Biomedical subjects

B Peterson

Publications and source records attributed to B Peterson.

At least 19 recordsLinked to original sources

PubMed2006

Denitrification across landscapes and waterscapes: a synthesis.

Denitrification is a critical process regulating the removal of bioavailable nitrogen (N) from natural and human-altered systems. While it has been extensively studied in terrestrial, freshwater, and marine systems, there has been limited communication among denitrification scientists working in these individual systems. Here, we compare rates of denitrification and controlling factors across a range of ecosystem types. We suggest that terrestrial, freshwater, and marine systems in which denitrification occurs can be organized along a continuum ranging from (1) those in which nitrification and denitrification are tightly coupled in space and time to (2) those in which nitrate production and denitrification are relatively decoupled. In aquatic ecosystems, N inputs influence denitrification rates whereas hydrology and geomorphology influence the proportion of N inputs that are denitrified. Relationships between denitrification and water residence time and N load are remarkably similar across lakes, river reaches, estuaries, and continental shelves. Spatially distributed global models of denitrification suggest that continental shelf sediments account for the largest portion (44%) of total global denitrification, followed by terrestrial soils (22%) and oceanic oxygen minimum zones (OMZs; 14%). Freshwater systems (groundwater, lakes, rivers) account for about 20% and estuaries 1% of total global denitrification. Denitrification of land-based N sources is distributed somewhat differently. Within watersheds, the amount of land-based N denitrified is generally highest in terrestrial soils, with progressively smaller amounts denitrified in groundwater, rivers, lakes and reservoirs, and estuaries. A number of regional exceptions to this general trend of decreasing denitrification in a downstream direction exist, including significant denitrification in continental shelves of N from terrestrial sources. Though terrestrial soils and groundwater are responsible for much denitrification at the watershed scale, per-area denitrification rates in soils and groundwater (kg N x km(-2) x yr(-1)) are, on average, approximately one-tenth the per-area rates of denitrification in lakes, rivers, estuaries, continental shelves, or OMZs. A number of potential approaches to increase denitrification on the landscape, and thus decrease N export to sensitive coastal systems exist. However, these have not generally been widely tested for their effectiveness at scales required to significantly reduce N export at the whole watershed scale.

Agriculture↗

PubMed2005

Meta-analysis to evaluate the role of interferon in follicular lymphoma.

PURPOSE: To determine whether interferon (IFN) -alpha2, when given with or following chemotherapy, influences response rate, remission duration, and survival in newly diagnosed patients with follicular lymphoma. PATIENTS AND METHODS: Ten phase III studies evaluating the role of IFN-alpha2 in 1,922 newly diagnosed patients with follicular lymphoma were analyzed. Updated individual patient data were used to perform meta-analyses for response, survival, and remission duration. RESULTS: The addition of IFN-alpha2 to initial chemotherapy did not significantly influence response rate. An overall meta-analysis for survival showed a significant difference in favor of IFN-alpha2, but also showed significant heterogeneity between studies. Further analyses were carried out in order to explain this heterogeneity, and to define the circumstances in which IFN-alpha2 prolonged survival. The survival advantage was seen when IFN-alpha2 was given: (1) in conjunction with relatively intensive initial chemotherapy (2P = .00005), (2) at a dose >/= 5 million units (2P = .000002), (3) at a cumulative dose >/= 36 million units per month (2P = .000008), and (4) with chemotherapy rather than as maintenance therapy (P = .004). With regard to remission duration, there was also a significant difference in favor of IFN-alpha2, irrespective of the intensity of chemotherapy used, IFN dose, or whether IFN was given as a maintenance strategy or with chemotherapy. CONCLUSION: When given in the context of relatively intensive initial chemotherapy, and at a dose >/= 5 million units (>/= 36 x 10(6) units per month), IFN-alpha2 prolongs survival and remission duration in patients with follicular lymphoma.

Adolescent↗

PubMed2005

What is the best postoperative treatment for patients with pT3bN0M0 adenocarcinoma of the prostate?

