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Biomedical subjects

M Becich

Publications and source records attributed to M Becich.

12 recordsLinked to original sources
PubMed2001

Identification of a novel gene with increasing rate of suppression in high grade prostate cancers.

Prostate cancer is the second leading cause of cancer-related deaths in the United States. However, the underlying molecular events for prostate cancer development are not clear. In this study, we applied the recently developed technology known as differential subtraction chain (DSC) to identify a novel gene whose expression is inactivated in high grade prostate cancer. This gene, designated as SAPC, is expressed in normal prostate acinar cells. Its expression is dramatically down-regulated in high grade prostate cancers (4/4) but is unaltered in low grade prostate cancers. It encodes a 7.7-kd protein. Its sequence shares some homology with the cysteine-rich domain of 2-5A-dependent RNase L, which is a critical component of the interferon-induced apoptosis cascade. The selective inactivation in the more aggressive prostate cancers holds promise for SAPC as a potential prognostic marker for high grade prostate cancer.

Amino Acid Sequence↗
PubMed2000

Defining the role of anatomic pathology images in the multimedia electronic medical record--a preliminary report.

The development of the Multimedia Electronic Medical Record System (MEMRS) offers new opportunities for integrating medical imaging data with text-based clinical data. The effective integration of pathology images into the patient's medical record poses some significant technical and organizational challenges. Before these challenges can be met, it is imperative that we investigate the value and utility of providing these images to clinicians. In this study we examined attitudes towards use of pathology images in Image Engine, a MEMRS under development at the University of Pittsburgh Cancer Institute (UPCI). We conducted semi-structured standardized interviews with a cohort of practicing oncologists, all of whom had significant experience with Image Engine. This study is a first step towards elucidating the potential barriers, uses, and value of anatomic pathology images in the MEMRS.

Attitude of Health Personnel↗
PubMed1999

Cold-temperature plastic resin embedding of liver for DNA- and RNA-based genotyping.

The standard practice of tissue fixation in 10% formalin followed by embedding in paraffin wax preserves cellular morphology at the expense of availability and quality of DNA and RNA. The negative effect on cellular constituents results from a combination of extensive cross-linking and strand scission of DNA, RNA, and proteins induced by formaldehyde as well as RNA loss secondary to ubiquitous RNase activity and negative effects of high temperature exposure during paraffin melting, microscopic section collection, and tissue adherence to glass slides. An effective strategy to correlate cellular phenotype with molecular genotype involves microdissection of tissue sections based on specific histopathological features followed by genotyping of minute representative samples for specific underlying molecular alterations. Currently, this approach is limited to short-length polymerase chain reaction amplification (<250 bp) of DNA, due to the negative effects of standard tissue fixation and processing. To overcome this obstacle and permit both cellular morphology and nucleic acid content to be preserved to the fullest extent, we instituted a system of cold-temperature plastic resin embedding based on the use of the water-miscible methyl methacrylate polymer known as Immunobed (Polysciences, Warminster, PA). The system is simple, easy to adapt to clinical practice, and cost-effective. Immunobed tissue sections demonstrate a cellular appearance equivalent or even superior to that of standard tissue sections. Moreover, thin sectioning (0.5-1.0 microm thickness) renders ultrastructural evaluation feasible on plastic-embedded blocks. Tissue microdissection is readily performed, yielding high levels of long DNA and RNA for genomic and transcription-based correlative molecular analysis. We recommend the use of Immunobed or similar products for use in molecular anatomical pathology.

Cold Temperature↗
PubMed1999

Pathology imaging on the Web. Extending the role of the pathologist as educator to patients.

The increasing role of patients in medical decision making and the growing availability of medical information are changing the physician-patient relationship. One aspect of this change is that patients are searching for medical information on the Internet and are visiting sites, including pathology sites, that were not originally intended for patient use. This article describes evidence for this activity and how the University of Pittsburgh Medical Center Department of Pathology has evolved mechanisms to handle patient use of its web site.

Diagnostic Imaging↗
PubMed1994

Alternative splicing of CD44 pre-mRNA in human colorectal tumors.

Expression of the CD44 molecule has been linked to tumor growth and metastases in both human and rodent cancers. Alternatively spliced variants expressed in rat and mouse tumors have been shown to confer metastatic potential to non-metastatic carcinoma cell lines, and human homologues of rat variant mRNA sequences are expressed in human tumors. In the present study matched sets of RNA from adenocarcinomas of the colon and distant normal mucosa were assayed for CD44 expression by quantitative RT-PCR. Retrospective analysis revealed that colonic tumor cells had both quantitative and qualitative differences in CD44 expression when compared to normal mucosa. These were: 1) an increase in levels of CD44 transcripts, 2) an increase in levels of alternatively spliced transcripts, 3) the presence of larger alternatively spliced transcripts with inserts > 400 bases and 4) the primary alternatively spliced CD44 isoform in colonic adenocarcinomas in all cases is CD44R. Interestingly, two patterns of CD44 isoform expression termed "variant dominant" or "balanced" patterns of expression, based on the ratio of variant to standard CD44 transcripts (R+V's/H), could be differentiated. An unfavorable prognosis was suggested for tumors expressing increased levels of CD44 variant exons previously associated with tumor metastasis. Specifically, patients with tumors expressing the "variant dominant" pattern of expression irregardless of Dukes classification and Dukes C and D staged tumors of both patterns exhibited a poorer prognosis.

