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D Jones

Publications and source records attributed to D Jones.

At least 145 records · Page 8Linked to original sources
PubMed2000

Design and fabrication of a half-beam wedge for treatment of breast patients.

PURPOSE: The Radiation Oncology Department of Kansas University Cancer Center on the average treats approximately 60 breast patients per year. Many of them require large field sizes with widths greater than 20 cm. Our purpose is to design a half-beam wedge that is lighter in weight than a standard wedge for larger field sizes. This could replace the compensator and reduce the number of monitor units. We have designed and fabricated half-beam wedges for a Varian linear accelerator, with the angles of 15, 30 and 45 degrees for a 6 MV photon beam. A set of dosimetry data for these wedges was entered into a treatment planning computer. The treatment plans generated using these newly designed wedges were compared with those using standard wedges. METHODS AND MATERIALS: From basic principles, the geometry for the design of the wedges was calculated for three angles, 15, 30 and 45. Using trays provided by Varian, three brass wedges were milled and attached to the trays. Measurements were taken in a water phantom with three wedge angles, 15, 30 and 45, for treatment planning purposes. CONCLUSION: The design and fabrication of a half-beam wedge for the use of treatment with large field sizes could reduce the need for fabrication of a compensator. This would also reduce the time required for treatment and give a better dose distribution.

Breast Neoplasms↗
PubMed2000

Prevalence of adolescent injury from recreational exercise: an Australian perspective.

PURPOSE: To report the prevalence of recent adolescent recreational and sporting activities and associated injury. METHODS: Data were collected during three school terms in 1997 using a validated questionnaire administered once only to 3538 girls and boys aged 11-12 years and 15-16 years. These students comprised 97.5% of the students in these age ranges in randomly selected state and private schools in the Adelaide metropolitan area (South Australia). Participants identified up to three recreational and/or sporting activities in which they had participated in the previous week. Data were collected on the nature and extent of participation, and on associated injuries. Participation and injury reports were summarized descriptively in gender strata in the two adolescent age groups and stratum specific odds ratios were used to explore injury risk. RESULTS: Subjects reported participating in 8997 sporting and/or recreational activities in the preceding week (an average of 2.5 participations per student). Over 140 sports and recreational pursuits were represented, incorporating organized and nonorganized activities undertaken in teams, social groups, or alone. Approximately 25% of adolescents reported at least one recreational injury. Injuries were mostly minor, reflecting soft tissue trauma and skin abrasions. Organized group sport incurred the highest risk of injury. There were marked gender and year level differences in injury risk in a number of common activities. CONCLUSIONS: These findings support the need for ongoing education regarding injury prevention and management.

Adolescent↗
PubMed2000

A phase I trial of recombinant human thrombopoietin in patients with delayed platelet recovery after hematopoietic stem cell transplantation.

Delayed platelet recovery is a significant complication after both autologous and allogeneic hematopoietic stem cell transplantation (HSCT). A multicenter, phase I dose-escalation study of recombinant human thrombopoietin (rhTPO) was conducted to assess its safety and to obtain preliminary data on its efficacy in patients with persistent severe thrombocytopenia (<20,000/microL) >35 days after HSCT. Thirty-eight patients, 37 of whom were evaluable, were enrolled in the study from April 1996 through January 1997. rhTPO was administered at doses of 0.6, 1.2, and 2.4 microg/kg as a single dose (group A) or in multiple doses every 3 days for a total of 5 doses (group B). No significant adverse effects were observed. Ten patients had recovery of platelet counts during the 28-day study period; 3 of these 10 had an increase in marrow megakaryocyte content 7 days after completing treatment with rhTPO. When all baseline marrows were compared with samples after rhTPO treatment, there was no difference in marrow megakaryocyte content (P = 0.49). This study design could not answer the question of whether the recoveries of platelet counts observed in some patients were spontaneous or influenced by rhTPO treatment; nonetheless, the authors found no correlation between the dose of rhTPO and the recovery of platelet counts. Increases in serum TPO levels were dose-dependent and remained significantly elevated for up to 72 hours after treatment. To evaluate response, further studies of treatment strategies with rhTPO in patients with delayed platelet recovery are required.

