Making Informed Choices On Incorporating Chemoprevention into carE (MiCHOICE, SWOG 1904): Design and methods of a cluster randomized controlled trial.

INTRODUCTION: Women with atypical hyperplasia (AH) or lobular carcinoma in situ (LCIS) have a significantly increased risk of breast cancer, which can be substantially reduced with antiestrogen therapy for chemoprevention. However, antiestrogen therapy for breast cancer risk reduction remains underutilized. Improving knowledge about breast cancer risk and chemoprevention among high-risk patients and their healthcare providers may enhance informed decision-making about this critical breast cancer risk reduction strategy. METHODS/DESIGN: We are conducting a cluster randomized controlled trial to evaluate the effectiveness and implementation of patient and provider decision support tools to improve informed choice about chemoprevention among women with AH or LCIS. We have cluster randomized 26 sites across the U.S. through the SWOG Cancer Research Network. A total of 415 patients and 200 healthcare providers are being recruited. They are assigned to standard educational materials alone or combined with the web-based decision support tools. Patient-reported and clinical outcomes are assessed at baseline, after a follow-up visit at 6 months, and yearly for 5 years. The primary outcome is chemoprevention informed choice after the follow-up visit. Secondary endpoints include other patient-reported outcomes, such as chemoprevention knowledge, decision conflict and regret, and self-reported chemoprevention usage. Barriers and facilitators to implementing decision support into clinic workflow are assessed through patient and provider interviews at baseline and mid-implementation. RESULTS/DISCUSSION: With this hybrid effectiveness/implementation study, we seek to evaluate if a multi-level intervention effectively promotes informed decision-making about chemoprevention and provide valuable insights on how the intervention is implemented in U.S. TRIAL REGISTRATION: NCT04496739.

Continuous Combined Estrogen Plus Progestin and Endometrial Cancer: The Women's Health Initiative Randomized Trial.

BACKGROUND: While progestin addition to estrogen mitigates endometrial cancer risk, the magnitude of the effect on incidence, specific endometrial cancer histologies, and endometrial cancer mortality remains unsettled. These issues were assessed by analyses after extended follow-up of the Women's Health Initiative (WHI) randomized clinical trial evaluating continuous combined estrogen plus progestin use. METHODS: The WHI enrolled 16 608 postmenopausal women into a randomly assigned, double-blind, placebo-controlled trial. Women age 50 to 79 years with intact uteri with normal endometrial biopsy at entry were randomly assigned to once-daily 0.625 mg conjugated equine estrogen plus 2.5mg medroxyprogesterone acetate (n = 8506) as a single pill or matching placebo (n = 8102). Follow-up beyond the original trial completion date required reconsent, obtained from 12 788 (83%) of surviving participants. Analyses were by intent-to-treat. All statistical tests were two-sided. RESULTS: After 5.6 years' median intervention and 13 years' median cumulative follow-up, there were fewer endometrial cancers in the combined hormone therapy compared with the placebo group (66 vs 95 case patients, yearly incidence, 0.06% vs 0.10%; hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.48 to 0.89, P = .007). While there were somewhat fewer endometrial cancers during intervention (25 vs 30, respectively; HR = 0.77, 95% CI = 0.45 to 1.31), the difference became statistically significant postintervention (41 vs 65, respectively; HR = 0.59, 95% CI = 0.40 to 0.88, P = .008), but hazard ratios did not differ between phases (P difference = .46). There was a statistically nonsignificant reduction in deaths from endometrial cancer in the estrogen plus progestin group (5 vs 11 deaths, HR = 0.42, 95% CI = 0.15 to 1.22). CONCLUSION: In postmenopausal women, continuous combined estrogen plus progestin decreases endometrial cancer incidence.

Reliable evidence from placebo-controlled, randomized, clinical trials for menopausal hormone therapy's influence on incidence and deaths from breast cancer.