Adenocarcinoma↗
PubMed1994

Absence of immunohistochemical metallothionein staining in bladder tumor specimens predicts response to neoadjuvant cisplatin, methotrexate and vinblastine chemotherapy.

Pre-chemotherapy bladder tumor tissue was retrospectively analyzed in 21 patients treated with neoadjuvant cisplatin, methrotrexate and vinblastine. Immunohistochemical staining for 2 proposed mediators of drug resistance, p-glycoprotein and metallothionein, was performed and compared to chemotherapeutic response and survival. There was no significant relationship between staining for p-glycoprotein and the response to chemotherapy or survival. Patients with no detectable staining for metallothionein were statistically more likely to sustain a complete pathological response (p = 0.029) after chemotherapy than those with any detectable staining. No relationship between metallothionein immunostaining and survival was apparent. This study offers further evidence linking metallothionein in tumor resistance to cisplatin containing chemotherapy regimens.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

Formation of noninfectious HIV-1 virus particles lacking a full-length envelope protein.

Deletions were constructed within a functional human immunodeficiency virus type 1 (HIV-1) proviral clone in order to assess the role of the envelope protein in virus particle formation. A graded exonuclease deletion technique was used to produce 12 clones with deletions of 175-308 nucleotides in the first conserved domain of envelope. This included 9 clones with frameshift deletions and 3 clones with in-frame deletions. Isogenic pairs of env deletion clones were produced with or without an additional deletion in the vif and vpr genes. Upon transfection, all clones produced virus particles, as determined by p24 antigen, reverse transcriptase, and sucrose gradient assays with conditioned media. Virus particles produced from clones with deletions in env or vif and vpr, or both regions, banded on sucrose gradients with a mobility similar to that of virus produced by the parental clone. The p24 gag capsid protein in the particles was resistant to trypsin, but the particles were disrupted by treatment with Triton X-100, suggesting the presence of a surrounding lipid bilayer. Furthermore, electron microscopic studies revealed both mature and immature virus particles derived from COS cells transfected with the env deletion clones. Cocultivation experiments with lymphoid cells and cells transfected with each of the env deletion clones demonstrated that the virus particles were noninfectious.

Animals↗
PubMed1986

Prognostic value of purified protein derivative skin test and granuloma formation in patients treated with intravesical bacillus Calmette-Guerin.

We evaluated the prognostic value of purified protein derivative skin test reactivity and a granulomatous response in intravesical bacillus Calmette-Guerin therapy. We treated 62 patients with intravesical bacillus Calmette-Guerin once a week for 6 weeks. Purified protein derivative skin tests were performed before and after therapy. Cold cup bladder biopsies were examined in a blind retrospective manner for the presence of granulomas 6 weeks after completion of therapy. A significant correlation between status free of tumor and the presence of either granulomas or positive purified protein derivative skin tests was observed for the total patient population. Of 25 patients whose purified protein derivative test was converted from negative to positive 19 (77 per cent) remained free of tumor, while only 11 of 32 (34 per cent) whose test did not convert to purified protein derivative positive remained free of tumor (p equals 0.0006, chi-square). Similarly, 28 of 37 patients (77 per cent) who had a granulomatous response remained free of tumor, while only 8 of 25 (32 per cent) without a granulomatous response remained free of tumor (p less than 0.003, chi-square). The correlation was similar for each parameter when the total patient population was subdivided into patients treated for carcinoma in situ, residual tumor or prophylaxis. Calculation of predictive values showed that neither purified protein derivative responsiveness, granuloma formation nor a combination of both provided a highly accurate predictive index of therapeutic response in individual patients. False positive or negative rates, ranging from 23 to 24 per cent and 32 to 39 per cent, respectively, were observed. These results suggest that a link between immunological responsiveness and response to therapy exists but that neither the purified protein derivative skin test nor the granulomatous response exhibits sufficient immunological specificity to serve as accurate prognostic indicators in individual patients.

Adult↗
PubMedDate not supplied

Characterizing "blue blobs". Immunohistochemical staining and ultrastructural study.

OBJECTIVE: To investigate the nature and origin of "blue blobs" (Bbs) in atrophic Pap smears in postmenopausal women and to study their clinical significance. STUDY DESIGN: A retrospective study of 412 atrophic Pap smears from postmenopausal women was done to detect the presence of Bbs. The smears from 24 cases showing Bbs were further studied to evaluate the nature of the Bbs with special stains, immunohistochemistry and electron microscopy. RESULTS: Bbs showed a heterogeneous morphology, with variable numbers and staining intensity. The diameter of Bbs was approximately equivalent to that of a parabasal/intermediate squamous cell. Special stains showed Bbs to be positive for periodic acid-Schiff and methyl green pyronin and negative for mucicarmine and calcium. Immunohistochemistry revealed Bbs to be positive for cytokeratin, epithelial membrane antigen and carcinoembryonic antigen and negative for vimentin and muscle-specific actin. Some Bbs had residual ghost nuclear shadows. Electron microscopy revealed cellular skeletons with residual tonofilaments enmeshed within a loose cytoskeleton matrix and nuclei with variable degrees of degeneration. CONCLUSION: Special stains, immunohistochemistry and electron microscopy indicated that Bbs represent parabasal/intermediate squamous cells exhibiting various degree of degeneration. In general, Bbs appear to be of no clinical significance except as a source of potential diagnostic error.

Aged↗