Estrogen-prolactin dependency in 7,12-dimethylbenz(a)anthracene-induced tumors.

Hormonal influences on dimethylbenz(a)anthracene-induced tumor growth were investigated in detail by endocrine ablation and replacement of hormones. The majority of tumors regressed following ablation and most of them were reactivated by subsequent administrations of estrogen (0.1 to 5 mug) or prolactin (2 mg). Increasing numbers of tumors, however, were not stimulated by prolactin when administration was delayed, and a basal level of estradiol (0.01 mug) in addition to prolactin was required for reactivation of tumors. Nafoxidine hydrochloride, a competitor of estrogen at the receptor sites, arrested growth of a large portion of dimethylbenz(a)anthracene-induced tumors in intact animals but failed to retard growth of prolactin-stimulated tumors. On withdrawal of prolactin-nafoxidine, rapid regression of tumor occurred and readministration of prolactin failed to activate most of the tumors for as long as 28 days. Our results give good supporting evidence that estrogen plays a primary role in tumor growth. The interactions of prolactin and estrogen at tumor sites are necessary for regulatory events related to tumor growth.

On the mechanism of prolactin and estrogen action in 7,12 dimethylbenz(A)anthracene-induced mammary carcinoma in the rat. II. In vivo tumor responses and estrogen receptor.

In order to test the in vivo effect of prolactin on estrogen receptor (ER) binding capacity in tumors induced by 7,12 dimethylbenz(a)anthrancene (DMBA-tumor), growth of the tumors from changes in prolactin and estrogen levels was compared retrospectively with cytoplasmic ER levels. It was demonstrated that some tumors required prolactin, some needed prolactin-estrogen during their growth period anda small number were not influenced by hormonal milieu. ER was present in hormonally dependent tumors but was low or absent in hormonaly-independent tumors. Deletion of hormones by endocrine ablation in the host rat resulted in tumor regression loss of ER. Replenishment of ER and subsequent tumor growth were accomplished by injection of prolactin or prolactin-estrogen in endocrine ablated rats but were not achieved in rats bearing tumors exposed to prolactin-nafoxidine. Our results demonstrate that both estrogen and prolactin were essential for growth of hormonally dependent DMBA-tumors. Tumor growth was also prevented when cytoplasmic ER was not replenished , indicating that ER may be an indispensable prerequisite for growth. Prolactin, independently of or cooperatively with estrogen, stimulated ER binding capacity. These results support the hypothesis that there may exist a prolactin regulatory mechanism of estrogen action at the tumor site. The interactions of estrogen and prolactin in situ in modulating hormonal receptor binding capacities may contribute to the overall stimulatory effect of these two hormones on DMBA-tumors.

Intraoperative sustained limited expansion (ISLE) as an immediate reconstructive technique.

Intraoperative sustained limited expansion (ISLE) has provided ideal tissue replacement for coverage of small defects with an acceptably low complication rate. The ISLE technique may have more general applicability to the reconstructive surgeon than does chronic expansion because of the frequent need for additional local tissue at the time of surgery.

Tissue expansion in reconstruction of acquired auricular defects.

Over the past 10 years, tissue expansion has gradually become accepted as a useful adjunct to ear reconstruction with an autologous framework. The advantage of expanded tissue in these cases has been the addition of more tissue with similar color, texture, and sensation. In traumatic cases, the creation of well-vascularized tissue allows an improved anterior draping of skin over the cartilaginous framework and production of a well-defined posterior sulcus. Encroachment of hair onto the reconstructed ear is minimized because of the extra tissue produced by expansion. Under favorable conditions, tissue expansion is an acceptable and reliable method for partial or total ear reconstruction.

Noninvasive monitoring of tissue viability.

Noninvasive monitoring techniques are procedures of little or no morbidity that may be repeated frequently to assess tissue viability. The ideal noninvasive technique would be safe, sensitive, reliable, reproducible, simple to use, and inexpensive. Although no such ideal technique yet exists, several currently available methods have clinical usefulness. Visual fluorescein, fluorescein photography, and surface fluorometry all work by the same principle. We prefer the surface fluorometer because of its greater sensitivity, the more objective nature of the data it provides, and the greater frequency with which it can be repeated. Ultrasound Doppler techniques are useful preoperatively in locating vessels and assessing their patency, and we have found the bidirectional Doppler quite helpful in the postoperative monitoring of replanted or revascularized digits. The laser Doppler, photoplethysmograph, and surface thermometer have not been as helpful in our experience. Transcutaneous oxygen measurement shows great promise for the postoperative monitoring of replants and free tissue transfers.

