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Biomedical subjects

G Peterson

Publications and source records attributed to G Peterson.

At least 37 records · Page 2Linked to original sources
PubMed2000

Experience with prophylactic oral ciprofloxacin in gynecological cancer patients developing severe chemotherapy-induced neutropenia.

The development of significant neutropenia is a relatively frequent complication of cytotoxic chemotherapy of malignant disease. In an effort to develop a cost-effective management strategy to prevent serious infectious events associated with severe chemotherapy-induced neutropenia, patients treated in the Gynecological Oncology Program of the Cleveland Clinic Taussig Cancer Center have been administered ciprofloxacin, a potent broad-spectrum antibiotic, 500 mg orally twice a day, beginning at the time of documentation of grade 4 neutropenia. The antibiotic is continued until granulocyte recovery. A total of 44 patients (57 treatment courses) have been treated in this manner. There have been no complications of therapy and no episodes of subsequent infections due to ciprofloxacin-resistant organisms. Two patients required hospital admission following the development of significant fever, despite the use of ciprofloxacin. While these results are encouraging and suggest that the use of prophylactic ciprofloxacin is a highly cost-effective management approach in this setting, randomized controlled trials are necessary to define the ultimate benefit of this clinical strategy.

Adult↗
PubMed2000

Paclitaxel-associated hypersensitivity reactions: experience of the gynecologic oncology program of the Cleveland Clinic Cancer Center.

PURPOSE: : This study expands the existing limited data as to whether patients developing clinically significant paclitaxel-induced hypersensitivity reactions can continue to be treated with this important antineoplastic agent and how such retreatment might be undertaken. PATIENTS AND METHODS: More than 450 patients received paclitaxel, either as a single agent or in a combination regimen, for a female pelvic malignancy in the Gynecologic Oncology Program of the Cleveland Clinic Cancer Center from January 1995 through December 1998. RESULTS: Of the more than 450 patients, 44 (approximately 9%) developed at least one episode of a clinically relevant hypersensitivity reaction to the cytotoxic drug. All 43 individuals (plus an additional four patients referred to our center after having previously experienced a severe paclitaxel-associated hypersensitivity reaction at another institution) who were retreated with paclitaxel were ultimately able to receive the agent. Five patients required treatment with a standardized desensitization regimen, developed by our group, to successfully receive paclitaxel. DISCUSSION: On the basis of this large single-institution study of paclitaxel-associated hypersensitivity reactions, we conclude that with appropriate precautions essentially all individuals experiencing these reactions can be safely treated with this agent.

Adult↗
PubMed2000

Phase I trial of paclitaxel plus megestrol acetate in patients with paclitaxel-refractory ovarian cancer.

Increased expression of P-glycoprotein has been proposed as one important mechanism for inherent or acquired drug resistance of malignant disease to cytotoxic chemotherapy. In experimental systems, hormonal agents, including megestrol acetate (MA), have been shown to be capable of reversing P-glycoprotein-mediated multidrug resistance to natural products, including paclitaxel. Because paclitaxel is one of the most active cytotoxic agents in ovarian cancer (OC), we sought to determine whether retreating patients with well-defined paclitaxel-resistant OC with a combination of paclitaxel and MA would result in clinically relevant reversal of that resistant state. In this Phase I trial, 44 patients with OC or primary peritoneal carcinoma received paclitaxel (135-175 mg/m2 over 3 h) plus an oral loading dose (800-9600 mg over 24 h) and subsequent maintenance dose (800-3200 mg/day x 3 days) of micronized MA. Both the loading dose and maintenance therapy were delivered in four equal daily doses. Therapy was repeated every 21 days, assuming recovery from the toxicity of the prior course. There were no intrapatient dose escalations. The major toxicity of the regimen was peripheral neuropathy (32% of patients; 11% grade 2-3), although four individuals developed major venous blood clots and one suffered a stroke. Four patients exhibited biological evidence of antineoplastic effects, although only one patient experienced improvement in clinically relevant symptoms. Although pharmacokinetic studies were not performed as a component of this study, prior evaluation of MA pharmacokinetics and in vitro data examining the concentrations of the agent required to reverse P-glycoprotein-mediated paclitaxel resistance suggest that the majority of our patient population achieved levels of MA theoretically capable of producing this desired effect. We conclude that the level of activity and toxicity pattern observed in this trial, associated with the combination of paclitaxel and MA, does not provide strong support for further exploration of the regimen as a treatment strategy to overcome paclitaxel resistance in OC.

Adult↗
PubMed1999

Use of low-dose oral prednisone to prevent paclitaxel-induced arthralgias and myalgias.

