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Biomedical subjects

C Collins

Publications and source records attributed to C Collins.

At least 163 records · Page 9Linked to original sources

Florid papillomatosis of the nipple: a clinico-pathological surgical problem.

Adenoma or florid papillomatosis of the nipple is a rare, benign condition which resembles the clinical appearances of Paget's disease of the nipple and the histological appearances of papillary carcinoma of the breast. We describe a case which illustrates the pitfalls in diagnosis and proposes a safe management procedure for breast and nipple lesions.

Breast Neoplasms↗

Characterization and organization of DNA sequences adjacent to the human telomere associated repeat (TTAGGG)n.

We present a strategy for the cloning of DNA sequences adjacent to the tandemly repeated DNA sequence (TTAGGG)n. Sequence analysis of 14 independently isolated clones revealed the presence of non-repetitive sequences immediately adjacent to or flanked by blocks of the simple repeat (TTAGGG)n. In addition, we provide sequence information on two previously undescribed tandemly repeated sequences, including a 9 bp repeat and a modification of the (TTAGGG)n repeat. Using different mapping approaches six sub-clones, free of the TTAGGG repeat, were assigned to a single human chromosome. Moreover, in situ hybridization mapped one of these subclones, G2 - 1H, definitively to the telomeric band on chromosome 4q. However, Bal 31 insensitivity suggests a location in a more subterminal region. All the (TTAGGG)n-adjacent unique sequences tested are highly conserved among primates but are not present in other mammalian species. Identification and mapping of TTAGGG-adjacent sequences will provide a refined insight into the genomic organization of the (TTAGGG)n repeat. The isolation of chromosome specific TTAGGG-adjacent sequences from subtelomeric regions of all human chromosomes will serve as important end points for the genetic maps and will be useful for the molecular characterization of chromosomal rearrangements involving telomeres.

Base Sequence↗

Responses of elderly spouse caregivers.

In this paper three categories of variables were identified to predict spouses' reactions to caregiving roles: patient characteristics, the caregiving environment, and characteristics of the caregiver. Measures of these variables were administered to 159 spouse caregivers. Four domains of caregivers' responses were identified: negative emotional reactions, feelings of responsibility for the patient, feelings of abandonment by family, and impact of caregiving on daily schedules. These domains were influenced most by patient negative behaviors, physical health, and age, and by caregiver age, employment, and emotional status. Amount of assistance, affective support, and hours of care also were predictive of spouse responses.

Activities of Daily Living↗

Bone marrow involvement in epithelial ovarian cancer by immunocytochemical assessment.

The incidence of bone marrow involvement with epithelial ovarian cancer has been evaluated as a continuation of interest in autologous bone marrow support. Fifty-eight aspirates were obtained on 50 patients and 53 aspirates were evaluable. Immunocytochemistry with the monoclonal cytokeratin antibodies 35 beta H11 and 34 beta E12 was performed. There have been no complications. Twelve (23%) were positive and three were indeterminate. Stage, grade, and CA-125 level were not different in the two groups. No patient had a positive biopsy at the time of initial diagnosis. The majority of patients were drawn from second-look procedures; of these, 7 of 19 were positive. Five of twelve with positive aspirates died from disease versus 5 of 38 with negative aspirates, and patients with a positive aspirate had a longer overall survival time until death from disease. We can confirm the presence of epithelial ovarian cancer in 23% of patients at varying times in the course of their disease. We cannot identify risk factors for the development of this finding nor the viability of those cells when found in this data set.

Bone Marrow Diseases↗

Combined 5-fluorouracil and irradiation for transitional cell carcinoma of the urinary bladder.

Thirty-four patients have completed treatment on a bladder-preservation protocol using primary irradiation combined with infusion 5-fluorouracil (5-FU). 4,000 cGy pelvic irradiation was delivered in 5 weeks, with 1,000 mg/m2/day of 5-FU administered as a 96 hr infusion on days 1-4 of week 1 and 4. After a 3-week rest period, patients eligible for cystectomy underwent cystoscopy and biopsy. Those with residual tumor underwent cystectomy, and those without tumor received an additional cycle of chemotherapy and irradiation. Patients ineligible for cystectomy for reasons medical, surgical, or refusal received a third cycle without the 4-week delay or re-evaluation. With a median follow-up of 18 months (range 2-45 months), and with 25/34 patients having T3 (16) or T4 (9) tumors, 17 patients are NED, 4 have died of intercurrent deaths, 7 have died with bladder cancer, and 6 are alive with tumor (2 confined to the bladder). The actuarial cancer-specific survival for the entire group of patients is 64% (+/- 12%) at 45 months, with a freedom from relapse of invasive cancer of 54% (+/- 10%). Twenty-four of the 34 patients retained intact bladders, with 20/24 reporting entirely normal voiding. Of 18 potential surgical candidates, 13/16 (81%) who underwent pathologic re-staging after 2 cycles of chemoradiotherapy had no histologic evidence of residual cancer. Of these 13 patients, 8 remain NED and 2/13 have locally recurrent non-invasive tumors only. Treatment was well-tolerated, with 28/34 patients having received 100% of the planned 5-FU and 34/34 having received greater than 80%. This regimen appears more successful than radiotherapy alone in achieving complete tumor responses, and is an attractive alternative for patients who are unable to receive more aggressive chemotherapy/radiation combinations.