Adolescent↗
PubMed2000

Primary seminal vesicle carcinoma: an immunohistochemical analysis of four cases.

Primary adenocarcinoma of the seminal vesicles is an extremely rare neoplasm. Because prompt diagnosis and treatment are associated with improved long-term survival, accurate recognition of this neoplasm is important, particularly when evaluating limited biopsy material. Immunohistochemistry can be used to rule out neoplasms that commonly invade the seminal vesicles, such as prostatic adenocarcinoma. Previous reports have shown that seminal vesicle adenocarcinoma (SVCA) is negative for prostate-specific antigen (PSA) and prostate-specific acid phosphatase (PAP); however, little else is known of its immunophenotype. Consequently, we evaluated the utility of cancer antigen 125 (CA-125) and cytokeratin (CK) subsets 7 and 20 for distinguishing SVCA from other neoplasms that enter the differential diagnosis. Four cases of SVCA-three cases of bladder adenocarcinoma and a rare case of adenocarcinoma arising in a mullerian duct cyst-were immunostained for CA-125, CK7, and CK20. Three of four cases of SVCA were CA-125 positive and CK7 positive. All four cases were CK20 negative. All bladder adenocarcinomas and the mullerian duct cyst adenocarcinoma were CK7 positive and negative for CA-125 and CK20. In addition, CA-125 immunostaining was performed in neoplasms that commonly invade the seminal vesicles, including prostatic adenocarcinoma (n = 40), bladder transitional cell carcinoma (n = 32), and rectal adenocarcinoma (n = 10), and all were negative for this antigen. In conclusion, the present study has shown that the CK7-positive, CK20-negative, CA-125-positive, PSA/PAP-negative immunophenotype of papillary SVCA is unique and can be used in conjunction with histomorphology to distinguish it from other tumors that enter the differential diagnosis, including prostatic adenocarcinoma (CA-125 negative, PSA/PAP positive), bladder transitional cell carcinoma (CK20 positive, CA-125 negative), rectal adenocarcinoma (CA-125 negative, CK7 negative, CK20 positive), bladder adenocarcinoma (CA-125 negative), and adenocarcinoma arising in a mullerian duct cyst (CA-125 negative).

Adenocarcinoma↗
PubMed2000

Sodium phosphate enhances plasmid DNA expression in vivo.

Intramuscular injection of plasmid DNA results in myofiber cell expression of proteins encoded by the DNA. The preferred vehicle for plasmid DNA injections has been saline (154 mM sodium chloride) or PBS (154 mM NaCl plus 10 mM sodium phosphate). Here, it is shown that injection of luciferase or beta-galactosidase encoding plasmid DNA in a 150 mM sodium phosphate vehicle into murine muscle resulted in a two- to seven-fold increase in transgene expression compared with DNA injected in saline or PBS. When the DNA encoded secreted alkaline phosphatase, preproinsulin or interferon, sodium phosphate vehicle increased their serum levels by two- to four-fold. When the DNA encoded mouse erythropoietin, sodium phosphate vehicle increased hematocrits by two-fold compared with DNA injected in saline. When the DNA encoded influenza nucleoprotein, sodium phosphate increased anti-nucleoprotein antibody titers by two-fold. The expression of luciferase from plasmid DNA instilled into lung was increased five-fold compared with that in vehicle without sodium phosphate. Incubation of plasmid DNA with muscle extract or serum showed that sodium phosphate protected the DNA from degradation. Thus, a change from sodium chloride to sodium phosphate vehicle can enhance the expression of plasmid DNA in a tissue, possibly by inhibiting DNA degradation. Gene Therapy (2000) 7, 1171-1182.

Alkaline Phosphatase↗
PubMed2000

Recurrences in nodal T-cell lymphoma. Changes in histologic appearance and immunophenotype over the course of disease.

