Acute effects of continuous rotational therapy on ventilation-perfusion inequality in lung injury

Objective: To investigate ventilation-perfusion (V_A/Q) relationships, during continuous axial rotation and in the supine position, in patients with acute lung injury (ALI) using the multiple inert gas elimination technique. Design: Prospective investigation. Setting: Eighteen-bed intensive care unit in a university hospital. Patients and interventions: Ten patients with ALI (PaO₂/FIO₂ ratio < 300 mm Hg) were mechanically ventilated in a pressure controlled mode and placed on a kinetic treatment table. Measurements and results: Distributions of V_A/Q were determined 1) during rotation (after a period of 20 min) and 2) after a resting period of 20 min in the supine position. During axial rotation, intrapulmonary shunt (19.1 ± 15 % of cardiac output) was significantly reduced in comparison with when in the supine position (23 ± 14 %, p < 0.05), areas with “low” V_A/Q were not affected by the positioning maneuver. General V_A/Q mismatch (logarithmic distribution of pulmonary blood flow) was decreased during rotation (0.87 ± 0.37) in comparison with when the patient was in the supine position (0.93 ± 0.37, p < 0.05). Arterial oxygenation was significantly improved during continuous rotation (PaO₂/FIO₂ = 217 ± 137 mm Hg) as compared with in the supine position (PaO₂/FIO₂ = 174 ± 82 mm Hg, p < 0.05). The positive response of the continuous rotation on arterial oxygenation was only demonstrated in patients with a Murray Score of 2.5 or less, indicating a “mild to moderate” lung injury, while in patients presenting with progressive ARDS (Murray Score > 2.5), the acute positive response was limited. Conclusions: Continuous axial rotation might be a method for an acute reduction of V_A/Q mismatch in patients with mild to moderate ALI, but this technique is not effective in late or progressive ARDS. Further studies including a large data collection are needed. Received: 19 June 1997 Accepted: 6 November 1997     

Skeletal myoblast based delivery of angiogenic growth factors: a comparison between angiopoietin-1 and VEGF gene delivery for therapeutic angiogenesis in the heart

Introduction Extensive cell death and an associated myocardial dys- function are the common features of chronic heart disease. Given the inadequate ability of the human heart to regenerate, a more recent approach to counter the remodel- ing process is to compensate for the loss of functioning cardiomyocyte number through stem cell transplantation with angiomyogenic potential.1,2 The novel approach of heart cell therapy is to repopulate the scar tissue with myogenic cells that may be functional…     

Comparison of Laparoscopic <Emphasis Type="Italic">vs.</Emphasis> Open Access Surgery in Patients with Rectal Cancer: A Prospective Analysis

Purpose Laparoscopic surgery of colon cancer has been accepted to be oncologically adequate compared with open resection. However, the situation in rectal cancer remains unclear, because anatomy and complex surgical procedures might specifically influence the long-term outcome. This study was designed to analyze perioperative and long-term outcome of patients with rectal cancer after laparoscopic vs. open access surgery. Methods A total of 389 patients (1998–2005) were prospectively analyzed; 114 patients had laparoscopic beginning, and 25 patients had conversion and were separately analyzed. Eighty-nine patients remained in the laparoscopic group and 275 had open access surgery. Results Both groups were comparable regarding age, gender, tumor localization, stage, and complications. Differences were found in harvested lymph nodes (laparoscopic 13.5/open access 16.9; P = 0.001) and hospitalization (15.1/18.7 days; P = 0.037). Local recurrence rate and metachronous metastasis were comparable. In patients with deep anterior resection with total mesenteric excision, favorable long-term survival in the laparoscopic group was found (P = 0.035, log-rank). Conclusions Minimally invasive surgery is equivalent in the treatment of rectal cancer and shows advantages of shorter hospitalization and faster recovery. Especially in patients with low rectal cancer, minimally invasive surgery with exact preparation of the total mesenteric excision seems to be favorable compared with open access surgery.     

