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Biomedical subjects

F Lee

Publications and source records attributed to F Lee.

At least 217 records · Page 12Linked to original sources
PubMed1989

Transrectal ultrasonography in the evaluation of rectal and extrarectal disease.

Transrectal ultrasonography is a technique that is gaining popularity in the assessment of rectal and extrarectal disease. From April 1987 to May 1989, 53 transrectal sonograms were done to evaluate rectal disease. Twenty-seven of 30 adenocarcinomas have been correctly staged. The operative procedure and the decision to use preoperative radiotherapy have been influenced by the results of these studies. Recurrent tumors and less common anorectal disease have also been evaluated with this technique. When feasible to perform, ultrasonographically guided biopsies yield specimens that can provide added information on which to base a therapeutic approach.

Adenocarcinoma↗
PubMed1989

Prostatic cyst: report of 2 cases.

Prostatic cysts are rarely reported in the literature, however, their existence is not so rare as one may think. Two cases of prostatic cyst were found among 400 patients being examined by transrectal ultrasonography. The clinical manifestations of a cyst ranged from totally asymptomatic to urinary retention depending on cyst size and location. The diagnosis was attained by rectal examination, panendoscopy, cystourethrography and transrectal ultrasonography. The first case received an open prostatectomy and the second case was managed by puncture of a cyst.

Adult↗
PubMed1989

Transrectal biopsy of the prostate guided by transrectal ultrasound.

The use of transrectal ultrasound in combination with the Biopty System provides a high accurate, efficient, and safe method for the diagnosis and staging of prostate cancer. Because both diagnosis and staging may be attained easily using one comprehensive procedure, we recommend ultrasound guidance be used for all initial biopsies of the prostate. When transrectal ultrasound-guided biopsy of a palpable hypoechoic abnormality is negative for cancer, digitally guided biopsy must subsequently be performed. In some cases, palpable abnormality may not be seen on ultrasound. We advocate the use of our biopsy procedure as an integral extension of transrectal ultrasound of the prostate. In an outpatient setting, biopsy may be performed immediately after finding a suspect lesion on ultrasound. In this way, patients are spared time and anxiety, and society is spared medical costs.

Biopsy, Needle↗
PubMed1989

Prevention of postlaminectomy membrane: experimental and clinical observations.

An animal experimental study was performed to investigate the prevention of scar formation after laminectomy by applying Gelfoam, a free-fat graft and steroids as interposing material between the dura and muscles. There were 52 adult guinea pigs equally divided into four groups. They were sacrificed 2 weeks, 4 weeks and 12 weeks respectively after surgery. In the control group, there was young fibrous tissue at 2 weeks, which became more mature at 4 weeks. At 12 weeks, it became mature with varying thickness and canal extension. In the steroid group, it showed the same picture as the control group. In the Gelfoam group, there was foreign body reaction with disintegration of Gelfoam at 2 to 4 weeks. At 12 weeks, however in the free-fat graft group, viable fat graft could be seen at the laminectomy site with little fibrous tissue overlying the dura. In the clinical part, from September 1981 to September 1984, one of the authors (PQC) performed 100 laminectomies on patients with various causes of low back pain. A piece of free subcutaneous fat was laid on dura before wound closure. At follow-up, there was no adverse effect pertaining to its application. Most patients had considerable pain relief after the surgery. From the above observation, we believe that a free-fat graft is a simple and effective way to prevent postlaminectomy membrane. Steroids and Gelfoam do not have such advantage.

Adipose Tissue↗
PubMed1989

Constitutive production of lymphokines by cloned murine B-cell lymphomas--CH12 B lymphoma produces interleukin-4.

