Biomedical subjects

Freddi Lewin

Publications and source records attributed to Freddi Lewin.

8 recordsLinked to original sources

PubMed2006

Public health implications of smokeless tobacco use as a harm reduction strategy.

Harm reduction strategies involve promoting a product that has adverse health consequences as a substitute for one that has more severe adverse health consequences. Smokeless tobacco low in nitrosamine content offers potential benefits in reducing smoking prevalence rates. Possible harm arises from the potential for such products to serve as a gateway to more harmful tobacco products, public misinterpretation of "less harmful" as "safe," distraction from the public health goal of tobacco elimination, and ethical issues involved in advising those marketing these harmful products. We offer a research agenda to provide a stronger basis for evaluating the risks and benefits of smokeless tobacco as a means of reducing the adverse health effects of tobacco.

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PubMed2006

Flawed methods.

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Adult↗

PubMed2005

Randomized trial on two types of thermoplastic masks for patient immobilization during radiation therapy for head-and-neck cancer.

PURPOSE: Radiation therapy for head-and-neck cancer requires a reliable immobilization for an accurate and consistent treatment setup. This prospective, randomized study was done to compare two types of Posicast thermoplastic face masks, in terms of reproducibility, patient comfort, tolerability, and skin damage. METHODS AND MATERIALS: The patients were randomly assigned to use a head mask (HM) or a head-and-shoulder mask (HSM). Three-dimensional treatment planning was followed by fractionated external-beam radiation therapy. Reproducibility was assessed by comparing port films with simulator films twice during treatment and by comparing actual treatment table positions weekly. Patient tolerability and comfort were studied weekly. The radiation-induced skin damage was assessed every week according to the World Health Organization toxicity scale. RESULTS: A total of 260 patients were included, and 241 (93%) were evaluated. There were no statistically significant differences between the groups (HM or HSM) in terms of reproducibility. Patients using HSM experienced significantly more claustrophobia (p = 0.023). Patients allocated to HSM receiving > or = 60 Gy were found to have more skin reactions. CONCLUSIONS: The smaller HM reduced feelings of claustrophobia, as well as skin reactions, for patients receiving > or = 60 Gy. The smaller mask did not compromise the reproducibility of the setup.

Adult↗

PubMed2004

Long-term incidence of hypothyroidism after radiotherapy in patients with head-and-neck cancer.

PURPOSE: To determine the long-term incidence of postirradiation hypothyroidism (HT) in patients with head-and-neck cancer. METHODS AND MATERIALS: The incidence of overt HT was assessed prospectively in 391 patients with nonthyroid head-and-neck cancer admitted for radiotherapy (RT) consecutively between 1990 and 1996. Eighty-three patients were excluded from the analysis because of known thyroid disease before treatment (n = 27), no RT was given (n = 15), or inadequate follow-up (n = 41). Overt HT was defined as increased thyroid-stimulating hormone (TSH) in combination with decreased fT4/T4 or in combination with initiation of thyroxine replacement therapy. RESULTS: With a median follow-up of 4.2 years (range, 3 months to 10.9 years) for 308 evaluable patients, the 5- and 10-year Kaplan-Meier actuarial risks of HT were 20% and 27%, respectively. The median time until development of HT was 1.8 years (3 months to 8.1 years). Multivariate analysis showed that patients with bilateral RT to the neck had a higher risk of HT in comparison with unilateral neck RT (relative hazard, 0.37; p = 0.02). The addition of surgery to RT increased the overall risk of HT (p < 0.001); and if surgery involved the thyroid gland, the relative hazard was 4.74 (p < 0.001). For an elevated pre-RT TSH value, the relative hazard was 1.58 (p < 0.001). CONCLUSION: The incidence of overt HT after locoregional RT for nonthyroid head-and-neck cancer continues to increase with time, even after long-term follow-up. We recommend life-long TSH testing in these patients.

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PubMed2004

Adjusting for patient selection suggests the addition of docetaxel to 5-fluorouracil-cisplatin induction therapy may offer survival benefit in squamous cell cancer of the head and neck.

