Search PubMed⌕ Search

Biomedical subjects

D Bass

Publications and source records attributed to D Bass.

At least 55 records · Page 3Linked to original sources

Management of brain metastases: past, present, and future.

Brain metastasis is an important cause of morbidity and mortality in cancer patients. Because most of these patients die of systemic disease, the primary therapeutic goal is to improve the quality of life. Conventional therapy for brain metastases is usually whole-brain irradiation. Chemotherapy often results in regression of brain metastases in chemosensitive tumors. We review our institutional experience in the treatment of brain metastasis with both radiation and chemotherapy. In the future, improvement in the management of brain metastases will depend on improved chemotherapy, radiosensitizers, and radiotherapy techniques such as stereotactic radiosurgery.

Adult↗

Combination chemotherapy with or without thoracic radiotherapy in limited-stage small-cell lung cancer: a randomized trial of the Southeastern Cancer Study Group.

PURPOSE: The primary objective of this randomized prospective study was to compare the survival of limited-stage small-cell lung cancer (SCLC) patients treated with chemotherapy alone or chemotherapy plus thoracic radiotherapy (TRT). A secondary objective was to determine the effect of consolidation chemotherapy on survival. PATIENTS AND METHODS: This multiinstitutional phase III study included 386 patients with limited-stage SCLC. All patients received cyclophosphamide 1,000 mg/m2, doxorubicin 40 mg/m2, and vincristine 1 mg/m2 (CAV) every 3 weeks for six cycles. Irradiated patients received 30 Gy in 10 fractions during weeks 1 and 2 of chemotherapy. Fifteen Gy in five fractions was administered during week 7 (total dose, 45 Gy). Following CAV, responding patients were randomized to receive two cycles of consolidation chemotherapy (cisplatin 20 mg/m2/d for 4 days plus etoposide 100 mg/m2/d for 4 days) or observation. RESULTS: Complete (46% and 38%; P = .14) and overall response rates (67% and 64%; P = .58) were not statistically significantly different. Although not significantly different, median (14.4 v 12.8 months) and 2-year survival (33% v 23.5%) rates favored the irradiated patients. Grade 4 hematologic toxicity was greater in irradiated patients (60% and 39%; P < .001). Patients given consolidation chemotherapy experienced superior median (21.1 v 13.2 months; P = .028) and 2-year survival (44% v 26%; P = .028) rates. CONCLUSION: The concurrent use of TRT and CAV chemotherapy as administered in this study failed to improve the survival of limited-stage SCLC patients compared with CAV alone. Life-threatening hematologic toxicities were more frequent with combined-modality therapy. The survival of limited-stage patients treated with CAV (with or without TRT) was improved with two cycles of cisplatin and etoposide consolidation therapy. Whether similar survival results could be achieved with cisplatin and etoposide alone requires additional study.

Adult↗

Severe COPD and acute respiratory failure. Correlates for survival at the time of tracheal intubation.

The recognition of a reversible cause for acute respiratory failure (ARF) is frequently difficult in patients with severe chronic obstructive pulmonary disease (COPD). We sought to identify clinical findings present at the time of tracheal intubation that were associated with successful weaning and short-term survival among a population of male veterans with severe COPD. Over a 5-year period (1987 to 1991), 39 episodes of ARF requiring mechanical ventilation (MV) were identified in 33 men with severe COPD. All the patients had a baseline FEV1 < 1 L. Univariate analysis suggested a higher serum albumin level and absence of pulmonary infiltrates on chest radiography distinguished survivors (weaned from MV for 72 h) from nonsurvivors (died while undergoing MV or within 72 h of weaning). Multivariate analysis revealed the absence of pulmonary infiltrates on initial chest radiography was the strongest correlate for survival. To examine the significance of these correlates in ARF complicating milder COPD, 19 patients with lesser degrees of chronic airways obstruction and ARF were also studied. Unlike patients with severe COPD, the presence or absence of pulmonary infiltrates on chest radiography was not correlated with survival in patients with milder chronic airways obstruction. Analyzing all COPD patients with ARF, the mortality risk associated with the presence of pulmonary infiltrates on chest radiography increased dramatically with declining baseline lung function. Mortality risk ratio analysis revealed the greatest likelihood for survival was predicted by a higher baseline FEV1 and the absence of pulmonary infiltrates on chest radiography. The extent of baseline airways obstruction alone was not correlated with short-term survival in either group. These observations suggest that in the subset of patients with severe COPD and ARF, the presence of pulmonary infiltrates on chest radiography at the time of tracheal intubation may be associated with less likelihood for survival. An exacerbation of COPD may infrequently be the terminal illness in these patients.

Acute Disease↗

Olive (Olea europea) and privet (Ligustrum vulgare) pollen allergens. Identification and cross-reactivity with grass pollen proteins.

