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Biomedical subjects

D Jones

Publications and source records attributed to D Jones.

At least 307 records · Page 17Linked to original sources

Late mortality of long-term survivors of childhood cancer.

PURPOSE: To determine the frequency and patterns of late mortality among long-term survivors of childhood cancer. MATERIALS AND METHODS: Medical records of patients who survived at least 5 years after the diagnosis of childhood cancer were reviewed to determine the causes of subsequent deaths. Estimated 15-year survival and standardized mortality ratios for deaths from nonneoplastic treatment complications were compared with adjusted United States population estimates. The study included 2,053 patients who had survived > or = 5 years, grouped by treatment eras that reflected increased intensity of therapy and significantly improved survival (early era, 1962 to 1970; recent era, 1971 to 1983). RESULTS: There have been 258 subsequent deaths in the 2,053 childhood cancer survivors; 169 occurred 5 to 10 years postdiagnosis and 89 > or = 10 years post diagnosis. For the study period as a whole, deaths were attributed to recurrent primary malignancy in 61% of cases, second malignancy in 20%, nonneoplastic treatment complication in 10%, and unintentional injury/suicide in 8%. Late death from recurrent disease decreased significantly for survivors treated in the recent era (P < .0001), while the risk of death from second malignancies increased, although not statistically significantly (P = .10). Projected 15-year survival estimates for all > or = 5-year survivors in both treatment eras was greater than 90%, but differed from expected rates. CONCLUSION: Late mortality from recurrence after treatment for childhood cancer decreases with more effective initial therapy. Prolonged disease-free status is associated with an expected survival that approaches that of the general population for patients treated from 1971 through 1983. The impact of more recent intensified and novel therapies for high-risk patients remains to be determined.

Adolescent↗

The effect of regular salbutamol on lung function and bronchial hyperresponsiveness in normal subjects and nonasthmatic atopic subjects with allergic rhinitis.

BACKGROUND: The effects of regular inhaled beta-agonist treatment on lung function remain a controversial issue. In an earlier study, the administration of regular inhaled salbutamol resulted in negative changes in FEV1 not only in asthmatics, but also in nonasthmatic atopic subjects. OBJECTIVE: The aim of this study was to confirm these findings and also to examine whether regular inhaled salbutamol would increase bronchial hyperresponsiveness in atopic or normal individuals. DESIGN: The study was a randomized, double-blind, placebo-controlled, crossover investigation. PARTICIPANTS: There were two groups: 10 normal healthy subjects (group A) and nine nonasthmatic atopic subjects (group B). INTERVENTIONS: Subjects received inhaled salbutamol or identical placebo for periods of 6 weeks, the dose being increased in stepwise fashion at 2-week intervals. MEASUREMENTS: Changes in lung function were assessed by measuring spirometric values, airways conductance, and changes in complete and partial expiratory flow volume curves. Changes in these parameters following a methacholine challenge were used to assess bronchial hyperresponsiveness. RESULTS: No statistically significant differences in lung function or bronchial hyperresponsiveness were noted to occur as the result of treatment in either group. CONCLUSION: Our results do not support the view that regular inhaled salbutamol in normal or atopic subjects without asthma causes adverse changes in the airways.

Administration, Inhalation↗

Virtual environments for the rehabilitation of disorders of attention and movement.

The incidence of perceptual-motor disorders arising from stroke is steadily increasing in the population of Europe and USA. This chapter sought to define the role that virtual environments may have in designing remedial programmes for rehabilitation following stroke in the areas of attentional retraining and the reacquisition of perceptuo-motor skills. Principles for the structure of guided learning were identified and emphasis placed on the need to identify when and how virtual environments technology can introduce added value to the therapy situation.

Attention Deficit Disorder with Hyperactivity↗

Avian leukemias and lymphomas: interplay between retroviruses and herpesviruses.

Avian leukemias and lymphomas are caused primarily by retroviruses and herpesviruses. The protooncogenes activated by avian retroviral insertions in B & T-cell lymphomas will be summarized, with discussion on a new common insertion site, bravo, associated with RAV-O LTR insertion. Two novel interactions between avian retroviruses and Marek's disease herpesvirus (MDV) will be described: one involves direct interactions between putative viral oncoproteins and the other integrative recombination between these two viruses.

Alpharetrovirus↗

Cloning, expression and sequence analysis of the Bartonella henselae gene encoding the HtrA stress-response protein.

