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Biomedical subjects

J Ro

Publications and source records attributed to J Ro.

36 records · Page 2Linked to original sources
PubMed1988

Amplified and overexpressed epidermal growth factor receptor gene in uncultured primary human breast carcinoma.

We analyzed the epidermal growth factor receptor gene using a complementary DNA probe of the epidermal growth factor receptor gene in 21 uncultured primary breast carcinomas and found that the gene was amplified in three of these tumors. We further demonstrated by immunohistochemistry using a monoclonal antibody to the epidermal growth factor receptor that the receptor protein product of this gene was overexpressed and displayed elevated kinase activity. Our data indicate that one of the molecular mechanisms for overexpression of epidermal growth factor receptor in human breast cancer is epidermal growth factor receptor gene amplification without rearrangement in a subset of tumors.

Adult↗
PubMed1988

The emerging role of Fusarium infections in patients with cancer.

Infection due to Fusarium species is an increasing cause of serious potentially fatal disease in patients with cancer. We described 9 patients with infection caused by Fusarium species during a 4-year period at the M. D. Anderson Hospital. The spectrum of infections included disseminated disease in 4 patients, skin or soft-tissue infections in 3, pneumonia in 1, and fungemia in 1. All 4 patients with disseminated infection had culture- and biopsy-proven skin lesions caused by Fusarium species and the blood cultures yielded the organism in 3 of these 4 patients. Maxillary sinusitis was the presenting manifestation of Fusarium infection in 2 of these 4 patients, suggesting that paranasal sinuses are potential portals of entry for the infection. Eight patients had a hematological malignancy and 7 were neutropenic at the onset of their infection. Patients with deep-seated infections remained neutropenic and died from infection despite treatment with amphotericin B. All 5 isolates tested in vitro showed resistance to ketoconazole and miconazole, whereas 3 were susceptible to amphotericin B. Fusarium species could play a role in producing myelosuppression and fungal cultures are required to differentiate it from the more commonly encountered Aspergillus species. Fusarium species are emerging as a serious, potentially fatal, pathogen in patients with cancer.

Adolescent↗
PubMed1987

Disseminated Geotrichum candidum infection.

The pathogenicity of the fungus Geotrichum candidum in humans has not been clearly defined. A patient with acute leukemia who developed a fatal disseminated G. candidum infection while neutropenic is described. At autopsy examination, this patient was misdiagnosed on the basis of histopathology as having disseminated candidiasis until G. candidum was isolated from postmortem culture specimens. The emergence of this organism as an occasional pathogen in leukemic patients is of interest and illustrates the importance of obtaining fungal cultures. There is a need for more effective drugs for antifungal prophylaxis and therapy.

Agranulocytosis↗
PubMed1987

Ultrastructural observations on smooth muscle tumors.

The ultrastructure of a series of primary and metastatic smooth muscle tumors is reviewed. Myofilaments and other smooth muscle features were present in all primary leiomyosarcomas of the soft tissues and uterus. They were also present but were less plentiful in most of the metastatic leiomyosarcomas. Electron microscopy is therefore a useful method to establish the diagnosis of a suspected leiomyosarcoma. Stromal tumors of the gastro-intestinal tract may require correlated immunocytochemical and ultrastructural studies for their identification: 9 of the 50 cases examined were positive with immunostaining for S-100 protein, and 16 tumors with epithelioid transformation did not show evidence of smooth muscle differentiation by electron microscopy.

Actin Cytoskeleton↗
PubMed1987

An examination of the ability of d-tubocurarine to evoke contraction and mediator release from superfused trachea and parenchymal strips isolated from the guinea pig.

