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Biomedical subjects

W C Waltzer

Publications and source records attributed to W C Waltzer.

At least 19 recordsLinked to original sources
PubMed2002

Increased expression of activation markers in renal cell carcinoma infiltrating lymphocytes.

PURPOSE: As manifested by the presence of immune competent cells, failure to control the progression of renal cell carcinoma by a local immune response attests to impaired local cell mediated immunity. To test this hypothesis we compared the expression of T-cell activation markers in renal cell carcinoma infiltrating lymphocytes with the expression of activation markers of peripheral blood lymphocytes in the same patients. MATERIALS AND METHODS: Tumor infiltrating lymphocytes were harvested from a patient with renal cell carcinoma undergoing radical nephrectomy. Peripheral blood was obtained before surgery. Tumor infiltrating and peripheral blood lymphocytes were incubated with monoclonal antibodies defining specific differentiation and activation markers on the cell surface, and analyzed by flow cytometry. Cell subsets are expressed as a fraction of the total number of mononuclear cells. RESULTS: The T-cell subset level was significantly higher in peripheral blood than in renal cell carcinoma tissue of the same patient. However, the level of activated T-cell subset expressing HLA-DR was significantly higher in renal cell carcinoma tissue than in peripheral blood. The levels of interleukin-2 receptor and transferrin receptors expressing T-cell subsets were also significantly higher in carcinoma tissue than in peripheral blood. Natural killer cells were found in significantly higher proportions in renal cell carcinoma than in peripheral blood. CONCLUSIONS: These results point to significant activation of T, B and natural killer tumor infiltrating lymphocytes. The inability of tumor infiltrating lymphocytes to mount an effective immune response to renal cell carcinoma may be secondary to the presence of suppressive factors in the tumor that prevent tumor infiltrating lymphocytes from transforming into effector cells. These factors may be particularly valuable for the further study of renal cell carcinoma-host interactivity.

Aged↗
PubMed2002

Down regulation of CD45 expression on CD4 T cells during acute renal allograft rejection: evidence of a decline in T suppressor/inducer activity.

Acute rejection is associated with the activation of helper and cytotoxic cells. A shifting balance between the suppressor/inducer CD45+ CD4+ and T helper/inducer (CD4+CD45-) cells may be responsible for the transition from quiescence to overt rejection. We examined the kinetics of CD45 expression on CD4+ T cells in renal allograft recipients from pretransplant values to acute rejection and after reversal of rejection, searching for a shift in balance between helper/inducer and suppressor/inducer cell subsets. Using two color flow cytometry, the peripheral blood levels of CD4+, CD4+CD45- [T helper/inducer (Thi)], CD4+CD45+ [T suppressor/inducer (Tsi)], CD3+, and CD8+ T cells subsets and their interrelationships, were determined in 49 patients prior to transplantation, and in 10 of them, during acute rejection and after its reversal. Results were analyzed and compared to data obtained from 10 healthy blood donors. Acute rejection was associated with a significant decline in CD45+ CD4+ expression compared to quiescent phase (22% +/- 3.7% vs. 26.5% +/- 3.2%, p = 0.05) and controls (29.5% +/- 6.2%, p = 0.01). No difference was observed compared to pretransplant levels (19.9% +/- 3.2%, p = ns). CD45-/CD45+ (Thi/Tsi) ratio was lowest during quiescence (0.75) compared to rejection (0.97, p = 0.05), in controls (0.98, p = 0.05) and pretransplant values (1.4, p = 0.01). Acute rejection was characterized by higher Thi/CD8+ and lower Tsi/CD8+ ratio (103 and 88 respectively, p = 0.045), compared to clinical quiescence (104 and 116 respectively, p = 0.039). These data suggest that acute rejection is associated with down regulation of CD4+CD45+ suppressor/inducer subset. This shift may account for the transition from quiescence to overt rejection, concurring with reports on CD4+CD45 regulatory function.

Acute Disease↗
PubMed2000

Identification of RS as a flagellar and head sperm protein.

RS is 20-kDa microtubule-associated protein found in several human tissues. Sequence analysis showed that the polypeptide is highly related to a rat protein whose level has been previously reported to be correlated with sperm fertility. The present study examines the intracellular distribution of RS in spermatozoa from both humans and rats employing a specific antibody to the polypeptide and immunofluorescence microscopy. We demonstrate that in humans, RS is mainly a flagellum protein, but in rats, it is also abundant in the sperm head. In the sperm tail, RS was found to be co-localized with beta-tubulin, a major component of the axoneme, suggesting that RS is also associated with the flagellum axoneme. Contrary to a previous report, incubation of isolated spermatozoa from both humans and rats in the presence of ornidazole, a reported male contraceptive drug in rats, did not result in modulation in the level of RS, suggesting that the drug does not act directly on sperm RS. Mol. Reprod. Dev. 55:189-196, 2000.