In an invited editorial, Dr Shapiro proposes that vaginal bleeding leading to unblinding and subsequent detection bias explains the breast cancer increase seen with estrogen plus progestin in the Women's Health Initiative (WHI) clinical trial (1) . In the context of a uniform detection program of protocol-mandated annual mammography and breast examinations, such a proposal is medically implausible. Dr Shapiro suggests detection bias would identify a larger number of 'slowly growing tumors that would otherwise remain clinically silent'. The findings of more advanced cancers with increased deaths from breast cancer in the estrogen plus progestin group refute this conjecture. During early post-intervention phases of both WHI hormone therapy trials, when breast cancer detection bias is asserted by Dr Shapiro because participants had been informed of randomization assignment, breast cancer incidence rates were lower (rather than higher) than during intervention. Thus, Dr Shapiro's claims are directly refuted by findings from the WHI randomized clinical trials. Health-care providers should be aware that randomized clinical trial evidence supports estrogen plus progestin increasing breast cancer incidence and deaths from breast cancer. In contrast, among women with prior hysterectomy, randomized clinical trial evidence supports estrogen alone reducing breast cancer incidence and deaths from breast cancer.

Health risks and benefits from calcium and vitamin D supplementation: Women's Health Initiative clinical trial and cohort study.

SUMMARY: The Women's Health Initiative (WHI) double-blind, placebo-controlled clinical trial randomly assigned 36,282 postmenopausal women in the U.S. to 1,000 mg elemental calcium carbonate plus 400 IU of vitamin D(3) daily or placebo, with average intervention period of 7.0 years. The trial was designed to test whether calcium plus vitamin D supplementation in a population in which the use of these supplements was widespread would reduce hip fracture, and secondarily, total fracture and colorectal cancer. INTRODUCTION: This study further examines the health benefits and risks of calcium and vitamin D supplementation using WHI data, with emphasis on fractures, cardiovascular disease, cancer, and total mortality. METHODS: WHI calcium and vitamin D randomized clinical trial (CT) data through the end of the intervention period were further analyzed with emphasis on treatment effects in relation to duration of supplementation, and these data were contrasted and combined with corresponding data from the WHI prospective observational study (OS). RESULTS: Among women not taking personal calcium or vitamin D supplements at baseline, the hazard ratio [HR] for hip fracture occurrence in the CT following 5 or more years of calcium and vitamin D supplementation versus placebo was 0.62 (95 % confidence interval (CI), 0.38-1.00). In combined analyses of CT and OS data, the corresponding HR was 0.65 (95 % CI, 0.44-0.98). Supplementation effects were not apparent on the risks of myocardial infarction, coronary heart disease, total heart disease, stroke, overall cardiovascular disease, colorectal cancer, or total mortality, while evidence for a reduction in breast cancer risk and total invasive cancer risk among calcium plus vitamin D users was only suggestive. CONCLUSION: Though based primarily on a subset analysis, long-term use of calcium and vitamin D appears to confer a reduction that may be substantial in the risk of hip fracture among postmenopausal women. Other health benefits and risks of supplementation at doses considered, including an elevation in urinary tract stone formation, appear to be modest and approximately balanced.

Intervention approaches against I/R-induced arterial insufficiency in reconstructive surgery.

Ischemia and reperfusion in skeletal muscle is unavoidable during many reconstructive surgeries. Typical examples include replantation, transplantation, and free muscle transfer. One important complication during or after surgery is arterial insufficiency or a no-reflow phenomenon. The microcirculation is a primary target of ischemia and reperfusion injury. Vasoconstriction, poor blood flow, and capillary no-reflow, are the prominent features in the microcirculation seen during reperfusion. Currently, extensive efforts have focused on the theory that reactive oxygen species induce endothelial dysfunction in the microcirculation during reperfusion. Some intervention approaches, including ischemic preconditioning, are developing to interfere with or modulate the pathophysiological processes that are set in motion during ischemia and reperfusion.

The initiating factors of late preconditioning in skeletal muscle.

PURPOSE: The goal of these studies was to determine the initiating factors for late preconditioning in the microcirculation of skeletal muscle. MATERIALS AND METHODS: The cremaster muscle of male Sprague-Dawley rats underwent 4 h of ischemia and then 60 min of reperfusion. Ischemic preconditioning (IPC) consisted of 45 min of ischemia but was done 24 h before the 4 h of ischemia. To mimic the effects of IPC in the late phase, adenosine (ADO) or sodium nitroprusside (SNP) was given 24 h before the prolonged ischemia via local intraarterial infusion. To block the effects of IPC in the late phase, 8-sulfophenyl-theophylline (a nonspecific ADO receptor blocker) or N(W)-nitro-l-arginine (a nonselective nitric oxide synthase antagonist) was given prior to IPC. Microvascular response to IPC and pharmacological preconditioning were determined by measuring arteriole diameters and capillary perfusion using intravital microscopy. RESULTS: Administration of ADO or SNP on day 1 without IPC produced a similar microvascular protection against prolonged ischemia/reperfusion on day 2 as that induced by IPC alone. In contrast, blocking ADO receptors or nitric oxide synthase on day 1 just prior to IPC eliminated the IPC-induced microvascular protection seen on day 2. In addition, inhibition of nitric oxide synthase on day 1 diminished the protection induced by ADO, but blocking ADO receptors on day 1 did not compromise the protection induced by SNP. CONCLUSION: The results from these studies suggest that up regulation of ADO is the initiating factor with secondary up regulation of nitric oxide in late preconditioning. Both ADO and nitric oxide contribute to initiating microvascular protection in the late phase of IPC.