The relationship between curare-induced mediator release and contraction in superfused guinea pig trachea and parenchymal strips was examined. In trachea, curare produced histamine release and contraction with peak release occurring in the first 90 sec (collection period 1) after challenge. Peak contraction developed later (collection periods 4-6). Curare-induced contraction of parenchymal strips was inconsistent and smaller than that found in trachea. No histamine could be detected in parenchymal strip superfusate samples. Curare also was selective in releasing histamine from monodispersed airway cells vs. peripheral lung cells. No leukotriene bioactivity or immunoreactivity could be detected after curare challenge of tissues or cell suspensions. Tracheal contractions, but not histamine release, occurring early (first 5 or 6 collection periods) after challenge were antagonized by mepyramine, 10(-6) M, and phenoxybenzamine, 3 X 10(-5) M. Combination of FPL55712, 10(-5) M, with mepyramine did not further alter tracheal contraction. Contractions occurring later after challenge and total histamine release were enhanced by indomethacin, 5 X 10(-6) M. Indomethacin also increased contractions in the presence of mepyramine. With mepyramine and indomethacin, LY171883, 1 and 3 X 10(-6) M, and nordihydroguaiaretic acid, 3 X 10(-5) M, antagonized tracheal contractions to curare, 3 X 10(-3) M, but not to 1 X 10(-3) M, without altering histamine release. Indomethacin prolonged return to base line of tracheal tension after challenge with exogenous histamine. After addition of LY171883 or nordihydroguaiaretic acid, the return of tracheal tension after histamine was not different from that seen without drug pretreatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

S-100 protein and myoepithelial neoplasms.

Besides advancing our knowledge of histogenesis, immuno-cytochemical studies of salivary gland tumors have added an important objective component to the diagnosis and classification of the tumors. Cellular localization of S-100 protein now allows identification of myoepithelial cells and tumors composed of these cells. The four tumors presented in this report illustrate the diagnostic advantages afforded by S-100 protein immunocytochemistry.

Adult↗
PubMed1986

Nuclear deoxyribonucleic acid heterogeneity of ovarian borderline malignant serous tumors.

Sixteen borderline malignant serous ovarian tumors and seven well-differentiated invasive serous ovarian carcinomas were examined with the technique of Feulgen microspectrophotometry for the determination of nuclear deoxyribonucleic acid (DNA) ploidy patterns (diploid versus aneuploid) and ploidy levels of the stem cell lines. Of the nine stage I-II borderline malignant tumors, only one (11%) was aneuploid. In contrast, four of seven (57%) stage III borderline malignant neoplasms and all stage III carcinomas were aneuploid. The stem cell modal values in all borderline serous tumors were less than triploid (3N) while in five of seven carcinomas stem cell modal values were greater than triploidy. This contrast in ploidy patterns and ploidy levels may explain the differences in biologic behavior between borderline malignant serous tumors and invasive serous carcinomas of the ovary.

Adult↗
PubMed1983

Pulmonary scar carcinoma. A clinicopathologic analysis.

To delineate differences between scar and non-scar pulmonary carcinoma, the charts, autopsy protocols and chest roentgenograms of 80 male patients (autopsied) between 1975 and 1980, were reviewed. Nineteen patients (24%) had documented scar carcinomas. The comparison revealed scar carcinomas to possess certain distinctive features: A higher histologic distribution of adenocarcinoma (58% versus 15% in non-scars) and the frequent presentation (53%) with only nonpulmonary symptoms and signs related to metastasis. In scar carcinomas both bronchoscopy and sputum cytology were ineffective as initial diagnostic tools since chest findings were absent or minimal. Chest x-ray was negative in 9 of the 19 patients with scar cancer and remained negative until death in seven. In 10 of 19 instances, pulmonary scar carcinomas presented with only nonpulmonary symptoms and showed a tendency to metastasize while clinically undetectable. The differences noted between scar and non-scar carcinomas of the lung appear to depend on the peripheral location of these tumors and not on the adenocarcinoma histology.

Adenocarcinoma↗
PubMed1978

Effect of indomethacin on collagen metabolism of rat fracture callus in vitro.

The collagen metabolism of callus tissue from closed, non-immobilized rat femoral fractures was studied in vitro after in vivo treatment with indomethacin 2 mg/kg/day for 6, 9 and 12 days after fracture. Total hydroxyproline synthesis and incorporation of hydroxyproline into collagen were found to be significantly increased after indomethacin treatment, whereas no significant difference was found regarding collagen resorption. The results suggest that the recently demonstrated inhibition of fracture healing by indomethacin is not brought about by an inhibition of collagen synthesis.

