Biomedical subjects
Publications and source records attributed to K Fan.
Adenomatoid tumors are generally restricted to the epididymal region and occasionally the spermatic cord in the male. Herein we report on a case of adenomatoid tumor apparently originating from the ejaculatory duct which to our knowledge has not been reported previously.
A papillary adenomatous polyp of the verumontanum was studied morphologically and immunochemically. This rare polypoid neoplasm displayed rather typical prostatic acinar epithelium, and by immunoperoxidase method differentiation products of prostatic origin could be demonstrated easily. Findings support the concept that this type of lesion is prostatic in origin and probably arising from ectopic prostatic tissue in the prostatic urethra. The clinical symptoms of this lesion usually are hematospermia or hematuria, and this lesion can be effectively treated by transurethral excision.
Immunochemical studies of post-mortem lung tissue from a patient suffering from diffuse pulmonary interstitial fibrosis were conducted. Identifiable deposition of IgG on the alveolar septa was noted by immunoperoxidase and immunofluorescein methods. The antemortem serum obtained from the patient showed high affinity immunologic binding to normal human lung tissue. An antibody-antigen reaction was also detectable by microcomplement fixation procedure with buffer extracts of normal lung tissue, while normal pooled serum showed no significant reaction. These findings, in addition to the gross, light microscopic, and electron microscopic observations, strongly suggest that a humoral antibody mediated reaction is one of the underlying pathogenetic mechanisms eliciting the morphologically and clinically observable manifestations of diffuse interstitial pulmonary fibrosis.
Rat glioma (C6) cells can be induced to morphological and biochemical differentiation by culturing in serum-deprived conditions. The induced differentiated cells were found to preferentially synthesize some distinct cytoplasmic proteins, and the rate of synthesis quantitatively correlated well with the degree of morphological differentiation, whereas the total mRNA synthesis was decreased in the differentiated cells. These findings suggest that reduced total mRNA syntheses and preferential translation of differentiation-related mRNAs are parts of the biochemical events during the differentiation process of neuroglia.
In a retrospective correlative analysis of postmortem findings and antemortem transurethral resection specimens from 81 patients with prostatic carcinoma a simple and reliable prediction index was found. This index was derived from the transurethral resection specimen in regard to the probability of ultimate bone metastasis by tumor and was obtained by dividing the number of prostatic tissue chips involved with tumor by the total number of prostatic tissue chips examined microscopically. We found that when 75 per cent or more of the transurethral resection chips were involved with tumor, regardless of the degree of tumor differentiation, the probability of bone metastasis was more than 9.0 (greater than 90 per cent), whereas the probability was 0.58 for 50 to 75 per cent involvement, 0.38 for 30 to 50 per cent involvement, 0.27 for 20 to 30 per cent involvement, 0.10 for 10 to 20 per cent involvement and 0.06 for less than 10 per cent involvement. Other tumor grading systems, such as the Gleason system, also were compared. A good correlation was obtained by the Gleason grading system in the prediction of bone metastasis but the system is not as simple or as reproducible as the tumor involvement index described herein. Other parameters, such as prostatic acid phosphatase and prostatic specific antigen as determined by the immunoperoxidase method, had no specific or significant value in the prediction of bone metastasis. Our findings reaffirm the relatively old concept that the extensiveness of tumor involvement in the transurethral resection specimen is the single most important factor in the prediction of the clinical behavior of the prostatic carcinoma.
Sarcomatous proliferation of the fibroblast-like stromal cells in renal cell carcinoma was found in three patients who had apparently tumor-associated hypercalcemia but no evidence of bone metastases. The proliferation of stromal cells was not found in 20 patients who also had renal cell carcinoma without hypercalcemia. Immunoreactive parathormone-like substance was detected in two of the three patients with hypercalcemia, despite high levels of serum calcium. The parathormone assay was not conducted on the third hypercalcemic patient, however. Buffer extract from one of the tumors associated with hypercalcemia was able to elicit an increase of the serum calcium in rats, whereas buffer extract from a tumor not associated with hypercalcemia failed to induce hypercalcemia in rats. Findings suggest that the stromal cells of renal cell carcinoma may play a role in the tumor-associated hypercalcemia. The exact nature of the hypercalcemic agent is uncertain. However, in the case studied it appears that a parathormone-like substance was responsible.
The kinetics of S-100 protein synthesis was studied in synchronized cultured glioma (C6) cells. The peak of the synthesis was detected at G1-phase of the cell cycle and apparently was not population density-dependent, since sparsely cultured G1-phase cells synthesized the same proportion of the protein per cell as that of confluent cultures, whereas the total cellular protein synthesis was found steadily increasing throughout the intermitotic phases.
The specific mRNA of myelin basic protein (MBP) was isolated from active myelinating rat brains. The isolated mRNA was able to direct the synthesis of immunochemically detectable MBP in a wheat-germ cell free protein synthesis system. There was, however, no evidence of neuronal translational control of the in vitro MBP synthesis kinetics found within the experimental parameters. The possibility of neuronal control of MBP gene expression is therefore postulated likely to be at the transcriptional level.
Two enzymatic activities associated with myelination were determined in a neuron-glial heterokaryon system. Significant increases of 2',3'-cyclic nucleotide-3'-phosphohydrolase (CNP) and UDP-galactose-ceramide galactosyl transferase (CGalt) activities were noted in heterokarya produced in vitro between 17-day-old rat cerebral neurons and differentiated cultured rat glioma (C6) cells; rat cerebral neurons and calf brain white matter glial cells or differentiated neuroblastoma 2a cells and differentiated C6 cells. Morphological expression of differentiation, such as neurite extension, was also noted in the heterokarya. Findings suggest that the glial expression of myelination related enzymatic activities could be under a neuronal regulatory control and further suggest that the interaction of neurons and glia is necessary for myelinogenesis and maintenance of the myelin sheath components.
The activity of the myelination-related enzyme, 2', 3'-cyclic nucleotide 3'-phosphohydrolase (CNP), was determined in neurologically normal living and postmortem human spinal fluids, for the purpose of examining the differences in enzymatic activity level and stability. A significant elevation of the enzymatic activity was found in the postmortem samples, and the activity in spinal fluid was labile with respect to postmortem time and sample storage conditions. Findings suggest that caution should be exercised in the interpretation of CNP activity in spinal fluid samples.
Horseradish peroxidase or peroxidase conjugated immunoglobulin binds strongly to the collagen in formalin fixed, paraffin embedded human tissue sections. The binding reaction is neither immunological nor organ specific, and may cause confusion in the interpretation of immunoperoxidase reactions in tissue sections containing collagen. This binding reaction can also be useful in identifying collagen fibers in paraffin processed tissue sections.
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A hybrid cell line was established by cell fusion between a cloned Balbic myeloma that is resistant to 8-azaguanine and produces immunoglobulin (gammaG and free kappa chain) and C57BL/6N lymphoma that is resistant to bromo-deoxyuridine and does not produce immunoglobulins. The hybrid cells contained the membrane antigens of both parents; they synthesized free kappa chain; no synthesis of gammaG (gamma(2a)) heavy chain was detected.
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