The purpose of this paper to identify the optimal therapy after radical prostatectomy (RP) for patients with adenocarcinoma of the prostate invading the seminal vesicles (pT3bN0M0 or SVI). A PubMed search using the keywords 'prostate', 'seminal vesicle', 'prostatectomy', 'radiotherapy', 'androgen blockade' was performed to identify literature regarding rates of disease failure in patients with SVI who are observed or treated with androgen blockade (AB), radiotherapy (RT) or RT + AB after RP. The outcome of 68 patients treated at Duke University with post-operative AB, RT or RT + AB for pT3bN0M0 is also presented. More than 70% of patients with SVI develop disease recurrence after surgery. For many, recurrence occurs within 2 y after RP. These patients have poor control rates with postoperative RT alone. While experience with AB and RT+AB is limited, control rates are generally superior to RT alone. At Duke University, after a median follow-up of nearly 4 y, patients treated with RT + AB or AB alone for pT3bN0M0 achieved better 5-y progression-free survival (PFS) compared with those who received RT alone (78 and 68 vs 30%, P = 0.03 and 0.046, respectively). There was no PFS difference between those who received AB alone or RT + AB (68 vs 78%, P=0.5). Seminal vesicle invasion confers a poor prognosis after RP. SVI is a consistent predictor of poor outcome after RT. The limited data available examining AB and RT + AB in pT3bN0M0 disease, including data from Duke University, are encouraging. Nonetheless, postoperative AB, RT and RT + AB for pT3bN0M0 disease require prospective evaluation, as RP alone is rarely curative.

Adenocarcinoma↗

PubMed2003

A phase II study of cladribine treatment for fludarabine refractory B cell chronic lymphocytic leukemia: results from CALGB Study 9211.

Cladribine has been reported to have little activity in fludarabine- refractory chronic lymphocytic leukemia (CLL). We sought to determine whether resistance to therapy with cladribine in fludarabine-refractory CLL patients represented primary drug resistance or the inability to tolerate the myelosuppression associated with this therapy. Patients with fludarabine refractory CLL patients without severe thrombocytopenia (platelets >/=50 x 10(9)/l) or granulocytopenia (neutrophils >1.5 x 10(9)/l) were enrolled. All patients received cladribine (0.14 mg/kg) as a 2-h intravenous infusion daily for 5 days, repeated every 4 weeks. Patients received up to six cycles of therapy. Twenty-eight patients enrolled; 13 had intermediate (Rai stage I or II) and 15 high (Rai stage III and IV) risk stages. No patient had a complete remission, but nine (32%; 95% confidence interval, 15-49%) attained a partial remission when assessed using the modified NCI criteria (1996). The median time to relapse for responders was 12 months, while median progression-free survival for the entire group was 9 months (95% confidence interval, 4-14 months). The median overall survival was 2.2 years (95% confidence interval, 0.8-3.1 years). Response was predicted by pre-treatment Rai status with seven of 13 (54%) intermediate risk vs two of 15 (13%) high-risk patients responding (P = 0.04). Toxicity was myelosuppression and infections (grade 3-5: neutropenia 75%, thrombocytopenia 68%, and infections 43%). Cladribine has modest clinical activity and considerable toxicity in a very selected group of patients with fludarabine-refractory CLL lacking pre-treatment neutropenia and thrombocytopenia.

Adult↗

PubMed2002

Toxicity of select beta adrenergic receptor-blocking pharmaceuticals (B-blockers) on aquatic organisms.

One class of pharmaceutical compounds identified in U.S. and European waters are the B-adrenergic receptor blocking compounds (B-blockers). However, little information is available on the potential aquatic toxicity of these compounds. Therefore, Hyalella azteca, Daphnia magna, Ceriodaphnia dubia, and Oryias latipes (Japanese medaka) were exposed to metoprolol, nadolol, and propranolol to determine potential toxicity. Average 48-h LC(50) for propranolol to H. azteca was 29.8 mg/L. The no-observed-effects concentration (NOEC) and lowest-observed-effects concentration (LOEC) for propranolol affecting reproduction of H. azteca were 0.001 and 0.1 mg/L, respectively. The average propranolol and metoprolol 48-h LC(50)s for D. magna were 1.6 and 63.9 mg/L, respectively. C. dubia 48-h LC(50)s were 0.85 and 8.8 mg/L for propranolol and metoprolol, respectively. The NOEC and LOEC of propranolol affecting reproduction in C. dubia were 0.125 and 0.25 mg/L, respectively. In O. latipes, the propranolol 48-h LC(50) was 24.3 mg/L. Medaka growth was decreased at 0.5 mg/L propranolol. A 2-week medaka reproductive study indicated significant changes in plasma steroid levels; however, no changes in the average number of eggs produced or number of viable eggs which hatched was observed. In a 4-week follow-up propranolol exposure, the total number of eggs produced by medaka and the number of viable eggs that hatched were decreased at concentrations as low as 0.5 microg/L. Based on this study and the expected aqueous environmental exposure levels, adverse effects of propranolol to invertebrate populations is unlikely; however, further reproductive studies are need to elucidate the risk to teleosts.