Protein blotting studies showed that three olive pollen components with mol. wts approximately 18-19, 20 and 40 kD can be considered to be major allergens. For privet pollen, the highest recognition frequencies were for allergens of mol. wts approximately 20, approximately 19, approximately 40 and approximately 70 kD. When results with the 62 subjects examined were separated into groups corresponding to their geographical locations, viz. Italy, France and Australia, subjects sensitized to olive, but not other pollens (some Italian subjects), were found to show higher frequencies of recognition of major olive allergens than subjects sensitized to olive pollen via cross-reacting allergens from unrelated pollen sources (the Australian and French subjects). Blotting, adsorption and elution and inhibition studies clearly demonstrated allergenic cross-reactivity (that is, antigenic cross-reactivity detected by IgE antibodies) between olive, privet, ryegrass (Lolium perenne) and couch grass (Bermuda grass: Cynodon dactylon) pollen components. As with our previous findings with birch pollen, we conclude that the presence of pollen-reactive IgE antibodies may not necessarily be a true reflection of the sensitizing pollen species.

Allergens↗

Postsurgical adjuvant chemotherapy with or without radiotherapy in women with breast cancer and positive axillary nodes: a South-Eastern Cancer Study Group (SEG) Trial.

In a prospective study of 622 women with breast cancer, those with one to three histologically positive axillary lymph nodes were randomised after mastectomy to receive cyclophosphamide 100 mg/m2 orally on days 1-14, methotrexate 40 mg/m2 intravenously on days 1 and 8, and fluorouracil 600 mg/m2 intravenously on days 1 and 8 every 28 days for six cycles (CMF x six), or for twelve cycles of the same chemotherapy (CMF x 12). Those with > or = four positive nodes were randomised to one of these two groups or to 5000 cGy of postmastectomy regional radiotherapy (RT) followed by six cycles of the same chemotherapy (RT + CMF x six). With about 10 years median follow-up, there was no significant difference in survival or disease-free survival among the three groups. There was evidence of decreased locoregional recurrence in patients with > or = four nodes who received RT + CMF x six (relative risk 0.53, P = 0.067). Multivariate analysis indicated that the presence of > or = four positive nodes (negatively) and the percentage of ideal (full) dose of CMF received (positively) were the strongest factors predictive of survival. This study shows no advantage for 12 over six cycles of CMF chemotherapy in women with breast cancer and positive axillary nodes. There was a suggestion of decreased locoregional recurrence but no improvement in survival with radiotherapy for women with > or = four positive nodes.

Adult↗

Cognitive problem-solving skills training and parent management training in the treatment of antisocial behavior in children.

This study evaluated the effects of problem-solving skills training (PSST) and parent management training (PMT) on children (N = 97, ages 7-13 years) referred for severe antisocial behavior. Children and families were assigned randomly to 1 of 3 conditions: PSST, PMT, or PSST and PMT combined. It was predicted that (a) each treatment would improve child functioning (reduce overall deviance and aggressive, antisocial, and delinquent behavior, and increase prosocial competence); and (b) PSST and PMT combined would lead to more marked, pervasive, and durable changes in child functioning and greater changes in parent functioning (parental stress, depression, and overall symptoms). Expectations were supported by results at posttreatment and 1-year follow-up. PSST and PMT combined led to more marked changes in child and parent functioning and placed a greater proportion of youth within the range of nonclinic (normative) levels of functioning.

Adolescent↗

Screening for colorectal neoplasia: a multicenter study in Israel.

We report the design and results of the first Israeli multicenter screening program for colorectal neoplasia. The screening protocol comprised a risk questionnaire, fecal occult blood testing, flexible sigmoidoscopy and colonoscopy. A total of 5,601 individuals were screened in five medical centers, 55% being asymptomatic with low or average risk. Colorectal tumors were found in 12.3% of screenees, the majority being adenomas. The risk for large bowel neoplasia was greatest in persons with a personal history of colorectal neoplasia (neoplasia rate 473.2/10(3)) and was increased in those with inflammatory bowel disease, a family history of colorectal tumor, or past history of cured breast cancer. European-born Jews had a 50% greater risk than non-European-born Jews. Persons at high risk were more likely to return for repeat screening than those at low or average risk. However, approximately 15% of persons at high risk actually thought that they were of average risk. Fecal occult blood testing was markedly less reliable than flexible sigmoidoscopy and had a false-negative rate of 84.4%. The results demonstrate that existing medical facilities in Israel can be used to screen at least those individuals with increased risk for colorectal neoplasia.

Adenoma↗

Symmetric infection of rotavirus on polarized human intestinal epithelial (Caco-2) cells.

