P4-07-07: Circulating Tumor Cells Predict Survival in Non-Metastatic Breast Cancer

Background: Circulating tumor cells (CTCs) predict outcome in metastatic breast cancer (BC), but their prognostic significance in non-metastatic BC is unclear. This study determined whether CTCs could be identified in non-metastatic BC patients and 2) if CTCs predict relapse-free and overall survival.

Methods: Clinical stage I-III BC patients seen at a single tertiary cancer center provided informed consent to participate in an IRB-approved study involving collection of blood (7.5 ml x 2 tubes) before systemic therapy and at the time of surgery for their primary BC. CTCs were detected using the Cell SearchTM system. A positive result was defined as the presence of two or more cells per 7.5 ml blood since a threshold for positivity has not been established in primary BC. Statistical analyses were done using STATA-IC 11 software.

Results: We prospectively evaluated 291 patients. Mean age was 54 years, and median follow-up was 30 months. 54% (157) had T1 tumors, 36%(104) T2, 6% (18) T3, and 4%(12) had T4 disease; 37% (107/289) were clinically node-positive (LNs) by axillary ultrasound and FNA. Two or more CTCs were identified in 10% (29) patients. Seventy-seven percent (225) patients were hormone receptor positive, 11% (32) were HER2 positive while 16% (48) expressed no receptors. Sixteen percent (48) were tumor grade 1, 50% (143) were grade 2 and 34% (98) were grade 3. Systemic chemotherapy and/or endocrine therapy were administered in 80% (233/289) of patients. Sixty-eight percent (167/244) of patients were post-menopausal. Additionally, there was no significant correlation between CTCs with primary tumor size, lymph node status, estrogen or progesterone receptor status, HER2 amplification or tumor grade. Thirty-eight percent (6/16) of all relapses occurred in patients with 2 or more CTCs (HR: 4.48 (95% C.I. 1.61−12.45), Logrank P 0.002) while 40% (4/10) of all deaths occurred in patients with 2 or more CTCs (HR: 4.54 (95% C.I. 1.27−16.25), Logrank P 0.011).

Conclusions: CTCs were a significant predictor of disease-free and overall survival in non-metastatic breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-07.

P5-01-17: HER2 Amplification in Primary Tumor: A Potential Marker for Presence of Circulating Tumor Cells in Inflammatory Breast Cancer Patients?

Background: Inflammatory breast cancer (IBC) is a rare but aggressive form of invasive breast cancer accounting for 3–6% of all cases and have higher rates of distant recurrence. Circulating tumor cells (CTCs) are known to predict outcome in metastatic breast cancer (BC) patients, but little is known about their prognostic significance in non-metastatic BC. We hypothesized that CTCs can be identified in patients with IBCs and may correlate with primary tumor characteristics. Methods: All patients had blood samples collected at the time of primary surgery. CTCs (per 7.5 ml blood) were detected using the Cell Search™ system (Veridex) and were defined as nucleated cells lacking CD45 but expressing cytokeratins (CK) 8, 18, or 19. The presence of ≥ 1 epithelial cells meeting morphologic criteria for malignancy was considered a positive result. Statistical analyses employed Chi square and Fisher's exact tests using STATA IC 11. Results: We prospectively evaluated 41 IBC patients enrolled in an IRB approved protocol undergoing surgery for stage I-III breast cancer. Median follow-up was 30 months. Mean age was 52 years. Thirty five patients (94%) had positive lymph nodes (LNs) at presentation, 30 (75%) had high-grade tumors and 20 (53%) had lymphovascular invasion. Eleven patients (28%) were ER positive, 11 (27%) were PR positive and 18 (44%) were HER2 positive. IBCs were more likely to be high grade (P<0.0001), ER negative (P<0.0001), PR negative (P<0.0001), HER2 positive (P<0.0001), High Ki-67 (P= 0.005) and had a BMI of more than 25kg/m2 (P=0.04). Eleven (27%) patients were CTC positive. CTCs were more likely be found in HER2 positive (8/18; 44%) vs. HER2 negative primary tumors (3/20; 15%) [OR= 4.53; 95% C.I. = 1.02−19.52; P= 0.04]. We found no statistically significant correlations between primary tumor characteristics (ER, PR, LNs, high grade) and presence of CTCs. Conclusions: About a quarter of IBC patients had CTCs at the time of primary surgery. In these patients HER2 overexpression predicted the presence of CTCs. Studies with longer follow-ups is needed to determine if CTCs predicted survival.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-01-17.

