Infusions of isotopically labeled [3H] androstenedione with measurement of [3H] estrone in normal breast and breast tumor tissue have been carried out in an attempt to determine the contribution that aromatization makes to the estrogen content of breast tissues. After infusion of [3H] androstenedione for 12h there was significant uptake of this steroid by normal breast and breast tumors. [3H] Estrone was detected in all samples of normal breast tissue examined so far but not in all tumors. Aromatase activity when measured in vitro was found to be higher in breast tumors than in fat next to the tumor or normal breast fat. Studies in which we have examined the effect of epidermal growth factor on aromatase activity in cultured breast adipose tissue suggests that the response may be influenced by a subject's menopausal status. Results from these preliminary studies suggest that the aromatization of androgens may make a significant contribution towards the estrogen content of some breast tumors and that growth factors may also be involved in regulating aromatase activity.

Adipose Tissue↗

PubMedDate not supplied

Recent advances in the development of steroid sulphatase inhibitors.

Inhibition of steroid sulphatase is now an important target for the development of new drugs for the treatment of women with endocrine-dependent breast tumours. The first potent sulphatase inhibitor identified, oestrone-3-O-sulphamate (EMATE) proved. unexpectedly, to be oestrogenic. A number of strategies have therefore been adopted to design and synthesize a non-oestrogenic inhibitor. For this, a number of modifications have been made to the A and D rings of the oestrone nucleus. 2 Methoxyoestrone-3-O-sulphamate, while having similar in vitro and in vivo sulphatase inhibitory potency to that of EMATE, was devoid of oestrogenic activity when tested at 2 mg/kg in an ovariectomised rat uterine weight gain assay. 17-Deoxyoestrone-3-O-sulphamate was also a potent steroid sulphatase inhibitor and while it was devoid of oestrogenic activity when tested at 0.1 mg/kg, did stimulate uterine growth at 1.0 mg/kg. As an alternative approach to the use of steroid-based inhibitors a number of single ring, bicyclic non-fused ring, and two fused ring sulphamate analogues were designed, synthesized and tested for their ability to inhibit steroid sulphatase activity. In general, although the single ring and bicyclic non-fused ring sulphamate analogues could inhibit sulphatase activity, they were considerably less potent than EMATE. The mono- and bis-sulphamate derivatives of 5,7-dihydroxyisoflavone were relatively potent, inhibiting in vivo steroid sulphatase activity by 62 and 81% respectively at a single oral dose of 10 mg/kg. A study of the structure-activity relationship of a series of coumarin-based sulphamates has led to the development of a number of potent non-steroidal inhibitors, one of which has a similar potency to that of EMATE. The identification of potent steroid- and non-steroid-based sulphatase inhibitors will enable the therapeutic value of this therapy to be examined in the near future.

Animals↗

PubMedDate not supplied

Acceleration of wound healing in aged rats by topical application of transforming growth factor-beta(1).

The impaired wound healing associated with aging may reflect inadequate secretion or delivery of cytokines. Transforming growth factor-beta(1) is a mitogenic polypeptide with beneficial effects on wound healing. In the present study we questioned whether topical administration of transforming growth factor-beta(1) could improve the wound healing process in aged rats in vivo. Wound repair (from 1 to 14 days) was analyzed in full-thickness incisional wounds from 2-year-old rats with or without a single topical application of transforming growth factor-beta(1) (1 microg/wound) at the time of wounding. Identical wounds from 3-month-old, untreated rats served as controls. Histologic analysis showed a marked delay in several aspects of wound repair in the aged rats in comparison with that noted in the younger animals. Immunostaining of the wounds for proliferating cell nuclear antigen showed a reduction in the number of cycling fibroblasts in old rats. In addition, the number of capillaries per unit area of the wound as determined by a stain for Griffonin (Bandeiraea) simplicifolia lectin, and the number of inflammatory cells as identified by an antibody specific for macrophages, were also reduced in the wound area in old rats. Treatment with transforming growth factor-beta(1) resulted in marked enhancement of the following parameters: cell proliferation, inflammatory cell and fibroblast influx, wound closure, and angiogenesis. As seen with in situ hybridization, a similar temporal pattern of expression of messenger RNAs corresponding to type I procollagen and Secreted Protein, Acidic and Rich in Cysteine (osteonectin), known to be prevalent in healing wounds, was observed in both young and aged rats. However, the levels of mRNA corresponding to these secreted proteins appeared to be reduced in wound tissue from aged rats. Treatment with transforming growth factor-beta(1) subsequently resulted in an increase in the expression of both type I procollagen and Secreted Protein, Acidic and Rich in Cysteine mRNA in the wound tissue from aged rats. In summary, a single topical application of transforming growth factor-beta(1) to the wounds of aged rats at the time of wounding was associated with a healing response that, in all the parameters of wound repair examined, was similar to that of young rats. Topical transforming growth factor-beta(1) might therefore be beneficial in the treatment of dermal wounds in the aged.

