Evaluation of CMV Brite kit for detection of cytomegalovirus pp65 antigenemia in peripheral blood leukocytes by immunofluorescence.

The CMV Brite antigenemia kit was compared with culture and an established cytomegalovirus pp65 antigenemia assay (CMV AG). Of 300 clinical specimens tested, 92 were positive by CMV Brite, 83 were positive by CMV AG, and 34 were positive by culture. Discrepancies could be attributed to anticytomegalovirus therapy or low-level antigenemia.

Pharmacokinetics and scintigraphy of indium-111-DTPA-MOC-31 in small-cell lung carcinoma.

UNLABELLED: Radiolabeled MOC-31 retains its immunoreactivity and shows good in vivo immunolocalization to human SCLC xenografted in nude rats. METHODS: We evaluated the immunotargeting properties and safety of 111In-labeled monoclonal antibody (MAb) MOC-31 (125 MBq, 5 mg) in six patients with histologically proven small-cell lung cancer (SCLC). Scintigraphy and pharmacokinetics were performed up to 3 days after injection. RESULTS: No adverse reactions were found after injection of MAb MOC-31. Pharmacokinetics obtained from plasma radioactivity showed plasma disappearance described most properly by a monoexponential model with a mean half-life value of 17.0 +/- 1.4 hr. HPLC analysis documented the monomeric MOC-31 without evidence of immune complexes or radioactive lower molecular weight fractions. Mean 24-hr urinary excretion of radioactivity was 4.3% of the injected dose. Scintigraphy detected primary tumor or metastases in five of six patients. Localization of radioactivity in normal tissue was restricted, but additional experiments need to be performed to elucidate possible cross-reactivity of MOC-31 with normal tissue in vivo. CONCLUSION: Preliminary results justify further studies to reveal the possible usefullness of radiolabeled MOC-31 in the therapeutic and diagnostic management of SCLC.

Impaired antigen-specific B-cell response and altered splenic microstructure in mice following continuous administration of IL-4 in vivo.

The effect of long term in vivo administration of IL-4 on the induction of antigen-specific B cells, the splenic microenvironment and the yield of antigen-specific antibody producing hybridomas was studied. Immunization with DNP-KLH, followed by 12 weeks continuous IL-4 treatment resulted in increased numbers of total splenic (non-DNP) IgM and IgG AFC (antibody forming cells) on day 5 after booster, whereas the DNP-specific IgG and IgG1 AFC were reduced compared to age-matched control animals not treated with IL-4. In addition, an almost 300-fold increase in non-DNP IgE was found while the IgE anti-DNP response was minimal. When the splenic cells were used in a fusion protocol, a relative decrease in yield of antigen-specific hybridomas was found in the long term IL-4 treated mice. Immunohistological staining of spleen sections from mice treated with IL-4 up until the time of booster revealed reduced B-cell follicle area and germinal centre numbers. These results show that extensive IL-4 treatment reduced antigen-specific B-cell formation and suggests a reduction in the number of B cells entering the memory B-cell pathway in the spleen.

Radioimmunodetection of human small cell lung carcinoma xenografts in the nude rat using 111in-labelled monoclonal antibody MOC-31.

The applicability of mouse monoclonal antibody MOC-31 for in vivo radioimmunodetection of human small cell lung cancer (SCLC) was investigated in a nude rat xenograft model. MOC-31 is reactive with a 38 kD pancarcinoma membrane antigen. [111In]DTPA-MOC-31 showed good in vivo immunolocalisation to xenografted SCLC cells, whereas antigen-related uptake was low in normal rat tissues and in a control antigen-negative, human-derived tumour. Non-antigen-related uptake in the liver could be blocked by pretreatment with irrelevant antibody. It is concluded that MOC-31 can be used for radioimmunodetection of SCLC in vivo and may be suitable as a targeting device in patients.

Magnetite as a potent contrast-enhancing agent in magnetic resonance imaging to visualize blood-brain barrier disruption.

Imaging of blood-brain barrier damage by magnetic resonance was currently studied as to the potential of dextran-magnetite particles (DMP) for contrast enhancement. For that purpose, dextran-T10 (average molecular weight: 10.9 Kilodalton) was complexed with magnetite (Fe3O4) in ammonia. Experimental testing of the agent was made in vivo using Wistar rats with a freezing injury to the brain. DMP was i.v. injected at a dose of 90 microM Fe/kg b.w. followed by 2% Evans blue (0.6 ml). Control animals with trauma were studied without administration of DMP. Histochemical assessments were made to analyze the tissue distribution of DMP in the brain, kidney and liver after fixation in 4% formalin. MR imaging was conducted with 1.5 Tesla field strength with a circular coil 15 min after the freezing insult and administration of DMP. T1- and T2-weighted images were obtained using spin echo sequences among others. Regression analyses indicated a 50% reduction of T1 at a DMP concentration of 48 microM Fe, while for T2 only 4 microM/Fe(DMP) were sufficient for a 50% reduction. DMP was also accumulating in other organs, particularly in the Kupffer cells of the liver. Administration of DMP led to recognition of the freezing lesion as black area in agreement with macroscopical findings obtained by autopsy. In animals with a freezing lesion without administration of DMP, only T2-weighted images demonstrated a somewhat higher intensity attributable to the disruption of the blood-brain barrier. The present findings demonstrate the usefulness of DMP for contrast enhancement of lesions following disruption of the blood-brain barrier.