P4-06-02: Microscopic Disease in Blood and Bone Marrow Predicts Survival in Early Stage Breast Cancer

Background

Disseminated tumor cells (DTCs) in the bone marrow have been identified in 30% of stage I - III breast cancer (BC) patients and predict survival. Circulating tumor cells (CTCs) in the blood predict outcome in metastatic BC, but their prognostic significance in primary BC is unclear. This study determined whether: 1) DTCs and CTCs could be identified in significant numbers of non-metastatic BC patients and 2) if these cells predict relapse-free (RFS) and overall survival (OS).

Methods: Clinical stage I-III BC patients seen at a single tertiary cancer center provided informed consent to participate in an IRB-approved study involving collection of blood (7.5 ml x 2 tubes) and bone marrow (10 ml from bilateral iliac crests), and at the time of surgery for their primary BC. DTCs were assessed using an anti-cytokeratin antibody cocktail (MNF 116, CK 8,18, and 19, CAM 5.2, and AE1/AE3) following ficoll enrichment and cytospin. A positive result for DTCs was defined by presence of one or more CK-positive cells meeting morphologic criteria for malignancy. CTCs were detected using the Cell SearchTM system. A positive result was defined as the presence of one or more cells per 7.5 ml blood since a threshold for positivity has not been established in non-metastatic BC. Statistical analyses used chi-square and Fischer's exact test.

Results: We prospectively evaluated 313 patients. Mean age was 53 years, and median follow-up was 32 months. Forty-two percent of patients (131) had T1 tumors, 36% (112) T2, 10% (30) T3, and 13% (40) had T4 disease. Forty-five percent of patients (141/312) had positive lymph nodes. DTCs were identified in 29% (91/313) and CTCs in 25% (79/313) of all patients. Seven percent (21/313) of patients had both DTCs and CTCs. In the overall cohort, 26 (8%) patients relapsed and 15 (5%) died. Ten percent (9/91) of DTC positive patients died compared to 3% (6/222) of those who did not have DTCs (p=0.01). Similarly, 6% (7/79) of those who had CTCs died compared to 3% (8/234) of those who did not (p=0.03). Fifteen percent (12/79) of CTC positive patents relapsed compared to 6% (14/234, P=0.01) of those who were CTC negative. Simultaneous presence of DTCs and CTCs was a strong predictor of RFS (log rank p=0.030, HR= 2.8, 95% C.I. 1.20- 8.10) as well as OS (log rank p=0.026, HR= 3.66, 95% C.I. 1.03- 13.00) at 2 years. Combined presence of DTCs and CTCs was a predictor of outcome and these findings persisted after adjusting for variables including hormone receptor status, HER2 status, primary tumor size, grade, and preoperative lymph node status. There was no significant correlation between DTCs and/or CTCs with other primary tumor characteristics.

Conclusions: Circulating and disseminated tumor cells can be identified in a significant number of non-metastatic breast cancer patients. Both CTCs and DTCs predicted outcome, and their combined presence was an independent predictor of survival.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-06-02.