Journal Article↗

PubMedDate not supplied

Increased fibrovascular invasion of subcutaneous polyvinyl alcohol sponges in SPARC-null mice.

The expression of SPARC (secreted protein acidic and rich in cysteine/osteonectin/BM-40) is elevated in endothelial cells participating in angiogenesis in vitro and in vivo. SPARC acts on endothelial cells to elicit changes in cell shape and to inhibit cell cycle progression. In addition, SPARC binds to and diminishes the mitotic activity of vascular endothelial growth factor. To determine the effect(s) of SPARC on angiogenic responses in vivo, we implanted polyvinyl alcohol sponges subcutaneously into wild-type and SPARC-null mice. On days 12 and 20 following implantation, SPARC-null mice showed increased cellular invasion of the sponges in comparison to wild-type mice. Areas of the sponge with the highest cell density exhibited the highest numbers of vascular profiles in both wild-type and SPARC-null animals. The endothelial component of the vessels was substantiated by immunoreactivity with three different markers specific for endothelial cells. Although sponges from SPARC-null relative to wild-type mice were populated by significantly more cells and blood vessels, an increase in the ratio of vascular to nonvascular cells was not apparent. No differences in the percentage of proliferating cells within the sponge were detected between wild-type and SPARC-null sections. However, elevated levels of vascular endothelial growth factor were associated with sponges from SPARC-null versus wild-type mice. An increase in vascular endothelial growth factor production was also observed in SPARC-null primary dermal fibroblasts relative to those of wild-type cells. In conclusion, we have shown that the fibrovascular invasion of polyvinyl alcohol sponges is enhanced in mice lacking SPARC, and we propose that increased levels of vascular endothelial growth factor account, at least in part, for this response.

Animals↗

PubMedDate not supplied

Special patient care in the undergraduate curriculum.

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Curriculum↗

PubMedDate not supplied

Chemical and antigenic properties of the cell wall of Actinomyces viscosus (Strain T6).

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Actinomyces↗

PubMedDate not supplied

Intraoperative placement of the nasoenteric feeding tube: a practical alternative?

BACKGROUND: The provision of early postoperative enteral feeding may be enhanced by the placement of enteral feeding access during celiotomy, but surgeons are often reluctant to pursue this option because of the extra effort required. METHODS: We conducted a retrospective review of our 2-year experience with 60 sequential intraoperative nasoenteric feeding-tube placements and included data on demographics, diagnosis, surgery, type of feeding tube, formula, tolerance, and complications. Our surgeons placed intraoperative nasoenteric feeding tubes at their discretion in a variety of subjects who were undergoing elective or urgent celiotomies. RESULTS: The surgeries largely involved the upper gastrointestinal tract, and feeding-tube placements were readily accomplished. The majority of patients received enteral feedings within 3 postoperative days and achieved feeding rates of 50 mL/h or greater. The average duration of feeding-tube use was 1 week, accounting for 399 feeding days overall. There were no serious complications attributable to feeding-tube placement or use, but inadvertent tube removal by patients or staff was a limitation. CONCLUSIONS: Intraoperative placement of the nasoenteric feeding tube may be a reasonable option for treating the surgical patient at nutritional risk who faces a limited course of impaired oral intake postoperatively.

