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Biomedical subjects

M Mazumdar

Publications and source records attributed to M Mazumdar.

At least 19 recordsLinked to original sources
PubMed2006

Measuring tumor response and shape change on CT: esophageal cancer as a paradigm.

BACKGROUND: Accurate response assessment is essential for evaluating new cancer treatments. We evaluated the impact of Response Evaluation Criteria in Solid Tumors (RECIST), World Health Organization (WHO) criteria and tumor shape on response assessment in patients with metastatic esophageal cancer. PATIENTS AND METHODS: In 19 patients with metastatic esophageal cancer in a phase II trial of bryostatin-1 and paclitaxel, response was retrospectively assessed for 89 lesions with RECIST and WHO criteria on baseline and serial follow-up CT scans. The eccentricity factor (EF) was introduced for measuring the degree to which tumor shape diverges from a perfect sphere [EF = radical1-(LPD/MD)(2), where LPD is the largest perpendicular diameter and MD is the maximal diameter]. RESULTS: The disagreement rate in best overall response categorization between RECIST (unidimensional) and WHO (bidimensional) criteria was 26.3%. Change in eccentricity was significantly greater (P < 0.01) for patients with disagreement (mean 0.31, range 0-0.91). When the short axis was used for unidimensional lymph node measurement, disagreement between WHO and RECIST lessened. CONCLUSIONS: Response assessment by WHO and RECIST differs substantially. Greater change in eccentricity is associated with greater discordance between WHO and RECIST. The discordance between WHO and RECIST may impact on how effective a therapy is judged to be.

Adult↗
PubMed2006

Attempts to rationalize protein crystallization using relative crystallizability.

Protein crystal growth (PCG) remains the bottleneck of crystallography despite many decades of study. The nucleation zone in the two-dimensional-phase diagram has been used to evaluate the relative crystallizability of proteins, which is expressed as a percentage over the phase area delineated by experimental protein and precipitating agent concentration ranges. For protein-salts which are subject to a direct temperature effect on solubility, as represented by Egg Lysozyme, a decrease in temperature augments the nucleation zone percentage whereas for those with retrograde solubility as a function of temperature, for example fructose-1,6-bisphosphatase in the presence and absence of AMP, an increase in temperature can significantly enhance the relative crystallizability. These results have been confirmed by the number of "hits" using PEGs as precipitating agents in Sparse Matrix Screen experiments for different proteins and are in excellent agreement with the relative crystallizability. The relationship between solubility dependence, relative crystallizability and crystallization success, has been evidenced. Such crystallizability can become a guide to identify efficient crystallization regions, providing a rational approach to PCG and structural biology.

Adenosine Monophosphate↗
PubMed2006

Prospective, blinded comparison of helical CT and CT arterial portography in the assessment of hepatic metastasis from colorectal carcinoma.

OBJECTIVE: This prospective blinded comparison of helical CT and helical CT arterial portography aimed to detect liver metastasis from colorectal carcinoma. METHODS AND MATERIALS: 50 patients with colorectal carcinoma were evaluated comparing helical CT with helical CT arterial portography. Each imaging study was evaluated on a 5-point ROC scale by radiologists blinded to the other imaging findings, and the results were compared, with the surgical and pathologic findings as the gold standard. RESULTS: Of the 127 lesions found at pathology identified as metastatic colorectal cancer, helical CT correctly identified 85 (69%) and CT portography 96 (76%). When subgroups with lesions <3 cm (48 patients) and patients with maximum tumor size <3 cm (18 patients) were considered, CT portography was always better than helical CT in terms of sensitivity, specificity, positive predictive value, and negative predictive value. ROC analysis adjusting for multiple lesions per patient revealed significantly greater area under the curve (AUC) for the subgroup of lesions <3 cm (CT-AUC of 77% and CT portography AUC of 81%; P = 0.002). CONCLUSIONS: For identification of large metastases, helical CT and CT portography have similar yield. However, for detection of small liver metastases, CT portography remains superior for lesion detectability.

Colorectal Neoplasms↗
PubMed2006

X-linked creatine transporter defect: a report on two unrelated boys with a severe clinical phenotype.