Interaction of angiogenesis inhibitor TNP-470 with basic fibroblast growth factor receptors.

TNP-470 is a synthetic analogue of fumagillin that acts as a potent angiogenesis inhibitor. Recently, our laboratory demonstrated that systemic administration of TNP-470 (5.0 mg/kg) decreased the rate of cutaneous wound healing by greater than 20%. In this study, we tested the hypothesis that TNP-470 interferes with the wound repair-stimulating action of basic fibroblast growth factor (bFGF) by competing with endogenous bFGF for its binding sites on the receptor protein. The influence of TNP-470 was examined in vitro in a ligand competition assay of high- and low-affinity receptor binding to (125)I-bFGF in NIH/3T3 cells. Results demonstrated that recognition of (125)I-bFGF by low-affinity growth factor binding sites was significantly decreased (P < 0.01) in the presence of TNP-470. However, TNP-470 inhibition of radiolabeled bFGF binding to high-affinity sites was not significantly affected (P = 0.07). In view of recent studies demonstrating that the low-affinity receptors of bFGF were heparan sulfate proteoglycans, we suggest that the influence of TNP-470 on diminished wound healing is due to its direct recognition by these molecules.

An animal model to study microcirculatory changes associated with vascular delay.

Vascular delay is a surgical procedure that renders a flap partially ischaemic several days prior to its transfer in order to increase its viability after its transfer. Though much debate exists regarding the actual mechanism of vascular delay, most theories agree that changes in the microcirculation play a key role. In this paper, we describe four experiments that establish the ear of the homozygous (hr/hr) hairless mouse as an effective model for directly viewing and measuring delay-induced changes in microcirculation. In our first experiment, we compared mouse ears that were delayed (n = 18) with ones that were not (control) (n = 13) and showed that vascular delay significantly (P < 0.05) reduced ear flap necrosis. In a second experiment, we delayed mouse ears for 2 (n = 9), 4 (n = 14), 6 (n = 10), 8 (n = 10), 10 (n = 10), 20 (n = 18), 40 (n = 10) and 80 (n = 11) days and found that the reduction in necrosis becomes statistically significant (P < 0.05) over non-delayed controls (n = 12) after a minimum delay period of 6 days. In a third experiment, we delayed mouse ears by ligating only the vein (n = 14), only the artery (n = 11), only the nerve (sympathectomy) (n = 14), and vein, artery and nerve (n = 14) of the main neurovascular pedicle and found significant (P < 0.05) reductions in flap necrosis in all groups compared to nondelayed controls (n = 12). Finally, in a fourth experiment, we measured vessel directionality changes in mouse ears that were delayed for 6 (n = 4), 10 (n = 4), 20 (n = 4), 40 (n = 4) and 80 (n = 4) days, and found that directionality changes became significant (P < 0.05) at 6 days of delay and remained so for all the days studied when compared with non-delayed controls (n = 4).

Traditional criteria for observation of splenic trauma should be challenged.

Age less than 55 years, normal Glasgow Coma Score (GCS), and absence of hypotension are traditional criteria for the selection of adult patients with blunt splenic trauma for observation. The objective of this study is to challenge these criteria. Two hundred twelve patients who presented with blunt splenic injury between 1992 and 1997 were identified from the Trauma Registry at our Level I trauma center. The patients were divided into three groups: 100 patients (47%) were observed, 108 (51%) underwent immediate splenorrhaphy or splenectomy, and 4 (2%) failed observation. The three groups were compared by participants' ages, GCSs, and histories of hypotension. No statistical differences were noted between the successfully observed patients and those requiring immediate surgery with respect to these criteria. Of the 4 patients who failed observation, all were younger than 55 years, all had a GCS >12, and all were normotensive. Our findings suggest that traditional criteria used to select patients for splenic trauma observation are not absolute indicators and should be liberalized: patients can be successfully observed despite having criteria that, in the past, would have led to immediate operative intervention.