P4-06-04: Detection of HER2 Gene Amplification in Circulating Tumor Cells and Disseminated Tumor Cells by Fluorescence In Situ Hybridization Using OncoCEE™

BACKGROUND: The status of HER2 gene amplification in circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) might provide useful information for monitoring response to trastuzumab therapy, and may provide a basis for consideration of trastuzumab in patients with HER2 negative primary tumors who have HER2 positive CTCs and/or DTCs. The majority of techniques utilized for detection of minimal residual disease are limited in their ability to allow detailed phenotypic and genotypic evaluation of the cells. We report the utility of a microfluidic platform (OncoCEE™,Biocept, San Diego) for detecting HER2 gene amplification in CTCs and DTCs in patients with non-metastatic breast cancer.

METHODS: Peripheral blood (10ml) and bone marrow (BM) (1-2ml) were collected from patients with clinical stage I-III breast cancer in acid citrate dextrose solution (BD, Franklin Lakes, NJ) and anti-clumping reagent (OncoCEE-Sure™). Mononuclear cells were recovered using a Percoll density gradient method, incubated with a mixture of 10 primary capture antibodies (Abs), introduced into CEE™ microchannels, stained with fluorescent anti cytokeratin (CK) and CD45 abs and finally processed for fluorescence in situ hybridization (FISH) using probes specific to centromere 17 (spectrum green) and HER2 (spectrum arrange). The ratio of HER2:CEP17 >2.2 in any CK+/CD45- and CK-/CD45- cell was regarded as positive for HER2 gene amplification.

RESULTS: Peripheral blood and/or BM from 78 patients (65 BM; 70 blood; 57 matched blood and BM) with T1NO (39), T1N1 (8), T2N0 (12), T2N1 (2), T2N2 (1), T2N3 (3), T3N0 (2), T3N1 (2), T3N2 (1), T4N0(5), T4N1 (3), with HER2+ (n=12) and HER2− (n=58) primary invasive breast tumors were studied. The 12 patients with HER2+ primary tumors had HER2+ DTCs in 3/12 (25%) and HER2+ CTCs in 1/9 (11%) cases respectively. HER2+ DTCs and HER2+ CTCs occurred in 12/55 (24%) and in 4/63 (6%) of the patients with HER2− primary breast tumors. HER2+ CTCs and DTCs occurred simultaneously in only 2 patients and in either blood (3) or BM (13) in the remaining patients.

CONCLUSION: 1. The cell enrichment and extraction microfluidic technology (OncoCEE™) provides a sensitive platform for evaluation of HER2 gene amplification of CTCs and DTCs.

2. HER2+ primary tumors were associated with either HER2+ CTCs or DTCs in 25% of the patients.

3. HER2+ CTCs or DTCs occurred in 28% of patients with HER2−primary tumor.

4. Discordant HER2 status was contributed mainly by HER2+ DTCs occurring in HER2 - primary tumors.

5. The clinical significance of evaluating the status of HER2 gene amplification in CTCs and DTCs in the management of patients with breast cancer needs to be evaluated prospectively in larger clinical trials.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-06-04.

Liquid-liquid extraction and flat sheet supported liquid membrane studies on Am(III) and Eu(III) separation using 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine as the extractant

Solvent extraction and supported liquid membrane transport studies for the preferential removal of Am(3+) from feeds containing a mixture of Am(3+) and Eu(3+) was carried out using 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (n-Pr-BTP) as the extractant. Diluent plays an important role in these studies. It was observed that the distribution coefficients deteriorate significantly for both Am(3+) and Eu(3+) though the separation factors were affected only marginally. The transport studies were carried out at pH 2.0 in the presence of NaNO(3) to result in the preferential Am(3+) transport with high separation factors. Effect of different experimental parameters, viz. feed composition, stripping agents, diluents of the organic liquid membrane and membrane pore size was studied on the transport and separation behaviour of Am(3+) and Eu(3+). The supported liquid membrane studies indicated about 85% Am(3+) and 6% Eu(3+) transport in 6h using 0.03 M n-Pr-BTP in n-dodecane/1-octanol (7:3) diluent mixture for a feed containing 1M NaNO(3) at pH 2 and a receiver phase containing pH 2 solution as the strippant. Consequently, a permeability coefficient of (1.75 ± 0.21) × 10(-4)cms(-1) was determined for the Am(3+) transport. Stability of the n-Pr-BTP and its SLM was also studied by carrying out the distribution and transport experiment after different time intervals.

