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Biomedical subjects

R B Alexander

Publications and source records attributed to R B Alexander.

At least 37 records · Page 2Linked to original sources
PubMed1995

Parenchymal sparing surgery in patients with hereditary renal cell carcinoma.

The von Hippel-Lindau syndrome is the most well known cause of familial renal cancer. Because affected individuals with renal lesions can have complex, multisystem manifestations of von Hippel-Lindau disease, our renal management strategy has included parenchymal sparing surgery whenever possible. From May 1988 to January 1993, 20 patients with hereditary renal cell carcinoma (19 with von Hippel-Lindau disease and 1 with hereditary papillary renal cancer) underwent renal exploration with the intent of performing parenchymal sparing surgery. A total of 7 nephrectomies and 27 parenchymal sparing procedures was performed. Additional procedures performed included 2 bilateral adrenalectomies for pheochromocytomas, 1 resection of a renal vein thrombus and 1 resection of a pancreatic islet cell tumor. Renal atrophy occurred in 3 of 27 kidneys (11%) treated by parenchymal sparing surgery. In 8 kidneys of 7 patients new solid lesions developed and in 14 kidneys of 12 patients no new solid lesions developed during a mean followup of 26 months (range 6 to 60 months). The use of parenchymal sparing surgery in patients with familial forms of kidney cancer is based on a desire to maintain renal function as long as possible while reducing the risk of metastases. The potential advantages and disadvantages of more ablative surgical treatment requiring subsequent dialysis or transplantation in patients with existing or potential central nervous system, eye, pancreas and/or adrenal tumors must be weighed against the possibility of renal cancer metastases or recurrence when deciding on the use of parenchymal sparing surgery.

Adult↗
PubMed1994

Loss of HLA haplotype and B locus down-regulation in melanoma cell lines.

The expression of HLA class I molecules on tumor cells is vital for CD8+T cell recognition of tumor Ags. Loss of HLA class I Ag expression as a result of defective beta 2-microglobulin genes has been described in melanoma cells. To further evaluate mechanisms of tumor escape, HLA class I Ag expression was compared in 24 metastatic melanoma cell lines and 20 melanocyte strains by FACS analysis with use of allele-specific mAbs. Total loss of HLA class I Ag expression was not noted; instead, two relatively common phenomena were identified: 1) A variable degree of expression of HLA-B Ags by melanoma cell lines and melanocytes; however, HLA-A Ags were consistently expressed in all cell types. Furthermore, HLA-B locus Ag expression was detected in vivo in only one of six frozen section specimens obtained from six patients having metastatic melanoma. 2) Loss of allelic expression was noted in two of 14 HLA-A2 (14%) and one of three HLA-A29 (33%) melanoma cell lines and included a full haplotype, which suggests loss of a genomic fragment. Allele-specific PCR amplification demonstrated deletion of genes in linkage disequilibrium within the MHC class II, III, and I regions. Aberrations of HLA class I expression in tumor lines should be considered when assessing MHC-restricted phenomena in in vitro models.

Alleles↗
PubMed1994

Evaluation of color Doppler intraoperative ultrasound in parenchymal sparing renal surgery.

A renal parenchymal sparing surgical approach may be recommended in select patients with von Hippel-Lindau disease and renal cancer or in those with sporadic renal cancer and limited normal renal function. We performed 27 partial nephrectomies or enucleations in 17 patients with the use of intraoperative ultrasound to examine a subset of all renal lesions identified on preoperative examination. Of 24 lesions deep in the renal parenchyma that were examined, localized or identified with intraoperative ultrasound 18 were characterized as cystic and 6 as solid. The deep cystic lesions were characterized with ultrasound as benign simple cysts. Intraoperative ultrasound was used to locate and mark the line of incision over 2 impalpable solid renal cell carcinomas. Four solid renal cell tumors extended deep into the renal parenchyma where color Doppler intraoperative ultrasound helped to define the plane of dissection adjacent to vital vascular structures. Renal hypothermia was not used in 3 renal operations based on intraoperative ultrasound findings.