Adult↗

Analysis of T lymphocytes cloned from the synovial fluid and blood of a patient with Lyme arthritis.

Cloned T lymphocytes reactive with Borrelia burgdorferi proteins were isolated from a patient with chronic Lyme arthritis. All of the T cell clones which proliferated in response to Borrelia proteins were CD3 + CD4 + CD8 - TCR alpha beta + and HLA-DR restricted. One T cell clone (GN30) exhibited HLA-DR-restricted cytotoxic activity against antigen-presenting cells pulsed with Borrelia antigen. In response to Borrelia antigen, the T cell clones produced TNF-alpha, INF-gamma, and GM-CSF. There are at least three distinct spirochetal proteins recognized by the four T cell clones analyzed. Purified Borrelia proteins triggered the HLA-DR-restricted proliferative and cytotoxic responses, as well as lymphokine secretion by two of the T cell clones. The spirochetal protein which triggered the HLA-DR-restricted proliferative and cytotoxic activities of the T cell clone (GN30) isolated from synovial fluid is the 41 kd flagellar protein.

Antigens, Bacterial↗

Homologous recombination in hybridoma cells: dependence on time and fragment length.

Mutant hybridoma-myeloma cell lines that are defective in immunoglobulin production are expected to be useful for defining the molecular requirements of immunoglobulin gene expression. The analysis of such mutants would be greatly facilitated if they could be mapped by marker rescue, i.e., by identifying the segments of wild-type DNA that can restore the normal phenotype by homologous recombination with the mutant chromosomal immunoglobulin gene. To assess the feasibility of this type of mapping, we have measured the efficiency with which fragments of wild-type DNA recombine with a mutant hybridoma immunoglobulin gene and restore normal immunoglobulin production. We found that most if not all recombinants were detectable 2 days after DNA transfer and that the frequency of gene restoration increased with increasing length of the transferred mu gene fragments, between 1.2 and 9.5 kilobases. These results indicate that the available technology should be adequate to map mutations in the mu gene to within approximately 1 kilobase.

Animals↗

Linkages between immunization and breastfeeding promotion programs.

Breastfeeding promotion and immunization are important interventions of child survival programs, especially in developing countries. Linkages between breastfeeding promotion programs and the Expanded Programme on Immunization (EPI) in developing countries mean that health care workers can make use of every contact with the mother and child to reinforce the educational messages of both programs. Breastfeeding does not interfere with vaccinations administered in accordance with the routine schedule recommended by the EPI Global Advisory Group for use in developing countries. Breastfeeding benefits the EPI and the EPI also benefits breastfeeding. The maximum reduction of morbidity and mortality will be achieved when all child survival interventions are applied in a balanced, complementary manner as envisaged in the concept of primary health care.

Breast Feeding↗

Low-intensity grids improve sensitivity of amsler grid testing in diabetic patients without background retinopathy.

We tested 22 eyes of 12 diabetic patients without retinopathy for visual loss using four types of Amsler grids. The Amsler grids, in order of decreasing intensity, were the standard white, bright red, fine red, and threshold (through cross-polarizing filters). The threshold grid detected the largest number of scotomas--16 versus 12, seven, and seven, respectively--and the largest total area of all scotomas--1594 degrees 2 of arc versus 1237, 994, and 927, respectively. In addition, metamorphopsia lessened as grid intensity decreased. These results demonstrate that the sensitivity of Amsler grid testing for visual loss in diabetics without retinopathy improves by decreasing the intensity of the grid used.

Adult↗

Mutations of the mouse mu H chain which prevent polymer assembly.

Earlier work has shown that truncated mu-chains lacking the carboxy-terminal C mu 4-tail region are secreted as monomeric rather than polymeric IgM and that the monomer phenotype is not due to the lack of a disulfide bond at Cys-575 in the tail. In order to define with greater precision, the molecular requirements for IgM polymer assembly, we have isolated several mutant hybridomas which produce monomeric IgM. For three such mutants, we synthesized cDNA clones of their mu mRNA and identified a mutation in the mu-chain which was responsible for the failure to assemble polymers. Mutant 205 has a 2-bp deletion which results in a termination codon after amino acid 556, effectively deleting the last 20 amino acids of the mu-chain. In conjunction with earlier reports, this result shows that the tail plays some role in assembly other than providing Cys-575, the penultimate amino acid, for disulfide bond formation. Both mutant 21 and mutant 201 have an A to G transition, which results in Tyr-455 in the fourth constant domain being replaced by a cysteine. We conclude that the integrity of both the C mu 4 domain and the 19 amino acid tail are required for the mu H chain to be assembled into polymeric IgM.

