Real-time 3-D dark-field microscopy for the validation of the cross-linking process of alginate microcapsules

Alginate-based microencapsulation is a promising method for long-term maintenance of cellular and membrane function of the cells and tissue fragments required for in vitro and in vivo biosensors, for tissue engineering and particularly for immunoisolation of non-autologous transplants. Microcapsules of high mechanical strength and optimum permeability can be produced by injection of BaCl2 crystals into alginate droplets before they come into contact with external Ba2+. A key requirement is that the system parameters (number of crystals, speed of the crystal stream etc.) are properly adjusted according to the mannuronic and guluronic acid ratio and the average molecular mass of the alginate as well as to the diameter of the microcapsules. Robust, reliable, rapid and low-cost validation tools are, therefore, needed for assurance of the microcapsule quality. Here, we describe a novel three-dimensional (3-D) dark-field microscopy that allows the real-time measurement of the number and spatial distribution of the injected Ba2+ ions throughout the microcapsules after treatment with sulphate. This novel method requires only a conventional microscope equipped with three polarising filters and a double aperture stop. In contrast to confocal laser scanning microscopy images, peripherally attached BaSO4 precipitates can clearly be distinguished from internal ones. The data also demonstrate that several steps of the alginate gelling process must be improved before such immunoisolation can be used in patients.     

Live births resulting from unintended pregnancies: is there variation among states? The PRAMS Working Group.

CONTEXT: States need data on live births resulting from unintended pregnancies in order to assess the need for family planning services; however, many states do not collect such data. Some states may use extrapolated rates from other states. METHODS: Pregnancy Risk Assessment Monitoring System (PRAMS) data were assessed to explore the feasibility of extrapolating data on the percentage of live births resulting from unintended pregnancies from states that collect these data to states that do not. Data on women who had live births between 1993 and 1995 were examined for eight states: Alabama, Florida, Georgia, Michigan, New York (excluding New York City), Oklahoma, South Carolina and West Virginia. Logistic regression was used to determine state variation in the odds of delivering a live birth resulting from an unintended pregnancy after adjustment for maternal race, marital status, age, education, previous live birth and participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). RESULTS: The percentage of live births resulting from unintended pregnancy ranged from 33% in New York to 49% in Alabama, Georgia and South Carolina. Compared with women in Alabama, women in Oklahoma were more likely to deliver a live birth resulting from an unintended pregnancy (odds ratio of 1.2, confidence interval of 1.1-1.3) and women in New York State were less likely (odds ratio of 0.7, confidence interval of 0.6-0.8) to have such a birth. However, unmarried white women in New York had lower odds of having a live birth resulting from an unintended pregnancy and married black women in Michigan had higher odds of having a live birth resulting from unintended pregnancy than their counterparts in Alabama. Although the percentages varied, in all eight states women who were black, were unmarried, were younger than 20 years of age, had less than 12 years of education or had more than one child had higher percentages of live births resulting from unintended pregnancy than women with other demographic characteristics. CONCLUSIONS: Data on which women have the greatest risk of delivering a live birth resulting from an unintended pregnancy may be extrapolated from one state to another, but the rate of such births may overestimate or underestimate the problem from one state to another.     

Analgesic doses of fentanyl impair oxidative metabolism of neonatal hepatocytes

BACKGROUND/PURPOSE: Studies in human surgical neonates have shown that intraoperative fentanyl analgesia results in greater fall in perioperative body core temperature compared with morphine analgesia. The aim of the study was to compare in a neonatal animal model the biochemical effect of fentanyl and morphine on hepatocyte oxidative metabolism. METHODS: Hepatocytes were isolated from suckling rats and the oxygen consumption from palmitate was measured polarographically. In experiment A, fentanyl and morphine within the respective analgesic serum ranges were added to hepatocytes to assess the effect on oxygen consumption. In experiment B, fentanyl was added to hepatocytes in the presence of inhibitors of mitochondrial respiration to investigate its site of action. In experiment C, hepatocytes were incubated with either fentanyl or morphine, centrifuged, and then examined ultrastructurally by electron microscopy. RESULTS: In experiment A, fentanyl inhibited oxygen consumption by up to 40% (P < .01). Morphine inhibited oxygen consumption to a maximum of 25% (P < .01). In experiment B, in the presence of oligomycin, fentanyl increased the inhibition of oxygen consumption; however, in the presence of myxothiazol, no further inhibition by fentanyl occurred. In experiment C, mild ultrastructural alterations to hepatocytes were observed after incubation with fentanyl but not with morphine. CONCLUSIONS: This study demonstrates that therapeutic doses of two commonly used analgesic drugs impair neonatal hepatic oxidative metabolism. Fentanyl exerts a greater effect than morphine by diminishing liver oxygen consumption by up to 40%. The inhibitory effect of fentanyl occurs directly on the mitochondrial respiratory chain, either on substrate oxidation or on the thermogenic proton leak. The findings of this study are relevant to the perioperative management of surgical neonates.     

Adjuvant and neoadjuvant chemoradiation therapy for primary colorectal cancer

The management of rectal cancer presents substantial challenges. Patients with T3 and/or node-positive rectal cancers are at high risk for local failure and distant metastases (DM). Adjuvant radiation has been shown to decrease local recurrence (LR) rates; however, this local therapy has not been demonstrated to improve survival when compared to surgery alone. In several prospective randomized trials adjuvant chemoradiation with 5-fluorouracil-(5-FU)-based chemotherapy improved LR rates, DM rates, and overall survival (OS). The optimal chemotherapeutic regimen has not been determined; however, studies comparing standard IV bolus 5-FU administration with continuous infusion (CI) 5-FU demonstrated that CI administration was superior. Preoperative therapy has potential advantages over adjuvant therapy such as less acute bowel toxicity and improved sphincter preservation. Preoperative chemoradiation has been shown in several studies to improve LR rates and OS when compared to surgery alone. Our current approach to patients with resectable T3 or N1 cancer in the distal two-thirds of the rectum on preoperative staging is preoperative chemoradiation with planned postoperative chemotherapy. This regimen offers the best chance for local control and disease-free survival while potentially downstaging the tumor and improving sphincter preservation.     

