BioGlue surgical adhesive for thoracic aortic repair during coagulopathy: efficacy and histopathology.

BACKGROUND: We hypothesized that induction of coagulopathy in sheep would model clinical needle hole and surgical bleeding from synthetic graft anastomoses, and that a new tissue bioadhesive (BioGlue) would control postoperative blood loss during surgical repair of the thoracic aorta. METHODS: Sheep were anticoagulated with aspirin and heparin. A bypass was made using end-to-side anastomoses of a graft to a partially occluded descending thoracic aorta. Experimental anastomoses (EXP, n = 9) were treated with BioGlue, and control anastomoses (CON, n = 5) were treated with Surgicel to gain intraoperative hemostasis. RESULTS: EXP animals exhibited significantly reduced postsurgical bleeding (CON median 955 mL versus EXP median 470 mL, p < 0.003), a reduced rate of blood loss over the first 2 postoperative hours (CON median 210 mL/hr versus EXP median 92.5 mL/hr, p < 0.006), and over the entire recovery period (CON median 158 mL/hr versus EXP median 86 mL/hr, p < 0.05), and reduced total blood loss (CON mean 1,497 +/- 691 mL versus EXP mean 668 +/- 285 mL, p < 0.008). On histologic examination of tissues explanted after 3 months, BioGlue was relatively inert and demonstrated a minimal inflammatory response. CONCLUSIONS: The use of BioGlue significantly reduced the volume and rate of postsurgical bleeding in a coagulopathic sheep model for thoracic aortic operations. Histopathologically, BioGlue generated only a minimal inflammatory response. This new surgical tissue bioadhesive should prove extremely beneficial for coagulopathic patients undergoing thoracic aortic or vascular procedures.

Multiple oblique illumination and high-definition microscopy for breast fine-needle aspirates.

The ability of multiple oblique illumination (MOI) and high-definition microscopy (Edge R-400 3-D microscope) to improve resolution of cellular detail in the evaluation of cytopathological specimens of Pap smears and thyroid fine-needle aspirates (FNAs) has been demonstrated. However, previous experiments showed that the advantages of MOI and high-definition stereo microscopy were less certain for the breast FNAs. We hypothesized that these findings were due to the lack of sample thickness for the breast FNA specimens. To test this hypothesis, we analyzed breast FNA specimens that were significantly thicker (10.5 microm). The number of lights (1, 2, 3, 4) and the angle of light (+1.5, 0, -3) were varied independently, creating 12 groups. Three images at each combination of settings were digitally captured and analyzed to obtain a histogram. The coefficient of resolution (Cr) was calculated to mathematically evaluate the grayscale histograms for intensities (0-255), where Cr = [¿IM - IN¿ x (N)] (IM, median pixel intensity; IN, measured pixel intensity; and N, number of pixels at given intensity). Mean Cr values demonstrated that the angle of light obliquity was not a factor in altering the resolution and contrast (p = .9). However, there was a significant increase in resolution, as measured by mean Cr values, as the number of lights was successively reduced from four lights to one light. Thus, the thicker specimen did show that increases in resolution were a significant function of the number of lights utilized.

A sheep model for thoracic aortic surgery in the presence of systemic coagulopathy.

Surgical repair of aneurysms, traumatic injuries, or congenital anomalies of the thoracic aorta are associated with high morbidity and mortality mainly as a result of excessive and uncontrollable hemorrhage from diffuse coagulopathy. We developed a model in sheep that simulates this coagulopathic state for experimentation with thoracic aorta surgery. This experimental animal model involves administering a 600-mg aspirin suppository once a day for the 2 days preceding surgery and a final dose on-call to surgery. Prior to cross-clamping the aorta, an intravenous (i.v.) bolus of heparin (400 IU/kg) was administered. Thirty minutes later, the i.v. heparin bolus was repeated. Pre- and intraoperative activated clotting time was 101 +/- 10 s and >1500 s (p < .0001); prothrombin time, 21 +/- 1 s and >100 s (p < .0001); and activated partial thromboplastin time, 20 +/- 1 s and >50 s (p < .0001), respectively. We utilized a partial cross-clamp-and-sew technique to anastomose a woven, gelatin-impregnated, 16-mm tube graft end-to-side to the descending thoracic aorta. Mean total blood loss was 1367 +/- 282 mL, which included mean blood loss from time of release of aortic cross-clamp to close (422 +/- 135 mL) and mean total blood output from chest tube drain (945 +/- 203 mL). The mean time to achieve hemostasis at suture lines after aortic cross-clamp release was 15.5 +/- 6.6 min. In conclusion, a sheep model with induced coagulation defects was successfully developed and reproducible for experimentation involving thoracic aortic surgery.

Preoperative chemotherapy-sensitized radiation therapy for cervical metastases in head and neck cancer.