We examined the patterns of relapse or persistence in 37 cases of nodal peripheral T-cell lymphoma (PTCL) to address the morphologic and immunophenotypic findings. Relapses were documented in lymph node (25 cases) and/or a variety of extranodal sites at a mean of 21 months after presentation; several cases recurred as late as 13 years. Persistent bone marrow involvement was a feature of angioimmunoblastic lymphoma (AIL) and histiocyte-rich and small-cell tumors. Relapses in anaplastic tumors often involved unusual extranodal sites. The majority of relapsed PTCLs retained a similar histologic appearance, pattern of nodal involvement, and immunophenotype. Histologic progression, as assessed by increased numbers of large cells, was seen in 3 cases of AIL, in 1 case with an initial small cell morphologic appearance, and in 2 cases of PTCL with an initial mixed small and large cell appearance. Immunostains for T-cell activation markers showed increased immunoreactive cells in 5 of the 6 cases, whereas increased numbers of p53-positive tumor cells were noted in 3 of the 6 cases. The discrete large cell transformation occasionally seen in B-cell lymphoma and extranodal T-cell lymphoma was not observed in these cases.

Adolescent↗
PubMed2000

Influence of Helicobacter pylori on reactive oxygen-induced gastric epithelial cell injury.

Risk factors for gastric cancer are receiving renewed attention in light of the recent positive association of Helicobacter pylori infection with gastric cancer. The effect of H.pylori on the balance between oxidants and antioxidants in the stomach is not well known. In this study, we investigated if exposure of gastric cells to H. pylori increases oxidant-associated gastric epithelial cell injury. A human gastric epithelial cell line (AGS) was grown on 96-well clusters, then exposed overnight to either live H.pylori (four cagA(+) and four cagA(-)) or broth culture supernatant from an isogenic H.pylori cagA(+) strain with and without vacA activity. Incubation of AGS cells with cagA(+) and cagA(-) H.pylori strains before exposure to reactive oxygen species (ROS) reduced cell viability on average to 73.7% and 39.5% of controls, respectively. The percent viability of cells exposed to ROS after incubation with control broth, vacA(-) broth and vacA(+) broth was 97.7%, 70.5% and 63.5%, respectively. Experiments were then performed to evaluate the effects of H.pylori exposure on the activities of ROS-scavenging enzymes [catalase, glutathione peroxidase and superoxide dismutase (SOD)] and formation of 8-hydroxy-2-deoxyguanosine (8-OH-dG) adducts in AGS cells. Overnight exposure to cagA(-) strains reduced catalase activity by 42%; in contrast, exposure to cagA(+) H.pylori strains increased catalase activity by 51%. Glutathione peroxidase activity increased with exposure to both cagA(-) and cagA(+) strains by 95% and 240%, respectively. Total SOD activity increased 156% after exposure to cagA(+) strains and was marginally increased (52%) with exposure to cagA(-) strains. CuZn-SOD protein levels, assayed by enzyme-linked immunosorbent assay, were not significantly altered by exposure to H.pylori strains; however, Mn-SOD concentrations were significantly increased (P: < 0.02) after exposure to both cagA(-) and cagA(+) H.pylori strains. Exposure of AGS cells to cagA(+) and cagA(-) H.pylori was associated with, on average, 44.5 and 99.0 8-OH-dG/10(6) dG, respectively. The increase in catalase, glutathione peroxidase and SOD activity is associated with fewer 8-OH-dG DNA adducts and reduced susceptibility of AGS cells to lethal injury from ROS after exposure to cagA(+) H.pylori strains when compared with exposure to cagA(-) H.pylori strains. Alteration in the activity of ROS-scavenging enzymes by the presence of H. pylori may in part be responsible for the increased risk of gastric cancer in persons infected with H.pylori.

Antigens, Bacterial↗
PubMed2000

Eye examinations for VA patients with diabetes: standardizing performance measures.

