhesion of the lubricant to the drug-crospovidone agglomerates. These interactions adversely affected the disintegration time and drug dissolution rate from hand-filled, uncompacted capsules. Although the initial specific surface area of magnesium stearate was higher than that of sodium stearyl fumarate, flaking of magnesium stearate due to particulate-particulate interactions caused a large increase in the surface area. The adhesion of the magnesium stearate flakes to the drug-crospovidone agglomerates resulted in a decrease in the drug dissolution rate.

Drug-excipient interactions resulting from powder mixing. III: Solid state properties and their effect on drug dissolution.

Micronized prednisone was used to study the effect of powder mixing on drug-excipient interactions and their effect on in vitro dissolution from uncompacted, hand-filled capsules. Two powder formulations contained CaHPO4 X 2H2O (dibasic calcium phosphate dihydrate) as a filler and potato starch or sodium starch glycolate as a disintegrant. The third powder formulation contained pregelatinized starch as a disintegrant/filler. The lubricant in these formulations was magnesium stearate. When drug, CaHPO4 X 2H2O, and the disintegrant were thoroughly mixed and hand filled into capsules without compaction, only approximately 70% of the drug dissolved in 30 min. The incomplete dissolution of the drug was caused by the formation of agglomerates and the inclusion of the drug particles by these agglomerates. In contrast, when a mixture of drug and pregelatinized starch was used, complete dissolution of the drug was achieved after 30 min due to the absence of agglomeration and inclusion. Prolonged mixing of the formulation containing CaHPO4 X 2H2O with magnesium stearate resulted in a decrease in the dissolution rate. The total amount of the drug dissolved at the end of 30 min was reduced from 70 to 20%. The decrease in the rate of drug dissolution resulted from drug-excipient interactions which caused flaking of the magnesium stearate particles. The adhesion of these flakes to the drug particles and drug-excipient agglomerates resulted in hydrophobic coating which reduced water penetration. The rate of drug dissolution was not affected when drug and pregelatinized starch were mixed with magnesium stearate for a prolonged time due to the absence of magnesium stearate flaking and film formation.

Effect of moisture and crushing strength on tablet friability and in vitro dissolution.

The friability and dissolution of a formulation of compressed tablets were studied by varying the granulation moisture and tablet crushing strength. A general quadratic response surface model was used to analyze the data. The response surface contour plots of tablet friability consisted of a series of ellipsoidal curves. The optimum friability corresponding to a granulation moisture content and a tablet crushing strength was a simple minimum. The in vitro dissolution contour plots showed a stationary ridge system. Along the ridge, a large number of combinations of tablet crushing strength and granulation moisture represented 100% drug dissolution. The contour overlays of friability and dissolution contour plots showed a region where both the friability and dissolution requirement could be met. The analysis of the data by means of multiple linear regression was helpful in understanding the role of granulation moisture and tablet crushing strength on tablet friability and in vitro dissolution.

Mixing of pharmaceutical solids. II: Evaluation of multicomponent mixing of cohesive powders in cylindrical shear mixer.

The mixing of three organic carboxylic acids with micronized lactose, all cohesive in nature, was studied using a cylindrical shear mixer. Three mixing indexes (s/sigma A, s/sigma R, and the Ashton-Valentin mixing index) were used to evaluate mixing of the three drugs with lactose. The results suggested that maximum homogeneity was reached after 45 min of mixing. However, different mixing indexes showed different sensitivity to homogeneity of the individual components. The mixing index s/sigma A, which is based on setting standard specifications, appears to provide a better evaluation of homogeneity of individual components compared to the mixing indexes based on complete random mixing theory. The latter did not approach unity for any drug component used in this study. These results suggested that mixing of cohesive powders is a complex process and cannot be explained fully by simple theory based on complete random mixing.

Mixing of pharmaceutical solids. III: Multivariate statistical analysis of multicomponent mixing.

The multicomponent mixing for cohesive powders was evaluated by multivariate statistical methods. Tests were carried out for the sampling technique, completely random state and completely segregated state. Hotelling's statistics were not helpful in testing the practical sampling technique. Comparisons of the mixing indexes based on univariate and multivariate statistics indicated excellent consistency in optimizing mixing time. Neither mixing index approached unity because cohesive powders do not reach a completely random state. The multivariate mixing index was smaller than the univariate indexes largely due to interparticular forces among small cohesive particles.