Deletions in chromosome arms 3p and 11q are new prognostic markers in localized and 4s neuroblastoma.

PURPOSE: To find new nonrandom chromosomal changes in neuroblastoma (NB) with a potential to forecast the patient's outcome, alterations in chromosome arms 3p and 11q were investigated. EXPERIMENTAL DESIGN: Frequency and prognostic potential of 3p and 11q alterations in 144 NBs were analyzed using interphase fluorescence in situ hybridization with DNA probes for 3p26 and 11q23. Aberrations were defined as deletion (monosomy of a specific region) or imbalance (at least two intact and additional 3p26- or 11q23-deleted chromosomes). RESULTS: Forty-two of 144 cases (29%) displayed 11q alterations (21% deletions, 8% imbalances). Most aberrations were associated with stage 4 disease (28 of 59, 47%) but were also present in localized and 4s tumors (14 of 85, 16%; P = 0.007). Patients with 11q deletion/imbalance were significantly older at diagnosis (P < 0.001). Changes in 3p were detected in 26 of 144 (18%) samples (15% deletions, 3% imbalances). These alterations were also associated with stage 4 [20 of 59 (34%) versus 6 of 85 (7%) in stages 1-3 and 4s, P = 0.007], and the median age was increased (P < 0.001). Aberrations in both chromosomes were highly associated with each other (P < 0.001). MYCN amplification (MNA) was detected in 10% and 12% of tumors with 11q and 3p alterations, and changes in 1p36 occurred in 13% and 26% of the 3p- and 11q-aberrant tumors. MYCN amplification and 11q deletion/imbalance tended to show an inverse correlation (P = 0.07) as well as 1p and 3p deletion/imbalance (P = 0.07). Patients with 3p and 11q abnormalities in localized/4s tumors showed an inferior outcome compared with those without these alterations (P = 0.002 and P = 0.0027, respectively), in particular in MYCN single copy tumors (P < 0.0001 and P = 0.0006, respectively). CONCLUSION: Alterations in 3p and 11q are frequent nonrandom aberrations in NB and define a new high-risk subgroup in MYCN single copy stage 1-3 and 4s disease.     

Dietary folate intake and lung cancer risk in former smokers: a case-control analysis.

No studies have focused on the role of dietary folate intake in risk of lung cancer in former smokers, in whom dietary folate intake is less likely confounded with current smoking. Therefore, we evaluated the association between dietary folate intake and risk of lung cancer in a population of 470 histopathologically confirmed incident lung cancer cases from M. D. Anderson Cancer Center and 472 cancer-free controls from enrollees at a community-based multispecialty physician practice, frequency-matched on age (5 years), sex, and ethnicity. Dietary folate intake levels were estimated from a National Cancer Institute standard food frequency questionnaire. Unconditional logistic regression analyses were used to calculate the crude and adjusted ORs and their 95% CIs. Dietary folate intake from natural food was significantly higher among the controls than among the cases (P < 0.001), and folate intake above the control median value was associated with a 40% decreased risk of lung cancer (adjusted OR, 0.60; 95% CI, 0.45-0.79). A significant inverse dose-response relationship between increasing dietary folate and decreasing risk of lung cancer was also evident (adjusted OR, 1.02; 95% CI, 0.71-1.47; OR, 0.67; 95% CI, 0.46-0.99; and OR, 0.53; 95% CI, 0.35-0.80 for the second, third, and fourth quartiles of average folate intake, respectively; P for trend <0.001). A more pronounced inverse association between dietary folate intake and lung cancer risk was observed among subjects who drank alcohol, had smoked relatively more, those who did not take supplemental folate, and those who reported a family history of lung cancer. Our data suggest that there is a possible protective role of dietary folate in lung carcinogenesis, a finding which may have implications in public health and cancer prevention.     

Intestinal permeability in kwashiorkor

Intestinal permeability can be assessed non-invasively using the lactulose-rhamnose (L-R) test, which is a reliable measure of small intestinal integrity. AIMS: To determine risk factors for abnormal intestinal permeability in kwashiorkor, and to measure changes in L-R ratios with inpatient rehabilitation. DESIGN: A case-control study of 149 kwashiorkor cases and 45 hospital controls. The L-R test was adapted to study kwashiorkor in Malawi, with testing at weekly intervals during nutritional rehabilitation. Urine sugars were measured by thin layer chromatography in London. RESULTS: The initial geometric mean L-R ratios (x100) (with 95% confidence interval) in kwashiorkor were 17.3 (15.0 to 19.8) compared with 7.0 (5.6 to 8.7) for controls. Normal ratios are < 5, so the high ratios in controls indicate tropical enteropathy syndrome. Abnormal permeability in kwashiorkor was associated with death, oliguria, sepsis, diarrhoea, wasting and young age. Diarrhoea and death were associated with both decreased L-rhamnose absorption (diminished absorptive surface area) and increased lactulose permeation (impaired barrier function) whereas nutritional wasting affected only L-rhamnose absorption. Despite, clinical recovery, mean L-R ratios improved little on treatment, with mean weekly ratios of 16.3 (14.0 to 19.0), 13.3 (11.1 to 15.9) and 14.4 (11.0 to 18.8). CONCLUSION: Abnormal intestinal permeability in kwashiorkor correlates with disease severity, and improves only slowly with nutritional rehabilitation.