Microcirculatory changes following different temperature washouts in a free flap model.

In spite of the extensive experimental work on vascular washout in free flap surgery, an optimal temperature for the washout solution has not been established. This study was designed to determine the effect of the washout solution temperature on the degree to which the microcirculation is cleared of blood. The cremaster muscle flap in the rat was used, in which the microcirculation can be directly viewed and the presence of blood and perfusion parameters within various vessels can be measured during and after washout. Washout was started with a single, high-pressure infusion and continued at 130 mmHg for 15 minutes. The temperature of the washout solution was either 2-3, 20-22, or 35 degrees C. In all three groups, washout cleared the microcirculation almost completely within the first minute. However, we observed that a cold or room temperature washout cleared the microcirculation more completely than a warm washout did. The temperature of the washout solution did not effect post washout capillary perfusion and/or arterial diameters.

Angiogenesis inhibitor TNP-470 inhibits murine cutaneous wound healing.

BACKGROUND: TNP-470 (AGM-1470) is a potent inhibitor of angiogenesis with potential therapeutic applications in neoplastic and angio-proliferative diseases. This study evaluated its effect on cutaneous wound healing in a murine dorsal excisional wound model. MATERIALS AND METHODS: Full-thickness wounds (1.60 cm2) were created on the dorsum of homozygous/hairless mice (7 to 9 weeks). Wound areas were measured on alternate days for 16 days. Experimental groups consisted of (1) TNP-470 administered in doses of 0.05, 0.5, and 5.0 mg/kg on Days 0, 2, and 4 or Days 0 through 6; (2) TNP-470 (5.0 mg/kg) coadministered with minocycline (4.0 and 10 mg/kg) on Days 0, 2, and 4; and (3) TNP-470 (5.0 mg/kg on Days 0, 2, and 4) coadministered with topical basic fibroblast growth factor (bFGF) 1. 0 microg/wound on Days 0, 1, and 2. Hematoxylin and eosin staining was used to compare experimental and control wounds. RESULTS: TNP-470 administration significantly decreased wound healing in a dose-dependent manner versus controls (P <.05). The 5.0 mg/kg concentration yielded the greatest effect by maintaining an average wound area 20.4% greater than controls and a marked delay in wound healing on H&E staining. Alternate-day dosing was as effective as consecutive day administration. Minocycline did not augment the wound healing inhibition of TNP-470. Coadministration of TNP-470 and bFGF eliminated any rate-altering effect of TNP-470 upon wound healing and resulted in wound areas similar to controls. CONCLUSION: Therapy with TNP-470 induces a significant delay in murine cutaneous wound healing. This effect may be exploited for use in situations where wound healing is excessive and debilitating. Topical application of bFGF can overcome TNP-470-induced wound healing inhibition.

Estimation of the correlation between nutrient intake measures under restricted sampling.

Food frequency questionnaires (FFQs) are commonly used to assess dietary intake in epidemiologic research. To evaluate the FFQ reliability, the commonly used approach is to estimate the correlation coefficient between the data given in FFQ and those in food records (for example, 4-day food records [4DFR]) for nutrients of interest. However, in a dietary intervention study, a criterion for eligibility may be to select participants who have baseline FFQ-measured dietary intake of percent energy from fat above a prespecified quantity. Other instruments, such as the 4DFR, may be subsequently administrated only to eligible participants. Under these circumstances, analysis without adjusting for the restricted population will usually lead to biased estimation of correlation coefficients and other parameters of interest. In this paper, we apply likelihood-based and multiple imputation (MI) methods to accommodate such incomplete data obtained as a result of the study design. A simulation study is conducted to examine finite sample performance of various estimators. We note that both the MI estimate and the maximum likelihood (ML) estimate based on a bivariate-normal model are not sensitive to departures from this normality assumption. This led us to investigate robustness properties of the ML estimator analytically. We present some data analyses from a dietary assessment study from the Women's Health Initiative to illustrate the methods.

Inhibition of wound contraction with locally injected lathyrogenic drugs.