Amino Acid Sequence↗
PubMed2000

Acute histologic changes in human renal tumors after cryoablation.

BACKGROUND AND PURPOSE: Cryoablation is a treatment option for some patients with small, exophytic lesions of the kidney. Several investigators have evaluated the effects of cryoablation in normal renal tissue of animals. The purpose of this study was to investigate the tissue changes following cryoablation in human renal tumors. PATIENTS AND METHODS: We prospectively evaluated patients with solid renal lesions (1.5-1.8 cm) confirmed by CT, MRI, or both. Metastatic work-up for all patients was negative. All lesions were biopsied prior to freezing. Two patients with bilateral renal tumors underwent argon-gas-based CRYOcare System (Endocare, Irvine, CA) treatment via an open approach. A 3-mm cryoprobe was placed directly into each tumor. A single 15-minute freeze preceded an active thaw (helium gas) for each lesion. Iceball dimensions were monitored by intraoperative ultrasonography. After successful cryoablation, partial nephrectomy was performed to remove the lesion, and the renal tissue underwent histologic evaluation. RESULTS: The cryoprobes achieved a temperature of -135 degrees C. No bleeding was noted, and there were no intraoperative or postoperative complications with a mean follow-up of 3 months. Histologically, freezing of renal tissue resulted in coagulative necrosis and hemorrhage beyond the boundaries of the lesions. There was a zone of demarcation between the viable and nonviable tissue. CONCLUSIONS: In our series, cryoablation was effective in destroying tumor tissue in vivo in human kidneys. Freezing was sufficient to achieve a negative surgical margin. Cryoablation of renal tumor is an alternative to the currently available nephron-sparing surgical techniques. The long-term effect of tumor tissue destruction by cryosurgery requires further investigation.

Aged↗
PubMed1998

Androgen induction of urokinase gene expression in LNCaP cells is dependent on their interaction with the extracellular matrix.

Urokinase-type plasminogen activator (uPA) plays a central role in tissue remodeling and cell invasion. In the present study, we examined the expression of uPA in the prostate cancer cell lines LNCaP, DU-145 and PC-3. In contrast to DU-145 and PC-3, the androgen-responsive cell line LNCaP does not express uPA. However, seeding LNCaP cells on fibronectin-coated plates stimulated a low level of uPA expression which was further induced upon exposure of the cells to dihydrotestosterone (DHT). Concomitant with the expression of uPA, an androgen-regulated expression of uPA receptor (uPAR) was induced. These results suggest that the interaction of LNCaP cells with the extracellular matrix plays a dominant role in the androgen control of uPA and uPAR gene expression.

Dihydrotestosterone↗
PubMed1995

T-tube drainage of infected penile corporeal chambers.

Insertion of semirigid penile prosthesis is a surgical option to correct male erectile dysfunction. Postoperative infection of penile prosthesis necessitates removal and drainage of corporeal chambers. We describe a technique to drain infected corporeal cavities with T-tubes.

Drainage↗
PubMed1994

Current status of immunological monitoring in the renal allograft recipient.

With the appropriate combined use of different immune monitoring techniques, it is possible to derive sensitive diagnostic parameters for the transplant surgeon. However, the core biopsy or cytological examination of the graft continues to represent the gold standard for evaluating the specificity and sensitivity of these methods. With the development of newer monoclonal antibodies and a better understanding of the impact of immune processes on the behavior of various activation linked, T cell associated surface antigens, one may be able to secure further valuable information, with enhanced diagnostic and prognostic accuracy.

ABO Blood-Group System↗
PubMed1994

Endourologic management of complications in renal allografts.

Because of the altered anatomy, the presence of immunosuppression, the possibility of graft rejection, and the serious implications of a problem involving a solitary kidney, the transplanted kidney presents unique challenges in the diagnosis and treatment of urologic complications. Historically, the mortality rate in these patients has been as high as 68%, and as many as 15% of the allografts have been lost. Today, endourologic procedures are used for prompt diagnosis, temporization, and even definitive management of many urologic complications, and many patients and allografts are being saved. The authors review present techniques and suggest others that may be available in the future.

Humans↗