Adult↗
PubMed1994

Dilation of lower ureteral strictures with Van Andel catheters.

We present a simple method to dilate ureteral strictures, which was performed in 7 patients with metastatic cancer (1 breast, 1 lymphoma, 2 ovarian and 3 colorectal tumors) who presented with newly discovered obstruction in the distal ureter. The obstruction was due to tumor in the pelvis in 5 patients and to pelvic radiotherapy in 2. A 0.035-inch guide wire was passed beyond the stricture cystoscopically. In each case a double pigtail stent could not be passed beyond the stricture over the guide wire. The strictures were then dilated with progressively larger Van Andel catheters passed over the guide wire through the cystoscope. Following dilation a 7.5F to 8.5F soft double pigtail catheter was easily advanced. All patients had good drainage on followup radiographic studies. The method is presented as an alternative to balloon dilation of lower ureteral strictures when the goal is placement of an adequate diameter indwelling ureteral stent.

Adult↗
PubMed1993

Mechanisms of adoptive immunotherapy: improved methods for in vivo tracking of tumor-infiltrating lymphocytes and lymphokine-activated killer cells.

Adoptive immunotherapy with tumor-infiltrating lymphocytes (TIL) and lymphokine-activated killer cells has been demonstrated to mediate regression of tumors in murine models and in selected patients with advanced cancer. Improved methods for monitoring immune cell traffic, particularly to sites of tumor, are needed to elucidate mechanisms of antitumor activity and optimize treatment protocols. Traditional cell tracking methods such as fluorescent protein labeling and radiolabeling using 111In, 125I, or 51Cr are limited by isotope half-life, leakage or transfer of label from immune cells, and toxicity or altered cell function caused by the labeling process. Labeling with genetic markers allows long-term cell tracking but is laborious to perform and difficult to quantitate. We have used two recently described lipophilic cell tracking compounds (PKH26 and 125I-PKH95) which stably partition into lipid regions of the cell membrane to track immune cells in vivo. Concentrations of each tracking compound which had no adverse effects were determined for a variety of murine TIL and lymphokine-activated killer cell functions. Viability was unimpaired at labeling concentrations of up to 5 microM for PKH95 and 20 microM for PKH26. TIL proliferation was unaltered by labeling with up to 5 microM PKH95, 20 microM PKH26, or a combination of 15 microM PKH26 and 5 microM PKH95. In vivo cytotoxic effector function and in vivo therapeutic efficacy of lymphokine-activated killer cells and TIL were also unimpaired by labeling with 20 microM PKH26 or 1 microM 125I-PKH95. Subsequent studies in an adoptive transfer immunotherapy model used 125I-PKH95 to track the biodistribution of TIL in tumor and in non-tumor-bearing animals and PKH26 fluorescence to monitor microdistribution within tissues and distinguish TIL from host T-cells. The results suggest that differential accumulation, selective retention, or proliferation at the tumor site cannot account for the observed pattern of therapeutic efficacy. We hypothesize that a minimum number of TIL must reach the tumor site in order to achieve a demonstrable therapeutic effect.

Animals↗
PubMed1993

Cytoreductive surgery prior to interleukin-2-based therapy in patients with metastatic renal cell carcinoma.

From May 1985 to December 1990, 93 patients with the clinical diagnosis of metastatic renal cell carcinoma and their primary tumor in place were evaluated for cytoreductive surgery as preparation for systemic therapy with regimens based on interleukin-2. These patients had typical sites of metastatic disease and manifestations of paraneoplastic syndromes. Patients underwent removal of the primary tumor, as well as debulking when this could be performed safely. Thirty-two percent of patients (30/93) had a second surgical resection in addition to their nephrectomy, frequently because of the large size of the primary tumor and its invasion of adjacent structures. Thirteen percent of patients (12/93) experienced postoperative complications. There were no perioperative mortalities. Forty percent of patients (37/93) who underwent nephrectomy could not be treated with immunotherapy, usually because of progression of disease. A preoperative ECOG status greater than or equal to 2 was the only significant risk factor associated with failure to undergo immunotherapy (P = 0.043). The response rate to immunotherapy in the 56 patients receiving interleukin-2 was 27 percent (4 CR, 11 PR).

