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Biomedical subjects

B Mason

Publications and source records attributed to B Mason.

At least 55 records · Page 3Linked to original sources
PubMed1991

An investigation of the safety of the blood reinfusion step used with tunneled venous access devices in children with cancer.

Infection has been identified as the most serious potential complication of the indwelling catheter. As a result, the primary nursing goal using the catheters is to prevent infection. Nurses must frequently manipulate the catheters when securing blood specimens and are concerned that this manipulation may serve as a source of infection for the immunocompromised pediatric oncology patient. One particular step in catheter manipulation during blood sampling is blood reinfusion, ie, residual blood in the catheter is withdrawn and set aside while a second sample is collected for laboratory analysis but is subsequently returned to the patient through the catheter. The purpose of this study was to examine this nursing procedure for its potential of contaminating the blood sample that was to be reinfused, or for the potential of reinfusing a sample that contained preexisting pathogens independent of the procedure itself. An experimental design was used with 21 patients randomly assigned to an experimental group (unclean procedure to exaggerate the potential to incur pathogens during the process), and 21 randomly assigned to a control group (usual clean procedure followed with the reinfusion sample). The usual blood sampling procedure was altered for all participants as the typical amount of blood that normally constitutes the reinsertion sample was not reinserted, but was instead used to complete certain microbial analyses. Of the 42 participants, 17 were male and 25 were female; 35 were white and seven were black; 22 were diagnosed with leukemias and 20 with solid tumors. The age range for participants was 2 to 20 years (mean = 9.4 years, SD = 4.8).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Hygienic hand disinfection tests in three laboratories.

A comparative study was made in three laboratories of a test for hygienic hand disinfection. Staphylococcus aureus was applied to the fingertips of a total of 74 volunteers (49 female and 25 male) and the effect of washing with three chlorhexidine preparations and one non-medicated soap was assessed after one and five applications. Fingertip inoculation is convenient and is a realistic representation of the in-use situation. Although significant differences were obtained between log10 reductions in test organisms using the same formulation in different centres, and different periods in the same centre, the maximum differences after a single application of a preparation were small, e.g. between centres 0.39 and between periods in the same centre 0.55, and after multiple applications the maximum difference between centres was 0.42 and between periods in the same centre it was 0.51. The differences between preparations were similar in all centres. This test compares well with other similar tests and products can be placed in rank order of effectiveness. It is concluded that this test, if carried out under the controlled conditions described, is sufficiently reproducible between laboratories and repeatable within laboratories to be used as a standard test.

Chlorhexidine↗
PubMed1990

Influence of superovulation on endometrial and embryonic development.

The authors have studied the temporal relationship between follicular rupture and endometrial development in 13 women during a natural ovarian cycle (length 25 to 35 days), and subsequently after standard treatment with clomiphene citrate, human menopausal gonadotropin and human chorionic gonadotropin (hCG) to induce multiple folliculogenesis for oocyte recovery, in vitro fertilization, and embryo freezing (cycle length 23 to 27 days). An endometrial biopsy was taken during both cycles 1.5 to 2.0 days after the oocytes had been released or removed. The samples were examined by light and transmission electron microscopy. Samples of peripheral blood were taken at defined times for hormone analysis. After treatment 11 subjects (85%) had advanced morphological development of the endometrium (8 women by 3 to 4 days, 3 women by 1 to 2 days). The concentrations of plasma estradiol (E2) and progesterone (P) on the days of follicular rupture and endometrial biopsy were significantly raised in the treatment cycles. The concentration of total urinary estrogens on the day of hCG administration and the mean change in the concentration of plasma E2 (treatment/control) on the days of endometrial biopsy were positively correlated with the extent of endometrial advancement. In addition, the mean change in the concentration of plasma P (treatment/control) was markedly increased on the days of follicular rupture and endometrial biopsy in those subjects with an advanced endometrium. Embryonic development was not so obviously related to the extent of superovulation. Asynchronous endometrial and embryonic development may therefore contribute to the low pregnancy rate in these patients.

Adult↗
PubMed1990

Dose-intense weekly cyclophosphamide, methotrexate, 5-fluorouracil, vincristine and prednisolone (CMFP) in advanced breast cancer.

