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Biomedical subjects

M E Chen

Publications and source records attributed to M E Chen.

11 recordsLinked to original sources
PubMed1998

Isolation and characterization of PAGE-1 and GAGE-7. New genes expressed in the LNCaP prostate cancer progression model that share homology with melanoma-associated antigens.

The LNCaP progression model of human prostate cancer consists of lineage-related sublines that differ in their androgen sensitivity and metastatic potential. A differential display polymerase chain reaction was employed to evaluate mRNA expression differences between the LNCaP sublines in order to define the differences in gene expression between the androgen-sensitive, nontumorigenic LNCaP cell line and the androgen-insensitive, metastatic LNCaP sublines, C4-2 and C4-2B. An amplicon, BG16.21, was isolated that showed increased expression in the androgen-independent and metastatic LNCaP sublines, C4-2 and C4-2B. Hybridization screening of a lambda gt11 expression library with BG16.21 revealed two transcripts, both homologous to BG16.21 at the 3' end. A GenBankTM data base search using the GCG Wisconsin software package revealed the shorter approximately 600-bp transcript (designated GAGE-7) to be a new member of the GAGE family. The second approximately 700-bp transcript was a novel gene (designated PAGE-1, "prostate associated gene") with only 45% homology to GAGE gene family members. RNA blot analysis demonstrated that GAGE-7 mRNA was expressed at equal levels in all lineage related prostate cancer cell sublines, while PAGE-1 mRNA levels were elevated 5-fold in C4-2 and C4-2B as compared with LNCaP cells. Neither GAGE-7 nor PAGE-1 demonstrated any regulation by androgens in the prostate cancer cell lines used in this study. PAGE-1 and GAGE-7 expression was found to be restricted to testes (high) and placenta (low) on human multiple tissue Northern blots. As GAGE/MAGE antigens were reported previously to be targets for tumor-specific cytotoxic lymphocytes in melanoma, these results suggest that PAGE-1 and GAGE-7 may be related to prostate cancer progression and may serve as potential targets for novel therapies.

Amino Acid Sequence↗
PubMed1997

Optimization of prostate biopsy strategy using computer based analysis.

PURPOSE: We evaluated and optimized the detection of cancer by prostate biopsies. We developed a stochastic computer simulation model of ultrasound guided biopsies using mathematically reconstructed radical prostatectomy specimens. Use of this technique allows rapid evaluation of a variety of factors for their effect on prostate biopsy results. We used this model to analyze the effectiveness of sextant biopsies, which have been widely adopted in clinical practice. We also analyzed other biopsy schemes. MATERIALS AND METHODS: A total of 607 tumor foci from 180 serially sectioned whole mount radical prostatectomy specimens was mapped and digitized. The cancers had been clinically diagnosed by a variety of biopsy strategies. Simulated parasagittal sextant biopsies were performed for each case. Forty simulation runs (each consisting of a set of 6 biopsies) were performed for each prostate, with realistic random variations in sextant biopsy localization programmed in each run. Cancer detection by biopsy was considered reliable if 90% of the simulation runs for each prostate were positive for cancer. A summary algorithm was used to map the tumor foci. RESULTS: Simulation of sextant biopsies demonstrated reliably detected cancer in only 107 of 147 patients (73%) in whom total tumor volume was greater than 0.5 cc. There was little correlation between total length of cancer in biopsy cores and tumor volume. Change of biopsy angle from 30 to 45 degrees did not result in significantly increased detection rates. Similarly, placing all biopsies more laterally did not increase overall detection rates. When we mapped tumor foci from the 40 cases in which sextant biopsies did not reliably detect tumor, we found that the foci were distributed in areas not biopsied by the sextant method, that is the transition zone, midline peripheral zone and inferior portion of the anterior horn of the peripheral zone. A 10-core biopsy scheme incorporating these areas as well as the posterolateral prostate reliably detected cancer in 141 of 147 patients (96%) with total tumor volumes greater than 0.5 cc. CONCLUSIONS: Prostate cancer of significant volume can be present in areas not sampled by standard sextant biopsies. Biopsies of the transition zone, midline peripheral zone and inferior portion of the anterior horn of the peripheral zone should be considered for re-biopsy strategy after negative sextant biopsies. Sampling of these additional areas also can be incorporated in an initial biopsy scheme to increase overall initial rates of detection of prostate cancer.

Biopsy↗
PubMed1997

Risk of urethral, vaginal and cervical involvement in patients undergoing radical cystectomy for bladder cancer: results of a contemporary cystectomy series from M. D. Anderson Cancer Center.