We report two unrelated boys with the X-linked creatine transporter defect (CRTR) and clinical features more severe than those previously described with this disorder. These two boys presented at ages 12 and 30 months with severe mental retardation, absent speech development, hypotonia, myopathy and extra-pyramidal movement disorder. One boy has seizures and some dysmorphic features; he also has evidence of an oxidative phosphorylation defect. They both had classical absence of creatine peak on brain magnetic resonance spectroscopy (MRS). In one, however, this critical finding was overlooked in the initial interpretation and was discovered upon subsequent review of the MRS. Molecular studies showed large genomic deletions of a large part of the 3' end of the complete open reading frame of the SLC6A8 gene. This report emphasizes the importance of MRS in evaluating neurological symptoms, broadens the phenotypic spectrum of CRTR and adds knowledge about the pathogenesis of creatine depletion in the brain and retina.

Child, Preschool↗
PubMed2006

Reproduction phase-related expression of beta-endorphin-like immunoreactivity in the nucleus lateralis tuberis of the female Indian major carp Cirrhinus mrigala: correlation with the luteinising hormone cells-ovary axis.

The present study aimed to determine whether beta-endorphin immunoreactivity (bEP-ir) in the neurones of the nucleus lateralis tuberis (NLT) is linked to the seasonal cycle and shows correlation with the number of luteinising hormone (LH) cells in the pituitary gland and ovaries in the teleost, Cirrhinus mrigala. Although LH cells were moderately immunostained during the resting phase (December to January), the morphological profile suggested increased synthetic and secretory activity during the preparatory (February to April) and prespawning (May to June) phases. However, LH immunoreactivity was greatly reduced (P < 0.001) in the spawning (July to August) phase, suggesting massive discharge of the hormone; this pool was partly replenished in the postspawning (September to November) phase. The ovaries grew rapidly in the preparatory and prespawning phases; maximal size was attained during spawning, when ovulation occurred. Thereafter, the ovaries regressed. The NLT of C. mrigala is divisible into the pars lateralis (NLTl) and medialis (NLTm). During the postspawning and resting phases, bEP-ir was readily detectable in the NLTm as well as NLTl neurones. However, a steady reduction in the immunoreactivity was observed in the NLTm neurones during the preparatory through spawning phases (P < 0.001), suggesting a negative correlation with the LH cells-ovary axis. Thus, the inhibitory influence of beta-endorphin on the gonadotrophin-releasing hormone (GnRH)-LH axis appears to be attenuated during the preparatory through spawning phases. This may be necessary for the rapid stimulation of the axis culminating in spawning. Neurones of the NLTl also showed a gradual reduction in bEP-ir during the preparatory and prespawning phases (P < 0.01) and may therefore play a similar role. However, significant augmentation of the immunoreactivity was noticed in these neurones during the spawning phase (P < 0.001), the physiological significance of which is unknown. Although the present study demonstrated a temporal correlation between the beta-endorphin in the NLT, LH cells and the ovary, we suggest that the peptide in the NLTl and NLTm may show functional duality during the spawning phase.

Animals↗
PubMed2004

Predicting survival of patients with metastatic renal cell carcinoma.

The relationship between pretreatment clinical features and survival was studied from patients treated on clinical trials for metastatic renal cell carcinoma (RCC) at the Memorial Sloan-Kettering Cancer Center. The primary analysis was performed on 670 patients treated with cytokines or chemotherapy, from which a multivariate model was derived to predict survival. Studies which followed addressed: (1) the survival of patients given interferon-alpha as first-line therapy; (2) a comparison of survival for patients treated with chemotherapy versus cytokine therapy; and (3) survival of patients with non-clear cell histology. Prospective identification of patients more likely to benefit from cytokine therapy is important as a stratification factor in phase III trials, and in risk-directed therapy.

Antineoplastic Agents↗
PubMed2004

Documentation of immune profile of microglia through cell surface marker study in glioma model primed by a novel cell surface glycopeptide T11TS/SLFA-3.