B cells can be activated by T-independent antigens or mitogens such as lipopolysaccharide (LPS) which will induce proliferation and differentiation of the B cells into Ig-secreting cells, without the intervention of T cells. The precise mechanism of T-independent proliferation and differentiation of B cells is still unclear. It is possible however that antigen-stimulated B cells may produce some factors which play a role in T-independent B-cell responses. In addition, since it has now been established that B cells can function as antigen-presenting cells, it is possible that they too secrete a molecule which is involved in the activation of T cells, analogous to IL-1 production by antigen-presenting macrophages. A number of human B-cell lines, as well as human normal B cells activated appropriately, have been shown to produce various cytokines, and similar studies are now being undertaken in the mouse. In the present study, six cloned murine B-cell lymphomas of different origin were analyzed for the presence of mRNA encoding a number of lymphokines by hybridization of specific cDNA probes to poly-A RNA, followed by the sensitive S1 nuclease digestion technique. The lymphokines included (IL-) 1, 2, 3, 4, 5, and neuroleukin. Whereas none of the lines expressed detectable levels of IL-2, IL-3, or IL-5 mRNA, all the lines expressed high levels of neuroleukin mRNA. Three of the lymphomas (CH12, CH31, and NBL) expressed low levels of IL-1 mRNA. The most striking finding was that one lymphoma, CH12, constitutively expressed IL-4 mRNA. This mRNA appeared to be functional, as IL-4 activity measured by the HT-2 T cell proliferation assay could be detected in supernatants collected from CH12 cells. The growth-inducing activity of CH12 supernatant on HT-2 cells could be completely blocked by an anti-IL-4 monoclonal (11B11), but not by an anti-IL-2 antibody (S4B6), consistent with our observations that CH12 cells produce IL-4 but not IL-2. CH12 cells were also found to express high affinity receptors for IL-4. Proliferation of CH12 cells was not affected by the addition of exogenous IL-4. Addition of anti-IL-4 antibodies to CH12 cells in culture caused a slight but reproducible increase in their proliferation at low cell numbers, which is probably not highly significant. These findings open the possibilities that murine B lymphocytes are capable of lymphokine production or alternatively that aberrant lymphokine production underlies B-lymphocyte transformation.

Animals↗
PubMed1988

Identification of IL-6 as a T cell-derived factor that enhances the proliferative response of thymocytes to IL-4 and phorbol myristate acetate.

Thymocytes undergo a vigorous proliferative response when stimulated with a combination of IL-4 and PMA. We have found that conA-induced supernatants from a number of Th cell clones could enhance the level of IL-4/PMA-induced proliferation of unseparated thymocytes 0.5- to 2-fold and of peanut agglutinin-positive thymocytes 2- to 10-fold. These supernatants did not contain IL-2 or IFN-gamma, and the enhancing activity could be chromatographically separated from IL-3, -4, -5, and granulocyte/macrophage CSF. The possibility that the thymocyte enhancement factor contained in these supernatants was IL-6 was suggested when murine rIL-6 was found to have similar activity. Further evidence for the identity of these two factors was obtained when an IL-6 assay, based on plasmacytoma growth, was used to test column fractions showing thymocyte enhancement. All fractions active in the thymocyte enhancement assay also had activity in the plasmacytoma growth assay. These observations suggest that the thymocyte-stimulating activity present in the T cell supernatants was due to IL-6.

Adjuvants, Immunologic↗
PubMed1988

The AKR thymoma BW5147 is able to produce lymphokines when stimulated with calcium ionophore and phorbol ester.

We produced the T cell hybridoma D9C1.12.17 by fusing an IL-4-producing T cell clone D9.1Hi with the AKR thymoma BW5147. The resulting hybridoma produced IL-2 as well as IL-4 even though none of the parental cells produced IL-2 after stimulation with Con A. The production of IL-2 was confirmed at the mRNA level by using an S1 nuclease protection assay. Further analysis indicated that Con A-induced IL-2 production was a common phenomenon among T cell hybridomas derived from this fusion. Although BW5147 does not produce detectable lymphokines after Con A stimulation, this line was able to produce IL-2, granulocyte-macrophage colony stimulating factor, and small amounts of IL-3 and IFN-gamma when stimulated with calcium ionophore and phorbol ester. The latter agents are thought to mimic the activating signal(s) delivered through the Ag:MHC TCR. This observation indicates that BW5147 has the ability to produce lymphokines but may lack component(s) which couple the extracellular signal to lymphokine production, and suggests that in T cell hybridomas, part of the spectrum of lymphokines produced may be contributed by BW5147.

