Biomedical subjects

S J Melnick

Publications and source records attributed to S J Melnick.

9 recordsLinked to original sources

PubMed2000

Clinical application of four and five-color flow cytometry lymphocyte subset immunophenotyping.

A 1995 survey of clinical flow cytometry laboratories in the United States determined that 63% of clinical laboratories used one or two-color, 33% used three-color, 4% used four-color, and none used five-color panels. We show the feasibility and advantages of acquiring routine clinical four-color, six-parameter and five-color, seven-parameter analysis on blood samples derived from a pediatric population. The panels were evaluated by comparing the following cell characteristics: size, internal structure, and up to five distinct fluorochrome-conjugated antibodies to cell surface antigens: CD3, CD16+CD56, CD19, CD8, and CD4. These samples were processed on a commercially available instrument without any special modifications. A comparison of two-color and four-color as well as four-color and five-color panel analysis showed no statistical difference between the groups. We propose that the five-color, single-tube panel will (1) eliminate the need for isotype controls; (2) the relative proportions of lymphocyte subpopulations may be used to validate the operator-defined window, replacing CD45; (3) eliminate the need to run a common factor, in order to establish and maintain a reproducible lymphocyte window between tubes; and (4) create a more complete clinical picture by generating 32 unique, mutually exclusive phenotypes (permutations). Our results show that it is feasible to acquire and integrate seven-parameter data. This may be a powerful tool for immunophenotyping cells in a modern clinical diagnostic cytometry laboratory.

Antigens, CD↗

PubMed2000

Neoplasm as a cause of brachial plexus palsy in neonates.

Two patients with neonatal onset of arm weakness resulting from neoplastic involvement of the brachial plexus who were initially considered to have obstetric brachial plexus palsies are reported. The first patient was a 7-day-old female who presented with a left supraclavicular mass that was first detected at 2 days of age and left proximal arm weakness. The weakness involved the whole arm within 3 days. The mass was a malignant rhabdoid tumor. The second patient was a 28-month-old male who presented with slowly progressive right arm weakness, which began at 3 weeks of age, and episodes of scratch marks on the arm that began at 4 months of age. Magnetic resonance imaging revealed a plexiform neurofibroma of the brachial plexus. The features that are suggestive of a brachial plexus palsy caused by a neoplasm rather than of obstetric brachial plexus palsy include the following: the onset of weakness after the first day of age, with a progressive course; a history of a normal delivery and birth weight; the absence of signs of a traumatic injury or injuries; the appearance before 7 days of age of a growing supraclavicular mass without radiographic evidence of a clavicular fracture; and recurrent scratch marks on the weak arm.

Arm↗

PubMed1999

Multidrug resistance in human tumors--molecular diagnosis and clinical significance.

BACKGROUND: Multidrug resistance (MDR) of human tumors is one of the major reasons for the failure of chemotherapy in refractory cancer patients. MDR can be intrinsic or acquired, depending on the time of its occurrence, either at diagnosis or during chemotherapy. Molecular investigations in MDR during the last two decades have resulted in the isolation and characterization of genes coding for P-glycoprotein, multidrug resistance-associated protein, lung resistance-related protein, drug resistance-associated protein, breast cancer resistance protein, and adenosine triphosphate-binding cassette protein. Several molecular probes, primer pairs, and monoclonal antibodies have been developed over these years to quantify the regulation and expression of these drug resistance markers in tumor cells. Methodologies have also been standardized to estimate the gene amplification, mRNA and protein expression, and functionality of drug resistance proteins in clinical specimens from cancer patients. METHODS AND RESULTS: This review describes these drug resistance genes and techniques for detection and quantification of their expression and function. CONCLUSIONS: Because these markers have clinical significance and usefulness, currently available technology warrants the application of these markers in clinical oncology.

Antibodies, Monoclonal↗

PubMed1999

Acute lymphoblastic leukemia.

This article reviews the laboratory methodologies used to evaluate acute lymphoblastic leukemia (ALL) in children and their role in establishing a diagnosis and prognosis of this disease. These methodologies are: morphology, flow cytometry, cytogenetics, and molecular diagnostics. Additionally, immunophenotypic classifications of ALL and criteria for establishing a diagnosis of ALL independent of morphology are described.

Child↗

PubMed1994

Subcutaneous nodules as a dermatologic manifestation of bacteremia due to Pseudomonas aeruginosa.