STATEMENT OF THE PROBLEM: The sheep erythrocyte membrane glycoprotein T11TS/SLFA-3 can form a ligand-receptor complex with CD2 present on immunocyte and exert stimuli for activation and proliferation. Regression of brain tumor with the application of T11TS indicates the probable role of microglia, the chief immunomodulatory cell within the brain compartment. In the present study microglial activation and immunophenotypic modulation were assessed in T11TS treated brain tumor-bearing animal models. Rat glioma models induced by chemical carcinogen ENU were treated with three consecutive doses of T11TS. Microglial cells from brain were isolated and assessed through E-rosette formation, SEM and FACS for CD2, MHC class II, CD25, and CD4. The preliminary indication of presence of CD2 on microglia through E-rosette formation was confirmed by SEM and FACS. MHC class II and CD2 single and double positive subpopulations exist, and their expression is also modulated in different doses of T11TS. A general trend of highest receptor saturation and microglial activation, measured through the activation marker CD25 and CD4 expression, was observed in 2nd dose of T11TS administration, which was then dampened via a complex immune feedback mechanism in the 3rd dose.

Alkylating Agents↗
PubMed2004

The functional assessment of cancer therapy-BRM (FACT-BRM): a new tool for the assessment of quality of life in patients treated with biologic response modifiers.

PURPOSE: This paper reports on the development and validation of two biologic response modifier (BRM) subscales for use with the Functional Assessment of Cancer Therapy-General (FACT-G) quality of life (QOL) questionnaire. METHODS: Using the FACT-G as a base, 17 additional questions related to symptoms common to interferon and retinoid therapy were developed. Data collected at baseline (n = 191) and week 2 (n = 168) in a randomized trial of interferon +/- 13-cis-retinoic acid in advanced renal cell carcinoma patients were used to validate this measure. RESULTS: Using a combined empirical and conceptual approach, the 17 questions were reduced to 13 questions consisting of two subscales: 'BRM-physical' (7 items; baseline coefficient alpha(alpha) = 0.70; week-2 alpha = 0.75) and 'BRM-mental' (6 items; baseline alpha = 0.79; week-2 alpha = 0.78). Internal consistency of the trial outcome index (TOI) combining physical well-being, functional well-being and the BRM subscales, was 0.91 for baseline assessments and 0.92 for week 2. Discriminant validity was demonstrated for the TOI by its ability to differentiate among prognostic risk groups, and for the total FACT-G, TOI and total FACT-BRM scores by their ability to distinguish between groups differing in performance, response and toxicity status. CONCLUSIONS: The 'BRM-physical' and 'BRM-mental' subscales can be combined with the FACT-G to form the 'FACT BRM' scale, useful for measuring QOL in cancer patients who are receiving treatment with biologic response modifiers.

Activities of Daily Living↗
PubMed2004

Neo-adjuvant chemotherapy for primary high-grade extremity soft tissue sarcoma.

BACKGROUND: The purpose of this study was to retrospectively analyze the relationship between neo-adjuvant chemotherapy (NAC) and outcome in patients with high-grade extremity sarcomas. PATIENTS AND METHODS: Inclusion criteria were high-grade, deep, >5 cm extremity soft tissue sarcomas. Patients diagnosed between 1990 and 2001 were treated with surgery only (n=282) or NAC containing doxorubicin/ifosfamide/mesna (AIM) (n=74). The stratified Cox proportional hazards model was used to test the effect of NAC on disease-specific survival and recurrence while adjusting for known prognostic factors. RESULTS: NAC was associated with improved disease-specific survival for this cohort of patients (P=0.02). This overall improvement appears to be driven by the benefit of NAC on disease-specific survival for patient with tumors >10 cm. The 3-year disease-specific survival for tumors >10 cm was 0.62 (95% CI: 0.53-0.71) for patients not receiving NAC and 0.83 (95% CI: 0.72-0.95) for patients receiving NAC. CONCLUSION: NAC with AIM was associated with a significant improvement in disease-specific survival in patients with high-grade extremity soft tissue sarcomas >10 cm. These data emphasize the need for further prospective clinical studies of neo-adjuvant or adjuvant chemotherapy for patients with large high-grade extremity sarcomas.

Adolescent↗
PubMed2001

The ORF3 protein of hepatitis E virus binds to Src homology 3 domains and activates MAPK.