Weekly chemotherapy with cyclophosphamide 80 mg m-2 day-1 p.o. continuously, methotrexate 35 mg m-2 week-1 i.v., 5-fluorouracil 500 mg m-2 week-1 i.v., vincristine 1.4 mg m-2 i.v. every two weeks and prednisolone 20 mg m-2 day-1 p.o. continuously (CMFVP) was prospectively studied in 45 previously untreated outpatients with advanced breast cancer to determine the feasibility of delivering a dose-intense regimen. Of 40 evaluable patients, complete response (CR) occurred in one patient, partial response (PR) in 20 (CR + PR 53%), stable in eight, progression in 11 and five were unevaluable for response. The median relapse-free survival for responders was 25 weeks and median survival for all patients was 31 weeks. The mean dose intensity relative to the Cooper regimen fell from 1.02 to 0.6 within the first 4 weeks of treatment and the median dose intensity achieved for all patients on study was only 0.52. Eighty-seven per cent of patients had treatment delays with a mean of 3.9 delays per patient and 71% had dose reductions. Neutropenia was the major toxicity with WHO grade 3 or 4 neutropenia (less than 1.0 x 10(9) l-1) in 62% of patients and three septic deaths while neutropenic. Dose-intense weekly CMFVP in this schedule cannot be delivered to previously untreated outpatients with advanced breast cancer.

Adult↗
PubMed1990

Rare ectopic pregnancies after in-vitro fertilization: one unilateral twin and four bilateral tubal pregnancies.

Between 1985 and 1989, one unilateral twin and four bilateral tubal pregnancies were encountered among 124 extrauterine pregnancies and 1648 intrauterine pregnancies following in-vitro fertilization and embryo transfer. The two factors associated with this high incidence of single and multiple extrauterine pregnancies were tubal damage and multiple embryo transfer. Embryos at different stages of development appear to have the capacity to implant ectopically. Despite advances in diagnostic capabilities, ectopic pregnancy remains a major cause of maternal mortality. Early diagnosis prior to rupture must be made if mortality and morbidity are to be abolished. The use of transvaginal sonography has improved the diagnosis of ectopic pregnancy and should be routinely used in all pregnancies following assisted conception. The identification of an intrauterine pregnancy should not be sufficient to rule out the possibility of an extrauterine pregnancy or even bilateral tubal pregnancies.

Adult↗
PubMed1989

Studies on folliculogenesis and in vitro fertilization outcome after the administration of follicle-stimulating hormone at different times during the menstrual cycle.

The authors have undertaken a prospective, randomized clinical trial of six treatments to optimize folliculogenesis in patients prior to oocyte collection, in vitro fertilization, and embryo transfer. All treatments involved the administration of the same daily dose of follicle-stimulating hormone (FSH), but at different times during the antecedent and/or current menstrual cycle. There was a significant difference (P less than 0.01, chi-square test) between treatments in the clinical pregnancy rate/patient (19 clinical pregnancies, 67 patients). No advantages were observed for regimens that involved starting treatment during the antecedent cycle. The study was continued with the three treatments that started during the current cycle (24 clinical pregnancies, 58 patients). The most cost-effective regimen was clomiphene citrate, 100 mg/day for days 2 to 6 inclusive; FSH, 150 units/day for days 1 to 4 inclusive; and human menopausal gonadotropin, 150 units/day from day 5 until the day of human chorionic gonadotropin administration.

Adult↗
PubMed1989

Risk factors for sensitization by blood transfusions. Comparison of the UW/Madison and UC/San Francisco donor-specific transfusion experience.

We have tested the predictive model for risk of sensitization by donor-specific transfusions developed at the University of California, San Francisco for its applicability to the DST experience at UW/Madison. Patient sample sizes between the two groups were similar (n = 249 for UW/Madison, n = 261 for UCSF) and the two groups of patients had similar compositions in terms of mean age, ABO type, baseline panel-reactive antibody, and pregnancy rate. The two groups differed in that the UW/Madison group had a higher percentage of males, diabetic patients, previously transplanted patients, and 0 haplotype-matched (2 HLA-mismatched related and unrelated) recipients. In addition, all the UW/Madison patients received azathioprine (AZA) whereas only half the UCSF group was given AZA. Despite these differences, application of the UCSF model for prediction of sensitization by DST gave remarkably similar results in our patient population, with pregnancy, prior transplant, baseline PRA, and HLA antigen sharing giving similar odds ratios and P values. However, when female sex was included in the model along with the other variables, the significance of pregnancy risk disappeared. We have developed an alternative multivariate model using stepwise logistic regression that identifies baseline PRA greater than 40%, female sex, and prior transplant as significant risk factors for sensitization, while number of HLA (A, B, DR) antigens shared and increasing recipient age significantly decreased risk of sensitization by DST.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1989

Cadaveric renal transplantation with quadruple immunosuppression in patients with a positive antiglobulin crossmatch.

