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Biomedical subjects

R Hawks

Publications and source records attributed to R Hawks.

8 recordsLinked to original sources
PubMed2004

Outcomes of unrelated cord blood transplantation in pediatric recipients.

We report results of unrelated cord blood transplants (UCBT) in 29 pediatric recipients in one center and the risk factors associated with survival. Median age: 9 years (0.5-20); diagnosis: ALL (9), AML (4), CML (1), HD (3), HLH (1), NHL (3), NBL (2); B-thal (1), FA (1), FEL (1), Krabbe (1), WAS (1), SAA (1); median follow-up: 11 months; conditioning: total body irradiation (TBI)-ablative (14), chemotherapy-ablative (6) and reduced intensity chemotherapy (9); GVHD prophylaxis: MMF/FK506 (18), cyclosporin A (CsA)+steroids+/-MMF (7) or CsA+methotrexate (MTX) (4); median total nucleated cells (TNC): 3.8 x 10(7)/kg (1.1-11); median CD34+: 2.3 x 10(5)/kg (0.2-9.9); and HLA match: 2 (6/6), 5 (5/6), 22 (4/6). Neutrophil engraftment by cumulative incidence curves 63% (median 28 (95% confidence interval (CI) 18-32)). Probability of >/=grade II acute graft-versus-host disease (aGVHD) by day +60 27%, >/=grade III aGVHD 20% and chronic graft-versus-host disease 3%. Estimated 1-year overall survival (OS) 46% (95% CI 30-71) and standard risk 60% (95% CI 29-100%). Variables associated with improved survival by multivariate analysis include non-TBI-ablative conditioning (P=0.024), CD34+/kg (P=0.038) and gender (P=0.048). These results suggest that CD34/kg cell dose and non-TBI-ablative conditioning may be important variables influencing OS following UCBT in pediatric recipients. Given the small number of patients, these results should be viewed cautiously.

Adolescent↗
PubMed1998

High-dose thiotepa and etoposide-based regimens with autologous hematopoietic support for high-risk or recurrent CNS tumors in children and adults.

The prognosis in patients with primary brain tumors treated with surgery, radiotherapy and conventional chemotherapy remains poor. To improve outcome, combination high-dose chemotherapy (HDC) has been explored in children, but rarely in adults. This study was performed to determine the tolerability of three-drug combination high-dose thiotepa (T) and etoposide (E)-based regimens in pediatric and adult patients with high-risk or recurrent primary brain tumors. Thirty-one patients (13 children and 18 adults) with brain tumors were treated with high-dose chemotherapy: 19 with BCNU (B) and TE (BTE regimen), and 12 with carboplatin (C) and TE (CTE regimen). Patients received growth factors and hematopoietic support with marrow (n = 15), peripheral blood progenitor cells (PBPC) (n = 11) or both (n = 5). The 100 day toxic mortality rate was 3% (1/31). Grade III/IV toxicities included mucositis (58%), hepatitis (39%) and diarrhea (42%). Five patients had seizures and two had transient encephalopathy (23%). All patients had neutropenic fever and all pediatric patients required hyperalimentation. Median time to engraftment with absolute neutrophil count (ANC) >0.5 x 10(9)/l was 11 days (range 8-37 days). Time to ANC engraftment was significantly longer (P = 0.0001) in patients receiving marrow (median 14 days, range 10-37) than for PBPC (median 9.5 days, range 8-10). Platelet engraftment >50 x 10(9)/l was 24 days (range 14-53 days) in children. In adults, platelet engraftment >20 x 10(9)/l was 12 days (range 9-65 days). In 11 patients supported with PBPC, there was a significant inverse correlation between CD34+ dose and days to ANC (rho = -0.87, P = 0.009) and platelet engraftment (rho = -0.85, P = 0.005), with CD34+ dose predicting time to engraftment following HDC. Overall, 30% of evaluable patients (7/24) had a complete response (CR) (n = 3) or partial response (PR) (n = 4). Median time to tumor progression (TTP) was 7 months, with an overall median survival of 12 months. These TE-based BCNU or carboplatin three-drug combination HDC regimens are safe and tolerable with promising response rates in both children and older adults.

Adolescent↗
PubMed1995

Overview: medications development for the treatment of drug abuse.

Drug abuse is of great public concern, and effective treatment strategies for opiate and cocaine dependence are urgently needed for the general addict population as well as for pregnant women and their infants. NIDA's effort to develop new pharmacotherapies as an adjunct to the treatment of opiate addiction has already led to the approval of LAAM and an NDA development program for buprenorphine. The momentum achieved by the new Medications Development Program's success with opiate addiction treatment must now be applied to the development of new treatments for cocaine addiction. With recent advances in neuroscience, imaging techniques, and pharmaceutical technology, the development of medications for significantly improving drug abuse treatment in a variety of directions holds real promise.

Cocaine↗
PubMed1989

A homogeneous group of persons with learning disabilities: adults with severe learning disabilities in vocational rehabilitation.

The results of a comprehensive psychoeducational assessment of adults having learning disabilities (LD) and participating in vocational rehabilitation are presented. The subjects were found to have low-average general intelligence; lower verbal than performance IQs; attention, reasoning, and auditory memory deficits; academic achievement at the fourth-/fifth-grade level; language problems; and low self-esteem. These results were contrasted with other studies of adults with LD in vocational rehabilitation, and all studies on this population reported similar findings. A comparison of studies of adults with LD who were clients of vocational rehabilitation with those in college or employed and with those who had been labeled as learning disabled in childhood indicated that the adults with LD in vocational rehabilitation seem to constitute a homogeneous group of persons with severe deficits. The need to subtype learning disabilities by severity and criteria for making such determinations are proposed.

Adult↗
PubMedDate not supplied

Cocaine pharmacokinetics in humans.

Cocaine was given by intravenous administration to human subjects and the concentrations in plasma were measured by gas chromatography--mass spectrometry. Many pharmacokinetic parameters were found to have a strong dose dependence over the range 1 - 3 mg/kg. The terminal plasma half-life in minutes is given by the equation t1/2(beta) = 13.5 + 24.5 dose (r = 0.946). The total plasma clearance in liters/kg per h is 2.51--0.67 dose (r = -0.973). From analysis of previously published data the absorption half-life t1/2(ab) is approximately 8 min for gastrointestinal and for nasal inhalation absorption. The bioavailability for nasal inhalation is approximately 60%. While routes of administration for modern recreational use could lead to unexpected drug accumulation in the blood it is not likely to occur from chewing coca leaves.

Adult↗