Multiplexed suspension array platform for high-throughput protein assays.

A multiplexed suspension array platform, based on SU8 disks patterned with machine-readable binary identification codes is presented. Multiple probe molecules, each attached to individual disks with different unique codes, provide multiplexed detection of targets in a small sample volume. The experimental system consists of a microfluidic chamber for arraying the particles in a manner suitable for high throughput imaging using a simple fluorescent microscope, together with custom software for automated code readout and analysis of assay response. The platform is demonstrated with a multiplexed antibody assay targeting 3 different human inflammatory cytokines. The suitability of the platform for other bio-analytical applications is discussed.

Addressing the mother-infant relationship in displaced communities.

Delivering appropriate care to refugee families requires complex care systems and models that take account of the social, cultural, and political dimensions as well as the psychologic dimension. Children born into these families are exposed to consequences of their own past experiences and also may be subject to the transmission of the traumas experienced by their parents. This exposure can lead to alterations in these children's individual creative resources. Early, tailored care should be provided for these families, so that the transmission of the trauma and its consequences can be managed or ameliorated.

American Society of Clinical Oncology clinical practice guidelines for the use of chemotherapy and radiotherapy protectants.

PURPOSE: Because toxicities associated with chemotherapy and radiotherapy can adversely affect short- and long-term patient quality of life, can limit the dose and duration of treatment, and may be life-threatening, specific agents designed to ameliorate or eliminate certain chemotherapy and radiotherapy toxicities have been developed. Variability in interpretation of the available data pertaining to the efficacy of the three United States Food and Drug Administration-approved agents that have potential chemotherapy- and radiotherapy-protectant activity-dexrazoxane, mesna, and amifostine-and questions about the role of these protectant agents in cancer care led to concern about the appropriate use of these agents. The American Society of Clinical Oncology sought to establish evidence-based, clinical practice guidelines for the use of dexrazoxane, mesna, and amifostine in patients who are not enrolled on clinical treatment trials. METHODS: A multidisciplinary Expert Panel reviewed the clinical data regarding the activity of dexrazoxane, mesna, and amifostine. A computerized literature search was performed using MEDLINE. In addition to reports collected by individual Panel members, all articles published in the English-speaking literature from June 1997 through December 1998 were collected for review by the Panel chairpersons, and appropriate articles were distributed to the entire Panel for review. Guidelines for use, levels of evidence, and grades of recommendation were reviewed and approved by the Panel. Outcomes considered in evaluating the benefit of a chemotherapy- or radiotherapy-protectant agent included amelioration of short- and long-term chemotherapy- or radiotherapy-related toxicities, risk of tumor protection by the agent, toxicity of the protectant agent itself, quality of life, and economic impact. To the extent that these data were available, the Panel placed the greatest value on lesser toxicity that did not carry a concomitant risk of tumor protection. RESULTS AND CONCLUSION: Mesna: (1) Mesna, dosed as detailed in these guidelines, is recommended to decrease the incidence of standard-dose ifosfamide-associated urothelial toxicity. (2) There is insufficient evidence on which to base a guideline for the use of mesna to prevent urothelial toxicity with ifosfamide doses that exceed 2.5 g/m(2)/d. (3) Either mesna or forced saline diuresis is recommended to decrease the incidence of urothelial toxicity associated with high-dose cyclophosphamide use in the stem-cell transplantation setting. Dexrazoxane: (1) The use of dexrazoxane is not routinely recommended for patients with metastatic breast cancer who receive initial doxorubicin-based chemotherapy. (2) The use of dexrazoxane may be considered for patients with metastatic breast cancer who have received a cumulative dosage of 300 mg/m(2) or greater of doxorubicin in the metastatic setting and who may benefit from continued doxorubicin-containing therapy. (3) The use of dexrazoxane in the adjuvant setting is not recommended outside of a clinical trial. (4) The use of dexrazoxane can be considered in adult patients who have received more than 300 mg/m(2) of doxorubicin-based therapy for tumors other than breast cancer, although caution should be used in settings in which doxorubicin-based therapy has been shown to improve survival because of concerns of tumor protection by dexrazoxane. (5) There is insufficient evidence to make a guideline for the use of dexrazoxane in the treatment of pediatric malignancies, with epirubicin-based regimens, or with high-dose anthracycline-containing regimens. Similarly, there is insufficient evidence on which to base a guideline for the use of dexrazoxane in patients with cardiac risk factors or underlying cardiac disease. (6) Patients receiving dexrazoxane should continue to be monitored for cardiac toxicity. Amifostine: (1) Amifostine may be considered for the reduction of nephrotoxicity in patients receiving cisplatin-based chemoth

Oxygen distribution in squamous cell carcinoma metastases and its relationship to outcome of radiation therapy.

