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Biomedical subjects

G O'Connell

Publications and source records attributed to G O'Connell.

At least 19 recordsLinked to original sources
PubMed1995

Obturator hernia: diagnosis through medical imaging.

A rare case of obturator hernia is presented in a patient with persistent small bowel obstruction. There was a paucity of specific signs and poor general health which caused a delay in diagnosis. Ultimately delayed films from a barium follow through showed barium-filled bowel in the region of the right obturator foramen: A computed tomography scan then confirmed the diagnosis by demonstrating the barium-filled small bowel herniating through the right obturator foramen. Other imaging modalities such as herniography, barium enemas and ultrasound have also been successfully employed to diagnose obturator hernias.

Aged↗
PubMed1995

Rectal endometriosis mimicking solitary rectal ulcer syndrome.

We report a unique case of rectal endometriosis mimicking solitary rectal ulcer syndrome. Several rectal biopsies were performed before the correct diagnosis of rectal endometriosis was made. The lesion had striking histologic features resembling colitis cystica profunda. The presence of two types of glands, i.e., colonic glands with marked depletion of mucin and endometrial glands, were readily apparent on immunohistochemical stain using anticarcinoembryonic antigen showing positive cytoplasmic stain for colonic glands but negative for endometrial glands. However, the distinction between colonic and endometrial glands was very difficult on hematoxylin-and-eosin-stained slides. Endometrial stroma was identified only in the sixth biopsy specimen. Although rare, rectal endometriosis should be considered in the differential diagnosis of solitary rectal ulcer syndrome.

Adult↗
PubMed1994

Role of cardiorespiratory abnormalities, smoking and dive characteristics in the manifestations of neurological decompression illness.

1. Blind analysis of contrast echocardiograms to detect intracardiac shunts, blind analysis of lung function tests for evidence of small airways disease, smoking history and dive characteristics were examined in an attempt to explain neurological symptoms that occurred within 5 min of surfacing from unprovocative dives. 2. Pulmonary abnormalities were significantly more frequent in those divers without intracardiac shunts (50%) than in those with shunts (0%). Smoking was more common in those divers without shunts (55% versus 15%), although this just failed to reach conventional significance levels. Divers without shunts experienced cerebral rather than spinal symptoms after significantly shallower dives with lower tissue nitrogen loads. Depths of dives, tissue nitrogen loads and clinical manifestations in those divers without shunts were similar to the findings in divers who had symptoms after rapid ascents. Despite conservative dive profiles, clinical manifestations in divers with shunts resembled those observed after missed decompression stops. 3. The findings suggest that occult lung disease, and probably smoking, increase the risk of neurological symptoms, even after unprovocative dives, and the similarity of the dive profiles and clinical manifestations to cases with rapid ascents suggest that pulmonary barotrauma and arterial gas embolism are responsible. In divers with intracardiac shunts the different dive profiles and clinical manifestations imply that there is another mechanism, involving different tissue and bubble nitrogen kinetics resulting in venous gas liberation and peripheral amplification in embolized tissues, rather than paradoxical embolism per se.

Adult↗
PubMed1992

Reversal of suppression of lymphokine-activated killer cells by transforming growth factor-beta in ovarian carcinoma ascitic fluid requires interleukin-2 combined with anti-CD3 antibody.

Ascitic fluid from human ovarian carcinoma (AF) has been shown to inhibit IL-2-induced lymphokine-activated killer (LAK) cell generation from peripheral blood mononuclear cells (PBMC) resulting from the presence of biologically active transforming growth factor-beta (TGF-beta). A 50% concentration of AF completely suppressed the LAK response to 100 units IL-2/ml and only partial reversal (less than 50%) could be achieved by increasing the IL-2 concentration to 1000 units/ml. We evaluated the ability of tumor necrosis factor-alpha (TNF-alpha, 1-1000 ng/ml) and anti-CD3 antibody (alpha-CD3, 1-100 ng/ml) to reverse AF-mediated suppression of IL-2-stimulated LAK generation. TNF-alpha alone did not generate significant LAK activity, but in the presence of suboptimal concentrations of IL-2 (10 and 100 units/ml), TNF-alpha significantly boosted the generation of LAK, but was unable to significantly reverse AF-mediated suppression of the IL-2 response (even at 1000 units/ml). In contrast, alpha-CD3 alone generated LAK activity at concentrations as low as 1 ng/ml and markedly enhanced generation of LAK activity when added to suboptimal concentrations of IL-2. alpha-CD3 combined with IL-2 significantly reversed AF suppression at 100 units IL-2/ml and at 1000 units/ml completely reversed suppression by two of three highly suppressive samples of AF. Significant reversal occurred with the third AF sample. It may be possible to overcome TGF-beta-mediated suppression by measures other than by increasing the IL-2 concentration.