Flexor digitorum superficialis tendon transfer for intrinsic replacement. Long-term results and the effect on donor fingers.

This study is a review of 127 hands in 100 patients in whom one or two FDS tendons were used to correct claw-hand deformity and/or loss of opposition of the thumb. In lumbrical replacement the results were graded as excellent in 16 hands (21%) and good in 43 hands (57%). For opponensplasty the results were excellent in 26 hands (32%) and good in 42 hands (51%). Possible defects that can develop in the donor finger are: swan-neck deformity, flexion posture of the DIP joint, not as part of the swan-neck deformity, check-rein deformity or flexion contracture, and insufficient finger flexion. Of the 158 fingers swan-neck deformity was seen in 15%, DIP flexion in 29%, check-rein deformity in 26% and insufficient finger flexion in 18%. The latter occurred with another defect. In 48 fingers (30%) no defects were observed.

Dextran-magnetite particles: contrast-enhanced MRI of blood-brain barrier disruption in a rat model.

Dextran-magnetite particles (DMP) were studied for their use as a MR contrast agent to visualize lesions with a blood-brain barrier (bbb) disruption. A freezing injury to the rat cerebral cortex was used as a model of bbb disruption. The biodistribution of iv-injected DMP was studied using atomic absorption spectrophotometry, electron microscopy, and MRI. One hour after injection, focal accumulation of the particles in capillary endothelial cells could be demonstrated in the freezing lesion. Despite the observation that the relaxivity of DMP in vivo appears to be less well pronounced than that in vitro, the MR imaging studies show that DMP can be used to visualize bbb disruption with adequate contrast.

Passage of DMP across a disrupted BBB in the context of antibody-mediated MR imaging of brain metastases.

To study the possible application of monoclonal antibody/dextran-magnetite conjugates in specific MR imaging of brain metastases, both components of these conjugates were tested for their ability to penetrate the endothelium during conditions of local blood-brain barrier (BBB) impairment. The passage of dextran-magnetite particles (DMP) across a disrupted blood-brain barrier was studied in a freezing lesion model using electron microscopy (EM) and MR imaging. One hour after i.v. injection, focal accumulation of DMP in capillary endothelial cells within the freezing lesion was shown by EM. In parallel with this, MR imaging indicated a strong contrast enhancement in the lesion. EM observations showed that the particles were still present in the endothelial cells four and eight hours after injection. The passage of an anti-small cell lung cancer (SCLC) monoclonal antibody across the endothelium of intracerebrally xenografted human SCLC was studied using immunohistological techniques. It was found that passage across endothelial cell occurred in the tumor within four hours after injection.

LAMA tumor in the rat as an experimental model for pre-B-cell leukemia.

A late pre-B-cell leukemia model in the rat, the LAMA tumor, is described. A mouse monoclonal antibody (HIS30) was developed against LAMA cells. HIS30 reacts with a membrane antigen in tumor tissue, whereas its reactivity with normal tissues is limited to the zona glomerulosa of the adrenal cortex and to the adrenal medulla. HIS30 was used for both the immunohistological detection of tumor cells in tissue sections and the immunolocalization of tumor cells in vivo. To enable in vitro studies with the LAMA model, an in vitro growing cell line (LAMA-K1) was established from the LAMA tumor. LAMA-K1 is immunophenotypically similar to the original tumor. Two tumor transplantation models were characterized. In the first model LAMA was implanted s.c., and local tumor growth occurred at the injection site, which was then followed by lymphatogenic and subsequently hematogenic tumor spread. In the second model i.v. transplantation caused direct hematogenic tumor dissemination. In both models early dissemination was especially prominent to the bone marrow, spleen, and liver. Later in the disease most visceral organs became involved, and partial paralysis of the animal was observed in the end stage of the disease. In combination with HIS30, the LAMA pre-B-cell tumor offers a model for both the investigation of in vivo transplanted tumor cells and for the in vivo detection of tumor cells by HIS30 in LAMA tumor-bearing rats.

Cholescintigraphy with 99mTc-diethyl-IDA for the detection of rejection of auxiliary liver transplants in pigs.

In 15 pigs an auxiliary liver was transplanted and cholescintigraphy with 99mTc-diethyl-IDA was performed to study the function of the livers separately. Serial scintigraphy of the recipient and donor liver was performed on days 3, 8 and 18 after transplantation and time-activity curves over 1 h after injection of the radio-tracer were generated for each liver. From these data the time at which the maximal activity was present in the liver (Tmax) and the time at which during the excretion phase half of this activity was still present in the organ (T1/2) were determined. Liver biopsy material from the recipient liver and the donor liver was obtained at (approximately) the day of one of the scintigraphic examinations and at autopsy. In all cases no histological abnormalities were found in the recipient liver. In 4 pigs there were no histological signs of rejection of the donor liver, in which cases the values for Tmax and T1/2 were normal. In 11 pigs histological signs of rejection were noticed and in all of these cases T1/2 was significantly prolonged, whereas no changes in Tmax were observed. Cholescintigraphy revealed an abnormal value for T1/2 a few days before the biopsy was taken in 10 of these 11 cases. Normal functioning or the prediction of rejection of the auxiliary liver transplant in pigs correlated significantly (P less than 0.01) with normal or prolonged T1/2 values. It is concluded that cholescintigraphy may be helpful in establishing the diagnosis of rejection of liver transplants.