Amino Acid Sequence↗

Resistance of paraquat and adriamycin in human breast tumor cells: role of free radical formation.

Generation and enhanced detoxification of toxic free radicals by glutathione peroxidase and glutathione transferase in human breast tumor cells have been suggested to play an important role in toxicity and in resistance to adriamycin. We have examined the biochemical basis of paraquat-induced free radical formation and the mechanism of resistance to this agent in human breast tumor cell lines. We have also compared the similarities and differences between adriamycin and paraquat in their mode of free radical formation and tumor cell kill. Anaerobic incubation of paraquat resulted in the formation of the paraquat cation radical in both the sensitive and resistant cells which increased with time and was enhanced by NADPH addition. Our studies show that while both adriamycin and paraquat form hydroxyl radicals (.OH) in these cell lines, adriamycin was 2-3 fold better at reducing oxygen. The formation of .OH was inhibited by exogenously added superoxide dismutase and catalase, indicating the involvement of both superoxide anion radical and hydrogen peroxide. In the adriamycin-resistant cell line, less .OH was formed by each of these drugs. While the .OH appeared to be formed outside by both adriamycin and paraquat in the drug-sensitive cells, experiments using chromium oxalate as a spin-broadening agent suggest that the drug-induced .OH formation in the resistant cells is an intracellular event. The adriamycin-resistant cell line was also cross-resistant to paraquat, suggesting a common mechanism of toxicity for both drugs. However, adriamycin was significantly more toxic (4000-times) to the sensitive cells suggesting that either other mechanisms or site-specific free radical formation are also important in biochemical mechanisms of adriamycin toxicity.

Breast Neoplasms↗

High-dose cyclophosphamide in the treatment of refractory lymphomas and solid tumor malignancies.

Twenty-two patients with refractory solid tumors or lymphoma were treated with a single course of high-dose cyclophosphamide (120 mg/kg intravenously [IV] over 2 days) whereas three patients received two courses each. Marrow infusion was not used. In the 22 courses evaluable for tumor response there were 14 responses (64%) of which 11 were partial responses (PR) (50%) and three complete responses (CR) (14%). In the 12 evaluable courses given in patients with lymphoid malignancies a partial response was obtained in seven (58%) and complete response in two (17%) for an overall response rate of 75%. The median duration of response was short: 2 months (range, 1-12 months). Twenty-seven courses were evaluable for toxicity. All patients had nadir polymorphonuclear leukocytes counts less than 500/mm3 with median time to recovery to a level greater than 500/mm3 of 9 days (range, 6-21 days). The median nadir platelet count was 30,000/mm3. One patient had prolonged thrombocytopenia of 225 days. There were two toxic deaths related to leukopenia, one secondary to Pneumocystis carinii pneumonia, and the second from probable sepsis and cholecystitis. Nineteen patients had previously received cyclophosphamide in standard doses. In the patients with lymphoid malignancies who had previously received cyclophosphamide, 22% achieved a CR with an overall response rate of 78%. High-dose cyclophosphamide may be given with acceptable toxicity in heavily pretreated patients. Given the short response duration in patients with progressive disease, the optimal results of such high-dose cyclophosphamide may be achieved when it is employed earlier in the natural history of the disease in conjunction with other alkylators, or as consolidation therapy.

Acute Kidney Injury↗

Influence of schedule of interleukin 2 administration on therapy with interleukin 2 and lymphokine activated killer cells.