OBJECTIVES: The aim of this study was to examine the clinical utility of low-dose oral prednisone in preventing severe paclitaxel-associated arthralgias and myalgias. METHODS: Patients treated with paclitaxel in the gynecologic oncology program of the Cleveland Clinic Foundation who developed arthralgias/myalgias which were uncontrolled through the use of nonsteroidal anti-inflammatory medications received low-dose oral prednisone (10 mg B.I.D. starting 24 h after the completion of chemotherapy and continuing for a total of 5 days) with their next paclitaxel course. RESULTS: Of 46 patients meeting the criteria for treatment with the oral prednisone regimen (i.e., subjective feeling of unacceptable discomfort despite the use of nonsteroidal anti-inflammatory agents), 39 (85%) experienced substantial relief of symptoms. All but one of the responding patients requested continuation of the oral prednisone regimen with subsequent paclitaxel treatment cycles. There were no significant toxicities noted in any patient receiving prednisone. CONCLUSION: This low-dose oral prednisone regimen results in substantial improvement in the majority of patients experiencing significant paclitaxel-associated arthralgias/myalgias.

Administration, Oral↗
PubMed1999

Persistent chemosensitivity to platinum and/or paclitaxel in metastatic endometrial cancer.

It has long been recognized that individuals with ovarian cancer who initially respond to a platinum-containing chemotherapeutic regimen may exhibt a second response to platinum (cisplatin or carboplatin) at the time of recurrence. In this report, we describe three individuals with metastatic endometrial cancer who demonstrated secondary responses to platinum/paclitaxel-based regimens. Endometrial cancer should be added to the list of malignancies for which platinum and/or paclitaxel are considered as second-line treatment options in patients previously responding to the agents.

Adenocarcinoma↗
PubMed1999

An effective and more convenient drug regimen for prophylaxis against paclitaxel-associated hypersensitivity reactions.

"Standard" prophylaxis for paclitaxel-associated hypersensitivity reactions has included the systemic administration of H1 and H2 histamine antagonists, along with oral dexamethasone taken both the night prior to, and the morning of, each paclitaxel treatment. To improve patient convenience and compliance with steroid delivery, the Gynecologic Cancer Program of the Cleveland Clinic Foundation has treated patients with an all-intravenous prophylaxis regimen (diphenhydramine 50 mg, famotidine 20 mg, dexamethasone 20 mg) given 30 min prior to paclitaxel (without any earlier oral steroid dosing). To date, we have treated more than 200 patients who received all courses of paclitaxel with this simplified prophylactic regimen, of whom approximately 9% developed hypersensitivity reactions (major or minor). This incidence is comparable to our previously reported experience with hypersensitivity reactions in a similar number of patients receiving the standard prophylaxis (including oral dexamethasone) with their initial course of paclitaxel, and subsequent cycles employing this all-intravenous program. We conclude that this "modified" regimen for paclitaxel-associated hypersensitivity reactions (with all drugs administered approximately 30 min prior to the delivery of paclitaxel) is as effective as, and more convenient than, the standard regimen, and avoids delaying chemotherapy as a result of a patient failing to remember to take one or both oral steroid doses.

Anti-Inflammatory Agents↗
PubMed1999

Dendritic cell-T-cell interactions support coreceptor-independent human immunodeficiency virus type 1 transmission in the human genital tract.

Worldwide, human immunodeficiency virus (HIV) is transmitted predominantly by heterosexual contact. Here, we investigate for the first time, by examining mononuclear cells obtained from cervicovaginal tissue, the mechanisms whereby HIV type 1 (HIV-1) directly targets cells from the human genital tract. In contrast to earlier findings in mucosal models such as human skin, we demonstrate that the majority of T cells and macrophages but none or few dendritic cells (DC) express the HIV-1 coreceptor CCR5 in normal human cervicovaginal mucosa, whereas all three cell types express the coreceptor CXCR4. To understand the role of coreceptor expression on infectivity, mucosal mononuclear cells were infected with various HIV-1 isolates, using either CCR5 or CXCR4. Unstimulated T cells become rapidly, albeit nonproductively, infected with R5- and X4-tropic variants. However, DC and T cells form stable conjugates which permit productive infection by viruses of both coreceptor specificities. These results indicate that HIV-1 can exploit T-cell-DC synergism in the human genital tract to overcome potential coreceptor restrictions on DC and postentry blocks of viral replication in unactivated T cells. Thus, mononuclear cells infiltrating the genital mucosa are permissive for transmission of both R5- and X4-tropic HIV-1 variants, and selection of virus variants does not occur by differential expression of HIV-1 coreceptors on genital mononuclear cells.