OBJECTIVE: To determine the efficacy of concurrent preoperative cisplatin chemotherapy and radiotherapy (CT/RT) for patients with advanced head and neck cancer and cervical metastatic disease. DESIGN: Retrospective analysis. SETTING: University hospitals. PATIENTS: Eighty-eight patients with operable stage III and IV squamous cell carcinoma of the head and neck and palpable cervical lymphogenous metastases received preoperative concurrent CT/RT followed by planned neck dissection. INTERVENTIONS: All patients undergoing CT/RT received concomitant continuous infusions of cisplatin (20 mg/m2) on days 1 to 4 and 22 to 25 of CT/RT. Thirty-nine patients underwent single-fraction (1.8-Gy) radiotherapy to 45.0 Gy, and 49 patients received 10 single-fraction (1.8-Gy) treatments, which were hyperfractionated (1.2-Gy twice a day) to 46.8 Gy. MAIN OUTCOME MEASURES: The 71 patients for whom complete post-CT/RT data were available were evaluated for clinical response in addition to survival. Histologic complete response (HCR) was confirmed from planned neck dissection specimens (n = 48) after clinical complete response (CCR) from initial CT/RT. Kaplan-Meier statistical analysis for disease-specific survival and overall survival was performed on all 88 patients who received CT/RT. RESULTS: A CCR and an HCR were noted in 78% (18/23) and 59% (10/17) of patients with N1 lesions, respectively, and in 60% (29/48) and 45% (14/31) of patients with N2-3 lesions, respectively. The percentage of patients with CCR who also had HCR was 67% (10/15) for patients with N1 lesions and 54% (14/26) for patients with N2-3 lesions. With a median follow-up of 18.5 months, the Kaplan-Meier disease-specific survival rate at 54 months (n = 88) was 70% (21/30) for patients with N1 lesions, 60% (24/40) for patients with N2 lesions, and 39% (7/18) for patients with N3 lesions. The overall survival and disease-specific survival rates at 5 years for all nodal groups combined were 36% (32/88) and 59% (52/88), respectively. CONCLUSIONS: A CCR to CT/RT was achieved in nearly two thirds of patients with head and neck cervical lymphogenous metastases, independent of nodal tumor load. Most patients (59% [24/41]) with CCR were pathologically tumor free before neck dissection.

Site-specific immunosuppression: mechanisms of cellular immunosuppression that are operative at local and systemic levels.

The cellular mechanisms by which topical cyclosporine A (tCsA) induces site-specific immunosuppression were investigated. Experiments were designed to elucidate how cyclosporine A (CsA) suppresses activated immunocytes in animals that are undergoing local alloactivation and concomitant tCsA immune suppression. Lewis rats received dual Lewis x Brown Norway rat skin allografts; the rats were treated with systemic CsA (sCsA) at 8 mg/kg/day for 10 days after grafting and then tCsA and vehicle thereafter. CsA added to mixed lymphocyte reactions 24 hours after culture initiation modeled the local effects of CsA on alloactivated immunocytes, and tCsA in conjunction with limited sCsA prolonged local skin allograft survival. CsA inhibited both antigen-specific and nonspecific activated alloresponses of immunocytes from animals that had received allografts and that underwent limited sCsA treatment only in a dose-dependent manner. When tCsA had been applied, immunocyte responses to a nonspecific antigen were extremely CsA-resistant as compared with those induced by antigen-specific suppression. However, this nonspecific alloresponse was fully suppressible with the use of elevated CsA doses (66 microg/mL); thus alloresponding immunocytes were significantly more sensitive to CsA if they were challenged with the donor antigen and preexposed to limited sCsA followed by tCsA in vivo.

An in vivo evaluation of a chondroitin sulfate solution to prevent postoperative intraperitoneal adhesion formation.

PURPOSE: The goal of this study was to determine the efficacy of a single intraperitoneal administration of a chondroitin sulfate solution in preventing postoperative adhesion formation. METHODS. Twenty-five Sprague-Dawley rats had a 1-cm(2) area of cecal serosa abraded. Controls (CON, n = 5) received no treatment, the chondroitin sulfate group (CS, n = 10) received chondroitin sulfate (0.013 g/kg) in 0.9% NaCl intraperitoneally (ip), and vehicle controls (VC, n = 10) received an equal volume of 0.9% NaCl solution ip before the abdomen was closed. All animals were sacrificed on postoperative day 10. The extent of adhesion was quantified according to Mazuji's adhesion grade (0 to 4: 0 = no adhesion and 4 = very dense adhesion) and quantitated after H&E, trichome, and immunohistochemical staining for fibrin and collagen type I and type III using digital image analysis. RESULTS: The mean Mazuji's adhesion grade in the CON was 4.0 +/- 0.0, in the VC 2.60 +/- 0.37, and in the CS 1.3 +/- 0.42 (P < 0.01 for CS vs CON and P < 0.05 for CS vs VC comparisons). The mean gray-scale intensity (0-255: 0 = dense amount and 255 = none) of adhesion density in the CON was 105. 5 +/- 5.5, in the VC 125 +/- 15.0, and in the CS 178.3 +/- 21.0 (P < 0.01 for CS vs CON and P < 0.05 for CS vs VC comparisons). The mean adjusted intensity stain indices (AISI) for fibrin and collagen type I in the CON were 59 +/- 17 and 53 +/- 19, in the VC 27 +/- 3 and 25 +/- 7, and in the CS 16 +/- 5 and 6 +/- 3, respectively (P < 0.05 between CS and CON comparisons). The AISI of collagen type III was not significant among all the groups (P > 0.1). CONCLUSIONS: The extent of early postoperative intra-abdominal adhesion formation as determined by gross assessment and from quantitation of fibrin and collagen type I deposition was significantly reduced by a single intraperitoneal administration of a chondroitin sulfate solution.

