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Biomedical subjects

H Kahn

Publications and source records attributed to H Kahn.

At least 37 records · Page 2Linked to original sources
PubMed1991

Hepatocellular carcinoma in a long-term survivor of intrahepatic biliary duct hypoplasia.

We describe the development of hepatocellular carcinoma (HCC) in a 46-yr-old woman with intrahepatic biliary duct hypoplasia. Her underlying liver disease was quiescent for many years until a dramatic rise in serum bilirubin was seen. Orthotopic liver transplantation was performed, and a large tumor was found during surgery. A bile-producing HCC was identified, infiltrating about 50% of an otherwise noncirrhotic liver which had a paucity of intrahepatic ducts. The findings of HCC in this long-term survivor of intrahepatic biliary duct hypoplasia indicates HCC may occur in patients with long-standing disease.

Bile Ducts, Intrahepatic↗
PubMed1991

Immunoglobulin-related amyloidosis presenting as recurrent isolated lymph node involvement.

Up to 37% of cases of generalized primary and secondary amyloidosis demonstrate lymph node involvement. Lymph node involvement as the presenting feature of generalized amyloidosis is uncommon. Isolated lymph node amyloidosis (that is, with no extranodal amyloidosis) is exceedingly rare; review of the literature reveals only two reported cases. A case of recurrent isolated lymph node amyloidosis is presented, with review of the literature.

Amyloidosis↗
PubMed1991

Poorly differentiated skin tumors. Beyond hematoxylin-and-eosin staining.

Although many tumors may be diagnosed by light microscopy alone, a few require further investigation. Selective use of antibodies by immunohistochemical techniques solves most diagnostic problems. The explosive discovery of many new antibodies often raises more questions than it answers, and electron microscopy still plays a significant role when used judiciously. It is important to recognize that every new antibody must be adequately assessed in the clinical situation and that its specificity, or lack thereof, is appreciated by both clinician and pathologist. With every new antibody, we increase our knowledge of basic disease processes. In the future, antibodies will be part of the pathologist's armamentarium for predicting disease outcomes. Not only will the cell of origin be identified but proliferation rates and production of various factors that influence metastatic potential will be delineated.

Humans↗
PubMed1990

Coronary excimer laser angioplasty: reduced complications and indium-111 platelet accumulation compared with thermal laser angioplasty.

The relative safety and thrombogenicity of pulsed excimer and thermal laser angioplasty systems were compared in 20 normal coronary artery segments in a total of seven pigs. Using similar over the wire catheter systems and laser delivery periods of 3 to 5 s, thermal laser angioplasty was achieved with a 1.3 mm metal probe heated with 10 W of continuous argon laser energy and excimer laser angioplasty was performed with a 4.5F excimer laser catheter consisting of 13 concentrically arranged 200 microns fiber optics delivering 35 to 40 mJ/mm2 of xenon chloride (308 nm) excimer laser irradiation at a repetition rate of 25 to 30 Hz and a pulse duration of 120 ns. On angiography, the incidence of vessel perforation (1 in 10 versus 3 in 10) and abrupt vessel closure (0 in 10 versus 2 in 10) was less with excimer compared with thermal laser angioplasty. Macroscopically, there was a greater incidence of mural and occlusive thrombus formation after thermal laser than after pulsed excimer laser angioplasty. Histologic examination confirmed that this thrombogenicity was associated with greater charring and coagulation necrosis of the media. Quantitative indium-111-labeled platelet deposition was significantly increased after thermal laser angioplasty (median 87.2 x 10(6)/cm length) compared with excimer-treated (0.4 x 10(6)/cm length) or control (1.2 x 10(6)cm length) segments (p less than 0.001). Thus, excimer laser angioplasty was found to result in fewer complications and, as a consequence, less thrombosis and platelet accumulation than did thermal laser angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1989

Vocational education and students with learning disabilities.

This inquiry focuses on the status of nearly 500 students with learning disabilities in 17 state-operated regional vocational-technical schools in a northeastern state. The inquiry addressed four primary concerns: patterns of assessment, career choice, school marks, and attendance. The data indicate that a variety of instruments were used in the assessment process and that the overall grade equivalent levels of attainment ranged between fifth- and seventh-grade levels. Children defined as learning disabled participated in a large number of vocational trade specialties and some 50% or more had school marks indicating that they were passing in these areas. Attendance was high. Many children with learning disabilities successfully perform in competitive vocational education programs designed to produce proficiency at the level of journey person.

Adolescent↗
PubMed1986

Role of immunohistochemistry in the diagnosis of undifferentiated tumors involving the skin.

Twenty undifferentiated skin tumors were examined by immunostaining in an attempt to achieve more precise identification. Light microscopy yielded only a differential diagnosis, whereas immunostaining of formalin-fixed, paraffin-embedded tissue sections with a panel of antibodies to intermediate filaments and other cell components led to a definitive diagnosis. Four cytokeratin-positive epithelial tumors were subtyped into squamous cell carcinomas and adenocarcinomas with the use of antibodies to different cytokeratin polypeptides. Fifteen vimentin-positive tumors were subdivided into malignant melanomas with the use of antibody to S-100 protein, lymphomas with the use of antibody to immunoglobulin, and mesenchymal tumors (angiosarcomas, atypical fibroxanthomas, dermatofibrosarcoma protuberans, and meningiomas) with the use of antibody to S-100 protein, factor VIII, and lysozyme. One desmin-positive tumor was diagnosed as a leiomyosarcoma of the skin. A scheme is presented for using immunohistochemistry to facilitate the diagnosis of undifferentiated tumors involving the skin.