Adrenergic beta-Antagonists↗

PubMed2001

Body composition characteristics are associated with the bone density of the proximal femur end in middle- and old-aged women and men.

OBJECTIVES: In the present study the associations between bone density of the proximal femur end and weight status, fat distribution patterns (FDI) and body composition parameters i.e. amount of body fat and lean body mass were tested in a sample of old aged women and men. METHODS: In 77 healthy women ranging in age from 60 to 92 years (x=71.8 years) and 62 healthy men ranging in age from 60 to 86 years (x=71.5 years) the bone mineral density (BMD of the proximal femur end and the body composition parameters absolute fat mass, relative fat mass, lean body mass and bone mineral content were estimated by dual energy X-ray absorptiometry. Additionally, the weight status (body mass index, BMI) and the FDI were calculated. The bone density of the proximal femur end was correlated with the absolute fat mass and the lean body mass as well as with the BMI and the FDI. RESULTS: BMD correlated in females significantly positively with parameters of body composition, in males no significant correlations between fat mass (absolute and relative) and BMD as well as BMD/stature was found. Furthermore, it was shown that the weight status (BMI; r(2)=0.13, P<0.0003 in males and r(2)=0.27, P<0.000 in females), and the lean body mass (r(2)=0.21, P<0.001 in males, r(2)=0.36, P<0.004 in females) were associated significantly positively with the BMD of the proximal femur end in both sexes. The absolute fat mass had a significant impact on BMD in the female subsample only (r(2)=0.24, P<0.000). CONCLUSIONS: A lower weight status and a low amount of lean body mass, indicating not only lack of biomechanical forces of the proximal femur end, but also a lack of physical activity can be assumed to be associated increased bone loss and the development of osteoporosis in both sexes. An association between low amount of fat tissue and decreased BMD was especially found in women and may be due to the reduced conversion rates from androgens to estrogens in a low amount of fat tissue.

Absorptiometry, Photon↗

PubMed2001

Lithium and valproate decrease inositol mass and increase expression of the yeast INO1 and INO2 genes for inositol biosynthesis.

Bipolar affective disorder (manic-depressive illness) is a chronic, severe, debilitating illness affecting 1-2% of the population. The Food and Drug Administration-approved drugs lithium and valproate are not completely effective in the treatment of this disorder, and the mechanisms underlying their therapeutic effects have not been established. We are employing genetic and molecular approaches to identify common targets of lithium and valproate in the yeast Saccharomyces cerevisiae. We show that both drugs affect molecular targets in the inositol metabolic pathway. Lithium and valproate cause a decrease in intracellular myo-inositol mass and an increase in expression of both a structural (INO1) and a regulatory (INO2) gene required for inositol biosynthesis. The opi1 mutant, which exhibits constitutive expression of INO1, is more resistant to inhibition of growth by lithium but not by valproate, suggesting that valproate may inhibit the Ino1p-catalyzed synthesis of inositol 1-phosphate. Consistent with this possibility, growth in valproate leads to decreased synthesis of inositol monophosphate. Thus, both lithium and valproate perturb regulation of the inositol biosynthetic pathway, albeit via different mechanisms. This is the first demonstration of increased expression of genes in the inositol biosynthetic pathway by both lithium and valproate. Because inositol is a key regulator of many cellular processes, the effects of lithium and valproate on inositol synthesis have far-reaching implications for predicting genetic determinants of responsiveness and resistance to these agents.