Adolescent↗

PubMedDate not supplied

Aging, cancer, and wound healing.

Aging processes can be described as recognizable series of molecular events within vital organ systems whose dysfunction gradually increase with time (reviewed by [1]). This dysfunction manifests itself as abnormal increases and decreases in gene expression and these events occur at a rate that exceeds the relative rate at which they can be corrected. The outcome of this progression is a steady decline in the capacity to successfully maintain an organism's peak physiology, which occurs approximately around the time of sexual maturation. The resulting changes increase the likelihood that an organism will eventually approach a state of increased vulnerability to disease and ultimately leads to death. Within the context of both wound healing and cancer, molecular mechanisms of aging-related changes affect an organism's ability to repair damaged cells and tissues through disregulation of some common molecular pathways. In the case of the former, wound healing is impaired as a result of an inability to adequately express genes which facilitate escape from cell stasis in order to commence and complete the healing process. In the latter case, the failure of a cell's repair mechanism to correct damage to DNA can lead to neoplastic transformation of a normal cell into one with unlimited growth potential. This review compares several of the molecular and cellular events associated with cancer and wound healing during aging.

Aging↗

PubMedDate not supplied

Influence of hormonal status of patients with cystic disease on the composition of cyst fluid and breast cancer risk.

The relationship between the composition of breast cyst fluid (BCF), the menstrual status and in addition some endocrine events in the history of patients (n = 131) with gross cystic breast disease was investigated. The dehydroepiandrosterone (DHA) levels in type II (K+/Na+ < 1) cysts of the follicular group were significantly higher compared to the type II cysts of the luteal or postmenopausal groups. For testosterone a significant difference existed between the type I (K+/Na+ > or = 1) follicular and type I postmenopausal groups. Estrone levels were significantly higher in type I BCF of patients in the luteal phase compared to both the follicular and postmenopausal type I cysts. Progesterone levels were lowest in the postmenopausal subgroups (both in type I and II cyst). Significant correlations were found between the number of pregnancies and the levels of DHA-sulfate and also progesterone in BCF. DHA levels were correlated with the period of lactation. The K+/Na+ ratios were the lowest in women who lactated for the longest period. The estrone was lowest in BCF of current oral contraceptive (o.c.) users while the estradiol was lowest in patients who had never used o.c. A history of previous o.c. use was associated with a significantly high mean DHA level. A significantly higher DHA and lower testosterone level were demonstrated in BCF of patients who had some previous gynecological interventions. The composition of BCF and the "life of cysts" and thus the rate of breast cancer risk may depend on hormonal status during the menstrual cycles or postmenopause and also on endocrine history of patients.

Adult↗

PubMedDate not supplied

Characteristics of cystic breast disease with special regard to breast cancer development.

BACKGROUND: This prospective study compares the characteristics of cystic disease of the breast (CDB) of patients who developed breast cancer (BCa) during the follow-up (1.25-4 years) period with those who did not. MATERIALS AND METHODS: K+, Na+, albumin, dehydroepiandrosterone (DHA), DHA-sulphate, oestrone, oestradiol, testosterone and progesterone levels were determined in breast cyst fluid (BCF). Patients presented data about their menstrual status, reproductive history, lactation period, date of first and the number of BCF aspirations, gynaecological interventions, use of oral contraceptives, family history of cancer, smoking habits and coffee consumption. The BCa incidence of patients was compared with the expected number of BCas in an age-matched group of 5143 women. RESULTS: Out of 147 patients 6 developed BCa. The standardized incidence rate was 6.29. There were significant differences in testosterone, oestrone and progesterone levels and also reproductive history of patients who developed BCa compared with patients without BCa. CONCLUSION: The above markers outline a subgroup of patients with the highest BCa risk.

Adult↗