Animals↗
PubMedDate not supplied

Feedback-controlled laser-mediated cartilage reshaping.

OBJECTIVE: To demonstrate feedback-controlled laser-mediated cartilage reshaping using dynamic measurements of tissue optical properties and radiometric surface temperatures. DESIGN: Flat cartilage specimens were reshaped into curved configurations using a feedback-controlled laser device. MATERIALS: Fresh porcine nasal septum, stripped of perichondrium and cut into uniform strips (25 x 10 x 1.5-2.1 mm) with a custom guillotine microtome. INTERVENTIONS: Cartilage specimens secured in a cylindrical reshaping jig (2.5 cm in diameter) and irradiated with an Nd:YAG laser (lambda = 1.32 microns, 25 W/cm2, 50-Hz pulse repetition rate). During laser irradiation, radiometric surface temperature was measured along with changes in forward-scattered light from a diode probe laser (lambda = 650 nm, 5 mW), using a lock-in detection technique. Sequential irradiation of the specimen outer surface was made (3 laser passes). Characteristic changes in tissue temperature and light-scattering signals were used to terminate laser irradiation. RESULTS: Effective reshaping was accomplished for both thin (1.5-mm) and thick (2.1-mm) specimens. Following reshaping, specimens were stored in saline solution at 4 degrees C for 21 days. No return to the original flat configuration was noted during this period. CONCLUSIONS: The prototype device effectively reshapes flat native porcine cartilage into curve configurations. The use of optical and thermal signals provides effective feedback control for optimizing the reshaping process.

Animals↗
PubMedDate not supplied

New spectrum of fungal infections in patients with cancer.

We report on 44 cancer patients who had serious infections with unusual fungal pathogens and who were cared for at our cancer center between 1974 and 1986. Twelve different fungal species accounted for these infections, including Trichosporon beigelii, Fusarium species, Geotrichum candidum, Curvularia species, Drechslera species, Penicillium species (but not Penicillium marneffei), Rhodotorula rubra, Pseudallescheria boydii, Pichia farinosa, Torulopsis pintolopesii, Saccharomyces cerevisiae, and Cunninghamella bertholletiae. Skin lesions were noted in seven patients, and sinusitis occurred in four. Twenty-four patients had disseminated infection, 12 had involvement of a single organ, and eight had fungemia alone. Features that correlated with a poor prognosis were persistent neutropenia and disseminated visceral infection but not fungemia alone. We suggest that unusual fungi have now emerged as significant pathogens in this patient population. Fungal sinusitis, previously caused by Aspergillus species and the phycomycetes, also occurs as a result of some of these newly recognized fungi. A high level of suspicion should be maintained when any of these unusual fungi are cultured from clinical specimens from immunocompromised patients.

Adolescent↗
PubMedDate not supplied

Analysis of the estrogen receptor gene structure in human breast cancer.

We studied the structure of the human estrogen receptor (ER) gene by Southern blot analysis in 34 tumor samples and normal breast tissues or peripheral blood samples from the same patients. No rearrangement or amplification of the ER gene was seen in either ER-positive or ER-negative breast tumors. One patient showed an apparent constitutional deletion of a non-allelic ("invariant") restriction fragment in DNAs from both normal leukocytes and bilateral breast tumors. Of 20 patients constitutionally heterozygous for an ER gene RFLP, only one showed tumor-specific loss of heterozygosity. This is consistent with the ER gene change we noted overall. At the c-myb locus on chromosome 6q adjacent to the ER gene, allele loss occurred in 1 out of 15 informative cases. In addition, tumor-specific allelic loss at the c-H-ras1 locus on chromosome 11p occurred in 4 of 22 informative cases, and at the D17S28 locus on chromosome 17p in 2 of 7 informative cases.

Alleles↗