Non-viral liposomal keratinocyte growth factor (KGF) cDNA gene transfer improves dermal and epidermal regeneration through stimulation of epithelial and mesenchymal factors

Keratinocyte growth factor (KGF) stimulates epithelial cell differentiation and proliferation, which are of major importance for wound healing. Local protein administration, however, has been shown to be ineffective due to enzymes and proteases in the wound fluid. We hypothesized that delivering KGF as a non-viral liposomal cDNA gene complex is a new approach that would effectively enhance dermal and epidermal regeneration. Twenty-two rats were given an acute wound and divided into two groups to receive weekly subcutaneous injections of liposomes plus the LacZ gene (0.2 microg, vehicle), or liposomes plus the KGF cDNA (2.2 microg) and LacZ cDNA (0.2 microg). Transfection was confirmed by histochemical assays for beta-galactosidase. Planimetry, histological and immunohistochemical techniques were used to determine protein expression, dermal and epidermal regeneration. Transfection and subsequent KGF expression was found in diving cells in the granulation tissue. Epidermal regeneration was improved by 170% in rats receiving the KGF cDNA constructs by exhibiting the most rapid area and linear wound re-epithelialization, P < 0.0001. KGF improved epidermal cell net balance by increasing skin cell proliferation and decreasing skin cell apoptosis, P < 0.0001. Dermal regeneration was further improved in KGF cDNA treated animals by an increased collagen deposition and morphology, P < 0.0001. KGF cDNA increased neo-vascularization and concomitant VEGF concentrations when compared with vehicle, P < 0.01. KGF cDNA did not only stimulate epithelial cells, but also mesenchymal cells through increases in IGF-I concentration, P < 0.005. Liposomes containing the KGF cDNA gene constructs were effective in improving epidermal and dermal regeneration. KGF gene transfer to acute wounds may represent a new therapeutic strategy to enhance wound healing.     

Validation of a prediction rule to maximize curative (R0) resection of early-stage pancreatic adenocarcinoma

Background:

The surgeon''s contribution to patients with localized pancreatic adenocarcinoma (PAC) is a margin negative (R0) resection. We hypothesized that a prediction rule based on pre-operative imaging would maximize the R0 resection rate while reducing non-therapeutic intervention.

Methods:

The prediction rule was developed using computed tomography (CT) and endoscopic ultrasound (EUS) data from 65 patients with biopsy-proven PAC who underwent attempted resection. The rule classified patients as low or high risk for non-R0 outcome and was validated in 78 subsequent patients.

Results:

Model variables were: any evidence of vascular involvement on CT; EUS stage and EUS size dichotomized at 2.6 cm. In the validation cohort, 77% underwent resection and 58% achieved R0 status. If only patients in the low-risk group underwent surgery, the prediction rule would have increased the resection rate to 92% and the R0 rate to 73%. The R0 rate was 40% higher in low-risk compared with high-risk patients (P < 0.001). High risk was associated with a 67% rate of non-curative surgery (unresectable disease and metastases).

Conclusion:

The prediction rule identified patients most likely to benefit from resection for PAC using pre-operative CT and EUS findings. Model predictions would have increased the R0 rate and reduced non-therapeutic interventions.     

Determinants of morbidity and survival after elective non-curative resection of stage IV colon and rectal cancer