Studies on the selective Am3+ transport, irradiation stability and surface morphology of polymer inclusion membranes containing Cyanex-301 as carrier extractant

Transport behaviour of Am(3+) across cellulose triacetate (CTA) based polymer inclusion membranes (PIM) containing Cyanex-301 (bis(2,4,4-trimethylpentyl)dithiophosphinic acid) as the carrier extractant and tri-n-butyl phosphate (TBP) or 2-nitrophenyloctylether (NPOE) as the plasticizer was investigated from different feed and strip conditions. The TBP plasticized membrane resulted back transport of Am when alpha-hydroxy iso-butyric acid was used as the complexing agent in the strip phase while no such effect was seen when ethylene diamine tetraacetic acid (EDTA) was used as the complexant. Effect of varying Cyanex-301 concentration and bipyridyl (bipy) concentration on Am transport was also investigated. Long term reusability of the membrane was studied by measuring the permeability coefficient (P) after exposing the PIMs to a maximum gamma ray dose of ∼ 200 kGy. The surface morphology of the membranes was analyzed by atomic force microscopy and the roughness parameter was correlated to transport efficiency.

Thermodynamics of complexation of lanthanides with 2,6-bis(5,6-diethyl-1,2,4-triazin-3-yl) pyridine

Solvent extraction studies on separation of trivalent actinides from lanthanides using 2,6-bis(5,6-dialkyl-1,2,4-triazin-3-yl) pyridines have shown promising results with respect to separation factor and efficiency in acidic medium. In order to understand their complexation behavior, the stability constant (log β) of trivalent lanthanides (La, Nd, Eu, Tb, Ho, Tm, Lu) with 2,6-bis(5,6-diethyl-1,2,4-triazin-3-yl)pyridine (ethyl-BTP) have been determined in methanol medium (ionic strength 0.01 M) using spectrophotometric titrations. The stoichiometry of the complexes is found to vary with the ionic size of lanthanide ion. The variation in log β across the lanthanide series is attributed to variation in solvation characteristics of the metal ion. Comparison of log β for Ln(III)–ethyl-BTP complexes with other alkyl derivatives showed increase in the stability with increasing length of the alkyl group due to hydrophobic interaction. In the case of Eu(III), the speciation was also corroborated by time resolved fluorescence spectroscopy. The thermodynamic parameters (Δ G, Δ H, Δ S) for complexation of Eu(III) with ethyl-BTP, were determined by microcalorimetry, which revealed strong metal ion–ligand interaction with the reactions driven mainly by enthalpy.

Liraglutide provides similar glycaemic control as glimepiride (both in combination with metformin) and reduces body weight and systolic blood pressure in Asian population with type 2 diabetes from China, South Korea and India: a 16-week, randomized, double-blind, active control trial(*)

AIM

To assess and compare the efficacy and safety of liraglutide with those of glimepiride, both in combination with metformin for the treatment of type 2 diabetes in Asian population from China, South Korea and India.

METHODS

A 16-week, randomized, double-blind, double-dummy, four-arm, active control trial was carried out. In total, 929 subjects with type 2 diabetes with a mean (±s.d.) age of 53.3 ± 9.5 years, HbA₁(c) of 8.6 ± 1.0% and body weight of 68.1 ± 11.7 kg were randomized (liraglutide 0.6, 1.2 or 1.8 mg once daily or glimepiride 4 mg once daily all in combination with metformin: 1 : 1 : 1 : 1). One subject withdrew immediately after randomization and before exposure.