Pharmacologic manipulation of the microcirculation in cutaneous and myocutaneous flaps in pigs.

The vascular effects of isoxsuprine, diazoxide, and isoproterenol were studied in arterial buttock flaps and latissimus dorsi myocutaneous flaps in pigs. Capillary blood flow to the skin and muscle of these flaps was measured by the radioactive microsphere (15-mu diameter) technique 6 hours postoperatively under pentobarbital anesthesia. It was observed that isoproterenol, a beta-adrenergic receptor agonist, was not effective in augmentation of skin blood flow in the arterial buttock flaps. However, isoproterenol significantly increased capillary blood flow to the arterialized portion of latissimus dorsi myocutaneous flaps compared with controls. Isoxsuprine and diazoxide (vascular smooth muscle relaxants) significantly (p less than 0.05) increased total capillary blood flow to the skin of arterial buttock flaps and to the skin and muscle of the latissimus dorsi myocutaneous flaps. However, the increase in capillary blood flow occurred mainly in the arterialized portion of these flaps. The capillary blood flow, which was supplied by the small arteries in the distal portion of the arterial buttock and latissimus dorsi flaps, was not increased by treatment with isoxsuprine or diazoxide. Therefore, there was also no increase in the maximum distance of capillary blood flow from the pedicle to the distal end of the flaps. These observations led us to hypothesize that different sizes (diameters) of arteries in the skin and muscle have different reactivity (or sensitivity) to vasodilatory drugs. In the present experiment, the large dominant artery of the arterial buttock and latissimus dorsi flaps responded to isoxsuprine or diazoxide (vascular smooth-muscle relaxants), resulting in an increase in blood supply to the capillaries in the proximal portion of the flaps. On the other hand, the small arteries in the distal portion (random portion) of these flaps were not sensitive to isoxsuprine or diazoxide. Therefore vasodilation did not occur, and there was no increase in blood supply to the capillaries in the distal portion of arterial buttock and latissimus dorsi flaps. This explanation also lent support to our previous report that treatment with isoxsuprine did not augment skin viability in the distal portion of arterial buttock and latissimus dorsi flaps. It is suggested that research in pharmacologic manipulation of skin blood flow and viability in skin flap surgery should emphasize the sensitivity of small arteries to various drug actions.(ABSTRACT TRUNCATED AT 400 WORDS)

Pathophysiology of skin flaps raised on expanded pig skin.

The pathophysiology of skin flaps raised on nonexpanded and expanded skin was studied in pigs. Skin expansion was achieved by gradual inflation of a subcutaneously implanted silicone tissue expander with sterilized isotonic saline over a period of 4 to 5 weeks. Comparisons were made of the skin flap viability and capillary blood flow among random acute and delayed skin flaps and skin flaps constructed on skin pockets implanted with noninflated or inflated tissue expanders. The extents of skin flap viability and capillary blood flow were similar among delayed skin flaps and skin flaps constructed on skin pockets but were significantly higher than those of acute random skin flaps raised on normal skin. It was concluded that skin viability and capillary blood flow in skin flaps raised on expanded skin were not compromised and the regulation of blood flow in skin flaps raised on nonexpanded or expanded skin pockets was similar to that seen in delayed skin flaps. The mechanisms of the delay phenomenon was discussed.

Hemodynamics and viability of acute neurovascular island skin flaps in rats.

Hemodynamics and skin survival were studied in acute 8 X 8 cm2 neurovascular island skin flaps in rats. Maximum blood flow and extent of fluorescein and 15 mu microsphere penetration in the skin flap occurred at about 24 hours after flap construction. However, maximum A-V shunt flow occurred at about 12 hours. It is concluded that ischemia in the acute skin flap, probably due to vasoconstriction, did occur in the early stage of the postoperative period. The opening of A-V shunts and vasodilation of the capillary bed in the later stage may be controlled by the same mechanism(s). It is also suggested that treatment which results in vasodilation in the skin flap in the early stages of the postoperative period may augment the extent of skin viability.

Experimental evidence for involvement of prostaglandins in viability and acute skin flaps: effects on viability and mode of action.