PURPOSE: Orthotopic bladder reconstruction in women is the focus of considerable interest. To define suitable candidates for orthotopic reconstruction among women with bladder cancer, we reviewed the risk of secondary urethral, vaginal and cervical involvement by transitional cell carcinoma in patients who underwent radical cystectomy at our institution. MATERIALS AND METHODS: We retrospectively reviewed the charts of women who underwent radical cystectomy for primary transitional cell carcinoma of the bladder between 1985 and 1995. These cases also were reviewed pathologically. RESULTS: Of 115 patients who underwent radical cystectomy for transitional cell carcinoma of the bladder 9 (8%) also had secondary transitional cell carcinoma of the urethra, including 2 with concomitant involvement of the vagina or cervix. In 4 patients (3%) the vagina or cervix was involved but not the urethra. Vaginal and cervical invasion correlated with stages T3b and T4 disease (p = 0.04). By logistic regression analysis the sole significant risk factor for urethral involvement was bladder neck involvement (p = 0.0005). Unlike previous studies 2 of 9 patients with secondary urethral transitional cell carcinoma did not have apparent cancer at the bladder neck. CONCLUSIONS: We report secondary urethral involvement without apparent bladder neck involvement in women with transitional cell carcinoma. Women who are candidates for orthotopic reconstruction should undergo biopsies of the bladder neck and urethra as part of the preoperative evaluation. In patients with palpable masses (stage T3b) on bimanual examination, transvaginal biopsies should also be considered. Intraoperative frozen sections of the urethral and vaginal margins should be obtained.

Adenocarcinoma↗
PubMed1993

Antisperm antibodies in cryptorchid boys.

To explore whether the development of antisperm antibodies might play a role in inhibiting the future fertility of cryptorchid boys, 32 boys who underwent orchiopexy and 21 boys who underwent other inguinal surgeries were examined for the presence of antibodies to donor sperm. This group was compared to 23 boys who underwent noninguinal surgery or who had unrelated medical conditions. Using the indirect immunobead assay, 28% of the boys in the study group were found to have antisperm antibodies. These were predominantly of the IgG isotype. In the comparison group, only 1 boy (4%) had antisperm antibodies (P < 0.05).

Adolescent↗
PubMed1991

Syndrome of mental retardation and distal arthrogryposis in sibs.

Two sisters presented with a syndrome of characteristic facial anomalies and distal arthrogryposis. The older sister is now 4 years old and is severely mentally retarded. Her sister died of respiratory failure due to hypoplastic lungs shortly after birth. The occurrence of this potentially lethal syndrome in 2 sisters with unaffected parents suggests autosomal recessive inheritance.

Arthrogryposis↗
PubMed1991

[Effect of Salvia miltiorrhiza co. on angiotensin II and atrial natriuretic polypeptide in rabbits].

Both angiotensin II (AII) and atrial natriuretic polypeptide (ANP) are related to the function of blood vessels, but differ in their actions. The authors observed the effect of Salvia miltiorrhiza Co. (SMC) on the activities of AII and ANP in rabbits by radioimmunoassay. It was found that the concentration of AII and ANP in plasma were significantly lower (P less than 0.05), and slightly lower in brain and atrial (P greater than 0.05) in SMC group than in control group. It indicated that the effect of SMC on blood vessels is related to changes of AII and ANP, and that the difference of peptide changes in brain and plasma might be due to the blood-brain barrier.

Angiotensin II↗
PubMed1978

Applying Yalom's principles to crisis work...some intriguing results.

In this paper, the writer has shared some of the results of an innovative eight- to sixteen-week, open-ended crisis group developed at the Community Mental Health Center at Strong Memorial Hospital. The group has been running for over a year and a half. Some of the significant findings were that process interventions can be creatively used in a modified manner to enhance the group interaction, while maintaining the crisis-oriented focus. There were two dimensions of process commentary described, the sense data material of an individual, interpersonal nature, and the mass group interventions with a broader, group development focus. In addition, the secondary function of the group, which was to serve as an assessment tool for an individual's capabilities in long-term group work, proved to be reliable for eighteen out of the twenty members, eventually referred to other groups. A theoretical framework, based on Yalom's work, as well as the writer's synthesis of previous crisis group theory, was outlined. Two clinical illustrations were described, using the paradigm. In closing, the writer wishes to validate the impression that crisis group work is indeed an exciting, clinical adventure. Each week the gestalt of the group varies, so that the crisis therapist must remain a versatile strategist and sensitive role model of communication theory. The interweaving of process issues with more concrete, content-focused group work provides the members with an in-depth, sharply practical interpersonal arena for growth.

Crisis Intervention↗