RESULTS

HbA₁(c) was significantly reduced in all groups compared with baseline. Treatment with liraglutide 1.2 and 1.8 mg was non-inferior to glimepiride (mean HbA₁(c) reduction: 1.36% points, 1.45% points and 1.39% points, respectively). No significant difference was shown in the percentage of subjects reaching American Diabetes Association HbA₁(c) target <7% or American Association of Clinical Endocrinologists target ≤6.5% between liraglutide 1.2 and 1.8 mg and glimepiride. Liraglutide was associated with a 1.8-2.4 kg mean weight reduction, compared with a 0.1 kg mean weight gain with glimepiride. Liraglutide led to a significantly greater reduction in systolic blood pressure (SBP) compared with glimepiride. Two subjects in the glimepiride group reported major hypoglycaemia while none in the liraglutide groups. Liraglutide was associated with about 10-fold lower incidence of minor hypoglycaemia than glimepiride. Gastrointestinal disorders were the most common adverse events (AEs) for liraglutide, but were transient and resulted in few withdrawals.

CONCLUSIONS

In Asian subjects with type 2 diabetes, once-daily liraglutide led to improvement in glycaemic control similar to that with glimepiride but with less frequent major and minor hypoglycaemia. Liraglutide also induced a significant weight loss and reduced SBP and was generally well tolerated. The most frequently reported AE was transient nausea. The effect of liraglutide in this Asian population is comparable to the effects seen in Caucasian, African American and Hispanic populations in global liraglutide phase 3 trials.

Abstract P3-02-01: Is Ethnicity a Predictor of Micrometastatic Disease in Early Stage Breast Cancer Patients?

Background: Ethnicity plays a role in breast cancer (BC) outcome, highlighted by the fact that African-American women have a higher BC mortality rate than do Caucasian women. Microscopic disease, including disseminated tumor cells (DTCs) in bone marrow and circulating tumor cells (CTCs) in peripheral blood, has been shown to predict worse outcomes as well. We sought to determine whether ethnicity was a significant predictor for the presence of DTCs and/or CTCs in stage I-III BC patients.

Methods: Patients provided informed consent to participate in an IRB-approved study involving collection of blood and bone marrow at the time of surgery for their primary BC. CTCs (per 7.5 ml blood) were detected using the Cell SearchTM system (Veridex) and were defined as nucleated cells lacking CD45 but expressing cytokeratins (CK) 8, 18, or 19; for this study we considered one or more positive cells meeting these criteria a positive result. DTCs were assessed using an anti-CK antibody cocktail (AE1/AE3, CAM5.2, MNF116, CK8 and 18) following cytospin. A positive result for DTCs was defined by presence of one or more CK positive cells meeting morphologic criteria for malignancy. Information on clinicopathological factors including ethnicity was obtained from a prospective database. Statistical analyses used Chi-square test on STATA IC11.

Results: We prospectively evaluated 224 patients undergoing surgery for stage I-III BC. Median follow-up was 22 months and mean age was 53 years. One hundred sixty seven patients (75%) were Caucasians, 22 (10%) were African-American (AA), 30 (14%) were Hispanic and 3 (1%) belonged to other ethnicities. CTCs were found in 25% (57/224) and DTCs in 30% (67/224) of patients. Patients of AA ethnicity were significantly more likely to have CTCs (50%, (11/22)) compared to the other ethnic groups (22%, (43/194)); {O.R. = 2.5, 95% C.I. = 1.35- 7.80, P = 0.002}, and had significantly higher numbers of CTCs (≥2 CTCs or ≥3 CTCs/7.5mL blood) than other ethnic groups (P = 0.001 and P &lt; 0.001, respectively). No statistically significant correlation was observed between other ethnic groups and CTCs. Patients of Hispanic origin were more likely to have DTCs (60%, (18/30)) as compared to other ethnic groups (25%, (49/194)); {O.R. = 4.4, 95% C.I. = 1.85- 10.80, P &lt; 0.0001}, while DTCs were less likely to be found in Caucasians (26%, (44/167)) as compared to the other ethnicities (40%, (23/57)); {O.R. = 0.52, 95% C.I. = 0.27 — 1.05, P = 0.046}. No significant association was found between occurrence of DTCs and AA ethnicity. In a multivariate analysis considering lymph node status, tumor size and tumor markers, ethnic origin was an independent predictor of microscopic disease.