Adolescent↗
PubMed1993

The management of isolated renal recurrence of renal cell carcinoma following complete response to interleukin-2 based immunotherapy.

The role of interleukin-2 based immunotherapy in advanced renal cell carcinoma is gradually expanding. Among patients who achieve significant responses to these regimens the subsequent development of isolated recurrences raises difficult management questions. We report 2 unusual cases of isolated recurrence in the remaining kidney following a sustained, complete response to interleukin-2 based adoptive immunotherapy. Both patients were treated with interleukin-2 based therapy following surgical resection of the primary renal tumor. The disease course of each patient is described and the literature is reviewed. Both patients were free of disease after relatively short-term followup. Surgery for patients with limited recurrence of renal cell carcinoma following an objective response to immunotherapy may, in select cases, be a reasonable treatment alternative.

Carcinoma, Renal Cell↗
PubMed1993

Regression of metastatic renal cell carcinoma after cytoreductive nephrectomy.

Fewer than 1% of patients with renal cell carcinoma are reported to experience spontaneous regression of metastatic lesions after nephrectomy. We report on 4 of 91 patients (4.4%) with metastatic renal cell carcinoma who had spontaneous regression of all metastatic lesions after cytoreductive nephrectomy. These patients were carefully selected before surgery for the ability to receive high dose interleukin-2. One patient had recurrence at 2 months, 1 had recurrence at 11 months, and 2 had no evidence of disease at 3 and 4.5 years.

Carcinoma, Renal Cell↗
PubMed1993

Use of interleukin-7, interleukin-2, and interferon-gamma to propagate CD4+ T cells in culture with maintained antigen specificity.

In contrast to CD8+ T cells, it has been difficult to establish consistently satisfactory conditions for the bulk culture of antitumor CD4+ T cells in either mice or humans. This difficulty is not limited to tumor antigen, since similar problems are encountered growing CD4+ T cells that recognize alloantigen, tetanus, or candida. Four basic findings are reviewed in this article, stemming from work with identical results in both human and mouse. (a) Although CD4+ T cells initially proliferate after exposure to appropriate antigen-presenting cells (APCs), such proliferation is not sustained; however, expansion of CD4+ T cells can be achieved with the addition of recombinant interleukin-2 (rIL2) or rIL-7. (b) Specific CD4+ responses to antigens are often better sustained with exogenous IL-7 than with exogenous IL-2. (c) Adding rIL-7 or rIL-2 permits sustained CD4+ T-cell proliferation, but subsequent culture restimulation is complicated by high background reactivity to APCs whether APCs are antigen pulsed or not; this problem can be overcome by addition of exogenous interferon-gamma (IFN-gamma) to the CD4+ cultures. (d) In certain instances proliferation is paradoxically impaired by reexposure to specific antigen, possibly reflecting apoptosis; this problem is also overcome by addition of rIFN-gamma to culture. We conclude that combinations of exogenous IL-7, IL-2, and IFN-gamma with APC restimulation can be used to sustain antigen-specific CD4+ T cells in culture. Using these techniques, antitumor CD4+ T cells were propagated from the peripheral blood of two tumor-bearing patients.

Animals↗
PubMed1992

Detection of antigen specific T lymphocytes by determination of intracellular calcium concentration using flow cytometry.