Antibodies↗
PubMed1986

Production of a monoclonal antibody specific for seminomas and dysgerminomas.

A monoclonal antibody (M2A, IgG2a) was produced against a cultured human ovarian epithelial adenocarcinoma cell line, HEY. Monoclonal antibody M2A reacted with a glycoprotein of molecular weight 40,000 on the surface of HEY cells. The affinity constant of the monoclonal antibody M2A for HEY cells was 10(9) M-1, and the number of binding sites on HEY cells was 2 X 10(4) per cell. The monoclonal antibody produced positive immunoperoxidase staining of fetal (but not adult) testis and of seminomas and dysgerminomas but did not stain various normal adult tissues or other gonadal or extragonadal tumors. Monoclonal antibody M2A may be useful for confirming a histological diagnosis of seminoma and dysgerminoma.

Antibodies, Monoclonal↗
PubMed1986

Production of a monoclonal antibody against a human osteosarcoma xenograft.

Monoclonal antibodies (MAbs) against a human sarcoma xenograft carried in BALB/c nu/nu mice were produced by immunizing BALB/c mice with tumor cells and fusing their spleens with the SP2/O-Ag 14 mouse myeloma cell line. Hybridoma supernatants were screened using cryostat tissue sections and an immunoperoxidase reaction for ability to stain osteosarcoma xenograft tumor cells but not tonsil lymphocytes. Of 73 supernatants tested, 19 reacted with both osteosarcoma tumor cells and lymphocytes, while three reacted only with osteosarcoma. One of the latter hybridomas was cloned by limiting dilution to establish a line producing an IgG1 MAb (OS-1). By immunoperoxidase, this MAb stained tumor cells in surgical biopsies of primary (6 of 7) and metastatic (1) osteosarcomas and showed limited cross-reactivity with other tumors. It also cross-reacted with some basement membranes, endothelium and muscular media of blood vessels, and smooth muscle, but not with parenchymal cells of various normal tissues. This MAb may prove useful for the immunohistochemical confirmation of a diagnosis of osteosarcoma in surgical pathology.

Animals↗
PubMed1986

Character development in adolescents.

This study explored the effects of a program consisting of communication and counseling skills, assertiveness training and moral dilemmas on the character development, i.e., moral reasoning, ego development, and assertiveness of high school students. It was hypothesized that exposure to the experimental treatment would enhance the character development of high school students. Fifty-four high school seniors enrolled in three psychology classes were assigned randomly to two treatment groups and one control group. Assessment instruments were the Defining Issues Test, to measure moral reasoning, the Washington University Sentence Completion Test, to measure ego development, and the Rathus Assertiveness Schedule, to measure assertiveness. A repeated measures analysis of variance was used to determine significant differences between control and treatment posttest means with respect to the dependent variables--moral reasoning, ego development, and assertiveness. The results demonstrated that the character development of the students in the experimental treatment group was affected significantly over time by the program.

Achievement↗
PubMed1986

Monoclonal antibodies to an epithelial ovarian adenocarcinoma: distinctive reactivity with xenografts of the original tumor and a cultured cell line.

Four monoclonal antibodies (mAb) (8C, 10B, M2A, and M2D) were produced against the human epithelial ovarian adenocarcinoma cell line, HEY. The affinity constants of binding of the mAb to cultured HEY cells were 8 X 10(8) M-1 (M2D) and 10(9) M-1 (8C and 10B). mAb 8C reacted with a major glycoprotein of Mr 90,000 on the surface of HEY cells. The four mAb differed from previously reported mAb to epithelial ovarian adenocarcinomas on the basis of their reactivity with cultured ovarian adenocarcinoma cell lines using a cell-binding radioimmunoassay, and their staining of cryostat sections of various human normal and tumor tissues using an immunoperoxidase reaction. All four mAb reacted with s.c. tumors derived by injecting cultured HEY cells into thymectomized CBA/CJ mice. However, only two of the four mAb (8C and 10B) also reacted with s.c. tumors of the original HEY xenograft from which the cultured cell line was derived. In addition, mAb 8C and 10B reacted by immunoperoxidase staining with 2 and 4 different cases, respectively, of 11 epithelial ovarian adenocarcinomas examined. Cultured HEY cells were adapted to grow i.p. in BALB/c-nu/nu mice and the i.p. tumors retained their reactivity with the monoclonal antibodies. These tumor-bearing mice offer a useful model system for studying the potential of mAb, especially 8C and 10B, for the diagnosis and treatment of patients with peritoneal extension of epithelial ovarian adenocarcinomas.

Adenocarcinoma↗
PubMed1985

Research results of Soviet scientists in some problems of occupational medicine. Review of the years 1981-1984.

The paper reviews the extensive and manifold research of Soviet scientists in occupational medicine. Monographs published in 1981-1984 have been referred to. The data on the maximum allowable concentrations of 23 substances are presented. It should especially be emphasized that, at present, great attention is being paid in the Soviet Union to the mutagenic, gonadotoxic and embryotoxic, as well as other biological, effects of the substances under study. A short review has been presented of the research dealing with the setting of standards for substances coming in contact with the skin of the hands. Occupational hygiene aspects of problems related to the introduction of new substances and technological processes have been considered, and research on the effects of harmful factors (toxic substances, vibration, etc) on health and the early diagnosis of occupational pathology has also been reviewed.

Animals↗