Conclusions: Nearly one-third of primary BC patients have CTCs and/or DTCs. African-American women were much more likely to have CTCs and Hispanic patients had significantly more DTCs than did patients of other ethnicities. Ethnicity was an independent predictor of microscopic disease. These findings may shed some light on the higher BC mortality rates found in certain ethnic groups.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-02-01.

Abstract P3-02-02: Influence of Body Mass Index on Presence of Disseminated Tumor Cells in Clinical Stage I-III Breast Cancer Patients

Background: Disseminated tumor cells (DTCs) are found in approximately one third of clinical stage I-III breast cancer (BC) patients, and published reports show that presence of DTCs is an independent predictor of outcome. While higher body mass index (BMI) is associated with increased risk of breast cancer recurrence and lower survival rates in BC patients, women with lower BMIs may have lower bone density and higher bone turnover. We hypothesized that increases in bone turnover may result in the release of bone growth and “homing” factors that facilitate BC metastasis to bone and provide a “pre-metastatic niche” for BC cells. The purpose of this study was to determine if a correlation existed between DTCs and BMI in early stage BC patients.

Methods: We obtained informed consent and collected bone marrow samples from 262 clinical stage I-III BC patients who were participants in an IRB-approved clinical study from 2/2005- 2/2010. All marrow samples were collected at the time of surgery for the primary tumor. DTCs were assessed using anti-pancytokeratin (CK) antibody cocktail (AE1/AE3, CAM5.2, MNF116, CK8 and 18) following cytospin. The presence of one or more CK positive cells meeting morphologic criteria for malignancy was considered a positive result for DTC. Patients with a BMI of (18.5 — 24.9) kg/m2 were considered “normal weight”, those with a BMI of (25 - 29.9) kg/m2 “overweight” and a BMI greater than 30 kg/m2 was used to designate them as “obese”. Information on clinicopathological factors including BMI (measured on initial presentation) was obtained from a prospective database. Statistical analyses used Chi-square and non-parametric tests for trend.

Results: Median follow-up was 19 months and mean age was 53 (25-80) years. Eighty-four patients (32%) were normal weight, 85 (32%) were overweight and 91 (35%) were obese. Seventy-eight (30%) patients had DTCs present at the time of assessment. Obese patients were significantly less likely to show presence of DTCs as compared to those who had a BMI &lt; 30 kg/m2 (20/78; 26% vs. 71/184; 39%) {O.R. = 0.55, 95% C.I. = 0.29- 0.96, P = 0.03}. DTCs were also less likely to be found in patients with BMI ≥25 kg/m2 as compared to those with BMI &lt; 25 kg/m2 (40/78; 51% vs. 136/184; 74%); {O.R. = 0.42, 95% C.I. = 0.04- 1.02, P = 0.03}. No statistically significant correlation was observed between primary tumor characteristics (ER, PR, HER2, lymph node status, tumor grade) and presence of DTCs. Finally, a non-parametric analysis demonstrated a trend in occurrence of DTCs across the ordered levels of patients’ BMI values (P= 0.013).

Conclusions: DTCs were much more common in patients with lower BMI. Further studies are needed to determine if patients with low BMI have unique microenvironmental factors within the bone that predisposes them to tumor cell dissemination.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-02-02.