The hepatitis E virus (HEV) is the causative agent of hepatitis E, an acute form of viral hepatitis. The biology and pathogenesis of HEV remain poorly understood. We have used in vitro binding assays to show that the HEV ORF3 protein (pORF3) binds to a number of cellular signal transduction pathway proteins. This includes the protein tyrosine kinases Src, Hck, and Fyn, the p85alpha regulatory subunit of phosphatidylinositol 3-kinase, phospholipase Cgamma, and the adaptor protein Grb2. A yeast two-hybrid assay was used to further confirm the pORF3-Grb2 interaction. The binding involves a proline-rich region in pORF3 and the src homology 3 (SH3) domains in the cellular proteins. Competition assays and computer-assisted modeling was used to evaluate the binding surfaces and interaction energies of the pORF3.SH3 complex. In pORF3-expressing cells, pp60(src) was found to associate with an 80-kDa protein, but no activation of the Src kinase was observed in these cells. However, there was increased activity and nuclear localization of ERK in the pORF3-expressing cells. These studies suggest that pORF3 is a viral regulatory protein involved in the modulation of cell signaling. The ORF3 protein of HEV appears to be the first example of a SH3 domain-binding protein encoded by a virus that causes an acute and primarily self-limited infection.

Amino Acid Sequence↗
PubMed2001

Predicting outcome to chemotherapy in patients with germ cell tumors: the value of the rate of decline of human chorionic gonadotrophin and alpha-fetoprotein during therapy.

PURPOSE: The prognostic significance of the rate of decline of the serum tumor marker alpha-fetoprotein (AFP) and human chorionic gonadotrophin (HCG) during the first two cycles of chemotherapy in germ cell tumor (GCT) patients was initially reported by us, but its value has been debated. We re-examined this issue in the context of the International Germ Cell Cancer Collaborative Group (IGCCCG) risk classification system and investigated the role of including in the analysis patients whose markers normalized early. PATIENTS AND METHODS: One hundred eighty-nine GCT patients with elevated AFP/HCG marker values treated with platinum-based chemotherapy between 1986 and 1998 were included in this analysis. Patients were classified as good, intermediate, or poor risk by the IGCCCG criteria and as having satisfactory or unsatisfactory marker decline. Risk and marker decline were correlated with response, event-free survival, and overall survival. RESULTS: Satisfactory marker decline predicted improved complete response (CR) proportion and event-free and overall survival (P <.0001). The CR proportion, 2-year event-free, and 2-year overall survival rates for patients with a satisfactory and unsatisfactory marker decline were 92% versus 62%, 91% versus 69%, and 95% versus 72%, respectively. Marker decline remained a significant variable for all three end points when adjusted for risk (P <.01) with the outcome differences most pronounced in the poor-risk group. CONCLUSION: The rate of marker decline during chemotherapy has prognostic value independent of risk and may play a significant role in the management of poor-risk patients. It is appropriate to include patients whose markers normalized early.

Adolescent↗
PubMed2001

A standardization method to adjust for the effect of patient selection in phase II clinical trials.

New combination regimens evaluated in phase II cancer clinical trials often show promising results compared to the standard therapy for a disease system. Selection of patients with a better prognosis can be a prominent factor for this optimism. For most disease systems, prognostic variables that are related to the outcome are available and are called risk factors. Patients are classified into risk categories depending on the number of risk factors they possess. The patient distribution is defined as the proportion of patients falling into each of these risk categories. Typically, the patient distribution observed for a phase II study differs from the standard therapy reports so that the outcomes are not comparable. A randomized trial is the ultimate step for establishing the efficacy of a new treatment. In order to determine whether a regimen should progress to a phase III trial, we suggest adjusting the standard therapy outcome for the effect of the observed phase II patient distribution. If the endpoint of interest is tumour response proportion, a weighted average utilizing the standard therapy response proportions and the phase II patient distribution would provide an estimate of the adjusted standard therapy response proportion. Confirmatory phase II trials often attempt to estimate median survival in addition to response proportion, since this is the primary endpoint for most phase III cancer studies. Because data are censored, we propose an adjustment method based on the bootstrap resampling technique. We illustrate the problem of disparate patient selection with data from melanoma studies and demonstrate the usefulness of the proposed adjustment method with data from bladder cancer studies. A simulation study indicates that the magnitude of the adjustment is heavily dependent on the degree of separation of the risk categories. SAS code is available on a website (http://lib.stat.cmu.edu) for easy implementation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Role of postchemotherapy adjunctive surgery in the management of patients with nonseminoma arising from the mediastinum.