Antibodies↗
PubMed1992

A rapid and simple method for the purification of tumor cells from ascitic fluid of ovarian carcinoma.

Rapid isolation of tumor cells growing in clumps from the ascitic fluid of patients with ovarian carcinoma was achieved by harvesting cells from ascitic fluid and subsequently passing them over a 30-microns nylon mesh filter. Single cells and small cell aggregates passed through the mesh, and large cell clumps that had not passed through the filter were isolated by backwashing. Morphologically, the cells in the clumps consisted almost entirely of tumor cells. The clumps were analyzed by immunocytochemistry and only a small proportion of cells (3.1 +/- 0.5% to 8.3 +/- 0.8%) stained with anti-CD45 monoclonal antibody (a panleukocyte marker for cells of hematopoietic origin). Most of the cells in clumps stained positively (90.6 +/- 1.7% to 97.5 +/- 0.5%) with 2G3 (a monoclonal antibody binding to a high-molecular-weight carcinoma-associated antigen). Unfiltered cell populations, however, contained up to 34.4 +/- 2.1% contaminating CD45+ non-tumor cells. This method should be useful for rapidly and easily obtained highly enriched fresh ovarian carcinoma cells from ascitic fluid in a form in which they grow naturally.

Antigens, CD↗
PubMed1992

A randomised, double-blind comparison of granisetron with high-dose metoclopramide, dexamethasone and diphenhydramine for cisplatin-induced emesis. An NCI Canada Clinical Trials Group Phase III Trial.

151 patients (149 evaluable) receiving their first course of chemotherapy containing cisplatin in a dose of at least 50 mg/m2 were randomised to receive either a single dose of intravenous granisetron 80 micrograms/kg or intravenous metoclopramide 2 mg/kg every 2 h for five doses plus a single dose of dexamethasone 10 mg and diphenhydramine. After 24 h, there was no significant difference between groups with respect to nausea or vomiting: in the granisetron group 46% of patients had no emesis, versus 44% of the standard group. Granisetron is an antiemetic agent with efficacy similar to that of high-dose metoclopramide plus dexamethasone.

Antiemetics↗
PubMed1992

Cisplatin-cyclophosphamide versus carboplatin-cyclophosphamide in advanced ovarian cancer: a randomized phase III study of the National Cancer Institute of Canada Clinical Trials Group.

PURPOSE: Given the potential for improved tolerance, a trial was initiated to compare the toxicity and efficacy of a standard regimen of cisplatin-cyclophosphamide (75 mg/m2 and 600 mg/m2, respectively) with an experimental regimen of carboplatin-cyclophosphamide (300 mg/m2 and 600 mg/m2, respectively) in women with postoperative macroscopic residual ovarian cancer. PATIENTS AND METHODS: Between 1985 and 1989, 447 (417 eligible) patients were randomized. Treatment arms were well balanced; most patients had stage III (82%), grade 3 (54%) tumors with bulky residual (greater than 2 cm in 59%), and good performance status (Eastern Cooperative Oncology Group [ECOG] 0 or 1, 77%). Response was assessed after six 4-week cycles. RESULTS: The treatments were equally deliverable, with 76% of patients completing their allocated regimen. The reported reasons for failure to complete treatment differed; toxicity/refusal predominated on the cisplatin arm, and progressive disease predominated on the carboplatin arm (P = .0092). Cisplatin-treated patients were more likely to develop neuropathy and nephropathy, and carboplatin patients experienced myelosuppression, particularly thrombocytopenia. Efficacy was similar, with no significant differences for the cisplatin and carboplatin arms in clinical response rate (57% v 59% in those with measurable disease), pathologic response rate (52% v 54% in those suitable for relaparotomy), time to progression (median, 56 v 58 weeks), or overall survival (median, 100 weeks v 110 weeks). Time to progression and survival were predicted by residual disease size, performance status, and treatment center (with those treated at centers that accrued more patients doing better). CONCLUSION: Neither regimen is optimal in that relapse remains the norm. It may be inappropriate to expect that any single regimen can be an effective therapy for all patients with advanced ovarian cancer. Both cisplatin and carboplatin are likely to have a role in future treatment strategies.

Adult↗
PubMed1992

Phase II study of mitomycin C and 5 fluorouracil in platinum resistant ovarian cancer.