OBJECTIVE: To demonstrate the potential of the Health Plan Employer Data and Information Set (HEDIS) for the calculation of a performance measure for eye exams in the diabetic population using Veterans Health Administration (VA) administrative data. DESIGN: We calculated a 1-year HEDIS-defined patient denominator and three alternative denominators that considered coding factors in identifying a VA patient as diabetic. We calculated the HEDIS-defined numerator, along with alternative specifications that captured other types of eye exams. Finally, we supplemented national data with VA pharmacy and Medicare claims data to identify all VA diabetic patients at 14 selected VA facilities and to establish a more accurate picture of non-VA health care utilization. RESULTS: The national average annual HEDIS-defined eye exam rate in the VA was 26% in fiscal 1997 compared with 39% for managed care organizations. Medicare utilization raised this by 15 percentage points at 14 northeastern VA hospitals. Over 2 years, at least two-thirds of diabetic VA patients had some type of eye exam through VA or Medicare. CONCLUSION: A HEDIS measure of eye exams for VA patients with diabetes can be calculated using VA administrative data only. However, the question remains to what extent the denominator and numerator accurately and completely identify all diabetic patients using VA services and all appropriate eye exams. We recommend caution in interpreting the results of performance measurement across different health care sectors based on what we currently know are data system limitations.

Adult↗
PubMed2000

Epidural ropivacaine with fentanyl following major gynaecological surgery: the effect of volume and concentration on pain relief and motor impairment.

In a prospective, randomized, double-blind study, 40 patients undergoing gynaecological oncology surgery received either 0.1% ropivacaine with fentanyl 1 microgram ml-1 or 0.2% ropivacaine with fentanyl 2 micrograms ml-1. A PCEA pump was set to deliver ropivacaine 8 mg with fentanyl 8 micrograms with each successful demand and a lockout period of 15 min without background infusion. Patients were observed for rest and activity pain VAS, side effect incidence, peak expiratory flow rate (PEFR), leg strength, sensory block to cold and pinprick, and PCEA usage into the second postoperative day. Passive and active pain scores for both groups were both satisfactory and comparable for the duration of the study. There were no differences between groups with regard to side effects. There was a 24% increase in total drug used in the high-concentration/low-volume group (P < 0.05). The study demonstrated that PCEA ropivacaine with fentanyl is an effective means of postoperative analgesia for this patient population. Reduced drug consumption with high-volume/low-concentration solution confirms similar findings by other investigators using alternate local anaesthetic agents, and suggests that the therapeutic ratio of ropivacaine is widened if a low-concentration/high-volume solution is used.

Adult↗
PubMed2000

A chromosomal abnormality in hyaline vascular Castleman's disease: evidence for clonal proliferation of dysplastic stromal cells.

The pathogenesis of the hyaline vascular variant of Castleman's disease is currently unknown; however, vascular and dendritic cell proliferations are common in this disorder. We report a clonal karyotypic abnormality (46,XX,t(1;16) (p11;p11), del(7)(q21q22),del(8)(q12q22)) in 15 of 20 cells obtained after short-term stromal cultures of a typical case of hyaline vascular Castleman's disease (HVCD). There was no histologic, immunohistochemical, or genotypic evidence of a clonal lymphoid or plasma cell proliferation supporting origin of this aberration from the stromal component, possibly dendritic cells. We re-examined 15 previous cases of HVCD and identified a spectrum of dysplastic changes in the follicular dendritic cells (FDC) of atrophic lymphoid follicles, with some cases showing expansions of FDC networks by CD21 immunostaining. We propose that localized clonal proliferations of stromal elements, particularly follicular dendritic cells, occur in typical HVCD and likely explain the increased incidence of FDC sarcomas in these patients.

Adult↗
PubMed2000

Precursor B-cell lymphoblastic lymphoma: a predominantly extranodal tumor with low propensity for leukemic involvement.