Animals↗
PubMed1988

Transrectal ultrasound in the diagnosis and staging of local disease after I125 seed implantation for prostate cancer.

A study was undertaken to assess the ability of transrectal ultrasound (TR/US), digital rectal examination (DRE), and Prostate Specific Antigen (PSA), to diagnose persistent prostate cancer following an I125 seed implant (SI). Twenty-six patients formed the study group. The median follow-up time was 38 months, and the range was 20 to 60 months. Eighty-eight percent (23/26) had suspicious lesions on TR/US, followed by ultrasound-guided biopsies. Biopsies were performed only on those patients having suspicious lesions on TR/US. Histologically proven adenocarcinoma was found in 81% (21/26) of the patients. Statistical evaluation was done using tissue obtained at biopsy as the "gold standard." The sensitivities for the DRE and PSA were 33% and 76%, respectively. The specificities for DRE and PSA were 50% and 0%, respectively. The positive predictive values for cancer were 91% by TR/US, 100% by DRE, and 89% by PSA. The negative predictive values were 13% for DRE and 0% for PSA. Overall detection rates (N = 26) were 81% for TR/US, 27% for DRE, and 62% for PSA. We conclude that ultrasound criteria for the presence of cancer are the same for both the post-irradiated prostate and the untreated prostate, and that TR/US is the most sensitive test for the diagnosis of persistent local cancer following I125 seed implantation.

Aged↗
PubMed1988

Multiple biological activities are expressed by a mouse interleukin 6 cDNA clone isolated from bone marrow stromal cells.

Interleukin 6 (IL-6) refers to the gene product that was characterized initially as beta 2 interferon/26-kDa protein produced by human fibroblasts and later was found to be identical to B-cell stimulatory factor 2, hybridoma/plasmacytoma growth factor, and probably hepatocyte-stimulating factor. Using the human IL-6 cDNA as a probe, we have isolated functional cDNA clones from mouse bone marrow stromal cell cDNA libraries. Sequence analysis of the mouse cDNA insert revealed significant homology between the human and mouse IL-6 cDNA clones both at the level of nucleotide (65%) and deduced amino acid (41%) sequences. The NH2-terminal sequence of the deduced protein is identical to a partial NH2-terminal sequence determined previously for a hybridoma/plasmacytoma growth factor and a plasmacytoma growth factor isolated from mouse T cells and macrophages, respectively. The mRNA for mouse IL-6 is expressed in IL-1-treated stromal cells and in activated T-cell and macrophage cell lines. Supernatants from COS-7 monkey cells transfected with the cDNA clone have plasmacytoma growth factor, hepatocyte-stimulating factor, and colony-stimulating factor activities, as well as the ability to support the growth of a factor-dependent myeloid cell line, thus revealing an additional biological activity for IL-6.

Amino Acid Sequence↗
PubMed1988

Percutaneous ablation of canine prostate using transrectal ultrasound guidance. Absolute ethanol and Nd:YAG laser.

Percutaneous absolute ethanol injections and Nd:YAG laser ablations were performed bilaterally in canine prostates (N = 13) using transrectal ultrasound guidance. Seventy-one percent (10/14) of the ethanol injections produced an intraglandular focus of hemorrhagic necrosis. Associated morbidity of ethanol injections included necrosis of the external prostatic sphincter and mucosa of the urethra and bladder. Ninety-two percent (11/12) of the laser ablations produced intraglandular foci of thermal tissue damage, which had distinct margins of transition between necrotic and viable cells. The areas of ablation were well visualized by ultrasound and had minimal associated morbidity. The results of this study demonstrate the technical feasibility and low potential morbidity of transrectal ultrasound guided Nd:YAG laser ablations in the canine prostate.

Animals↗
PubMed1988

Keratinocyte derived T-cell growth factor (KTGF) is identical to granulocyte macrophage colony stimulating factor (GM-CSF).