The purpose of this study was to compare the toxicity, immunomodulatory changes, and antitumor efficacy of interleukin 2 (IL-2) and lymphokine activated killer (LAK) cell therapy with two durations of IL-2 infusion. Patients with progressive melanoma, non-Hodgkin's lymphoma, renal carcinoma, or colon carcinoma received IL-2 at 3 X 10(6) units/m2/day on days 1-5 and 13-17, either by bolus injection every 8 h (q8h) or by continuous i.v. (CIV) administration. Peripheral blood mononuclear cells were harvested by leukapheresis on days 8, 9, and 10, were incubated in vitro for 5 days for generation of LAK cells, and were infused on days 13, 14, and 15. The first 11 patients were treated with IL-2 q8h, and the subsequent 13 patients were treated by CIV infusion. Toxicity consisted primarily of fever, chills, emesis, diarrhea, weight gain, and edema but did not require intensive care unit support and did not differ significantly between treatment groups. IL-2-induced lymphocytosis on day 8 was higher with CIV than with q8h administration with a mean lymphocyte count/microliter of 5610 +/- 700 (SE) versus 3300 +/- 500. Immunomodulatory changes observed on days 8 and 20 were also greater with CIV IL-2 and included an increase in peripheral blood mononuclear cell IL-2 receptor expression as well as a marked rise in the number of Leu-11+ and Leu-19+ peripheral blood mononuclear cells. The total leukapheresis yield per patient and total number of LAK cells infused per patient were higher with CIV than q8h administration, with 49.8 +/- 4.9 X 10(9) versus 39.4 +/- 5.4 X 10(9) and 42.6 +/- 5.0 X 10(9) versus 34.0 +/- 5.4 X 10(9), respectively. The cells infused displayed phenotypic evidence of activation and exhibited marked lytic reactivity to Daudi, Raji, and HT-144 targets. One complete and one minimal response were observed in 2 of 8 patients with metastatic renal cell carcinoma who received CIV IL-2 and LAK cells. The results show that IL-2 is more biologically active by CIV than q8h administration, as demonstrated by greater rebound lymphocytosis, LAK cell yield, and in vivo immunostimulation.

Adult↗

Cyclophosphamide, vincristine, cisplatin, VP-16 and radiation therapy in extensive small-cell lung cancer. A Southwest Oncology Group Study.

Patients with extensive small-cell lung cancer were given induction chemotherapy consisting of cyclophosphamide, vincristine, cisplatin, and etoposide (COPE) every 3 weeks for four cycles. Responding patients then received chest and elective whole-brain irradiation. Patients presenting with brain metastases received therapeutic brain irradiation during the first cycle of chemotherapy. No maintenance therapy was given, but two late intensification cycles of COPE were given at weeks 24 and 48. Among the 34 evaluable patients, the response rate to induction chemotherapy was 59%, with 10% achieving a complete response (CR) and 49%, a partial response (PR). Of the 18 patients who completed chest irradiation, 3 achieved a CR, producing an overall CR rate of 18%. Five patients completed the projected course of treatment. The median duration of response for all patients was 8 months (range, 2-30+ months) and the median survival was 9 months (range, 1-30+ months). Complete responders had a median response duration of 9 months and a median survival of 11 months. This regimen produced significant myelosuppression, with 5 neutropenic deaths (13%) occurring in the 38 patients evaluable for toxicity; an additional 16% required hospitalization for fever while neutropenic. Only six patients (13%) had nadir platelet counts of less than 50,000/mm3 with no episodes of thrombocytopenic hemorrhage. Nausea, vomiting, and neurotoxicity were mild to moderate in all patients. One patient with no evidence of disease died of radiation pneumonitis at 6 months. While producing significant toxicity, this regimen did not result in a CR rate or survival advantage that would suggest its superiority over standard regimens for small-cell lung cancer.

Adult↗

DNA damage, cytotoxicity and free radical formation by mitomycin C in human cells.

Mitomycin C (MMC), a quinone-containing antitumor drug, has been shown to alkylate DNA and to form DNA cross-links. The ability of MMC to alkylate O6-guanine and to form interstrand cross-links (ISC) has been studied using Mer+ and Mer- human embryonic cells. Mer+ (IMR-90) cells have been reported to contain an O6-alkylguanine transferase enzyme and are, in general, more resistant to alkylating agents than the Mer- (VA-13) cell line, which is deficient in the repair of O6-lesions in DNA. Studies reported here show that MMC is more cytotoxic to VA-13 cells compared to IMR-90 cells. The alkaline elution technique was used to quantify MMC-induced ISC, and double strand breaks (DSB) in these cells. The drug-dependent formation of DSB was significantly lower in IMR-90 cells than in VA-13 cells. In contrast, no significant difference in cross-linking could be detected at the end of 2-h drug treatment. Although a small increase in cross-link frequency was observed in the VA-13 cell line relative to the IMR-90 cell line 6 h post drug treatment, it is not clear whether monoalkylated adducts at the O6-position are formed, and contribute to cross-link formation for differential cytotoxicity in VA-13 cells. Electron spin resonance and spin-trapping technique were used to detect the formation of hydroxyl radical from MMC-treated cells. Our studies show that MMC significantly stimulated the formation of hydroxyl radical in VA-13 cells, but not in the IMR-90 cells. The formation of the hydroxyl radical was inhibited by superoxide dismutase (SOD) and catalase. In addition, the presence of these enzymes partially protected VA-13 cells from MMC toxicity but not IMR-90 cells. Further studies indicated that the decreased free radical formation and resistance to MMC may be due to the increased activities of catalase and glutathione transferase in the IMR-90 cell line. These results suggest that MMC-dependent DNA damage (alkylation and DNA DSB) and the stimulation of oxy-radical formation may play critical roles in the determination of MMC-induced cell killing.

Catalase↗