Immunolymphoscintigraphy for the detection of lymph node metastases from breast cancer.

The presence of metastases in the regional lymph nodes is the major prognostic factor in breast cancer in the absence of overt distant metastases and is also an important indicator of the need for adjuvant therapy in "early" breast cancer. Currently, the accurate assessment of axillary lymph node status requires axillary dissection which has an associated morbidity. An alternative method of identifying patients who are "node positive" has been developed by means of immunolymphoscintigraphy with s.c. administered radioiodinated monoclonal antibody. The 131I-labeled anti-breast cancer antibody (RCC-1; 400 micrograms) and cold iodine-labeled "blocking" antibody (Ly-2.1; 2 mg which is nonreactive with breast cancer) were injected s.c. into both arms and scintigraphy images were obtained 16-18 h after the injection, using the axilla contralateral to the side of the breast cancer as the control. Studies were reported as positive (and therefore indicative of lymph node metastases) if the amount of background-subtracted radioactive count in the axilla of interest exceeded the normal side by a radio equal to or greater than 1.5:1.0 as assessed by computer analysis. In 38 of 40 patients the findings on scintigraphy were correlated with operative and histopathological findings on the axillary dissection specimen or cytological findings of fine needle aspiration of axillary lymph nodes. In a prospective study of 26 patients, the method is more sensitive (86%) and specific (92%) than preoperative clinical assessment (57% sensitivity, 58% specificity) in the detection of axillary lymph node metastases; and by combining both modalities of assessment, there was an improvement in the sensitivity (100%) but a deterioration in the specificity (50%). There was no significant complication from this essentially outpatient procedure and only 1 of 40 patients developed a human anti-mouse antibody response. This novel and safe method of imaging may become a most useful adjunct in the surgical management of breast cancer.

Treatment of non-toxic multinodular goiter with radioactive iodine.

Fourteen patients with large non-toxic multinodular goiters were treated with 20 to 100 mCi (740 to 3,700 MBq) of radioactive iodine (iodine-131). In seven, the goiter had recurred after a partial thyroidectomy and four of these had had two operations. Eight had symptoms of respiratory obstruction, two had dysphagia, and the others sought treatment for cosmetic reasons. After administration of iodine-131, there was a significant decrease in goiter size in 11 of the 14 patients, and all those with obstructive symptoms showed improvement. No significant local side effects occurred, but hypothyroidism and Graves' disease each occurred once during follow-up from one to 13 years. Radioactive iodine in doses of 20 to 100 mCi is an effective, safe therapeutic alternative in patients with large non-toxic multinodular goiter, particularly when there is recurrence following surgery or when there are contraindications to surgery.

"Vascular" cerebral infarctions demonstrated by serial gamma-camera scinti photography.

The apparently paradoxical appearance of increased vascularity appearing in the radionuclide angiographic studies of a patient with cerebral infarction has recently been described and attributed to the "luxury perfusion syndrome". It is suggested that this phenomenon occurs more frequently than previously thought and in fact has been observed in nine patients presenting for a cerebral scan during a ten-month period. These cases are reviewed and an alternative explanation for the occurrence of increased vascularity on the dynamic study is submitted.

Early detection of left ventricular mural thrombi after acute Q wave myocardial infarction using 111In oxine-labelled autologous platelets.

Autologous 111In oxine-labelled platelet scintigraphy was used to detect left ventricular thrombi in 20 patients with anterior and 18 patients with inferior Q wave myocardial infarction within 48-72 h. Left ventricular thrombi were found in 8/20 patients with anterior myocardial infarction and in 1/18 patients with inferior myocardial infarction, giving a total incidence of 24%. Patients with left ventricular thrombi were older (64.3 versus 58.2 years), had higher peak creatinine kinase (CK) levels (4523 versus 2749 IU 1-1), lower ejection fraction (19.5 versus 37.8%, P less than 0.005) and were more likely to have an enlarged left ventricle than those without left ventricular thrombi (87.5 versus 54.5%, P less than 0.001). Left ventricular thrombi were found overlying sites of myocardial infarction in 8 out of 9 patients. Apical left ventricular thrombi were 1.7 times more common than septal left ventricular thrombi. All patients received minidose heparin for prevention of deep venous thrombosis. This technique is complementary to echocardiography and may provide additional information in the difficult cases where the decision about full-dose anticoagulation is in doubt.

99Tcm-labelled IgG scanning does not predict the distribution of intestinal inflammation in patients with inflammatory bowel disease.