BACKGROUND: Previous studies using systematically administered lathyrogens to inhibit wound contractures have produced inconsistent results. The purpose of this study was to investigate the effects of lathyrogenic drugs on wound contraction when injected locally. METHODS: Two symmetrical full-thickness wounds were made on the dorsum of either side of hairless (hr/hr) mice; thus, each animal served as its own control. Animals were divided into groups receiving daily local injections of beta-aminopropionitrile or D-penicillamine, or both beta-aminopropionitrile and D-penicillamine and normal saline vehicle (control side) for 5 or 10 days. The rate of contraction was determined by serial measurements of the surface area of each wound during the treatment period. At the end of the treatment period, the wounds were excised en bloc with the chest wall and prepared for blinded histological analysis. Granulation tissue thickness, number of fibroblasts in granulation tissue per unit area, number of inflammatory cells (neutrophils, lymphocytes, macrophages and mast cells) in subjacent muscle per unit area, and collagen deposition in subjacent muscle were determined. RESULTS: Wound contraction, granulation tissue thickness, and collagen deposition in subjacent muscle were decreased only in wounds treated with beta-aminopropionitrile plus D-penicillamine. Collagen deposition in subjacent muscle was also decreased in wounds treated with D-penicillamine alone. Neither drug alone nor the combination affected the number of inflammatory cells in subjacent muscle. Body weight was not affected by the experimental procedures. CONCLUSIONS: The combination of beta-aminopropionitrile and D-penicillamine is potentially useful for inhibiting contracture formation when injected locally.

Vascular delay in skeletal muscle: a model for microcirculatory studies.

Dynamic myoplasty is a relatively new use for muscle flaps and has led us to revisit the mechanisms of vascular delay as a means of optimizing blood supply to muscle flaps. Despite the well-documented effectiveness of vascular delay in skin flaps, vascular delay in muscle flaps has not been widely reported. Regardless of the many mechanisms postulated in the literature as contributors to the delay effect in skin, the one element common to all these hypotheses is the importance placed on changes in the microcirculation. Based on this factor, in the present study we developed and validated an animal model in which delay-induced microvascular changes could be measured in skeletal muscle flaps. We used the hairless mouse latissimus dorsi muscle flap because its vascular distribution is similar to that of humans and its thin structure will enable us in future studies to directly view and measure its microvasculature using videomicroscopy. In 12 animals, we found that delay significantly (p < 0.01) reduced necrosis of the distal part of the muscle from 57 +/- 9 percent in nondelayed flaps (n = 7) to 22 +/- 3 percent in delayed (n = 5) flaps. In these studies, we also determined that the hairless mouse latissimus dorsi muscle flap will serve as an excellent model for defining microvascular changes throughout delay.

Effect of low dose aspirin on thrombus formation at arterial and venous microanastomoses and on the tissue microcirculation.

In free flap/replantation surgery, failure is usually associated with thrombotic occlusion of a microvascular anastomosis (risk zone I) or, on occasion, flow impairment in the microcirculation of the transferred or replanted tissue (risk zone II). The objective of this study is to describe the effect of low dose aspirin on blood flow at both risk zones in microvascular surgery. Risk zone I: In rat femoral arteries and veins, thrombus formation was measured at the anastomoses using transillumination and videomicroscopy. Forty male Wistar rats were assigned in equal numbers to four groups: either arterial or venous injury with either aspirin (5 mg/kg systemically) or saline treatment. We found that aspirin significantly reduces thrombus formation at the venous anastomosis (p = 0.001). Risk zone II: In the isolated rat cremaster muscle downstream from an arterial anastomosis, we measured capillary perfusion, arteriolar diameters, and the appearance of platelet emboli for 6 hours in the muscle microcirculation. Sixteen male Wistar rats in two equal groups received either aspirin (5 mg/kg systemically) or saline. We found that in aspirin-treated animals, capillary perfusion is significantly (p = 0.002) improved, whereas arteriolar diameters and emboli only slightly increased. In conclusion, low dose aspirin inhibits anastomotic venous thrombosis and improves microcirculatory perfusion in our rat model. These studies provide quantitative data confirming and clarifying the beneficial effects of low dose aspirin in microvascular surgery.

Platelet-derived thromboxane A2 decreases microvascular perfusion after arterial repair.