Precursor B-cell lymphoblastic lymphoma (B-LBL) is uncommon and accounts for less than 10% of cases of lymphoblastic lymphoma. We collected 25 cases of B-LBL, occurring in children and adults, and report the clinical and histologic features. Patients with concurrent precursor B-cell acute lymphoblastic leukemia (B-ALL) or a history thereof were excluded. There was no evidence of bone marrow disease at the time of diagnosis in 23 patients; two patients had focal (<5%) involvement. Immunophenotypic analysis was performed in all cases using flow cytometry or immunohistochemical methods. The treatment and survival data available for a subset of patients with B-LBL were compared with those from a series of patients with B-ALL at our institution. The median age was 20 years (range, 5-68 yrs); 22 (88%) patients were younger than 35 years of age. There were 17 males and 8 females. The primary sites of disease were skin (nine cases), bones (five cases), soft tissue (four cases), lymph nodes, (three cases), breast (two cases), stomach and colon (one case), and mediastinum (one case). Clinical stage was stage I in 13 cases, stage II in seven cases, stage III in three cases, and stage IV in two cases. Histologically, each neoplasm was diffuse and composed of small to medium-sized lymphoid cells with blastic nuclear chromatin and a high mitotic rate. All cases were positive for B-cell antigens and terminal deoxynucleotidyl transferase. Thirteen (76.4%) of 17 cases analyzed were positive for CD10 and 13 (54.1%) of 24 cases assessed were positive for CD20. Of 14 patients with available survival data, all achieved complete clinical response after combination chemotherapy (13 patients) or surgical excision followed by local irradiation (one patient). Five (35.7%) patients subsequently relapsed, including the patient who had received only irradiation, and four of these patients died after a median survival time of 60 months. None of the patients had leukemia, although one patient developed extensive bone marrow involvement. Nine patients remained in complete remission and were alive at the last follow up (range, 6-144 months). Unlike precursor T-cell lymphoblastic lymphoma, which commonly involves lymph nodes and the mediastinum, B-LBL usually involves extranodal sites, most often the skin, and rarely presents as a mediastinal mass. With aggressive chemotherapy, patients with precursor B-LBL rarely develop leukemia and appear to have a better prognosis than do patients with B-ALL.

Adolescent↗
PubMed2000

Fluvoxamine reduces physiologic reactivity to trauma scripts in posttraumatic stress disorder.

This study assessed the effect of open-label fluvoxamine treatment for posttraumatic stress disorder (PTSD), depressive symptoms, and physiologic arousal to trauma cues. Baseline psychometric ratings and physiologic assessments of heart rate and blood pressure responses to individualized, taped trauma scripts were determined for 16 patients with PTSD and 16 mentally healthy age- and gender-matched control subjects exposed to at least 1 serious trauma. Patients with PTSD had greater autonomic reactivity than control subjects at baseline, with physiologic measures correlating with the severity of the PTSD for the combined groups. Discriminant analyses indicated that systolic blood pressure best classified patients with PTSD (75% sensitivity) and control subjects (100% specificity), with a stepwise discriminant analysis showing that combined physiologic variables correctly classified 75% of patients with PTSD and 100% of control subjects. After 10 weeks of fluvoxamine treatment (100-300 mg/day), patients' PTSD, depression, and physiologic reactivity improved significantly. Medicated patients with PTSD could not be distinguished statistically from untreated control subjects in any physiologic measure. This dampening of autonomic reactivity after drug treatment corroborates subjective measures of improvement, validating the reported efficacy of fluvoxamine in this open trial.

Adult↗
PubMed2000

Analysis of genetic and phenotypic heterogeneity in juvenile polyposis.

BACKGROUND: Juvenile polyposis syndrome (JPS) is characterised by gastrointestinal (GI) hamartomatous polyposis and an increased risk of GI malignancy. Juvenile polyps also occur in the Cowden (CS), Bannayan-Ruvalcaba-Riley (BRRS) and Gorlin (GS) syndromes. Diagnosing JPS can be problematic because it relies on exclusion of CS, BRRS, and GS. Germline mutations in the PTCH, PTEN and DPC4 (SMAD4) genes can cause GS, CS/BRRS, and JPS, respectively. AIMS: To examine the contribution of mutations in PTCH, PTEN, and DPC4 (SMAD4) to JPS. METHODS: Forty seven individuals from 15 families and nine apparently sporadic cases with JPS were screened for germline mutations in DPC4, PTEN, and PTCH. RESULTS: No patient had a mutation in PTEN or PTCH. Five different germline mutations were detected in DPC4; three of these were deletions, one a single base substitution creating a stop codon, and one a missense change. None of these patients had distinguishing clinical features. CONCLUSIONS: Mutations in PTEN and PTCH are unlikely to cause juvenile polyposis in the absence of clinical features indicative of CS, BRRS, or GS. A proportion of JPS patients harbour DPC4 mutations (21% in this study) but there remains uncharacterized genetic heterogeneity in JPS.