Sepsis due to Pseudomonas aeruginosa continues to be an important source of morbidity and mortality in hospitalized patients. Early recognition of this condition is of paramount importance in choosing specific therapy at the earliest possible moment. We present three cases in which P aeruginosa bacteremia was manifested by subcutaneous nodules. Although such lesions have been reported before, we place new emphasis on the uniqueness of this lesion to P aeruginosa, the feasibility of visualizing the organism and culturing it from biopsies of the lesions, and the possibility of choosing appropriate therapy early through recognition.

Aged↗

PubMed1989

Metastatic renal cell carcinoma presenting as a parotid tumor: a case report with immunohistochemical findings and a review of the literature.

Renal cell carcinoma presenting as an asymptomatic parotid mass is rare. Only 15 cases have been reported. We describe a 72-year-old man with widespread metastatic renal cell carcinoma presenting with a 2-year history of a slowly enlarging left parotid mass. Needle biopsy revealed a clear cell neoplasm. Immunoperoxidase studies for carcinoembryonic antigen were negative while those for vimentin and keratin were positive, consistent with a renal cell carcinoma. This is the first case reported in which the immunohistochemical findings of positive staining for vimentin and keratin have confirmed the presence of metastatic renal cell carcinoma. The histochemical features of various parotid clear cell tumors, as well as a review of renal cell tumors presenting as a parotid mass, will be discussed.

Aged↗

PubMedDate not supplied

Cytogenetic and molecular characterization of a congenital mesoblastic nephroma.

A newborn baby boy was diagnosed with the mixed form of congenital mesoblastic nephroma (CMN) representing both classic and cellular histology features in the renal tumor. Additionally, the patient had skin and bone lesions consistent with multifocal involvement of a generalized infantile fibromatosis (IFS). Both skin and bone lesions were distinctly different from CMN and did not represent metastasis. The primary tumor cell line (MCH-MN-1), established from the resected right kidney tumor, had a diploid DNA content. Cytogenetic studies revealed deletion on the long arm of chromosome 3 (q21q24) and duplication on the short arm of chromosome 11 (p15). MCH-MN-1 cells expressed ETV6-NTRK3 gene fusion transcripts, characteristic of cellular and mixed forms of CMNs. The cells had high p21 and low Bax mRNA expression in the reverse transcriptase-polymerase chain reaction (RT-PCR) assay. The high level of proliferative marker (Ki67) mRNA expression correlated well with the pluripotent nature of MCH-MN-1 in tissue culture (cell doubling time = 12.4 h). Our results showed that MCH-MN-1 might be a good model cell line for investigations on mesoblastic nephroma.

Chromosome Deletion↗

PubMedDate not supplied

The thermal properties of dilauryl phosphatidylethanolamine liposomes are affected by lipid source and preparation.

Dilauryl phosphatidylethanolamine (DLPE) dispersions in water ('liposomes') display phase metastability. We find, by differential scanning calorimetry (d.s.c.), that the new phases are dependent upon lipid source and temperature of initial hydration. These observations may explain inconsistencies in the reported metastability behaviour of saturated PEs.

Calorimetry, Differential Scanning↗

PubMedDate not supplied

Expression of apoptosis, cell proliferation, and drug resistance genes in pediatric Wilms' tumors.

The expression of genes associated with apoptosis, cell proliferation and drug resistance in tumor cells was investigated in two pediatric Wilms' tumor patients (MCH-WT-1 and MCH-WT-3) for their association with cell cycle, daunorubicin accumulation and clinical data. DNA content, cell cycle and drug accumulation were analyzed immediately after surgery by flow cytometry and mRNA expression by reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Primary cell cultures were established from tumor specimens and tumor cells in both cases showed epithelial morphology. Although cell proliferation markers (Ki67 and PCNA) were expressed in both cases, MCH-WT-3 showed higher levels of mRNA expression, which corresponded, with metastatic behavior of the tumor in the patient. While p53 and p21 mRNAs were expressed at low levels in MCH-WT1, MCH-WT-3 showed high levels of p21 mRNA only. The increased expression of cyclin kinase inhibitor (p21) in MCH-WT-3 compared to MCH-WT-1 correlated with a higher percentage of G0/G1 cell population in the tumor specimen. Despite the expression of multidrug resistance markers (MDR1 and LRP) in MCH-WT-1, flow cytometric analysis showed tumor cell populations with very low and high daunorubicin accumulation and with the absence of any effect for verapamil and dipyridamole on daunorubicin accumulation of tumor cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