Fourteen patients with relapsing ovarian cancer were treated with Mitomycin C (Mit C) and 5 Fluorouracil (5-FU). All but one patient (one responder) were defined as platinum resistant. The drug dosaging was Mit C 10 mg/m2 IV day 1 every 6 weeks, and 5-FU 500 mg/m2 IV days 1-3, every 3 weeks. Therapy was evaluated clinically and with ultrasound every 6 weeks. Toxicity was graded using the Gynecologic Oncology Group adverse criteria. All patients had been previously treated with platinum containing chemotherapeutic regimens with a mean cumulative total dose of 418 mg/m2 and 1308 mg/m2 of cisplatin and carboplatin, respectively. The mean time interval from completion of the last platinum containing regimen to entry in this study was 3.6 months. There were 4 responders, 1 complete, and 3 partial. The duration of the responses were 13 weeks for the complete responder, and 6, 6, and 12 weeks for the partial responders. No factor was identified which was predictive for response. Grade 3/4 granulocytopenia and thrombocytopenia were experienced by 43% and 21% of all patients respectively. Despite our documented response rate of 29%, the short duration of responses and high incidence of severe and life threatening hematologic toxicity preclude this regimen from being of any significant benefit to relapsing platinum resistant ovarian cancer patients.

Adult↗
PubMed1991

Two phase I studies of carboplatin dose escalation in chemotherapy-naive ovarian cancer patients supported with granulocyte-macrophage colony-stimulating factor.

Recombinant human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) may reduce myelosuppression and, thus, allow dose escalation of certain chemotherapeutic agents. We conducted two sequential phase I trials of escalating doses of carboplatin and a fixed dose and schedule of rHuGM-CSF in ovarian cancer patients who had not previously had chemotherapy, i.e., chemotherapy-naive patients. In the first trial, patients were assigned to regimens of increasing dose levels of carboplatin (starting at 400 mg/m2) and fixed doses and schedules of cyclophosphamide (600 mg/m2) and rHuGM-CSF (10 micrograms/kg given subcutaneously once daily on days 2-11). Chemotherapy was given every 3 weeks (regimen A). In the subsequent trial, the design was the same except that cyclophosphamide was omitted (regimen B). Fifteen patients received regimen A, and seven patients received regimen B. In regimen A, all three patients treated at the first dose level tolerated five cycles at full doses. Hematologic toxicity was dose limiting at the 600-mg/m2 dose level. When 500 mg/m2 carboplatin was given, six of eight patients tolerated three or four cycles at full doses before requiring dose reductions or treatment delays. In regimen B, doses could not be escalated above the first dose level (600 mg/m2) because of severe hematological toxicity. Nonhematological toxicity was tolerable and managed with acetaminophen, antihistamines, and/or nonsteroidal, anti-inflammatory medication. Compliance was excellent. We conclude that (a) rHuGM-CSF can be given safely and reliably to chemotherapy-naive ovarian cancer patients receiving these treatment regimens, (b) early and severe thrombocytopenia was a major problem with or without cyclophosphamide with doses of carboplatin at or above 600 mg/m2, and (c) 500 mg/m2 carboplatin administered every 3 weeks is the highest dose in regimen A that can be given safely in the outpatient setting.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Paraganglioma of the vulva.

A case of vulvar paraganglioma is reported. Following presentation with vulvar pain, a 1-cm nodule was excised from the labium minus of a 58-year-old woman. Histologically, the tumor was composed of nests of round eosinophilic cells with moderately pleomorphic nuclei, beneath an intact squamous epithelium. Ultrastructural studies indicated two cell types within the neoplasm: chief cells with numerous small neurosecretory granules and peripheral slender sustentacular cells. A reticulin stain confirmed the "zellballen" nature of the neoplasm, and the neoplastic cells showed moderate argyrophilia on a Grimelius stain. The immunoperoxidase stains for chromogranin and neuron-specific enolase were strongly positive in the neoplastic chief cells. Immunostaining using anti-S-100 antibody confirmed the finding of sustentacular cells by identifying many slender cellular processes among the chief cells. These light and electron microscopic findings are diagnostic of paraganglioma, an entity not previously reported in the vulva to our knowledge.

Cell Nucleus↗
PubMed1989

The effect of medroxyprogesterone acetate (Provera) on ovarian radiosensitivity.