Usefulness of various MRI sequences in the diagnosis of viral encephalitis

There is paucity of studies regarding the utility of various conventional MRI sequences in the diagnosis of viral encephalitis. The present study evaluates the usefulness of various MRI sequences in acute viral encephalitis. 88 consecutive viral encephalitis patients, aged 2-72 years were subjected to clinical evaluation. Consciousness was assessed by Glasgow Coma Scale (GCS). Serum or cerebrospinal fluid (CSF) was analyzed for dengue, Japanese encephalitis (JE), herpes, measles, echo, coxsackie and polio viruses using ELISA or PCR. Cranial MRI was done and T1, T2, FLAIR and DW images were obtained. The MRI changes were correlated with type of encephalitis and duration of illness. All the patients had altered sensorium and 37 had seizures. 22 patients had JE, 9 had dengue, 8 had herpes simplex encephalitis (HSE), 2 had Epstein-Barr virus encephalitis (EBVE) and 47 had non-specific encephalitis. The median duration of MRI study from onset was 10 days. In JE (20/22), HSE (8/8), and EBVE (2/2), MRI abnormalities were more common compared to dengue (2/9) and non-specific (20/47) encephalitis. The MRI abnormalities were more common in FLAIR (57.1%) compared to T2 (52.9%), DWI (38.1%) and T1 (19.3%) sequences. The mean ADC value in JE patients was lower (974.0±110.85×10⁻⁶ mm²/s) than HSE (1024.33±485.76×10⁻⁶ mm²/s). Additional MRI lesions were seen in 12.6% cases on FLAIR sequence. FLAIR and T2 sequences were more sensitive in revealing abnormalities in viral encephalitis.

Involvement of the Choroid Plexus in Neurotuberculosis: MR Findings in Six Cases

The majority of intracranial infections that cause meningitis are considered to start in the choroid plexus of the ventricles, but lesions involving the choroid plexus are rare. There are isolated case reports of the involvement of choroid plexus in tuberculous meningitis. The main imaging findings are abnormal enhancement of the thickened choroid plexus, asymmetric hydrocephalus with sequestrated temporal horn, periventricular edema and intraventricular septae formation. Six patients having tubercular involvement of choroid plexus were treated at our institution. This is probably the largest series of tubercular involvement of choroid plexus highlighting the imaging features of this rare manifestation of CNS tuberculosis.

Selective separation of radio-cesium from acidic solutions using supported liquid membrane containing chlorinated cobalt dicarbollide (CCD) in phenyltrifluoromethyl sulphone (PTMS)

A supported liquid membrane method was developed using chlorinated cobalt dicarbollide (CCD) in phenyltrifluoromethyl sulphone (PTMS) as the carrier, impregnated in PTFE flat sheet membranes for the selective separation of Cs(I) from nitric acid feed solution. Solvent extraction studies were carried out for optimizing the feed as well as strip conditions. >95% Facilitated transport of Cs(I) was observed in about 3h when 1M HNO(3) and 8M HNO(3) were used as the feed and strip solutions, respectively while 0.025M CCD in PTMS was used as the carrier extractant. Selectivity studies, carried out using a mixture of radiotracers viz. (51)Cr, (59)Fe, (99)Mo, (99m)Tc, (106)Ru, (137)Cs, (152)Eu and (241)Am, indicated selective transport of Cs(I) with DF values >100. Though reproducibility of the transport data was excellent when carried out in two successive transport experiments with freshly loaded carrier solvent, the stability of the membrane was poor which restricts its long term use.

Unusual magnetocaloric effect in R2Al (R = Dy, Ho, Er) compounds

The magnetic properties of the orthorhombic intermetallic compounds R(2)Al (R = Dy, Ho, Er) are reported. Dy(2)Al undergoes a long-range canted antiferromagnetic-type ordering below T(1) = 105 K, and a further spin reorientation-type ordering below T(2) = 33 K. The low temperature magnetic state of the sample is found to be quite unusual, where a large hysteresis loop is observed in the magnetization curves (coercive field ∼ 33 kOe at 2 K). The isostructural compositions Ho(2)Al and Er(2)Al show multiple magnetic transitions: however, they do not show a large hysteresis loop at low temperature. Dy(2)Al is also associated with an interesting magnetocaloric effect, which is negative and moderate around T(1), but becomes large and positive below T(2). The observed behavior is related to the large magnetocrystalline anisotropy and narrow domain wall propagation coupled with a field-induced state at low temperature.