PURPOSE: To evaluate the role of postchemotherapy surgery in patients with nonseminomatous germ cell tumors arising from the anterior mediastinum. PATIENTS AND METHODS: Thirty-two patients with nonseminoma arising from a mediastinal primary site were treated on a clinical trial at our center, and they underwent postchemotherapy surgery. The results of postchemotherapy surgical resection, frequency of viable tumor found during postchemotherapy surgery, and prognostic factors for survival were assessed. RESULTS: Complete resection of all gross residual disease was achieved in 27 patients (84%). Histologic analysis of resected residua postchemotherapy revealed viable tumor in 66%, teratoma in 22%, and necrosis in 12% of the specimens. Viable tumor included embryonal carcinoma, choriocarcinoma, yolk sac carcinoma, seminoma, and teratoma with malignant transformation to nongerm cell histology (eg, sarcoma). Clinical characteristics associated with a shorter survival after surgery included the presence of viable tumor in a resected specimen (P =.003) and more than one site resected during surgery (P =.06). There were no statistically significant differences in survival for patients who underwent surgical resection with normal markers compared with patients with elevated serum tumor markers (P =.33). A trend toward shorter survival was found in patients with increasing tumor markers before surgery compared with patients with normal and declining serum tumor markers (P =.09). CONCLUSION: Surgical resection of residual mass after chemotherapy plays an integral role in the management of patients with primary mediastinal nonseminoma. Teratoma and viable tumor were found in the majority of resected residua after chemotherapy. Because patients who undergo conventional salvage chemotherapy programs rarely achieve long-term disease-free status, selected patients with elevated markers after chemotherapy are considered candidates for surgical resection.

Adolescent↗
PubMed2001

Phase II trial of irofulven (6-hydroxymethylacylfulvene) for patients with advanced renal cell carcinoma.

The aim of this study was to determine the antitumor activity of irofulven (6-hydroxymethylacylfulvene) in patients with advanced renal cell carcinoma (RCC). Eligible patients had advanced renal cell carcinoma with bidimensionally measurable disease, a Karnofsky performance status of at least 70, life expectancy of greater than three months, no prior treatment with chemotherapy, and no evidence of brain metastases. Irofulven was administered at a dose of 11 mg/m2 by 5-min intravenous infusion, on 5 consecutive days. Cycles were repeated every 28 days. Thirteen patients were enrolled in this study and 12 were evaluable for response. Of the twelve evaluable patients, no major responses were achieved. Eight patients had stable disease as best response. Toxicity included myelosuppression and gastrointestinal side effects. At the dose and schedule used in this trial, irofulven did not produce clinical response in RCC.

Adult↗
PubMed2000

Ifosfamide, paclitaxel, and cisplatin for patients with advanced transitional cell carcinoma of the urothelial tract: final report of a phase II trial evaluating two dosing schedules.

BACKGROUND: A combination regimen of ifosfamide, paclitaxel, and cisplatin (ITP), recycled every 4 weeks, was reported in the treatment of previously untreated patients with advanced transitional cell carcinoma (TCC). This study sought to examine ITP at 3-week intervals to assess its feasibility and toxicity, compare the results for different schedules, and assess the impact of prognostic factors and postchemotherapy surgery on outcome. METHODS: ITP (ifosfamide 1.5 g/m(2) daily for 3 days, paclitaxel 200 mg/m(2) over 3 hours, and cisplatin 70 mg/m(2) on Day 1) was administered to patients with metastatic or unresectable TCC and was recycled every 4 weeks (for 30 patients) or 3 weeks (for 15 patients). Granulocyte-colony stimulating factor was given during each cycle. RESULTS: Thirty of 44 assessable patients (68%; 95% confidence interval, 52-81%) demonstrated a major response (10 complete responses [23%], 20 partial [45%]), with durations of response ranging from 4 to 36 months. At a median follow-up of 28 months, the median survival was 20 months. Eleven patients (25%) were disease free at last follow-up. Overall toxicity for the 15 patients whose treatment was recycled at 3 weeks was similar to that for patients treated every 4 weeks. Hematologic toxicity included anemia, thrombocytopenia, and febrile neutropenia. Febrile neutropenia was observed in 7 patients (16%) and in 3.3% of cycles of therapy. No Grade 4 nonhematologic toxicity was observed. Grade 3 nonhematologic toxicity included alopecia, renal insufficiency (11%), and neuropathy (9%). CONCLUSIONS: ITP is an active, well-tolerated regimen for previously untreated patients with TCC of the urothelial tract, resulting in a median survival of 20 months. Treatment can be recycled at 3-week intervals without enhanced toxicity.