Keratinocyte derived T-cell growth factor was initially described as a product of cultured neonatal keratinocytes and keratinocyte cell lines that induced the proliferation of HT-2 cells, a murine T-cell line that responds to IL-2 and IL-4 by incorporating 3H-Thymidine. Subsequently, KTGF has been purified to high specific activity and found to be distinct from IL-2 and IL-4 by a variety of biochemical, immunologic, and immunochemical criteria. Because it was found that certain HT-2 cell lines also proliferated in response to GM-CSF, the present study asked whether KTGF was related to GM-CSF. In this study, we demonstrate that antibodies to recombinant murine GM-CSF completely neutralize the capacity of KTGF to induce HT-2 proliferation without interfering with IL-2 or IL-4 induced HT-2 proliferation. Furthermore, poly-A+ RNA homologous to murine GM-CSF cDNA as judged by S1 nuclease analysis was detected in Pam 212 cells, and protein serologically homologous to GM-CSF was found in Pam 212 conditioned medium. We conclude that KTGF is identical to GM-CSF. The T-cell activating properties of GM-CSF require further exploration.

Colony-Stimulating Factors↗
PubMed1988

Comparison of Western blot (immunoblot) and glycoprotein G-specific immunodot enzyme assay for detecting antibodies to herpes simplex virus types 1 and 2 in human sera.

Sera from patients with culture-proven genital herpes infections were tested for herpes simplex virus type 1 (HSV-1)- and HSV-2-specific antibodies by both a Western blot (immunoblot) technique (WBA) and immunodot enzyme assays (IEAs) specific for HSV-1 or HSV-2 glycoprotein G (gG). Of 137 serum samples tested, none was mistyped by either WBA or IEA. Both tests were most sensitive with sera obtained at least 21 days after onset of primary HSV-2 infections or sera drawn during recurrent HSV-2 genital episodes: 75 of 76 (99%) such serum samples were positive for HSV-2 antibody by WBA and 73 of 76 (96%) were positive by IEA. Of sera drawn earlier than 21 days from onset of primary genital HSV-2, antibodies to HSV-2 were detected in 25% by WBA and 8% by IEA. In patients with culture-proven primary genital HSV-1 infection, WBA detected antibodies to HSV-1 proteins in 16 of 17 (94%) serum samples drawn at least 21 days after onset of primary genital HSV-1 infection, compared with 9 of 17 (53%) serum samples tested for gG-1 by IEA. Both WBA and IEA are accurate and sensitive tests for HSV-2 antibody in patients convalescing from a first episode or having symptomatic or asymptomatic recurrent genital herpes. WBA was more sensitive than IEA in detecting seroconversion following primary HSV-1 genital herpes, although both assays may miss persons undergoing early seroconversion to HSV-2.

Antibodies, Viral↗
PubMed1988

Differential stimulation of sea urchin early and late H2B histone gene expression by a gastrula nuclear extract after injection into Xenopus laevis oocytes.

Sea urchin early histone genes are active in preblastula embryos; late histone genes are maximally expressed during subsequent stages of embryogenesis. We used the Xenopus laevis oocyte to assay for trans-acting factors involved in this differential regulation. Sea urchin nuclear proteins were prepared by extracting gastrula-stage chromatin successively with 0.45, 1, and 2 M NaCl. We injected three fractions into oocytes along with plasmids bearing sea urchin early and late H2b histone genes. While neither the 0 to 0.45 M nor the 1 to 2 M salt fraction affected H2b gene expression, the 0.45 to 1 M salt fraction stimulated early and late H2b mRNA levels significantly. Late H2b gene expression was stimulated preferentially when the early and late genes were coinjected into the same oocytes. This extract did not stimulate the accumulation of transcripts of injected herpesvirus thymidine kinase genes or of the sea urchin Spec 1 gene, suggesting that the stimulatory activity is not a general transcription factor. We localized the DNA sequence required for the stimulatory effect to a region of the late H2b gene located between -43 and +62 relative to the transcription start site. A component of the 0.45 to 1 M salt wash fraction specifically bound to the 105-base-pair late gene DNA sequence and to the corresponding early gene fragment. The abundance of this binding activity decreased on a per genome basis during early development of the sea urchin.

Animals↗