In order to assess the value of 99Tcm-labelled-immunoglobulin G(99Tcm-IgG) in the assessment of the activity and distribution of intestinal inflammation in patients with inflammatory bowel disease (IBD), 99Tcm-IgG scans were performed in 18 patients. Patients were divided clinically into two groups, those with (ten patients) and those without (eight patients), intestinal inflammation. Disease activity and distribution were assessed by 111In-oxine granulocyte scanning and/or histological extent of inflammation at endoscopy or surgery in all patients with IBD and most of those without intestinal inflammation. In the assessment of the presence or absence of inflammation, a sensitivity of 80% and specificity of 87% were achieved. However, when the localization of intestinal inflammation was evaluated, only five of eight true positive scans were concordant with the distribution of intestinal inflammation as determined by other methods. Thus, significant areas of inflammation were missed in five of ten patients with IBD (two false negative, three incorrect localization of inflammation). Although 99Tcm-IgG scanning appears to have moderate sensitivity and acceptable specificity in the detection of intestinal inflammation, it performs poorly in assessing the distribution of inflammation and is, therefore, of little value in the assessment of patients with suspected or proven IBD.

Microleakage of several class V anterior restorative materials: a laboratory study.

The study was designed to evaluate the marginal leakage of abraded gingival areas in extracted teeth using five anterior composite resin acid-etch restorative materials and a glass ionomer cement, ASPA. In using three of the composite resin restorative materials, Simulate, Cervident, and Concise, there was a layer of unfilled resin between the etched tooth surface and the composite resin. Restodent and Enamelite were placed directly on the etched tooth surface. The results of the study indicate that there is a significantly greater degree of marginal leakage at the gingival margin than there is at the occlusal or incisal margin of composite restorations. In addition, greater marginal leakage was observed in those restorations where no layer of unfilled resin was placed between the etched tooth surface and the composite resin. The glass ionomer cement showed no marginal leakage at intervals of one day, three months, and six months; however, a small amount of leakage was observed at the incisal or occlusal and gingival margins at a year on half of the autoradiographs. A study has been initiated to determine leakage patterns around composite resin restorations placed in teeth with naturally occurring cervical erosion or abrasion.

Polarization sensitive optical low-coherence reflectometry for blood glucose monitoring in human subjects.

A device based on polarization sensitive optical low-coherence reflectometry is developed to monitor blood glucose levels in human subjects. The device was initially tested with tissue phantom. The measurements with human subjects for various glucose concentration levels are found to be linearly dependent on the ellipticity obtainable from the home-made phase-sensitive optical low-coherence reflectometry device. The linearity obtained between glucose concentration and ellipticity are explained with theoretical calculations using Mie theory. A comparison of results with standard clinical methods establishes the utility of the present device for non-invasive glucose monitoring.

Stimulated emission from the biexciton in a single self-assembled II-VI quantum dot.

Using two-photon excitation, stimulated emission from the biexciton state in a single CdSe/ZnSe quantum dot is observed in a two-pulse configuration. We directly time resolve the emission-absorption characteristics and verify the potential for laser action. By setting the polarization of the stimulation pulse, the recombination path of the biexciton and, by this, the state of the photons emitted in the decay cascade is controlled. We elaborate also the coherent response and address entanglement and disentanglement of the exciton-biexciton system.

Microleakage of several amalgam systems: an animal study.

Restorations placed without the application of cavity varnish to the cavity walls and the cavosurface angle exhibited significant marginal leakage after 24 hours and 3 months. At the end of 6 months a decrease in leakage was exhibited with all alloys. With the exception of two specimens, restorations placed after coating the cavity walls and the cavo-surface angle with cavity varnish demonstrated slight or no marginal leakage at all time intervals. The results of this study indicate that the marginal leakage of a conventional filing alloy, a conventional spherical alloy, and two high-copper alloys are approximately the same. The corrosion-resistant high-copper alloys showed the same degree of marginal leakage as the conventional alloys. The results of this study agree with those of a previously reported in vitro study on amalgam leakage.

Ventricular visualization on the brain scan associated with a corpus callosum tumour.

Ventricular visualization and a corpus callosum abnormality were diagnosed by brain scan and confirmed subsequently. Post mortem revealed an infiltrating microglioma impinging also on the floor of the lateral ventricle giving a naked eye appearance consistent with a granular inflammatory reaction of the ventricular surface.