Cervix Uteri↗
PubMed1999

Clinical features of hypersensitivity reactions to carboplatin.

PURPOSE: To characterize the clinical features of carboplatin-associated hypersensitivity reactions. PATIENTS: Patients with gynecologic malignancies treated at the Cleveland Clinic Foundation from June 1995 through July 1998 who experienced a carboplatin-associated hypersensitivity reaction were the subjects of this evaluation. RESULTS: Of the 205 patients treated with carboplatin during this time period, 24 (12%) developed a carboplatin hypersensitivity reaction. The median number of platinum (carboplatin plus cisplatin) courses for the first episode was eight (range, six to 21). Only three patients (13%) developed this toxicity during their initial chemotherapy regimen, with the remainder experiencing a reaction during their second (n = 15) or third (n = 6) carboplatin treatment program for recurrent disease. Thirteen patients (54%) developed at least moderately severe symptoms (diffuse erythroderma, tachycardia, chest tightness, wheezing, facial swelling, dyspnea, hypertension, or hypotension). In approximately one half of patients, the reaction developed after more than 50% of the carboplatin had been infused. Only one of three patients was successfully treated with the agent upon rechallenge. CONCLUSION: Carboplatin hypersensitivity reactions develop in patients who have been extensively pretreated with the agent. The clinical features are highly variable, but they are sufficiently different from those noted after the administration of paclitaxel that it should not be difficult to distinguish between reactions to the two agents. As carboplatin is increasingly used as initial and second-line chemotherapy of ovarian cancer and other malignancies, it can be anticipated that hypersensitivity reactions to the drug will become a more common and difficult clinical management issue.

Adult↗
PubMed1998

Role of biotin-containing membranes and nuclear distribution in differentiating human endometrial cells.

Human Ishikawa endometrial cells form domes when confluent monolayers are stimulated with fresh fetal bovine serum. Extensive structural and biochemical changes have been detected during the approximately 30 h differentiation period. The earliest detectable change involves the formation of multinucleated structures and the appearance of "granules" that stain for biotin within those structures. Nuclei become associated with each other and are ultimately enclosed within a biotin-containing membrane. Aggregated membrane-sheathed nuclei and the cells containing them begin to elevate from the dish as biotin staining becomes apparent in apical membranes. The elevated structures are called predomes and consist of one or more very large cells containing the sheathed nuclei. Apical membranes of these unusual cells extend far out into the medium in structures that resemble endometrial pinopods. A lumen under the elevated cells fills with transcytosed fluid. As differentiation proceeds, highly concentrated chromatin material that was flattened against apical and lateral membranes of the predome cells begins to disperse. Small mononuclear cells evolve from larger predome cells. Apical membranes of predome and dome cells continue to stain for biotin. Gel electrophoresis of SDS-solubilized biotin-containing membranes, followed by Western blot analysis using avidin-linked peroxidase, resulted in three stained bands with molecular weights similar to those of the mitochondrial carboxylases: propionyl carboxylase, methylmalonyl carboxylase, and pyruvate carboxylase.

Biotin↗
PubMed1998

Phase 2 trial of single agent ifosfamide/mesna in patients with platinum/paclitaxel refractory ovarian cancer who have not previously been treated with an alkylating agent.

Ifosfamide has been shown to possess modest activity in patients with platinum/cyclophosphamide refractory ovarian cancer. Current standard initial chemotherapy for ovarian cancer does not include an alkylating agent (paclitaxel substituting for cyclophosphamide). To evaluate the activity of ifosfamide in patients with refractory ovarian cancer who had not previously received an alkylating agent, 21 patients with platinum/paclitaxel refractory disease were treated with the drug as a single agent (1.8 g/m2/day x 3 days, with treatment repeated every 28 days). Treatment was reasonably well tolerated in most patients, although 1 individual was removed from study secondary to neurotoxicity. One patient exhibited an objective response of measurable disease, while a second individual had a major decrease in CA-125 levels (no measurable disease present) following therapy. An additional patient experienced disappearance of severe pelvic pain following treatment but failed to meet the criteria for a partial response. We conclude that ifosfamide has modest activity in platinum/paclitaxel refractory ovarian cancer. However, the level of effectiveness does not appear to be increased in individuals who are alkylating-agent naive, compared to previously reported experience in patients with prior exposure to this class of cytotoxic drugs (10-15% response rate).

Adult↗
PubMed1998

Experience with platinum-paclitaxel chemotherapy in the initial management of papillary serous carcinoma of the peritoneum.