We present a method for the detection of lymphocytes with specific reactivity to antigens on stimulator cells using flow cytometry. Cultured human T lymphocytes were loaded with the intracellular fluorochrome indo-1 and were mixed with stimulator cells. Using flow cytometry we could detect a specific increase in intracellular calcium in the T lymphocytes as well as conjugation between the T cells and the stimulator cells. Examination of antigen-specific CD4+ and CD8+ T cell clones demonstrated that the vast majority of T cells which were conjugated to antigen-bearing stimulator cells manifested a rapid increase in intracellular calcium. In contrast T cells conjugated to stimulator cells which did not bear specific antigen demonstrated no such increase in calcium. A similar finding was observed when examining polyclonal tumor infiltrating lymphocytes obtained from patients with melanoma. Tumor infiltrating lymphocytes with specific antitumor reactivity demonstrated an increase in intracellular calcium when conjugated to autologous tumor but not to allogeneic melanoma. In contrast to the T cell clones, only a small subpopulation of tumor infiltrating lymphocytes manifested this specific signal upon conjugation with autologous tumor. This suggests that tumor infiltrating lymphocyte cultures contain T cells with varying reactivities to tumor or may also imply heterogeneity in the stimulating tumor cell lines. The method allows for the detection of specific T cells on an individual cell basis in real time. The procedure is not lethal to the cell and sorting and subculturing of reactive T cell populations can be readily performed. The method could also be used to sort stimulator cells based on their ability to elicit an increase in intracellular calcium in selected T cells.

CD4 Antigens↗
PubMed1992

Tumor necrosis factor and chemotherapeutic drugs targeted at DNA topoisomerase II for the treatment of genitourinary malignancies.

Recombinant TNF as a single agent for human cancer appears to be of limited value. However, rTNF has synergistic anticancer effects when combined with chemotherapeutic drugs targeted at DNA topoisomerase II. This effect of rTNF has been observed in several in vitro and in vivo tumor models, both in animal and human studies. The mechanism of this interaction appears to involve lesions to the DNA of tumor cells mediated by inhibition of DNA topoisomerase II. The combinations of rTNF plus doxorubicin and rTNF plus etoposide administered systemically are currently under evaluation by clinical trials in patients with advanced cancers. Determination of the efficacy of such combination therapy must await the completion of phase I and II trails. Other routes of administration that might increase the local concentration of rTNF and could be combined with topoisomerase II-targeted drugs include intravesical administration and the use of tumor-infiltrating lymphocytes.

Animals↗
PubMed1992

The natural history of renal lesions in von Hippel-Lindau disease: a serial CT study in 28 patients.

OBJECTIVE: Von Hippel-Lindau disease is a multisystem disorder predisposing to renal cysts and cancer. The growth and development of these renal lesions have not been documented previously. We reviewed serial CT scans to determine the rates and patterns of growth of renal lesions associated with von Hippel-Lindau disease. SUBJECTS AND METHODS: Twenty-eight patients with von Hippel-Lindau disease and renal involvement, including the spectrum from simple cysts to solid masses, had follow-up examinations for at least 1 year (mean, 2.4 years; range, 1-12 years) with serial contrast-enhanced abdominal CT. Renal lesions were measured and characterized. Surgical correlation was available in 12 patients. RESULTS: Two hundred twenty-eight lesions (eight lesions per patient) were detected. On the basis of their CT appearance, 168 lesions (74%) were classified as cysts, 18 (8%) as cysts with solid components, and 42 (18%) as solid masses. Among 12 patients with pathologic confirmation, the solid components of cystic lesions and solid lesions almost always contained renal carcinoma. The majority of cysts remained the same size (71%) or enlarged (20%); 9% became smaller or entirely involuted during the follow-up period. Although it is generally presumed that renal cysts are precursors to cancers, the transformation of a simple cyst to a solid lesion was observed in only two patients. Among the 42 solid lesions, all but two enlarged with time, with a mean doubling time of 10 months. CONCLUSION: The renal lesions associated with von Hippel-Lindau disease exhibited wide differences in growth. The majority of renal cysts grew slowly but some involuted. Transition to solid renal cancer was rare among cysts. Complex cystic and solid lesions contained neoplastic tissue that uniformly enlarged. These data may be used to help predict the progression of renal lesions in von Hippel-Lindau disease.