Basic Helix-Loop-Helix Proteins↗

PubMed2001

[Significance of body weight status for bone density in the elderly and very old].

Reduced bone density and osteoporosis are significant health problems and contributors to disability and mortality among older women and men. Therefore the decline of bone mineral content (BMC) and bone mineral density (BMD) are aspects of ageing with great medical and social significance. In recent years a low body weight was declared to be an important risk factor for the development of osteoporosis. In the present study the impact of weight status, defined by the categories of the WHO, on BMC of the whole body and BMD of the proximal femur end, determined by dual energy x-ray absorptiometry (DEXA), were studied in 77 female and 62 male probands aged between 60 and 92 years (x = 71.7 yrs). With increasing weight status (BMI categories), BMC and BMD increased significantly (p < 0.001). This was true of both sexes. Even moderate overweight women and men (BMI 25.0-29.99) showed a significantly higher bone density than their normal weight counterparts (BMI < 25.0). In the present study a marked positive impact of body weight on bone density of old-aged women and men could be shown.

Aged↗

PubMed2001

Comparison of survival after mitral valve replacement with biologic and mechanical valves in 1139 patients.

OBJECTIVE: We sought to compare 10-year survival in patients after mitral valve replacement with biologic or mechanical valve prostheses. METHODS: Retrospective survival analysis was performed on data from 1139 consecutive patients older than 18 years of age undergoing mitral valve replacement with Carpentier-Edwards (n = 495; Baxter Healthcare Corp, Irvine, Calif) or St Jude Medical (n = 644; St Jude Medical, Inc, St Paul, Minn) prostheses. RESULTS: The 10-year survival was not statistically different between the patients receiving Carpentier-Edwards valves and those receiving St Jude Medical valves (P =.16). Adjusted survival estimates at 2, 5, and 10 years were 82% +/- 2% (95% confidence intervals, 79%-85%), 69% +/- 2% (95% confidence intervals, 64%-73%), and 42% +/- 3% (95% confidence intervals, 37%-48%), respectively, for the Carpentier-Edwards group and 83% +/- 2% (95% confidence intervals, 80%-86%), 72% +/- 2% (95% confidence intervals, 69%-76%), and 51% +/- 3% (95% confidence intervals, 45%-58%), respectively, for the St Jude Medical group. Predictors of worse survival after mitral valve replacement are older age, lower ejection fraction, presence of class IV congestive heart failure, coronary artery disease, renal disease, smoking history, hypertension, concurrent other valve surgery, and redo heart surgery. CONCLUSION: Choice of biologic or mechanical prosthesis does not significantly affect long-term patient survival after mitral valve replacement.

Age Factors↗

PubMed2001

Development of a protocol for coronal reconstruction of the maxillofacial region from axial helical CT data.

Using a fresh frozen cadaver head, a series of axial helical CT scans were obtained using varying imaging parameters both before and after traumatizing the head. The appearance of reformatted coronal images was optimized for the lowest radiation dose. A protocol for imaging the maxillofacial region was developed that produced diagnostic coronal reconstructed images from the axial helical CT data.

Cadaver↗

PubMed2000

Frequency and duration of hospitalization of patients with AD based on Medicare data: CERAD XX.

Medicare records on 477 Consortium to Establish a Registry for Alzheimer's Disease patients with AD for 1991 through 1995 showed a hospitalization rate of 0.37/person-year with a length of stay of 3.7 days/ person-year (average of 10 days/hospitalization). Unmarried and less-educated patients with AD were admitted to the hospital more frequently, and, along with black patients, had a longer length of stay. Frequency and duration of hospitalization were greater in the patients with AD than in Medicare beneficiaries in general, but the rate of diagnostic/therapeutic procedures was lower.

Alzheimer Disease↗

PubMed2000

Current health behaviors and readiness to pursue life-style changes among men and women diagnosed with early stage prostate and breast carcinomas.