Oxygen distribution was measured in 31 fixed lymph node metastases (mean diameter 4.4 cm +/- 0.8 cm) from squamous cell carcinoma of the head and neck by passing a needle electrode through each tumor under CT guidance. Thirteen tumors had uniform oxygen distribution with all measurements under 10 mm Hg. Six tumors had uniform oxygen distribution with all measurements above 10 mm Hg, and twelve tumors had variable oxygen distribution with measurements higher in the periphery than in the center. Response to radiation therapy was judged by changes in tumor volume 90 days following completion of therapy compared to pre-therapy volume. Eighteen tumors were considered complete responders (CR); eleven, non-responders (NR); two, partial responders (PR). No statistically significant difference in radiation dose or tumor size was seen in the PR and CR groups. Mean pO2 was 20.6 (+/- 4.4) mm Hg in the CR group and 4.7 (+/- 3.0) mm Hg in the NR group (p less than 0.001). Normalized pO2 content defined as the total tumor oxygen content normalized by dividing by the volume was 37.4 (+/- 8.2) mm Hg in the CR group and 8.2 (+/- 5.1) mm Hg in the NR group (p less than 0.001). The volume and oxygen levels of each tumor were tabulated and analyzed. Twelve tumors had greater than 26% of their volume containing a pO2 less than 8 mm Hg. Eleven of these were NR and one PR. Nineteen tumors had less than 26% of their volume containing a pO2 less than 8 mm Hg. Eighteen were CR and one PR (p less than 0.001). These data suggest that oxygen plays a significant role in human tumor response to radiation therapy. Oxygen measurements appear to allow separation of subgroups of patients with a poor prognosis who would most benefit from maneuvers to circumvent the hypoxic effect.

Quantitative lung scans for prediction of post-radiotherapy pulmonary function.

Quantitative perfusion scans were used to predict the proportion of pulmonary function lost by inclusion of lung in radiotherapy fields. Nineteen patients receiving radiotherapy for carcinoma of the lung had pulmonary function evaluated by forced expiratory volume at 1 second (FEV1) prior to and following radiotherapy. FEV1 measurement followed initiation of radiotherapy from two to 18 months (mean: seven months). Prior to radiotherapy quantitative lung scans were performed with Tc-99m macroaggregated albumin. On images acquired by computer, the radiotherapy field was drawn as a region of interest (ROI) and the proportion of count within this ROI relative to total lung count was determined. The total FEV1 was apportioned by the ROI ratio of count excluded from radiation ROI to total count in lungs to predict the FEV1 expected to be remaining after radiotherapy. In only two cases was the measured post-therapy FEV1 less than predicted (and then, by only 2% and 5%, respectively). The data indicate that quantitative perfusion lung scans can be used to predict conservatively the pulmonary function that may be expected to remain post-radiotherapy. Therapy fields may be adjusted in patients with underlying compromised pulmonary function to conserve a pre-selected FEV1.

Programmable large area digital microfluidic array with integrated droplet sensing for bioassays.

We describe a new device concept for digital microfluidics, based on an active matrix electrowetting on dielectric (AM-EWOD) device. A conventional EWOD device is limited by the number of electrical connections that can be made practically, which restricts the number and type of droplet operations. In an AM-EWOD, the patterned electrodes of a conventional EWOD device are replaced by a thin film transistor (TFT) array, as found in a liquid crystal display (LCD), facilitating independent control of each electrode. The arrays can have many thousand individually addressable electrodes, are fully reconfigurable and can be programmed to support multiple simultaneous operations. Each element is 210 µm × 210 µm in size and contains a circuit that measures the electrical impedance of the liquid above it. This is used to determine the presence and size of a droplet, a method that can improve assay reliability and accuracy. This sensor provides feedback, error detection and closed loop control of an assay sequence. We describe the design, fabrication and testing of a 64 × 64 format AM-EWOD device with impedance sensor functionality. A colorimetric assay is implemented on the device and used to measure glucose in human blood serum. Results are compared with the same assay performed on a microtitre plate.

Phonocardiographic method of assessing changes in left ventricular function after Starr-Edwards replacement of aortic valve.

A phonocardiographic method is described for measuring the time taken by the ball of a Starr-Edwards prosthesis to move to the apex of the cage at the onset of left ventricular ejection, and from this its acceleration can be derived. The acceleration is conspicuously increased in post-ectopic beats and in exercise, but is unaffected by posture and tachycardia induced by atropine or ventricular pacing. It is suggested that the acceleration of the ball is related to the initial acceleration of blood into the ascending aorta.

Diagnosis of osteomyelitis by MR imaging.

