Neural tissue engineering: Adrenal chromaffin cell attachment and viability on chitosan scaffolds

Abstract

This study introduces chitosan-based matrices as cell substrates for bovine chromaffin cell attachment in transplantation procedures. Chitosan ([1 → ] linked 2-amino-2-deoxy-β-O-glucopyranose), having structural similarity to glycosaminoglycans, was modified using several proteins (collagen, albumin and gelatin) to increase surface area and improve biocompatibility. In vitro, collagen-blended chitosan (CC) matrices were found to attach more readily to chromaffin cells than to gelatin- or albumin-blended matrices. Morphological evidence showed that the chromaffin cells attached to CC substrates integrated well with the hydrogel matrix and survived for at least two weeks, under in vivo culture conditions. The chromaffin cells within chitosan scaffolds also survived for at least two weeks in vitro and after subarachnoid grafting to rats. [Neural Res 1998; 20: 648–654]     

Early port-site metastasis during neoadjuvant chemotherapy in advanced stage ovarian cancer: report of two cases

Port-site metastases in gynecological malignancies subsequent to laparoscopy have been reported with an incidence of 1.1-16%. These metastases tend to be disappearing after primary debulking surgery and subsequent primary chemotherapy. Local resection, chemotherapy and/or radiotherapy have been defined in the management of these metastases with enhanced clinical success. However, in extremely rare cases these metastases were also defined very early during neoadjuvant chemotherapy. Herein, we present two ovarian cancer cases which are clinically diagnosed with port site metastasis during neoadjuvant chemotherapy following diagnostic laparoscopy. Although neoadjuvant chemotherapy is sometimes needed in cases of fully advanced ovarian cancers, port-site metastasis may be encountered during neoadjuvant chemotherapy. The possible poor prognosis of these patients, especially those who have ascites, should make us careful in performing diagnostic laparoscopy with preventive measures for port-site metastasis and to start the chemotherapy immediately.     

Patent Foramen Ovale among Patients with Mild Chronic Obstructive Pulmonary Disease and Unexplained Hypoxia

Purpose: To evaluate whether patent foramen ovale (PFO) is a contributing factor to hypoxia in patients with chronic obstructive pulmonary disease (COPD). Methods: Twenty‐one patients over 40 years of age with mild COPD (Forced expiratory volume (FEV1)/Forced Vital Capacity (FVC): > 50%) who had hypoxia (PO₂ < 80 mmHg, SaO₂ < 95%) that could not be explained by COPD alone were included in this study. Arterial oxygen pressures (PO₂) and arterial oxygen saturations (SaO₂) were recorded from laboratory evaluations of arterial blood gases. Respiratory function tests were performed to analyze the degree of COPD. Standard and contrast echocardiography was used to calculate pulmonary artery pressure (PAP) levels and to determine patients with a PFO. Results: The mean age of the patients was 64 ± 12 years. Four patients (19%) had a PFO. The mean PO₂, mean SaO₂, and mean PAP levels were 57.4 ± 6.8 mmHg, 90 ± 3.2%, and 33.8 ± 5.4 mmHg, respectively, in patients without PFO. The mean PO₂, mean SaO₂, and mean PAP levels were 46.5 ± 13.7 mmHg, 79.3 ± 12.8%, and 42.5 ± 6.5 mmHg, respectively, in patients with PFO. There were no statistically significant differences noted between the two groups in the PO₂ levels (P = 0.172) and SaO₂ levels (P = 0.065). A comparison of the PAP levels revealed a statistically significant difference between the two groups, with values that were more elevated in the PFO group than in the non‐PFO group (P = 0.031). Conclusion: This study demonstrated that PFO is not a contributing factor to deep hypoxia in COPD patients with lower PO₂ and SaO₂ levels; however, higher PAP levels were detected in patients with a PFO. Further studies involving a larger number of patients are needed to be conclusive. (Echocardiography 2010;27:687‐690)     

Immediate and Follow‐Up Results of Repeat Percutaneous Mitral Balloon Commissurotomy for Restenosis After a Succesful First Procedure

Background: The widespread use of percutaneous mitral commissurotomy (PMC) has led to an increase in restenosis cases. The data regarding follow‐up results of repeat PMC are quite limited. The aim of this retrospective analysis is to evaluate the immediate and midterm results of the second PMC, in patients with symptomatic mitral restenosis after a succesful first procedure. Methods: Twenty patients (95% female, mean age 37 ± 4 years) who have undergone a second PMC, 6.3 ± 2.5 years after a first successful intervention built the study group. All were in sinus rhythm, with a mean Wilkins score of 8.5 ± 1.2. Results: The valve area increased from 1.2 ± 0.2 to 1.9 ± 0.2 cm² and mean gradient decreased from 10.5 ± 3.4 to 6.1 ± 1.1 mmHg. There were no complications except for a transient embolic event without sequela (5%) and two cases (10%) of severe mitral regurgitation. The immediate success rate was 90%. The mean follow‐up was 70 ± 29 months (36–156 months). The 5‐year restenosis and intervention (repeat PMC or valve replacement) rates were 9.1 ± 5.2% and 3.6 ± 3.3%, respectively. The intervention free 5‐year survival in good functional capacity (New York Heart Association [NYHA] I–II) was 95.1 ± 5.5% and restenosis and intervention free 5‐year survival with good functional capacity was 89.7 ± 6.8%. Conclusions: Although from a limited number of selected patients, these findings indicate that repeat PMC is a safe and effective method, with follow‐up results similar to a first intervention and should be considered as the first therapeutic option in suitable patients. (Echocardiography 2010;27:765‐769)     

Surface dose and build-up region measurements with wedge filters for 6 and 18 MV photon beams

Purpose  

High-energy photons are most commonly used in radiotherapy to treat cancer. Wedge filters are required to obtain homogeneous dose distribution in the patient. Different wedge filter types create different surface doses. In this study, the effect of the virtual and physical wedge filters on the surface and build-up region doses was examined for 6- and 18-MV high-energy photon beams.