Adult↗
PubMed2000

Categorizing a prognostic variable: review of methods, code for easy implementation and applications to decision-making about cancer treatments.

Categorizing prognostic variables is essential for their use in clinical decision-making. Often a single cutpoint that stratifies patients into high-risk and low-risk categories is sought. These categories may be used for making treatment recommendations, determining study eligibility, or to control for varying patient prognoses in the design of a clinical trial. Methods used to categorize variables include: biological determination (most desirable but often unavailable); arbitrary selection of a cutpoint at the median value; graphical examination of the data for a threshold effect; and exploration of all observed values for the one which best separates the risk groups according to a chi-squared test. The last method, called the minimum p-value approach, involves multiple testing which inflates the type I error rates. Several methods for adjusting the inflated p-values have been proposed but remain infrequently used. Exploratory methods for categorization and the minimum p-value approach with its various p-value corrections are reviewed, and code for their easy implementation is provided. The combined use of these methods is recommended, and demonstrated in the context of two cancer-related examples which highlight a variety of the issues involved in the categorization of prognostic variables.

Antineoplastic Agents↗
PubMed2000

Prospective assessment of primary rectal cancer response to preoperative radiation and chemotherapy using 18-fluorodeoxyglucose positron emission tomography.

PURPOSE: The purpose of this prospective study was to determine the ability of fluorine-18 fluorodeoxyglucose positron emission tomography to assess extent of pathologically confirmed rectal cancer response to preoperative radiation and 5-fluorouracil-based chemotherapy. METHODS: Patients with primary rectal cancer deemed eligible for preoperative radiation and 5-fluorouracil-based chemotherapy because of a clinically bulky or tethered tumor or endorectal ultrasound evidence of T3 and/or N1 were prospectively enrolled. Positron emission tomography and CT scans were obtained before preoperative radiation and 5-fluorouracil-based chemotherapy (5,040 cGy to the pelvis and 2 cycles of bolus 5-fluorouracil with leucovorin) and repeated four to five weeks after completion of radiation and 5-fluorouracil-based chemotherapy. In addition to routine pathologic staging, detailed assessment of rectal cancer response to preoperative radiation and 5-fluorouracil-based chemotherapy was performed independently by two pathologists. Positron emission tomography parameters studied included conventional measures such as standardized uptake value (average and maximum), positron emission tomography-derived tumor volume (size), and two novel parameters: visual response score and change in total lesion glycolysis. RESULTS: Of 21 patients enrolled, prospective data (pretreatment and posttreatment positron emission tomography, and complete pathologic assessment) were available on 15 patients. All 15 demonstrated pathologic response to preoperative radiation and 5-fluorouracil-based chemotherapy. This was confirmed in 100 percent of the cases by positron emission tomography compared with 78 percent (7/9) by CT. In addition, one positron emission tomography parameter (visual response score) accurately estimated the extent of pathologic response in 60 percent (9/15) of cases compared with 22 percent (2/9) of cases with CT. CONCLUSIONS: This pilot study demonstrates that fluorine-18 fluorodeoxyglucose positron emission tomography imaging adds incremental information to the preoperative assessment of patients with rectal cancer. However, further studies in a larger series of patients are needed to verify these findings and to determine the value of fluorine-18 fluorodeoxyglucose positron emission tomography in a preoperative strategy aimed at identifying patients suitable for sphincter-preserving rectal cancer surgery.

Adenocarcinoma, Mucinous↗