OBJECTIVE: The objective of this study was to assess the activity and toxicity of combination platinum-paclitaxel chemotherapy in the initial management of patients with papillary serous carcinoma of the peritoneum (PSCP). METHODS: Patients initially treated at The Cleveland Clinic Foundation (CCF) for PSCP with platinum-paclitaxel combination chemotherapy regimens were identified and clinical information was abstracted by chart review. Toxicity data, progression-free survival, and overall survival were determined. RESULTS: Thirty-eight patients (36 Stage IIIC and 2 Stage IV) were identified. All chemotherapy was administered as outpatient infusions. All patients received paclitaxel (135 or 175 mg/m2) and 12 received cisplatin and 26 carboplatin. Two hundred thirty-two cycles were administered, with only three (1.3%) episodes of grade 3 toxicity and no grade 4 toxicity. Ninety-two percent of patients experienced at least a 50% reduction in their CA-125 levels and 55% experienced a greater than 90% reduction. Median progression-free survival (Kaplan-Meier) was 15 months and median overall survival was 40 months. Survival for optimally debulked patients (median not yet reached with median follow-up of 24 months) was significantly better than for suboptimally debulked patients (median 32.8 months) (P = 0.012). CONCLUSION: Platinum-paclitaxel chemotherapy regimens have substantial utility in the initial management of PSCP patients. The toxicity profile is modest. Carboplatin or cisplatin in conjunction with paclitaxel is the current first-line recommended chemotherapy for PSCP.

Adult↗
PubMed1998

Low-dose oral granisetron (1 mg) plus intravenous dexamethasone: efficacy in gynecologic cancer patients receiving carboplatin-based chemotherapy.

OBJECTIVE: The objective of this study was to determine the efficacy of a low-dose oral granisetron plus intravenous dexamethasone prophylactic antiemetic regimen in patients receiving carboplatin-based chemotherapy. PATIENTS AND METHODS: Patients with gynecologic malignancies being treated with either single-agent carboplatin or a carboplatin-paclitaxel regimen received a single 1-mg oral dose of granisetron 30 min prior to chemotherapy plus intravenous dexamethasone (20 mg) as prophylaxis for emesis. Patients either had not previously been treated with chemotherapy or had not received any cytotoxic drugs for >/=4 months prior to study entry. Effectiveness was evaluated based on the degree of control of nausea and vomiting during the 24 h following treatment. RESULTS: Of the 32 patients participating in this phase 2 trial, only 2 (6%) experienced any degree of nausea or vomiting within the first 24 h of chemotherapy administration. Both of these individuals had carcinomatosis and were experiencing emesis prior to chemotherapy. One patient developed mild delayed nausea >24 h after treatment. No major or minor toxic effects of the antiemetic regimen observed. CONCLUSION: A 1-mg dose of oral granisetron plus intravenous dexamethasone (20 mg) is a safe, effective, and relatively inexpensive prophylactic antiemetic regimen for patients receiving single-agent carboplatin or combination carboplatin-paclitaxel chemotherapy.

Adult↗
PubMed1998

Evidence that a "treatment-free interval of less than 6 months" does not equate with clinically defined platinum resistance in ovarian cancer or primary peritoneal carcinoma.

The standard definition of platinum-resistant ovarian cancer or primary peritoneal carcinoma commonly includes patients whose disease initially responded to a platinum-based combination regimen, but recurred less than 6 months after the completion of primary therapy. Recent experience with several patients with these malignancies treated in the Gynecologic Cancer Program of the Cleveland Clinic Foundation, whose disease recurred within this period but who subsequently responded to platinum therapy, calls into question the validity and clinical relevance of this commonly employed definition, both for the conduct of phase 2 trials of new agents in ovarian cancer and primary peritoneal carcinoma, and for the standard management of women in this clinical setting.

Aged↗
PubMed1998

Association between culturable human immunodeficiency virus type 1 (HIV-1) in semen and HIV-1 RNA levels in semen and blood: evidence for compartmentalization of HIV-1 between semen and blood.

Both qualitative and quantitative virologic measurements were compared between blood and genital compartments for 128 men infected with human immunodeficiency virus type 1 (HIV-1) to address several controversial issues concerning HIV-1 shedding in semen and to obtain further information about the distribution of virus between these two compartments. Evidence for viral compartmentalization was suggested by earlier studies that noted the poor correlation between blood and seminal virus load, phenotype, and genotype. Further support for this viral compartmentalization was based on the following observations between semen and blood: lack of association between culturability of virus in semen and viral RNA level in blood, discordant distribution of viral phenotypes, discordant viral RNA levels, a weak correlation between viral RNA level in semen and CD4 cell count in blood, differences in the biologic variability of viral RNA levels, and differences in the virus load response to antiretroviral therapy.

Adult↗