Treatment with prostaglandin synthesis inhibitors alone or combined with exogenous PGE2 significantly (p less than 0.05) increased skin viability in acute island skin flaps. Increased cutaneous blood flow was observed 15 minutes after skin flap construction in rats injected with ibuprofen (5 mg/kg) intraarterially before surgery compared with that in control rats. It is hypothesized, therefore, that prostaglandins may influence skin viability and the microcirculatory level.

Pathogenesis and treatment of infant skin strawberry hemangiomas: clinical and in vitro studies of hormonal effects.

Corticosteroid treatment of infant strawberry hemangiomas produced premature regression of growing lesions in patients less than a year of age, but not in patients with cavernous or port-wine hemangiomas. Abnormally elevated serum estradiol-17 beta levels were found in strawberry hemangiomas, fourfold higher than in control, cavernous, and port-wine hemangiomas which were adjusted for age and sex of the patients. Specific estradiol-17 beta receptor binding activity was studied in biopsy tissues obtained from normal prepubertal skin and skin from various kinds of hemangiomas. Minimal specific estradiol-17 beta binding activity was detected in tissues of normal skin and involuting strawberry, cavernous, or port-wine hemangiomas. Abnormally high levels of specific estradiol-17 beta binding sites were demonstrated by receptor assays and by in vitro tissue culture technique in nine tissue samples obtained from strawberry hemangiomas, seven of which responded definitely or probably to corticosteroid therapy. The in vitro estradiol-17 beta binding activity in these tissue explants was inhibited by low (5 micrograms/ml) and high (100 micrograms/ml) doses of cortisone. The present data seem to suggest that there may be a causal relationship between the presence of elevated serum E2 and specific estradiol-17 beta receptors in the pathogenesis of strawberry hemangiomas and in response to corticosteroid treatment of the hormone-sensitive hemangiomas.

Quantitative evaluation of mast cells in cellularly dynamic and adynamic vascular malformations.

Mast cells were counted in 78 histologic specimens from 70 patients with various vascular malformations showing cellularly dynamic and cellularly adynamic lesions. In growing stages of strawberry hemangiomas, there was an increased number of mast cells (mean 11.0 cells per high-power field in stage III and 23.7 in stage IV), as well as a high number of mast cells in the initial involution of strawberry hemangiomas (stage V, mean 21.0 cells per high-power field). In later involuting stages (stages VI and VII), the number of mast cells decreased (mean 9.3 in stage VI; mean 4.7 in stage VII). In cellularly adynamic lesions, i.e., port wine stains, the mean number of mast cells was 4.8, and in congenital arteriovenous malformations, it was 3.6. In normal skin, the mean number of mast cells was 3.2. In cellular hemangiomas that showed active growth (stages III to IV), the number of mast cells was strikingly low (mean 1.3). It seems that the mast cells are not responsible for the proliferation of the endothelium or for growth of the hemangioma. The markedly increased number of mast cells in the growing stages and initial involuting stage of strawberry hemangiomas parallels the gradual growth of fibrous connective tissue inside the tumor. Mast cells may thus be a precursor of the beginning of the involution of a strawberry hemangioma.

Photoradiation therapy of cutaneous angiosarcomas in mice.

Cutaneous angiosarcoma is a relatively rare but devastating malignant vascular tumor. It has a high incidence of recurrence following conventional therapeutic modalities applied either singly or in combination. The increased vascularity of cutaneous angiosarcomas, facilitating selective uptake and retention of a photosensitizing agent, such as hematoporphyrin derivative (HPD), suggests that these tumors would respond well to photoradiation therapy. To study the feasibility of this treatment modality, transplantable hemangiosarcomas were implanted in B6C3F1 female mice. Within 2.5 to 3.5 hours after intraperitoneal administration of HPD, fluorescence was recorded in the tumor as compared with surrounding normal skin. When these photosensitized tumors were exposed to 70 J/cm2 of laser energy from an argon-pumped dye laser at 630 nm, the tumors showed marked necrosis within 24 hours. In another series, the tumors were initially photosensitized with HPD for 3 hours and then treated with laser energy ranging from 0 to 96 J/cm2. A dual labeling procedure demonstrated a dose-related decrease in DNA synthesis rate in tumors that were exposed to 0 to 30 J/cm2 at 24 hours after treatment. Furthermore, tumor tissue exposed to laser energy in excess of 30 J/cm2 showed no significant cellular DNA synthesis. These data, supported by histologic evidence of tissue destruction, suggest that photoradiation therapy has a great potential as a therapeutic modality for cutaneous angiosarcomas.