Site-specific immunosuppression using a new formulation of topical cyclosporine A with polyethylene glycol-8 glyceryl caprylate/caprate.

PURPOSE: Dermal application of immunosuppressants can be an effective means of achieving site-specific immunosuppression (SITE) on skin allografts in burn wound management and in the treatment of various immune skin disorders. We have previously reported success with topical cyclosporine A (tCsA) in the treatment of skin allograft rejection in rats. Using a new tCsA formulation with a penetration enhancer (PE), polyethylene glycol-8 (PEG-8) glyceryl caprylate/caprate (Labrasol, Gattefossé, St. Priest, France), in a trinary drug delivery system, we hypothesized that we would induce SITE and significantly delay rejection of dual skin allografts in rats. METHODS: Dual rat skin allografts from Lewis x Brown-Norway (LBN) donors were grafted to Lewis (Lew) recipients. Experimental animals (EXP, n = 7) received a 10-day course of systemic cyclosporine (sCsA, 8 mg/kg/day) followed by topical application. One of the two allografts on each experimental animal received tCsA/PE application (5 mg/kg/day) until sacrifice (tCsA/PE-treated). The other allograft received vehicle only (vehicle-treated). Allogeneic controls (ALLO-CON, n = 9) received no sCsA or tCsA. First signs of rejection were determined based on the initial observation of erythema, hair loss, flakiness, and/or scabs. RESULTS: The mean time to rejection for ALLO-CON allografts was 6.3 +/- 0.7 days (t test, P = 0.0013); for vehicle-treated allografts, 12.3 +/- 3.8 days (paired t test, P = 0.0146); and for tCsA/PE-treated allografts, 25.6 +/- 5.4 days. The disparity of days to rejection between dual allografts in the ALLO-CON group was 0.0 +/- 0.0 day and that between the tCsA/PE- and vehicle-treated dual allografts was 13.3 +/- 3.9 days (t test, P = 0.0016). CONCLUSIONS: A new formulation of tCsA in a trinary drug delivery system is successful at delaying the onset of rejection in dual skin allografts in rats by SITE, and PEG-8 glyceryl caprylate/caprate may represent a potentially effective transdermal penetration enhancer.

The pKa of butaclamol and the mode of butaclamol binding to central dopamine receptors.

The pKa values for butaclamol (1), 1,2,3,5,6,10b beta-hexahydro-6 alpha-phenylpyrrolo[2,1-alpha]isoquinoline (2, McN-4612-Y), and 2-tert-butyl-1,3,4,6,7,11b beta-hexahydro-7 beta-phenyl-2H-benzo[alpha]quinolizin-2 alpha-ol (3, McN-4171) were determined to be 7.2, 9.1, and 7.0, respectively. The values for 1 and 3 are anomalous; however, the value for 1 (7.2) is not as low as the one reported in the literature (pKa = 5.9). We also determined pKa values for apomorphine, chlorpromazine, and lidocaine, for reference purposes (7.6, 9.2, and 7.9, respectively). The results indicate that 1 would not be predominantly unprotonated under the physiological conditions of receptor binding, rather it would be about 50% protonated. This fact may contravene a suggested binding model used to map the central dopamine receptor (viz., ref 3).

Analysis of N-(4-hydroxyphenyl)retinamide polymorphic forms by X-ray powder diffraction.

A quantitative X-ray diffraction method, with zinc oxide used as the internal standard, was developed for the analysis of polymorphic forms I and II of N-(4-hydroxyphenyl)retinamide. The standard curve relating peak height ratio to the percentage of form I was linear. The method was precise and accurate to within +/- 6%.

Kinetics of intravenous theophylline.

The pharmacokinetics of theophylline was studied in 6 normal, nonsmoking, adult male volunteers. A constant-rate intravenous infusion of 3.84 to 4.98 mg/kg of theophylline (as the ethylenediamine salt, aminophylline) was administered over 40 min. Serum theophylline concentrations were measured for 24 hr by means of a gas chromatographic method specific for theophylline. Within 30 min of an average intravenous dose of 4.4 mg/kg of theophylline, serum levels reached 10 microgram/ml. The highest serum level at the end of the infusion was 17 microgram/ml. The serum concentration-time data were fitted to a two-compartment open model and yielded a mean serum half-life (t1/2) of 11.02 hr, a value longer than those previously reported. Our results indicated that after the original loading dose of 4.4 mg/kg was infused for 40min, an immediate infusion rate of 1.40 mg/kg/hr (1.65 mg/kg/hr aminophylline) would be necessary to maintain a serum level of 10 microgram/ml.