When rotavirus infects the mature villus tip cells of the small intestine, it encounters a highly polarized epithelium. In order to understand this virus-cell interaction more completely, we utilized a cell culture-adapted rhesus rotavirus (RRV) to infect human intestinal (Caco-2) and Madin-Darby canine kidney (MDCK-1) polarized epithelial cells grown on a permeable support. Filter-grown Caco-2 cells and MDCK-1 cells, producing a transepithelial resistance of 300 to 500 and greater than 1,000 omega . cm2, respectively, were infected from either the apical or basolateral domain with RRV or Semliki Forest virus. Whereas Semliki Forest virus infection only occurred when input virions had access to the basolateral domain of MDCK-1 or Caco-2 cells, RRV infected MDCK-1 and Caco-2 monolayers in a symmetric manner. The effect of rotavirus infection on monolayer permeability was analyzed by measuring the transepithelial electrical resistance. Rotavirus infection on filter-grown Caco-2 cells caused a transmembrane leak at 18 h postinfection, before the development of the cytopathic effect (CPE) and extensive virus release. Electrical resistance was completely abolished between 24 and 36 h postinfection. Although no CPE could be detected on RRV-infected MDCK cells, the infection caused a transmembrane leak that totally abolished the electrical resistance at 18 to 24 h postinfection. Cell viability and the CPE analysis together with immunohistochemistry and immunofluorescence data indicated that the abolishment of resistance across the monolayer was due not to an effect on the plasma membrane of the cells but to an effect on the paracellular pathway limited by tight junctions. Attachment and penetration of rotavirus onto Caco-2 cells caused no measurable transmembrane leak during the first hour of infection.

Animals↗

Cypress (Cupressus sempervirens) pollen allergens: identification by protein blotting and improved detection of specific IgE antibodies.

On the basis of results of an investigation of the effects of different treatments employed, a dialysed and reduced extract of Cupressus sempervirens was separated electrophoretically on sodium dodecylsulphate-polyacrylamide gels before being transferred and then fixed with glutaraldehyde to nitrocellulose membrane. Probing with sera from 91 subjects allergic to C. sempervirens pollen followed by detection of bound IgE antibodies with [125I]-labelled anti-human IgE revealed 17 IgE-binding proteins in the molecular weight range 14-96 kilodaltons (kDa). One component, of molecular weight approximately 42 kDa, reacted with IgE antibodies in the sera of 81.3% of the allergic subjects and, for each of the subjects, this component bound the greatest quantity of IgE. Almost 50% of the sera recognized only the approximately 42 kDa component, reinforcing the conclusion that this component is the major allergen of C. sempervirens pollen. A comparative study employing C. sempervirens pollen allergen discs prepared commercially or in the laboratory showed that values of the uptakes of [125I]-anti-IgE indicating the presence of pollen-reactive IgE antibodies obtained with the latter discs were consistently higher (means 4.5 vs. 0.88), and that false-negative results were obtained when many sera were used with the commercial discs. The results of this study provide an essential basis for the production of standardized, safe and effective C. sempervirens pollen extract applicable to diagnosis and therapy of cypress pollen allergy.

Allergens↗

[Screening for colorectal neoplasms].

We screened groups at high risk for colorectal neoplasms, determining the efficacy of the leukocyte adherence inhibition test (LAI) for early detection, in comparison with that of the fecal occult blood (Hemoccult) test and sigmoidoscopy or colonoscopy. Those screened included 549 first-degree relatives of patients with colorectal cancer, 190 patients with a past history of colorectal adenoma or carcinoma and 67 with a past history of breast or gynecological cancer or inflammatory bowel disease. 146 normal volunteers served as controls. In 782 of those fully screened during a 3-year period, 121 had adenomas (15.5%) and 5 had invasive cancer (0.6%). The LAI test was positive in 21% of those at high risk and in 7.5% of the controls. The hemoccult test was positive in only 4.8%, but in 1/3 of them neoplasms were found. This predictive value of 33% compares with only 16% for the LAI test. That most of the neoplasms found were adenomas and not invasive cancer may be due to the relative youth of most of those screened. We conclude that the groups studied were indeed at high risk. The LAI test is not sensitive enough to identify benign adenomas but might serve as another risk-market for colorectal neoplasms. Long-term follow-up of those at high-risk with positive LAI tests may prove that we have identified a subgroup truly at risk.

Adenoma↗

Influenza A virus alters structural and biochemical functions of the neutrophil cytoskeleton.