A cloned fragment of Bartonella (Rochalimaea) henselae (Bh) DNA was found to direct synthesis of an immunoreactive protein in Escherichia coli (Ec). Sequence analysis revealed an open reading frame of 1509 nucleotides encoding a protein of 503 amino acids that exhibited extensive identity (over the entire protein) with the HtrA stress-response proteins of Brucella abortus (59%), Ec (37%) and Salmonella typhimurium (36%). When the putative htrA gene was amplified by polymerase chain reaction and used as template for in vitro transcription and translation, a protein with an apparent molecular mass of 62 kDa was synthesized from the plasmid template. These results suggest that the immunoreactive Bh protein is homologous to the HtrA class of stress-response proteins.

Bartonella henselae↗

Local control in synchronous bilateral Wilms tumor.

PURPOSE: To evaluate the role of radiation therapy (RT), chemotherapy (CT), and surgery in the local control of synchronous bilateral Wilms Tumor (WT). METHODS AND MATERIALS: Between 1962 to 1993, 45 children were treated for bilateral WT; 38 patients with synchronous tumors were reviewed. Initial surgery depended on the era of treatment and included unilateral nephrectomy (N)/partial nephrectomy (PN) and contralateral PN in 6, unilateral N/PN alone in 7, and biopsy only in 25. Chemotherapy (CT) consisted of vincristine, actinomycin-D, and adriamycin in 32 and vincristine/ actinomycin-D in 6. Radiation therapy (RT) was given to 32 patients. Treatment included both kidneys in 20, unilateral kidney plus contralateral renal bed in 9, unilateral kidney in 2, and unilateral renal bed in 1. Follow-up was 16 months to 25 years (median: 6.3 years). RESULTS: Local control (LC) has been maintained in 66 out of 76 sites (87%). For Stage I-II disease with initial N/PN, LC was 10 out of 12 with RT and 11 out of 11 without RT; for Stage III with initial N/PN, LC was 8 out of 9 with RT and 1 out of 1 without RT. Initial CT and RT was followed by delayed N/PN for 20 sites; LC was 15 out of 17 in post induction Stage I-II and 1 out of 3 in postinduction Stage III. In 23 sites undergoing biopsy and chemotherapy, LC was 19 out of 20 with RT and 1 out of 3 without RT. Seven of 23 sites had a complete response (CR) after induction CT, and LC was maintained in four out of four with RT and one out of three without RT. Univariate Cox Regression analysis demonstrated that sites receiving two drugs had a statistically significant increase in loco-regional relapse when compared to sites receiving three drugs (p = 0.004). Major morbidities related to multimodality therapy have included renal failure in one patient and small bowel obstruction requiring lysis of adhesions in two patients. CONCLUSIONS: Local control does not seem to be compromised by renal conservation therapy. Local control is excellent in sites treated with radiation therapy in combination with three drug chemotherapy.

Adolescent↗

Simultaneous blockade of intracellular calcium increases and of neuronal epileptiform depolarizations by verapamil.

The specific L-type calcium channel blocker verapamil exerts an antiepileptic effect on neurons. This effect is assumed to depend on the blockade of transmembraneous calcium flux during epileptic discharges. In order to test this hypothesis, fura-dextran loaded snail neurons were rendered epileptic by pentylenetetrazole (40 mmol/l). The effect of verapamil (20 or 40 mumol/l) on free intracellular calcium ([Ca2+]i) transients was investigated by means of fluorescence ratio-imaging and simultaneous intracellular membrane potential recording. During epileptic depolarization [Ca2+]i increased especially in the outermost submembraneous areas of the neuron. [Ca2+]i reached peak values 6-22 s after the onset of epileptic depolarizations. Application of verapamil progressively shortened the epileptic depolarizations. This shortening of epileptic depolarizations developed along with a diminution of the submembraneous calcium signals down to noise level. The effect was found to be reversible. It is concluded that the antiepileptic effect of verapamil depends largely on its ability to block transmembraneous calcium flux.

Animals↗

Microfabricated structures for integrated DNA analysis.

Photolithographic micromachining of silicon is a candidate technology for the construction of high-throughput DNA analysis devices. However, the development of complex silicon microfabricated systems has been hindered in part by the lack of a simple, versatile pumping method for integrating individual components. Here we describe a surface-tension-based pump able to move discrete nanoliter drops through enclosed channels using only local heating. This thermocapillary pump can accurately mix, measure, and divide drops by simple electronic control. In addition, we have constructed thermal-cycling chambers, gel electrophoresis channels, and radiolabeled DNA detectors that are compatible with the fabrication of thermocapillary pump channels. Since all of the components are made by conventional photolithographic techniques, they can be assembled into more complex integrated systems. The combination of pump and components into self-contained miniaturized devices may provide significant improvements in DNA analysis speed, portability, and cost. The potential of microfabricated systems lies in the low unit cost of silicon-based construction and in the efficient sample handling afforded by component integration.

Automation↗