Bone scans are highly sensitive for the diagnosis of acute osteomyelitis, but the difficulty of separating bone-marrow processes from soft-tissue disease limits the specificity and accuracy. A diagnostic technique capable of distinguishing bone-marrow processes from soft-tissue disease would improve the diagnostic accuracy of osteomyelitis. To evaluate the use of MR in the diagnosis of osteomyelitis, MR examinations were performed in 35 patients with suspected acute osteomyelitis. Twelve of these were proved to have osteomyelitis either by surgery (nine patients) or by clinical follow-up (three patients). In the other 23, osteomyelitis was excluded by surgery (12 patients) or by the clinical course (11 patients). Evidence of osteomyelitis on MR consisted of abnormalities of the bone marrow with decreased signal intensity on the T1-weighted images and increased signal intensity on the T2-weighted or short-T1 inversion recovery (STIR) images. MR and bone scintigraphy were interpreted by two radiologists who were given no clinical information other than to rule out osteomyelitis. The sensitivities of MR and static bone scan were 100% for bone-marrow abnormality. Because bone-marrow abnormality in osteomyelitis associated with healing fractures was incorrectly diagnosed by MR (one case) and bone scintigraphy (two cases), the sensitivities of MR and scintigraphy for the diagnosis of osteomyelitis were 92% and 82%, respectively. The specificities of MR and scintigraphy were 96% and 65%, respectively (p less than .05). The overall accuracy for the diagnosis of osteomyelitis was 94% for MR and 71% for bone scan (p less than .05). Because of its ability to separate soft-tissue disease from underlying bone marrow, MR may be used to evaluate patients with positive bone scintigraphy to improve the specificity and accuracy of diagnosis for osteomyelitis.

Computed-tomographic-guided biopsy of small apical and peripheral upper-lobe lung masses.

After undergoing unsuccessful bronchoscopic and fluoroscopic biopsy attempts, 15 patients with small, peripheral upper-lobe and apical lung masses underwent computed-tomographic-guided biopsy. Malignant tissue was obtained in all cases. No complications resulted.

CT staging of esophageal carcinoma in patients treated by primary radiation therapy and chemotherapy.

Primary radiation therapy with concurrent chemotherapy is under study as definitive and palliative therapy for patients with esophageal carcinoma. To evaluate the correlation between CT staging and outcome, we retrospectively reviewed the CT scans of 48 patients treated with primary radiation therapy and concurrent chemotherapy and correlated CT staging with disease-free survival, overall survival, and site of relapse. Excluding one patient who was understaged and six patients who died of problems unrelated to esophageal carcinoma, mean survival of CT stage I, II, and III patients was 14.7, 21.3, and 5.2 months, respectively. When the CT stage is modified by the presence of nodal involvement on CT, the mean survival of stage IIn and IIIn (nodes greater than 1.5 cm in diameter) and stage IV patients (distant metastases) was 16.4, 19.2, and 10.6 months, respectively. Despite thickening of the esophageal wall greater than 3.0 cm in five patients with stage IIn cancer, mean survival was still 19.2 months. Patients with pericardial effusion had the worst survival of only 4.3 months. Stage II patients had a significantly longer (p less than 0.05) disease-free period than all other groups and the difference between stage II and III patients was highly significant (p less than 0.01). Stage II patients were also more likely to be disease-free at the time of death or last follow-up (p less than 0.05). Computed tomographic staging of esophageal carcinoma is useful in radiation therapy treatment planning and predicting outcome of patients managed with a nonsurgical technique of concurrent radiation and chemotherapy.

Esophageal speech: double-contrast evaluation of the pharyngo-esophageal segment.

Alaryngeal voice is usually accompanied by esophageal speech; however, about 40% of laryngectomy patients are unable to achieve adequate esophageal speech and must rely on mechanical devices for communication. A technique was developed for performing double-contrast studies of the hypopharynx, cervical esophagus, and pharyngo-esophageal segment using thick barium and the air normally injected for speech. Simultaneous audio and video recordings obtained during esophageal speech allowed correlation of the quality of speech with the motion of the pharyngo-esophageal segment. In 35 patients with various degrees of fluency in esophageal speech, normal and abnormal function of the pharyngo-esophageal segment was documented. Inadequate esophageal speech can be related to abnormal motion of the pharyngo-esophageal segment.

Oxygen tension in human tumors: in vivo mapping using CT-guided probes.

The role of oxygen in tumor response to therapy has been studied for several decades. We describe a technique that allows in vivo measurement of oxygen in tumors using computed tomography to guide probes. In the evaluation of 16 tumors, oxygen tensions were found to be substantially lower than surrounding tissue and varied nonrandomly. This technique has allowed construction of detailed tumor oxygen level maps.

CT-guided laser therapy in resistant human tumors: phase I clinical trials.

Photodynamic therapy was performed on ten tumors in patients who did not respond to initial therapy and for whom no additional conventional therapy was available. A sensitizing agent (hematoporphyrin derivative [HpD]) was injected directly into each tumor under computed tomographic (CT) guidance to deliver high concentrations to the tumor and to minimize systemic toxicity. Three to 6 days after the injection, a clear Teflon sheath catheter was placed into the tumor under CT guidance. The tumor was exposed to red light (630-nm wavelength) through laser fiberoptics inserted in the sheath. The initial investigation confirmed the technical feasibility of CT-guided photodynamic therapy by means of intratumoral HpD injections and laser exposure through fiberoptics inserted in sheath catheters. The toxicity from a single treatment was minor, and the tumor response was encouraging.