Hemodynamics and vascular sensitivity to circulating norepinephrine in normal skin and delayed and acute random skin flaps in the pig.

Cutaneous circulation in 4 X 10 cm skin samples and delayed and acute random skin flaps constructed on the flanks of castrated Yorkshire pigs (13.3 +/- 0.7 kg; n = 12) were studied during intravenous infusion (0.5 ml per minute) of 5% dextrose solution (vehicle) and 5% dextrose containing norepinephrine (1 microgram/kg per minute). Total and capillary blood flow and A-V shunt flow were measured by the radioactive microsphere technique 6 hours after the raising of 4 X 10 cm single-pedicle acute and delayed random skin flaps using the technique and calculations published previously. Fluorescein dye test was also performed to assess vascular perfusion. It was observed that the capillary blood flow in the single-pedicle delayed skin flaps was similar to that in the normal skin, and the maintenance of this normal skin blood flow was not due to the closing of A-V shunt flow in the delayed skin flaps. Similarly, the significant (p less than 0.01) decrease in capillary blood flow and distal perfusion in the acute skin flaps compared with the delayed skin flaps was not due to the opening of A-V shunts in the acute skin flaps. There was no evidence to indicate that A-V shunt flow per se was the primary factor for the regulation of capillary blood flow in the acute and delayed skin flaps in the pig. Our data seemed to indicate that tissue ischemia in the distal portion of acute skin flaps was likely the result of vasoconstriction of the small random arteries which supplied blood to arterioles and A-V shunts, and locally released neurohumoral substances may play an important role in the pathogenesis of vascular resistance and ischemia in the acute skin flaps.

On the mechanism of hormone action in 7,12 dimethylbenz(a)anthracene-induced mammary tumor. I. Prolactin and progesterone effects on estrogen receptor in vitro.

The presence of ER in DMBA-tumors was demonstrated by the use of dextran-charcoal assay, sephadex chromatography, sucrose gradient sedimentation, and organ culture techniques. It was found that tumors have binding sites ranging from 10-13 to 10-15 moles/mg protein, and a dissociation constant of ER 10-9 to 10-10 M. In experiments with tumor explants, prolactin-insulin significantly stimulated ER binding capacity, as compared with control without prolactin. This stimulation was tissue-specific and inhibited by progesterone. Insulin had a synergistic effect on prolactin stimulation of ER. Our results presents a plausible explanation for tumor responses to these hormones in vivo. This interaction of prolactin, estrogen, and progesterone may be a common phenomenon for all estrogen-responsive tissues.

Improved ischemic island skin flap survival with continuous intraarterial infusion of adenosine triphosphate--magnesium chloride and superoxide dismutase: a rat model.

Neurovascular island skin flaps are still hampered by occasional necrosis of their most distal aspect. Cells subjected to prolonged hypoxic conditions become intracellularly depleted of needed metabolic substrates and eventually die. Once hypoxic conditions are improved, ischemic tissue suffers further injury from the rapid accumulation of oxygen free radicals. This study showed 53% survival of a standard random flap constructed on the inferior epigastric neurovascular bundle of a rat. Random flap survival increased to 65% after intraarterial infusion of adenosine triphosphate--magnesium chloride (ATP-MgCl2); to 75% after superoxide dismutase infusion; and to 98% after combined ATP-MgCl2 and superoxide dismutase infusion. Neither substrate appeared to act by increasing blood flow to the ischemic tissue.

LevoDopa test and estrogen receptor assay in prognosticating responses of patients with advanced cancer of the breast to endocrine therapy.

The ability of L-dopa to arrest pain can be used to predict objective response of skeletal disease to endocrine ablation or additive therapy. In the present study, 43 patients with painful skeletal metastases were evaluated for the relief of pain by L-dopa, given 250 mg to 500 mg orally every 4 hours for 4 days. Sixteen of the 25 responders to L-dopa had objective response to either previous or later hormonal therapy while all the 18 non-responders did not benefit from endocrine ablation. The results of L-dopa responses also correlated well to the presence of absence of cytoplasmic ER in tumor. These results demonstrate that both tests (L-dopa and ER) are reliable indicators, one complimenting the other, in prognosticating response to endocrine therapy and should be used prior to hormone treatment. Alternative therapy should be considered for patients who are non-responders to the L-dopa test and/or whose tumors contain negligible ER. The long term therapeutic value of L-Dopa, however, is limited.

Therapeutic value of nafoxidine hydrochloride in the treatment of advanced carcinoma of the human breast.