Adult↗
PubMed1991

Activation of programmed cell death by recombinant human tumor necrosis factor plus topoisomerase II-targeted drugs in L929 tumor cells.

The mechanism of death induced by recombinant human tumor necrosis factor (rHuTNF) in L929 tumor cells of C3H mice was investigated. Treatment with rHuTNF led to fragmentation of DNA into nucleosomal oligomers and to induction of the expression of TRPM-2, a programmed cell death-associated gene. Both events preceded cell death by several hours. Treatment with DNA topoisomerase II inhibitors accelerated both the rHuTNF-mediated DNA fragmentation and the elevation in TRPM-2 messenger RNA levels. These results suggest that rHuTNF exerts its cytotoxicity on L929 cells by activating programmed cell death, leading to apoptosis, and that topoisomerase II inhibitors enhance rHuTNF-mediated cytotoxicity by accelerating this process.

Animals↗
PubMed1991

In vivo proliferation of adoptively transferred tumor-infiltrating lymphocytes in mice.

The adoptive transfer of tumor-infiltrating lymphocytes (TILs) in conjunction with interleukin-2 (IL-2) administration can mediate a reduction in established pulmonary and hepatic metastases of a variety of murine tumors as well as in patients with metastatic melanoma. To characterize further the fate of adoptively transferred TILs, the uptake of the thymidine analog 5-[125I]iodo-2-deoxyuridine ([125I]UdR) into the DNA of dividing cells was used to study the in vivo proliferation and migration patterns of transferred TILs in C57BL/6N mice. Animals received 500 rad of total body irradiation prior to cell transfer to separate incorporation of radiolabel into endogenous lymphoid cells from that into transferred TILs. Mice were subsequently treated with i.v. injections of TILs or no cells followed by i.p. injections of Hanks' balanced salt solution or IL-2. At various time points, mice received [125I]UdR, and 20 h later tissues were removed and counted on a gamma analyzer. A proliferation index (PI) was calculated by dividing the mean cpm of organs of experimentally treated mice by the mean cpm of organs of control mice. Animals receiving TILs alone demonstrated small increases in [125I]UdR in the lungs, liver, and spleen of saline-treated controls (PI = 1.4, 1.6, and 1.7, respectively, on day 4), while animals treated with 50,000 U of IL-2 alone showed greater increases in the lungs, liver, kidneys, and spleen (PI = 3.9, 6.1, 3.3, and 15.8). Mice receiving TILs plus IL-2 demonstrated the highest levels of radiolabel incorporation in the same organs (PI = 10.5, 19.4, 10.2, and 22.4). Over a period of 10 days, TIL plus IL-2 treated animals continued to incorporate significantly greater amounts of [125I]UdR for as long as high-dose IL-2 was administered. Animals treated with TILs demonstrated increased incorporation of radiolabel with increasing doses of IL-2. Injection of irradiated TILs did not result in an increased uptake of [125I]UdR into these tissues, thus confirming that TIL proliferation is responsible for the radiolabel uptake in animals receiving TILs alone or TILs plus IL-2. Additionally, fluorescein-labeled anti-Thy-1.1 antibody identified proliferating TILs derived from congenic B6.PL Thy 1a/CY (Thy-1.1) animals in the lungs, spleen, and liver of recipient C57BL/6N (Thy 1.2) mice. In summary, we have demonstrated that adoptively transferred TILs distribute widely after i.v. injection and can proliferate in various tissues especially under the influence of exogenous IL-2.

Animals↗
PubMed1991

Adoptively transferred tumor-infiltrating lymphocytes can cure established metastatic tumor in mice and persist long-term in vivo as functional memory T lymphocytes.