Medroxyprogesterone acetate (Provera) is a drug that is commonly given to young women with cancer during chemotherapy and radiation to control heavy bleeding associated with anovulation. Because hypothalamic-pituitary-ovarian suppression has been associated with ovarian protection from the effects of chemotherapy and medroxyprogesterone acetate has been identified as a radiosensitizing agent, we explored the effects of medroxyprogesterone acetate on a rat model with known radiation injury characteristics. Sprague-Dawley rats were treated with medroxyprogesterone acetate or vehicle from day 22 to day 37 of life and were either irradiated or sham-irradiated on day 30 of life and then killed on day 44. Radiation with medroxyprogesterone acetate administration produced a greater loss in preantral and healthy control follicles than in control follicles. No suppression of luteinizing hormone or follicle-stimulating hormone had occurred by day 30 but ovarian glutathione content was reduced. These findings indicate that the administration of medroxyprogesterone acetate with radiotherapy may enhance ovarian injury.

Animals↗
PubMed1988

Toxicity of abdominopelvic radiation in advanced ovarian carcinoma patients after cisplatin/cyclophosphamide therapy and second-look laparotomy.

Twenty-seven advanced ovarian carcinoma patients who had received six courses of cyclophosphamide/cisplatin and had either microscopic disease (15 patients) or no pathologically detectable disease (12 patients) after second-look laparotomy were treated with abdominopelvic radiation (2250 cGy to the abdomen and pelvis and a 2250-cGy pelvic boost). Acute myelosuppression or gastrointestinal toxicity prevented completion of treatment in only three patients. However, bowel obstruction occurred in 13 (48%), ten of whom required surgery. Five of these ten had recurrent tumor, but the other five did not. Subsequently two of the latter five did develop a recurrence, one in the lung and one in the liver. A third patient died as an indirect result of radiation damage to the bowel. Median follow-up duration is 17 months from completion of radiation. So far, 13 (48%) have developed progressive disease: four (33%) of the 12 who had a negative second-look laparotomy and nine (60%) of the 15 who had microscopic disease before radiation. While acute toxicity is tolerable, the incidence of serious chronic bowel toxicity is high. Efforts should be made to alter this therapy in order to decrease the frequency of long-term morbidity.

Abdomen↗
PubMed1987

Effects of ionizing radiation and pretreatment with [D-Leu6,des-Gly10] luteinizing hormone-releasing hormone ethylamide on developing rat ovarian follicles.

To assess the effects of a gonadotropin-releasing hormone agonist, [D-Leu6,des-Gly10] luteinizing hormone-releasing hormone ethylamide, in ameliorating the damage caused by ionizing radiation, gonadotropin-releasing hormone agonist was administered to rats from day 22 to 37 of age in doses of 0.1, 0.4, and 1.0 microgram/day or vehicle and the rats were sacrificed on day 44 of age. There were no effects on estradiol, progesterone, luteinizing, or follicle-stimulating hormone, nor an effect on ovarian follicle numbers or development. In separate experiments, rats treated with gonadotropin-releasing hormone agonist in doses of 0.04, 0.1, 0.4, or 1.0 microgram/day were either irradiated or sham irradiated on day 30 and all groups sacrificed on day 44 of age. Irradiation produced a reduction in ovarian weight and an increase in ovarian follicular atresia. Pretreatment with the agonist prevented the reduction in ovarian weight and numbers of primordial and preantral follicles but not healthy or atretic antral follicles. Such putative radioprotection should be tested on actual reproductive performance.

Animals↗
PubMed1987

Ovarian toxicity of cyclophosphamide alone and in combination with ovarian irradiation in the rat.

The effects of radiation and chemotherapy on gonadal function are relevant to the morbidity induced by such treatments. Cyclophosphamide given i.p. to rats on Day 30 of age delayed vaginal opening, prevented vaginal cyclicity, and caused a reduction in serum estradiol and progesterone. Antral follicular atresia increased in a dose-dependent fashion in response to cyclophosphamide (0 mg/kg, 53.5%; 1 mg/kg, 67.3%; 50 mg/kg, 65.7%; 100 mg/kg, 73.9%; 150 mg/kg, 92.2%). Despite such alterations in ovarian function, serum gonadotrophins did not rise. The concurrent administration of 0, 20, 30, 40, 50, and 60 Gy of radiation to the exteriorized ovaries in rats receiving 50 mg/kg cyclophosphamide induced widespread loss of primordial, preantral, and healthy antral follicles associated with reduction in serum progesterone and estradiol. Such irradiation induced dose-related increases in serum follicle-stimulating hormone and luteinizing hormone. Parenteral cyclophosphamide and local irradiation appear to induce ovarian toxicity by different mechanisms.

Animals↗