Nafoxidine hydrochloride can provide additional palliation to patients who responded to previous endocrine ablation and had tumors containing an estrogen receptor. In the present study, 24 patients were evaluated for their response to nafoxidine therapy, 180 to 240 milligrams given orally per day. When tumor response was obtained, doses were reduced to 60 to 120 milligrams every other day or longer without loss of control. In the estrogen receptor positive group, eight of ten patients responded objectively to nafoxidine, while all seven estrogen receptor negative patients progressed with this therapy. These results demonstrated that nafoxidine is effective in the treatment of estrogen receptor positive cutaneous disease. These results demonstrated that nafoxidine is effective in the treatment of estrogen receptor positive cutaneous disease. Patients with lesions to other sites should receive cytoxic agents along with nafoxidine. Alternative therapy to nafoxidine should be considered for patients in whom the tumors contain negligible estrogen receptor.

Immediate versus chronic tissue expansion.

A quantitative comparison of the effects on tissues is performed between chronic tissue expansion, intraoperative expansion, and load cycling in a guinea pig model. Intra-operative expansion, which was developed by Sasaki as a method of immediate tissue expansion for small- to medium-sized defects, and load cycling, which was described by Gibson as a method using intraoperative pull, are compared with chronic tissue expansion on the basis of the following four parameters: amount of skin produced, flap viability, intraoperative tissue pressures, and histological changes. The chronically expanded group, which included booster and nonbooster expansions, produced a 137% increase in surface area, or a 52% increase in flap arc length, whereas intraoperative expansion resulted in a 31% increase in surface area, or a 15% increase in flap arc length. The load-cycled group, however, resulted in an almost negligible amount of skin increase. All three techniques exhibit immediate postexpansion stretchback. Flap viability is not impaired by any of the three techniques, in spite of the elevated pressures observed during expansion. Therefore, intraoperative expansion is effective primarily for limited expansion of small defects, whereas chronic tissue expansion still provides the greatest amount of skin increase when compared with other techniques.

Assessment of the fluorescein dye test for prediction of skin flap viability in pigs.

The visual fluorescein dye test for prediction of actual skin flap viability was evaluated in pigs. Two delayed random (4 X 10 cm) and arterial (4 X 20 cm) skin flaps were constructed on one flank of a pig, and four mirror-image skin flaps were raised acutely on the other flank of the same pig. Sodium fluorescein dye (15 mg/kg) was injected intravenously 1 and 18 hr after raising of flaps. The maximum length and area of dye stain in these flaps (N = 24) were assessed under Wood's lamp illumination, 15 min after dye injection. The actual maximum lengths and areas of skin survival of these flaps in the same pig were measured 7 days postoperatively. It was observed that visual fluorescein dye test performed 1 hr after surgery significantly (P less than 0.05) underestimated the maximum length and area of actual skin survival. On the other hand, when the fluorescein dye test was performed 18 hr postoperatively, the maximum length of dye stain and the maximum length of actual skin viability were highly correlated (r = 0.97, N = 24, P less than 0.01). Their mean values were similar (10.6 +/- 0.8 vs 10.8 +/- 0.7 cm, mean +/- SEM), and their mean coefficient of variation was 5.6 +/- 1.6%. Similarly, there was a high degree of correlation (r = 0.89, N = 24, P less than 0.01) between the maximum area of dye stain and actual skin flap viability. Their mean values were similar (68.3 +/- 4.5 vs 71.8 +/- 3.9%), and their mean coefficient of variation was 8.7 +/- 2.4%.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of antiestrogens tamoxifen and nafoxidine in the treatment of human breast cancer in correlation with estrogen receptor values. A phase II study.

Twenty-five patients with measurable metastatic breast cancer and assays for estrogen receptor (ER) were studied. Of the 16 ER positive patients on anti-estrogen therapy, one had complete disappearance of all tumor for seven months and seven patients had more than 50% reduction in their measurable tumor for an average duration of 8.8 months. Seven other ER positive patients had stabilization of their tumors for an average interval of 8.4 months. Only one of the 16 ER positive patients progressed promptly. Conversely there was only one partial response in the nine ER negative patients and only two ER negative patients had stabilization of disease. Six out of nine ER negative patients progressed promptly. Correlation existed between the duration of response and absolute estrogen receptor level of the tumor. There may be a positive correlation between the response to antiestrogen therapy and response to endocrine ablation but prospective studies must be done to further define the role of antiestrogens in this regard.