BACKGROUND: Cancer survivors are at increased risk for developing secondary tumors, diabetes, osteoporosis, and cardiovascular disease, thus making them an important target population for health-related interventions. However, little is known regarding cancer survivors' behaviors and their interest in pursuing healthier diets, exercise, and smoking cessation. METHODS: A 65-item survey was mailed to 1667 patients diagnosed with early stage carcinoma of the breast or prostate that requested data regarding demographics, health behaviors, stage of readiness for smoking cessation, exercise, increased fruit and vegetable (F&V) consumption, and decreased fat intake, as well as interest in specific health programs and when, relative to diagnosis, these programs should be offered. RESULTS: Responses from 978 cancer survivors suggested that the overwhelming majority (85%) reported their health as good to excellent. The majority of respondents (55%) ate fewer than 5 daily servings of F&Vs, with prostate carcinoma patients reporting eating significantly fewer servings than patients with breast carcinoma (P < 0.001). In contrast, 69% of respondents reported adherence to a low fat diet, again with lower practice rates among prostate carcinoma patients than patients with breast carcinoma (P = 0.006). The majority of respondents (58%) reported routine exercise and 8% were current smokers. Significantly more breast carcinoma patients than prostate carcinoma patients were current smokers (P = 0.03). There was strong interest in health promotion programs across behaviors, and a fair amount of concordance between low fat dietary behaviors and exercise, as well as consumption of five daily servings of F&Vs. The majority of patients expressed a preference for programs that could be delivered via mailed brochure, with 57% of respondents indicating that programs should be initiated at the time of diagnosis or soon after (within 6 months). CONCLUSIONS: The results of the current study suggest that although many cancer survivors already practice healthy life-style behaviors, there is a substantial proportion who do not. Interventions especially are needed to increase daily F&V intake; however, given the fair degree of clustering between dietary and exercise behaviors, multiple risk factor interventions also may be warranted. Among cancer survivors, receptivity is high for health promotion programs, especially those that can be delivered by mail and soon after diagnosis.

Adult↗

PubMed2000

Specific binding of IL-8 to rabbit alpha-macroglobulin modulates IL-8 function in the lung.

OBJECTIVE AND DESIGN: The purpose of this study was to compare chemotactic activity of IL-8 alone with that of IL-8 reacted with rabbit alpha-macroglobulins (alphaM) in vivo. METHODS: Initially the binding of recombinant human IL-8 (rhIL-8) to rabbit alphaM was studied. 125I-labeled rhIL-8 was incubated with alphaM, and electrophoresed on native 5% gels or SDS-polyacrylamide 4-20% gradient gels. Next, rhIL-8 or rhIL-8 bound to alphaM was administered via an endotracheal tube to rabbit's lungs. TREATMENT: An endotracheal tube was wedged into a segment of the lobe of each lung, and a sample instilled through the tube into this segment. After 4 h the lungs were lavaged. RESULTS: rhIL-8 bound to alphaM retained its full chemotactic activity in vitro but exhibited a diminished ability to induce the influx of neutrophils into the rabbit lung. CONCLUSIONS: The data suggest that alphaM may facilitate IL-8 clearance from the lung.

Animals↗

PubMed2000

Center surround receptive field structure of cone bipolar cells in primate retina.

In non-mammalian vertebrates, retinal bipolar cells show center-surround receptive field organization. In mammals, recordings from bipolar cells are rare and have not revealed a clear surround. Here we report center-surround receptive fields of identified cone bipolar cells in the macaque monkey retina. In the peripheral retina, cone bipolar cell nuclei were labeled in vitro with diamidino-phenylindole (DAPI), targeted for recording under microscopic control, and anatomically identified by intracellular staining. Identified cells included 'diffuse' bipolar cells, which contact multiple cones, and 'midget' bipolar cells, which contact a single cone. Responses to flickering spots and annuli revealed a clear surround: both hyperpolarizing (OFF) and depolarizing (ON) cells responded with reversed polarity to annular stimuli. Center and surround dimensions were calculated for 12 bipolar cells from the spatial frequency response to drifting, sinusoidal luminance modulated gratings. The frequency response was bandpass and well fit by a difference of Gaussians receptive field model. Center diameters were all two to three times larger than known dendritic tree diameters for both diffuse and midget bipolar cells in the retinal periphery. In one instance intracellular staining revealed tracer spread between a recorded cell and its nearest neighbors, suggesting that homotypic electrical coupling may contribute to receptive field center size. Surrounds were around ten times larger in diameter than centers and in most cases the ratio of center to surround strength was approximately 1. We suggest that the center-surround receptive fields of the major primate ganglion cell types are established at the bipolar cell, probably by the circuitry of the outer retina.

