Danazol administration after gonadotrophin-releasing hormone analogue reduces rebound of uterine myomas [published erratum appears in Hum Reprod 1998 Mar;13(3):780]

We report the results of administration of danazol after suspension of gonadotrophin-releasing hormone analogue (GnRHa) therapy for uterine myomas. A total of 21 women with uterine myomas was treated with 100 mg danazol for 6 months after GnRHa therapy. Uterine volume and endocrine status were monitored monthly by ultrasound and assay of plasma gonadotrophins, oestradiol and progesterone. The results show a rebound of uterine volume about 30% less than in controls at the end of danazol therapy. Menstrual cyclicity returned after 65 +/- 3 days in 16 subjects and five patients remained amenorrhoeic. Hormone assays confirmed renewed ovarian function in the women whose menstrual periods returned. Bone mineral content was substantially reduced during GnRHa treatment but improved significantly during danazol therapy even in the women who remained amenorrhoeic. These results show the utility of danazol in prolonging the therapeutic effects of GnRHa. The mechanism by which danazol inhibits rebound of uterine volume may be due to its antiprogesterone effects on uterine myomas.      

Characterization of antibody and selection of alternative drug therapy in hydrochlorothiazide-induced immune hemolytic anemia

The authors report the clinical and laboratory findings of a patient who had severe immune hemolytic anemia due to hydrochlorothiazide (HCTZ). In this case, the HCTZ antibody reacted not only with other thiazide and thiazide-like drugs, but also with a chemically unrelated diuretic, ethacrynic acid. These results indicate that HCTZ antibody activity is not restricted solely to the thiazides and imply that therapy with any of the reactive drugs would be contraindicated for this patient. The serologic screening for drug reactivity may be useful for selecting alternative therapy for patients with drug-induced immune hemolytic anemia.     

Contamination of platelet storage bags by phthalate esters

Phthalate esters are the most extensively used plasticizers in the manufacture of polyvinylchloride (PVC) plastic. Many medical devices used in the collection and storage of blood components are made of PVC plastic containing di(2-ethylhexyl) phthalate (DEHP). DEHP leaches at a rate of 100 micrograms/ml X d into platelet concentrate (PC) supernatant when PCs are stored in PVC containers. It is only possible to store PCs for 72 h in this DEHP plastic, after which time the platelet function has deteriorated and they cannot be used for transfusion therapy. Since it was desirable to find a container that permitted longer storage times and because of the concern for the toxicity of DEHP, new bags, manufactured with different plastic formulations without this plasticizer, were tested for PC storage. Using these new containers, such as the PL732 [polyolefin (PO) plastic], and the CLX300 and PL1240 [tri(2-ethylhexyl) trimellitate (TEHTM) PVC plastic], it was possible to store PCs for 5 d while preserving platelet function. In spite of these new plastic bags being manufactured without DEHP, we found DEHP and its metabolite mono(2-ethylhexyl) phthalate (MEHP) as contaminants of the supernatant of the PCs stored in these containers. After analyzing the plastic material of each of these containers, we were able to identify the source of the contamination as coming from the plastic materials that were used in the manufacture of the bags. The sterilization process of the PL732 bag was investigated, since it was found that when the plastic of the PL732 bag was analyzed prior to sterilization, no contamination by DEHP was detected; however, whether the PL732 bag was sterilized together with the primary PVC bag or separately, using ethylene oxide, contamination by DEHP was found, suggesting contamination of the sterilization unit by DEHP.     

Targeted gene disruption of murine CD7

CD7 is a 40 kDa type I transmembrane glycoprotein member of the Ig superfamily. CD7 is a marker of mature human T cells and NK cells, and is expressed early in their development. Cross-linking CD7 positively modulates T cell and NK cell activity as measured by calcium fluxes, expression of adhesion molecules, cytokine secretion and proliferation. CD7 associates directly with phosphoinositol 3'-kinase, and CD7 ligation induces production of D-3 phosphoinositides and tyrosine phosphorylation. Severe combined immunodeficiency has been associated with a lack of lymphocyte surface CD7. The CD7 ligand is unknown. The murine CD7 homolog is encoded by a single gene on chromosome 11. In order to characterize the role of CD7 in lymphocyte development and function we have eliminated the CD7 gene by targeted disruption. CD7- deficient mice display normal histology of thymus and spleen, normal lymphocyte populations in primary and secondary lymphoid tissues, and normal serum Ig levels. Specific antibody responses after immunization with T-dependent and T-independent antigens are equivalent in wild-type and CD7 knockout mice. CD7-deficient lymphocytes respond normally to T cell mitogenic and allogeneic stimuli, and display normal NK cell cytotoxicity.      

Influence of surface morphology and chemistry on the enzyme catalyzed biodegradation of polycarbonate-urethanes

Polycarbonate based polyurethanes were synthesized with varying hard segment content as well as hard segment chemistry based on three different diisocyanates,1,6-hexane diisocyanate (HDI), 4.4'-methylene bisphenyl diisocyanate (MDI) and 4,4-methylene biscyclohexyl diisocyanate (HMDI). The surface chemistry and morphology were characterized using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The polymers were incubated with cholesterol esterase (CE) in a phosphate buffer solution at 37 degrees C over 10 weeks. XPS results showed that the surface chemistry changed as the size and chemistry of the hard segment varied within the materials. AFM images exhibited distinctive surface morphologies for all polymers, and this was particularly apparent with changes in the hard segment chemistry. The results showed that the surface of HDI polymers consisted of relatively stiff rod-like structures, which corresponded to the soft segment domains. Polymers with a higher HDI content exhibited a dense top layer containing a relatively higher hard segment component, covering the sub-surface matrix of rod like structures. The MDI based polyurethane had large aggregates on its top surface, which corresponded to the aggregation of harder components. The HMDI based polycarbonate-urethane presented a relatively homogeneous surface where no phase separation could be detected. The relative differences in hard and soft segment content in their surface structure was supported by XPS findings. The analysis of the biodegradation results, concluded that enzyme catalyzed biodegradation within these materials was initiated in amorphous soft segment regions located in the region of the interface between hard and soft segments. A higher hard segment content at the surface contributed significantly to an increase in biostability. The findings provided an enhanced understanding for the role of surface molecular structure in the enzyme catalyzed biodegradation of polyurethanes.     

Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability

X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.      

Differential response to chemically altered polyethylene by activated mature human monocyte-derived macrophages

Macrophages and polyethylene (PE) particulate are currently recognized as being the two common denominators in the development of chronic inflammation, periprosthetic osteolysis, and subsequent implant failure. In this study, the effect of PE particulate surface chemistry on mature human monocyte-derived macrophage (MDM) function was investigated. Virgin high-density PE (HDPE: 4-10 microm) and HDPE oxidized by irradiation, thermal and chemical treatment were characterized by FT-IR and suspended in soluble type I collagen, which was subsequently solidified on glass coverslips. Human MDMs, derived from differentiating monocytes on polystyrene for 14 days, were trypsinized and cultured on collagen-particle substrata and collagen controls for 31 days. Analysis of conditioned media collected at 24h incubation showed a significantly higher level of IL-1beta secretion in virgin HDPE over oxidized HDPE or collagen controls, and a significant inhibition of IL-6 secretion in both virgin and oxidized samples. Esterase activity was increased in the medium at a significantly higher level in the virgin HDPE versus controls with the highest activity observed in oxidized HDPE at 31 days. These results illustrate the effect of PE particle surface chemistry (oxidation) on MDM cytokine secretion and esterase activity, and highlight the need to further investigate the potential of PE surface chemistry on modulating MDM function.