Adenomatous Polyposis Coli↗
PubMed2000

Orthostatic hypotension as a risk factor for stroke: the atherosclerosis risk in communities (ARIC) study, 1987-1996.

BACKGROUND AND PURPOSE: The association between orthostatic hypotension (OH) and stroke has rarely been investigated in longitudinal studies. The purpose of the present study was to determine whether OH predicts ischemic stroke in a middle-aged, biethnic population after adjustment for known stroke risk factors. Diastolic, systolic, and consensus OH were evaluated for baseline associations and for the ability to predict stroke. METHODS: In 11 707 persons from the Atherosclerosis Risk in Communities (ARIC) cohort who were free of stroke and overt heart disease at baseline, Cox proportional hazards analyses modeled the association between OH at baseline and incident ischemic stroke over 7.9 years of follow-up. OH was defined as a systolic blood pressure drop >/=20 mm Hg (systolic OH), a diastolic blood pressure drop >/=10 mm Hg (diastolic OH), or a drop in either (consensus OH) when a person changed from a supine to standing position. RESULTS: OH was predictive of ischemic stroke, even after adjustment for numerous stroke risk factors (consensus OH: hazard ratio, 2.0; 95% CI, 1.2 to 3.2). While the baseline characteristics associated with OH varied depending on the type of OH, all types of OH had a similar risk of stroke. CONCLUSIONS: OH is an easily obtained measurement that may help to identify middle-aged persons at risk for stroke.

Age Distribution↗
PubMed2000

Effects of polychlorinated biphenyls on the nervous system.

The neurological effects of polychlorinated biphenyls (PCBs) have been extensively investigated in humans and in animals. The main focus in human studies has been on the effects in neonates and young children, although studies of adults have also been conducted. A great deal of concern exists that even low levels of PCBs transferred to the fetus across the placenta may induce long-lasting neurological damage. Because PCBs are lipophilic substances, there is also concem that significant amounts might be transferred to nursing infants via breast milk. Studies in humans who consumed large amounts of Great Lakes fish contaminated with environmentally persistent chemicals, including PCBs. have provided evidence that PCBs are important contributors to subtle neurobehavioral alterations observed in newborn children and that some of these alterations persist during childhood. Some consistent observations at birth have been motor immaturity and hyporeflexia and lower psychomotor scores between 6 months and 2 years old. There is preliminary evidence that highly chlorinated PCB congeners, which accumulate in certain fish, are associated with neurobehavioral alterations seen in some newbom children. Subtle neurobehavioral alterations have also been observed in children bom to mothers in the general population with the highest PCB body burdens. Because of the limitations of epidemiological studies, these effects cannot be attributed entirely to PCB exposure. In one general population study, there was strong evidence that dioxins, as well as PCBs, were contributors to the neurobehavioral effects seen in exposed children. Children born to women who accidentally consumed rice oil contaminated with relatively high amounts of PCBs and chlorinated dibenzofurans (CDFs) during pregnancy also had neurodevelopmental changes. Studies in animals support the human data. Neurobehavioral alterations have been also observed in rats and monkeys following prenatal and/or postnatal exposure to commercial Aroclor mixtures, defined experimental congener mixtures, single PCB congeners, and Great Lakes contaminated fish. In addition, monkeys exposed postnatally to PCB mixtures of congeneric composition and concentration similar to that found in human breast milk showed learning deficits long after exposure had ceased. A few other generalizations can be made from the data in animals. It appears that ortho-substituted PCB congeners are more active than coplanar PCBs in modifying cognitive processes. In addition, one effect observed in both rats and monkeys--deficits on delayed spatial alternation--has been known to be induced by exposure to ortho-substituted PCBs, defined experimental mixtures, and commercial Aroclors. Both dioxin-like and non-dioxin-like PCB congeners have been shown to induce neurobehavioral alterations in animals. Changes in levels of neurotransmitters in various brain areas have also been observed in monkeys, rats, and mice. Of all the observed changes, the most consistent has been a decrease in dopamine content in basal ganglia and prefrontal cortex, but further research is needed before specific neurobehavioral deficits can be correlated with PCB-induced changes in specific neurotransmitters in specific brain areas.

Administration, Oral↗