Purpose  The benefit of elective primary tumor resection for non-curable stage IV colorectal cancer (CRC) remains largely undefined. We wanted to identify risk factors for postoperative complications and short survival. Methods  Using a prospective database, we analyzed potential risk factors in 233 patients, who were electively operated for non-curable stage IV CRC between 1996 and 2002. Patients with recurrent tumors, resectable metastases, emergency operations, and non-resective surgery were excluded. Risk factors for increased postoperative morbidity and limited postoperative survival were identified by multivariate analyses. Results  Patients with colon cancer (CC = 156) and rectal cancer (RC = 77) were comparable with regard to age, sex, comorbidity, American Society of Anesthesiologists score, carcinoembryonic antigen levels, hepatic spread, tumor grade, resection margins, 30-day mortality (CC 5.1%, RC 3.9%) and postoperative chemotherapy. pT4 tumors, carcinomatosis, and non-anatomical resections were more common in colon cancer patients, whereas enterostomies (CC 1.3%, RC 67.5%, p < 0.0001), anastomotic leaks (CC 7.7%, RC 24.2%, p = 0.002), and total surgical complications (CC 19.9%, RC 40.3%, p = 0.001) were more frequent after rectal surgery. Independent determinants of an increased postoperative morbidity were primary rectal cancer, hepatic tumor load >50%, and comorbidity >1 organ. Prognostic factors for limited postoperative survival were hepatic tumor load >50%, pT4 tumors, lymphatic spread, R1–2 resection, and lack of chemotherapy. Conclusions  Palliative resection is associated with a particularly unfavorable outcome in rectal cancer patients presenting with a locally advanced tumor (pT4, expected R2 resection) or an extensive comorbidity, and in all CRC patients who show a hepatic tumor load >50%. For such patients, surgery might be contraindicated unless the tumor is immediately life-threatening. Financial support  Neither one of the authors nor the institutions from which the work originated have asked for, accepted, or received any direct or indirect financial support from a third party regarding the matter and materials discussed in this paper.     

Laparoscopic partial pericystectomy of Echinococcus granulosus cysts in the liver.

Laparoscopic partial pericystectomy is a promising new therapeutical approach in surgery of hydatid liver disease. In combination with a review of the published results of laparoscopic therapy for hydatid disease the actual relevance of this technique should be defined. Together with our own experience with this technique we evaluated all patients with hydatid liver disease from Echinococcus granulosus published in literature operated either by pericystectomy or by partial pericystectomy. The review was projected as a search over DIMDI data access. This technique is practicable without increasing the risk of intraabdominal spillage of scolices if well-known security criteria are respected. Additional training is not necessary. Laparoscopic treatment of Echinococcus multilocularis is not possible yet, as complicated liver resections may be required for these patients. Hydatid hepatic cysts of E. granulosus however may be operated upon laparoscopically and do not necessarily require open surgery. While working under visual control minimal invasiveness is achievable and post-operative hospital stay can be reduced. This new technique is a feasible method, especially regarding obese patients, but on the other hand it is limited by a laparoscopically inaccessible intrahepatic localization (Segments IVa, VII, VIII and small centrally located cysts).     

Differential induction of apoptosis in undifferentiated and differentiated HL-60 cells by DNA topoisomerase I and II inhibitors

The effects of monocytic/macrophage and granulocytic differentiation induced by phorbol myristate acetate (TPA) and all-trans retinoic acid, respectively, were tested on the induction of apoptosis in human promyelocytic leukemia HL-60 cells treated with topoisomerase I and II inhibitors. Using a filter-binding assay, we observed a strong inhibition of DNA fragmentation induced by 3- and 24-hour continuous exposure to camptothecin, VP-16, VM-26, and m-AMSA in TPA- differentiated cells. The inhibition of the typical internucleosomal DNA fragmentation was confirmed by agarose gel electrophoresis. By contrast, drug-induced DNA fragmentation was not inhibited in retinoic acid-differentiated cells, and apoptosis occurred in these cells after 4 to 5 days in the absence of drug treatment. The TPA inhibitory effect was maximal after 24 hours of treatment and was correlated with differentiation, because phorbol dibutyrate ester was active, whereas 4- alpha-TPA, a nontumor promoter that does not induce differentiation, was not active. Using alkaline elution, we observed that TPA and retinoic acid differentiation were associated with changes in topoisomerase-mediated DNA breaks that were not correlated with their differential effects on drug-induced DNA fragmentation. Moreover, TPA also inhibited DNA fragmentation induced by vinblastine, cycloheximide, calphostin C, and x-rays. Using a cell-free system, we observed that DNA fragmentation was not inhibited in nuclei from TPA-differentiated cells. Rather, inhibition of apoptosis seemed to take place in the cytoplasm. We conclude that phenotypic changes associated with TPA- induced differentiation include inactivation of a cytoplasmic activity that can induce DNA fragmentation associated with apoptosis.