Animals↗

PubMed2000

Prolonged hypernatremia controls elevated intracranial pressure in head-injured pediatric patients.

OBJECTIVE: To determine the effects continuous infusions of hypertonic saline (3% NaCl) on intracranial pressure (ICP) control and describe the physiologic effects of hypertonic saline administered to closed head injury children. DESIGN: Retrospective chart review. SETTINGS: Pediatric intensive care unit of a children's hospital. PATIENTS: Sixty-eight children with closed head injury. INTERVENTIONS: Intravenous infusion of 3% hypertonic saline to increase serum sodium to levels necessary to reduce ICP < or =20 mm Hg. MEASUREMENTS AND MAIN RESULTS: The patients enrolled had similar Injury Severity Scores. Treatment effectively lowered ICP in these patients and ICP was under good control a majority of the time. Only three patients (4%) died of uncontrolled elevation of ICP. No adverse effects of supraphysiologic hyperosmolarity such as renal failure, pulmonary edema, or central pontine demyelination, were noted. CONCLUSIONS: Hypertonic saline administration to children with closed head injury appears to be a promising therapy for control of cerebral edema. Further controlled trials are required to determine the optimal duration of treatment before widespread use is advocated.

Child↗

PubMed2000

Use of hypertonic saline in the treatment of severe refractory posttraumatic intracranial hypertension in pediatric traumatic brain injury.

OBJECTIVES: To evaluate the effect of prolonged infusion of 3% hypertonic saline (514 mEq/L) and sustained hypernatremia on refractory intracranial hypertension in pediatric traumatic brain injury patients. DESIGN: A prospective study. SETTING: A 24-bed Pediatric Intensive Care Unit (Level III) at Children's Hospital. PATIENTS: We present ten children with increased intracranial pressure (ICP) resistant to conventional therapy (head elevation at 30 degrees, normothermia, sedation, paralysis and analgesia, osmolar therapy with mannitol, loop diuretic, external ventricular drainage in five patients), controlled hyperventilation (Pco2, 28-35 mm Hg), and barbiturate coma. We continuously monitored ICP, cerebral perfusion pressure (CPP), mean arterial pressure, central venous pressure, serum sodium concentrations, serum osmolarity, and serum creatinine. INTERVENTIONS: A continuous infusion of 3% saline on a sliding scale was used to achieve a target serum sodium level that would maintain ICP <20 mm Hg once the conventional therapy and barbiturate coma as outlined above failed to control intracranial hypertension. MEASUREMENTS AND MAIN RESULTS: The mean duration of treatment with 3% saline was 7.6 days (range, 4-18 days). The mean highest serum sodium was 170.7 mEq/L (range, 157-187 mEq/L). The mean highest serum osmolarity was 364.8 mosm/L (range, 330-431 mosm/L). The mean highest serum creatinine was 1.31 mg/dL (range, 0.4-5.0 mg/dL). There was a steady increase in serum sodium versus time zero that reached statistical significance at 24, 48, and 72 hrs (p < .01). There was a statistically significant decrease in ICP spike frequency at 6, 12, 24, 48, and 72 hrs (p < .01). There was a statistically significant increase in CPP versus time zero at 6, 12, 24, 48, and 72 hrs (p < .01). There was a statistically significant increase in serum osmolarity versus time zero at 12 hrs (p < .05) and at 24, 48, and 72 hrs (p < .01). Two patients developed acute renal failure and required continuous veno-venous hemodialysis; these were concurrent with an episode of sepsis and multisystem organ dysfunction. Both recovered full renal function with no electrolyte abnormalities at the time of discharge. CONCLUSION: An increase in serum sodium concentration significantly decreases ICP and increases CPP. Hypertonic saline is an effective agent to increase serum sodium concentrations. Sustained hypernatremia and hyperosmolarity are safely tolerated in pediatric patients with traumatic brain injury. Controlled trials are needed before recommendation of widespread use.