Influenza A virus (IAV) has previously been shown to alter chemotactic, oxidative, and secretory functions of polymorphonuclear leukocytes (PMNL). Because of the role of cytoskeletal proteins in these processes, studies were carried out to determine if IAV altered the PMNL cytoskeleton. PMNL were incubated with buffer of IAV, stimulated with f-met-leu-phe (FMLP), fixed and stained with NBD-phallacidin (NBD-Ph) and studied by flow cytometry. Mean F-actin fluorescence was increased 18% in virus treated cells pre-FMLP stimulation and 13% 5 and 10 min post-FMLP (P less than .03); no significant difference in F-actin fluorescence was noted in virus treated PMNL 15-30 s post-FMLP compared to control cells. PMNL exposed to the same conditions were solubilized and actin content was determined following SDS-PAGE of triton insoluble precipitates. Increased actin was recovered from virus treated compared to buffer treated cells before and after FMLP stimulation in the 8,000g precipitates (P less than .001). Immunofluorescent microscopy studies of F-actin distribution were done in PMNL stained with NBD-Ph following FMLP stimulation for 10 min. These studies showed an increased lamellipod F-actin/uropod F-actin ratio in PMNL pre-incubated with IAV compared to controls (4.6 vs. 1.0; P less than .025). Phosphorylation of specific cytoskeletal proteins was examined after immunoprecipitation. IAV alone altered phosphorylation of both vimentin and vinculin, and in stimulated PMNL virus led to decreased phosphorylation of vimentin and vinculin. These data show distributional and biochemical effects of IAV on PMNL cytoskeletal proteins, indicating additional targets for IAV interference in the PMNL signal-transduction-function process.

Actin Cytoskeleton↗

Empirical and clinical focus of child and adolescent psychotherapy research.

The present study evaluated the characteristics of research on child and adolescent psychotherapy. Published studies (N = 223) of psychotherapy from 1970 to 1988 were codified to characterize research, clinical, and methodological characteristics. The major results indicate that (a) treatment research focuses almost exclusively on the impact of treatment techniques with scant attention to influences (child/adolescent, parent, family, therapist) that may moderate outcome and (b) several characteristics of the children/adolescents and methods of treatment delivery and approaches depart markedly from those evident in the practice of treatment. Priorities for treatment research to place clinical practice on firmer empirical footing are discussed.

Adolescent↗

Immunization with baculovirus-expressed VP4 protein passively protects against simian and murine rotavirus challenge.

A baculovirus-expressed VP4 protein derived from the simian rhesus rotavirus (RRV) was used to parenterally immunize murine dams. VP4-immunized dams developed high levels of neutralizing antibodies against RRV and low levels of cross-reactive neutralizing antibodies against human strains Wa, ST3, and S2 and animal strains SA-11, NCDV, and Eb. Newborn mice suckled on VP4-immunized dams were protected against a virulent challenge dose of the simian strain RRV and against murine rotavirus Eb. The cross-reactive nature of the serum-neutralizing response generated by VP4 immunization and the protective efficacy of the immunization suggest that recombinant-expressed VP4 proteins should be considered as viable vaccine candidates.

Animals↗

An evaluation of arbaprostil at multiple doses for the treatment of acute duodenal ulcer: a randomized double-blind placebo-controlled international trial.

Six hundred and thirty patients were enrolled in a randomized double-blind placebo-controlled trial evaluating two arbaprostil dosages (25 micrograms and 50 micrograms) qid for 4 wk for the treatment of acute duodenal ulcers. The healing rates in the placebo, 25-micrograms, and 50-micrograms treatment groups were 39%, 51%, and 60%, respectively. Smoking was found to adversely affect the healing rates in all the treatment groups. Pain severity was less with either arbaprostil treatment. The only side effect found was diarrhea: 10%, 14%, and 32% in the placebo, 25-micrograms, and 50-micrograms treatment groups, respectively. Severe diarrhea occurred in 1% of those patients who received the 50-micrograms dosage regimen, but in none of the other two groups. Arbaprostil at these two dosage levels, when given for 4 wk, appears to be a safe and efficacious agent for the treatment of acute duodenal ulcers.

Acute Disease↗

Cognitive-behavioral therapy and relationship therapy in the treatment of children referred for antisocial behavior.

The present study evaluated alternative treatments for children (N = 112, ages 7-13) referred for severe antisocial behavior. Children were randomly assigned to one of three treatments: problem-solving skills training (PSST), problem-solving skills training with in vivo practice (PSST-P), which included therapeutically planned activities to extend training to settings outside of treatment, or client-centered relationship therapy (RT). PSST and PSST-P children showed significantly greater reductions in antisocial behavior and overall behavior problems, and greater increases in prosocial behavior than RT children. These effects were evident on measures obtained immediately after treatment and at a 1-year follow-up, and on measures of child performance at home and at school. PSST-P children showed greater changes than PSST children on measures of functioning at school at posttreatment, but these differences were no longer evident at follow-up. Children in both PSST conditions showed significant reductions in deviant behavior and improvements in prosocial behavior from pretreatment to follow-up, whereas RT children tended to remain at their pretreatment level of functioning. Notwithstanding the significant improvements, comparisons with nonclinic (normative) samples revealed that the majority of youth remained outside of the normal range of deviant behavior. Possible directions for improving treatment for antisocial youth are highlighted.

Adolescent↗