The significance of the antiglobulin crossmatch in the cyclosporine era remains controversial. Over an 11-month period, 124 recipients of cadaveric renal allografts (109 primary, 15 nonprimary) were retrospectively crossmatched via the antiglobulin technique. Criteria for recipient selection for transplantation included a negative T lymphocytotoxic (CDC) crossmatch for current and historical sera. Fourteen patients (11.3%) underwent transplantation in the setting of a negative T and positive antiglobulin crossmatch. The patient group included 10 female and 4 male patients with a mean age of 43.8 years. All but one patient received a primary transplant, and current sera were positive in the antiglobulin crossmatch in all cases. The mean HLA-ABDR match was 1.4 (range 0-4). Preoperative PRA titers ranged from 0 to 80% (mean 18.3%). All patients underwent successful renal transplantation with quadruple immunosuppression consisting of prednisone, azathioprine, and the sequential use of MALG/cyclosporine. There were no episodes of hyperacute rejection. However, 10 patients (71.4%) experienced acute rejection, including 7 episodes within 4 days of transplant. Early rejection was significantly more common in patients with a positive antiglobulin test (50% vs. 20.9%, P less than 0.05). The mean one-month serum creatinine was 1.7 mg/dl. Actual patient and allograft survival are 92.9% and 85.7%, respectively. Risk factors for a positive antiglobulin crossmatch included female sex and prior sensitization as measured by PRA. Although these patients represent a high-risk group for early rejection, no adverse effect on patient or graft survival was noted with quadruple immunotherapy. In conclusion, a positive antiglobulin crossmatch is no longer a contraindication to renal transplantation with current immunosuppressive strategies.

Adolescent↗
PubMed1989

Predicting survival in bilateral breast carcinoma.

Survival in 38 patients with bilateral breast cancer has been studied. The tumours were synchronous in 14 patients and metachronous in 24. Survival was less than that predicted for either tumour on the basis of a previously developed index involving lymph node status, oestrogen receptor content, progesterone receptor content, and patient age. Simple addition of the indices for the two tumours gave better predictor although this also overstated the prospects for survival for both synchronous and metachronous tumours. This experience suggests, therefore, that the prospects for survival for patients with suggests, therefore, that the prospects of survival for patients with synchronous or metachronous bilateral breast carcinoma is poor, and worse than might reasonably be anticipated.

Breast Neoplasms↗
PubMed1989

Combination chemotherapy versus single agents followed by combination chemotherapy in stage IV non-small-cell lung cancer: a study of the Eastern Cooperative Oncology Group.

During the last decade, the Eastern Cooperative Oncology Group (ECOG) has studied a series of combination chemotherapy regimens in metastatic (stage IV) non-small-cell lung cancer (NSCLC). In January 1984, the ECOG activated a randomized study, EST 1583, which concluded the evaluation of combination regimens in phase III trials and initiated the evaluation of single agents exclusively in previously untreated patients. The treatment regimens in EST 1583 consisted of: (1) mitomycin, vinblastine, and cisplatin (MVP); (2) vinblastine and cisplatin (VP); (3) MVP alternating with the regimen cyclophosphamide, doxorubicin, methotrexate, and procarbazine (CAMP); (4) carboplatin followed by the MVP regimen at the time of progression; and (5) iproplatin followed by MVP at the time of progression. From January 1984 to July 1985, 743 patients were entered on this trial and 699 fulfilled the eligibility requirements. The following objective response rates (complete plus partial remissions) were observed: first-line MVP, 20%; VP, 13%; MVP/CAMP, 13%; carboplatin, 9%; iproplatin, 6%; and second-line MVP, 6%. First-line MVP produced a significantly higher response rate than the other treatments (P = .03) adjusted for prognostic variables. Using analyses that were adjusted for prognostic covariates, survival for patients treated on a given regimen was compared with survival for all remaining patients. These analyses showed that treatment with carboplatin was associated with longer survival (median survival time, 31.7 weeks; P = .008) while initial treatment with MVP was associated with a trend for shorter survival (median survival time, 22.7 weeks; P = .09). It should be noted that none of these regimens appear to have produced a clinically meaningful prolongation of survival. Similar analyses evaluating time to progression disclosed that carboplatin-treated patients had a significantly longer time to progression (median time to progression, 29 weeks) than all remaining patients (P = .01). Life-threatening and lethal toxicities (toxicity grades 4 and 5) were greater on the combination regimens than on the single agents (P less than .0001). Based on these results, current group-wide ECOG trials in stage IV NSCLC consist of randomized phase II trials evaluating single agents.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Diagnostic criteria for dysthymic disorder.