Acute Disease↗

PubMed2000

Risk factors for severe neuropsychiatric toxicity in patients receiving interferon alfa-2b and low-dose cytarabine for chronic myelogenous leukemia: analysis of Cancer and Leukemia Group B 9013.

PURPOSE: Recombinant interferon alfa-2b (rIFNalpha2b) is a standard therapy for chronic myelogenous leukemia (CML). Severe neuropsychiatric toxicity has been described in patients receiving rIFNalpha2b, although the frequency of and the risk factors for developing this toxicity are not well described. The purpose of this study was to identify predictors for the development of severe neuropsychiatric toxicity in CML patients receiving rIFNalpha2b-based therapy. PATIENTS AND METHODS: From a prospective cohort of 91 Philadelphia chromosome-positive, previously untreated, chronic-phase CML patients treated on Cancer and Leukemia Group B (CALGB) 9013, a phase II trial of rIFNalpha2b plus cytarabine, the following were recorded at baseline: age, sex, race, pretreatment history of neurologic or psychiatric diagnosis, spleen size, blood counts, and peripheral blast count. Best response to treatment, rIFNalpha2b cumulative dose, dose duration, and dose-intensity were recorded during follow-up. Severe neuropsychiatric toxicity was defined as grade 3 or 4 events, according to CALGB expanded common toxicity criteria. Univariate and multivariate logistic regression analyses were used to identify variables that were associated with the development of severe neuropsychiatric toxicity. RESULTS: Severe neuropsychiatric toxicity developed in 22 patients (24.0%; 95% confidence interval [CI], 15.2% to 32.8%). Toxicity resolved after withdrawal of treatment in all patients. Five of six patients developed recurrence of symptoms with rechallenge. Twelve (63%) of 19 patients with a pretreatment neurologic or psychiatric diagnosis developed severe neuropsychiatric toxicity, as compared with 10 (14%) of 72 patients without a pretreatment neurologic or psychiatric diagnosis (P =.001), resulting in a relative risk of 4. 55 (95% CI, 2.33 to 8.88) for developing severe neuropsychiatric toxicity. No other variables were independently associated with the development of neuropsychiatric toxicity. CONCLUSION: CML patients with a pretreatment history of a neurologic or psychiatric diagnosis are at significantly increased risk of developing severe neuropsychiatric toxicity during therapy with rIFNalpha2b plus cytarabine. Monitoring for neuropsychiatric symptoms and avoiding rechallenge are recommended measures for such patients receiving rIFNalpha2b-based therapy.

Adult↗

PubMed2000

Diagnostic maxillofacial coronal images reformatted from helically acquired thin-section axial CT data.

OBJECTIVE: This study was undertaken to determine the sensitivity and specificity of coronal images reformatted from helical thin-section axial CT data obtained for the evaluation of maxillofacial fractures. MATERIALS AND METHODS: Multiple fractures were created in nine cadaver heads by blunt trauma and were then evaluated using a late-generation helical CT scanner. Two neuroradiologists then independently evaluated the axial and reformatted coronal maxillofacial images. Subsequently, they reviewed the axial and direct coronal CT images, which were considered the criterion standard. RESULTS: A total of 87 fractures were identified. An experienced neuroradiologist failed to identify one displaced fracture and two nondisplaced fractures when evaluating the reformatted coronal and direct axial images for an overall sensitivity of 97%. A less experienced neuroradiologist failed to identify a total of five minimally displaced or nondisplaced fractures for an overall sensitivity of 94%. For each radiologist, no significant difference in the time required to interpret the direct versus the reformatted coronal images was seen. CONCLUSION: Interpretation of axial and reformatted coronal images resulted in accurate identification of displaced maxillofacial fractures in cadavers. This study suggests that the added cost and radiation exposure associated with incremental direct coronal CT may not be necessary for detection of clinically significant maxillofacial fractures and that further evaluation of this protocol in live trauma patients is warranted. However, because nondisplaced fractures were not routinely detected using reformatted coronal images, physical examination and clinical suspicion will still also remain necessary to determine the need for further imaging.

Facial Bones↗