Tumor infiltrating lymphocytes (TILs) are derived from solid tumors by culturing single cell suspensions of the tumors in low dose interleukin-2 (IL-2) and intermittent tumor stimulation. We have investigated the survival of TILs after intravenous injection into tumor-bearing mice. Using several murine transplantable sarcomas, we examined the in vivo survival of TILs derived from B6.PL Thy 1a/CY mice (Thy-1.1), which were used to treat established experimental metastases in C57BL/6N (Thy-1.2) mice. Donor and host lymphoid cells could be clearly distinguished by fluorescence-activated cell sorting. We found that TILs or TILs + IL-2 could extend the survival of and, in some instances, cure established experimental hepatic and pulmonary metastases. Donor TILs could be recovered from treated animals at all time points tested; in mice cured of pulmonary metastases donor TILs could be detected as late as 119 days after intravenous injection even in the absence of exogenous IL-2. The administration of a relatively low dose of IL-2 in vivo to mice receiving TILs increased the number of donor TILs recovered from the lungs of cured animals 5-10-fold at all time points but did not change the period of time during which donor TILs could be detected in vivo. Additionally, TILs could be recovered from animals cured of established metastases and such cells retained their antitumor activity in vivo. Finally, when mice cured of pulmonary metastases by TILs or TILs + IL-2 were rechallenged with tumor, donor TILs specifically accumulated at the site of tumor rechallenge up to 4 months after adoptive transfer of TILs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Long-term survival of adoptively transferred tumor-infiltrating lymphocytes in mice.

We examined the long term survival of adoptively transferred, cultured tumor-infiltrating lymphocytes (TIL) in sublethally irradiated nontumor-bearing mice. TIL were produced by culturing Thy-1-enriched single cell suspensions from a variety of murine tumors in exogenous IL-2 along with irradiated tumor cells and splenocytes. TIL were adoptively transferred i.v. to mice and such animals demonstrated a statistically significant degree of protection from a subsequent i.v. tumor challenge. This protection lasted up to 6 wk and occurred in the absence of exogenous IL-2 administration in vivo. Using congenic B6.PL Thy-1 alpha/CY mice we demonstrated directly that TIL can survive in vivo for up to 6 wk and that the adoptively transferred TIL were the source of the relative immunity to subsequent tumor challenge. We conclude that TIL contain cells with substantial functional longevity in vivo even in the absence of exogenous IL-2. These studies are relevant to ongoing clinical trials of TIL as a therapy for patients with advanced cancer.

Animals↗
PubMed1990

Effects of tumor necrosis factor, alone or in combination with topoisomerase-II-targeted drugs, on human lung cancer cell lines.

Tumor necrosis factor alpha (TNF) exhibits cytotoxic activity on some solid tumors and has been reported to be synergistic with topoisomerase-II-targeted antineoplastic agents. A wide range of TNF concentrations (from 10 to 10,000 U/ml) was tested in 9 human lung cancer cell lines (5 small-cell and 4 non-small-cell carcinomas) using a semi-automated MTT assay. TNF was not cytotoxic in 8 cell lines, while an adenocarcinoma cell line was marginally sensitive to the cytokine. Using 125I-TNF we were able to show the presence of specific binding sites for TNF in 4/9 human lung cancer cell lines. Scatchard analysis of the marginally sensitive cell line showed high-affinity, saturable binding. With 5 cell lines we also tested whether TNF affected the cytotoxicity of doxorubicin and etoposide, 2 topoisomerase II-targeted drugs which are widely used in the therapy of lung cancer. No significant increase in cytotoxicity was seen when TNF was added to the 2 anti-neoplastic agents. In contrast to certain other human and mouse lines, human lung cancer cell lines appear to be resistant to TNF, despite the presence of the receptor in some of them; moreover, no synergistic effect of TNF and 2 topoisomerase-II-targeted drugs was evident in these human cell lines.

Antineoplastic Combined Chemotherapy Protocols↗