Previous work suggests that cod liver oil helps to protect the microcirculation from the consequence of thromboembolic events. The possibility that altered synthesis of thromboxane A2 accounts for the protective effects seen with cod liver oil was investigated in the present study. This was done using the combined thromboxane A2 synthetase inhibitor and thromboxane A2-prostaglandin H2 receptor blocker R68070 (Ridogrel). A standardized microvascular injury was inflicted on the right iliac artery of the rat to generate emboli. The downstream cremaster muscle was used to visualize the passage of the ensuing emboli and to assess the effects of this arterial injury on capillary perfusion and arteriole diameters. The number of visible emboli was not changed by either cod liver oil diet or Ridogrel administration. However, capillary perfusion was preserved by using cod liver oil (n = 7) and was significantly increased by using Ridogrel (n = 7) in comparison with untreated controls (n = 7) in which capillary perfusion was decreased because of the emboli. The administration of Ridogrel to cod liver oil-treated animals (n = 7) provided no additive benefit. The percentage change in A-2 vessel diameters in cod liver oil-treated (n = 7) animals was no different from the control group (n = 7). Ridogrel (n = 7), on the other hand, produced a significant increase in A-3 vessel (n = 21) diameters, but its effects were comparatively less in the cod liver oil-treated animals (n = 7). The formation of platelet aggregates (emboli) appears relatively independent of thromboxane A2 in the rat. Ridogrel is very effective in protecting the microcirculation, and these effects appear to be mediated by A-3 vasodilatation, which, therefore, is at least partially thromboxane A2-dependent. The positive effects of cod liver oil may be mediated by a mechanism that reduces thromboxane A2 synthesis, but further studies are necessary.

Prefabricated jejunal free-tissue transfer for tracheal reconstruction: an experimental study.

Reconstruction of long-segment tracheal defects is a problem for the reconstructive surgeon. Difficulties arise with the use of prosthetic materials because of their propensity for infection and extrusion. Autologous tissue is limited by poor structural characteristics and technical complexity. We propose a simple composite bioprosthesis that, through a process of prefabrication and subsequent neovascularization, may provide a functional tracheal analogue superior to existing forms of reconstruction. Ten rats had composite flaps constructed by combining an isolated, perfused, mucosectomized segment with an outer covering of a ring-reinforced woven Dacron vascular graft. This unit remained in the intraabdominal milieu for 20 days and was then inspected for viability, incorporation of jejunum and graft, flexibility, and tolerance to negative pressure. Seven experimental animals survived the initial phase. The jejunal bioprostheses in all cases tolerated negative pressures to -200 mmHg, rotation of 180 degrees, and flexion to 90 degrees without collapse of the graft segments. Vascular casts and standard histologic examination showed neovascularization of the Dacron graft and dense fibrovascular ingrowth into the interstices of the graft. We conclude that prefabrication utilizing autologous and prosthetic components to create a single axial flap for transfer is a feasible solution to long-segment tracheal reconstruction. Neovascularization permeates the full thickness of the prosthetic component and is accompanied by dense fibrous ingrowth during the delay period. This neotracheal analogue also possesses structural characteristics similar to those of the native trachea and a durable submucosal layer that can support ingrowth of epithelium.

Ischemia increases the angiogenic potency of basic fibroblast growth factor (FGF-2).

The aim of this study was to investigate the angiogenic response to exogenously administered basic fibroblast growth factor (FGF-2) in normal and ischemic skin, using the hairless mouse ear microcirculatory model. The hairless mouse ear is a well-established model for in vivo studies of skin microcirculation. Using this model, angiogenesis- and angiogenesis-associated changes in the microcirculation can be directly and continuously viewed and quantified in a variety of different experimental settings. To create ischemia in the mouse ear, all but one of the three to four feeding vessels nourishing the ear were ligated 3 days prior to a local subdermal injection of FGF-2 (9.3 + 1-0.5 mm/mm2) or saline into the dorsum of the ears. Angiogenesis was quantified by direct observation, at high magnification, of the injection site where increases in total vessel length (TVL) were measured repeatedly over 18 days following injection. We found a significant (P < 0.01) increase in TVL in normal and ischemic ears injected with FGF-2. Saline injection also induced a significant increase in TVL in ischemic ears. However, the angiogenic response to FGF-2 in ischemic ears was significantly stronger than saline alone in ischemic ears or saline or FGF-2 in normal ears. This response could be used clinically to accelerate angiogenesis and thus increase perfusion in ischemic tissue.

In vitro platelet aggregation studies in microvascular surgery research: a method in the rat model.

There is now a growing awareness of the central role of platelet function in microvascular thrombosis. Platelet aggregation studies remain one of the most useful ways of studying platelet function and response to different stimuli. This brief communication highlights some of the main variables that can affect platelet aggregation in rats and emphasizes the existence of important differences in these variables compared with human platelet aggregation.