The DSM-III (American Psychiatric Association 1980) criteria for dysthymic disorder selected a heterogeneous group of patients who overlapped with major depression and personality disorders in ways that were difficult to interpret. DSM-III-R (American Psychiatric Association 1987) revised the dysthymia criteria by (1) distinguishing early from late age of onset; (2) providing separate designations for primary and secondary states of dysthymia; (3) including a category of chronic major depression; and (4) revising the specific content of criteria. The performance characteristics of the new criteria set are yet to be tested--a necessary next step to inform the discussions that will culminate in DSM-IV. The remaining areas of greatest controversy are whether (1) early onset, primary dysthymic disorder should be redefined as depressive personality and placed on Axis II; (2) "double-depression" represents a real clinical phenomenon or a definitional artifact; and (3) the content of the diagnostic criteria can be made more specific for chronic depressions. The implications of possible changes and the workings of the DSM-IV Affective Disorders Work Group are discussed.

Depressive Disorder↗
PubMed1988

The sequential use of a luteinizing hormone-releasing hormone (LH-RH) agonist and human menopausal gonadotropins to stimulate folliculogenesis in patients with resistant ovaries.

The diagnostic response toward the administration of a luteinizing hormone-releasing hormone (LH-RH) analogue in the early follicular phase has been used sequentially with conventional human menopausal gonadotropin (hMG) treatment in patients who had previously failed to develop multiple follicles in response to a combination of hMG and clomiphene citrate. Nine of fourteen patients (64%) showed an increase in the number of preovulatory follicles and five subjects reached oocyte recovery for the first time. Two patients (22%) became pregnant after in vitro fertilization and embryo transfer during the treatment cycle and had healthy babies. It is suggested that this treatment regimen may be advantageous in some patients with resistant ovaries.

Adult↗
PubMed1988

Multivariate analysis of risk factors for sensitization and early rejection episodes in a donor-specific transfusion plus azathioprine protocol.

A total of 205 patients who underwent donor-specific transfusions with azathioprine (DST+AZA) treatment from 1982 to 1987 included 25 patients (12%) who developed antibodies cytotoxic to donor T cells (+T warm crossmatch). When we examined a series of 14 variables in relation to the risk of sensitization using a univariate analysis, panel-reactive antibody (PRA) pre-DST of greater than 40%, pregnancy, female sex, male-to-female DST, and HLA antigen match all were significant (P less than .05) risk factors. Of these variables, only PRA pre-DST greater than 40% proved to be statistically significant (P less than .002) in a multivariate logistic regression model (overall P less than .001). Of those patients who went on to transplant with the donor-specific kidney, 41/170 (24%) developed early on or before day 5 posttransplant) rejection episodes. Univariate analysis of 17 variables in relation to early (less than 5 days) rejection episodes indicated no significant variables. Nonetheless using a multivariate logistic regression model (overall P = .09), HLA match (P less than .004), perioperative transfusions (P less than .05), and azathioprine withdrawal for greater than 1 week during DST (P less than .05) all correlated with the incidence of early rejection episodes. In a smaller multivariate model involving 47 patients for whom MLC/blocking factor data were available, the presence of plasma blocking factor at the time of transplant was associated with a decreased incidence of early rejection (P = .07). We conclude that the factors that influence the rate of T+ sensitization are distinct from those that influence the rate of early rejection episodes in a DST+AZA protocol.

Antilymphocyte Serum↗