When induction chemotherapy is used in locally advanced squamous cell cancer of the head and neck (SCCHN), patients often receive cisplatin-5-fluorouracil (PF) followed by radical loco-regional therapy. Phase II studies of docetaxel-cisplatin-5-fluorouracil (TPF) induction therapy, with or without leucovorin (L), have achieved high survival rates versus those reported in phase III PF trials. However, the distribution of prognostic factors may vary between phase II and phase III study populations, making the extrapolation of phase II TPF/L results to phase III PF populations difficult. This study used a patient selection standardization method and Cox model to adjust for potential selection bias. Thus, the survival benefit from adding docetaxel into PF induction regimens in SCCHN could be more accurately assessed. The TPF/L dataset comprised 195 patients from six phase II trials. The PF dataset of 585 patients was derived from five large randomized trials included in the Meta-Analysis of Chemotherapy in Head and Neck Cancer (MACH-NC) database. TPF/L and PF datasets differed significantly concerning the distribution of several prognostic factors. Adjusting for these differences, the relative risk of death in the PF versus TPF/L datasets was 1.85 (95% confidence interval 1.37-2.49), corresponding to a 20% 2-year survival benefit (p < 0.0001). Sensitivity analyses confirmed that this improved 2-year survival rate of TPF/L over PF was robust, irrespective of the distribution of studied prognostic factors between treatment datasets. We conclude that this improved survival might be due either to docetaxel's pharmacologic effect or to uncontrolled prognostic factors.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

When does my treatment start?--The continuum of care for patients with head and neck cancer.

BACKGROUND AND PURPOSE: The clinical workup of patients with head and neck (H&N) cancer is often time-consuming. The overall time involved is obviously important to the treatment results, since delays in time can increase the risk for clinical upstaging resulting in a worse outcome. Although for ethical considerations, time delay is impossible to study in randomised trials. Major reorganisations for this group of patients have taken place in Stockholm during the 1990s. In this study, we measured the duration of the overall continuum of care experienced by the patients, in different time periods during the 1990s. MATERIALS AND METHODS: Two hundred and two patients from the population base of southern Stockholm were identified during different time periods. The continuum of care was identified as the period between the first presentation of the patient to the health care system to the first date of the patient's treatment for his/her cancer. This period was divided into several intervals reflecting the patient's perspective of his or her continuum of care. These intervals were then compared. RESULTS: Median time from first consultation to start of treatment increased between 1994 and 1999 from 67 to 89 days (P = 0.018). The increase of time occurred from referral from first care provider to ENT-specialist, from first visit to ENT-specialist to date of diagnosis. CONCLUSIONS: Different parameters such as duration of the continuum of care must be monitored before and after reorganisations.

Adult↗

PubMedDate not supplied

Cytokines and Epstein Barr virus (EBV) genes expression in blood chronic lymphocytic leukaemia (CLL) cells and their immortalised CLL cell lines.

We have encountered two unique chronic lymphocytic leukaemia (CLL) patients, PG and NN. Some blood CLL cells of these patients have been infected and carry Epstein Barr virus (EBV) in vivo. In spite of their early-activated G0/G1 stage of post germinal center (GC) memory cells, ex vivo EBV-carrying blood CLL cells of PG clone expressed LMPs and used specific QUK splice for their EBNA1 expression, similar to the EBV-carrying cells of non-B origin. Interestingly, EBV-carrying CLL cells of NN clone expressed LMP2a and used UK-splice for their EBNA1 expression, similar to the in vivo EBV-carrying high density normal B cells in the blood of healthy individuals. The CLL-derived lines but not normal lymphoblastoid cell line (LCL) used QUK- and YUK-splice for their EBNA1 expression. As expected, LCL and their permanent CLL-derived lines used Cp promoter and up-regulated their EBNA2 expression. Blood CLL cells and the CLL-derived cell lines of these patients spontaneously produced cytokines as shown by microarray assay. The types and quantities of cytokines might relate to their CLL origin and viral strain in the given CLL cells. Neither blood CLL nor their CLL-derived cell lines express any detectable apoptosis-inducer ligands, CD95L or Apo 3L. As a consequence of cell cycle progression, CLL-derived cell lines up-regulated their co-stimulator molecules CD80 and apoptosis-related receptor CD95. Since only the rare EBV-carrying CLL cells grew in vitro, the combination of viral genome and cytokines seems to be critical for the outgrowth of EBV-carrying CLL cells over their EBV-negative counterpart in vitro but not in vivo.

Cell Cycle↗

PubMedDate not supplied

Significance of RNA reference in tumour-related gene expression analyses by cDNA array.

The cDNA array technique is an efficient approach for studying the expression of a large number of genes in a single experiment. The cDNA array analysis indicates the relative level of corresponding gene expression from a specimen and a reference. Our investigation was performed to address the significance of reference RNA on the outcome of the cancer-related gene expression profile obtained from cDNA array analysis. Human head and neck squamous cell carcinoma (HNSCC) biopsies and 5 sources of RNA reference were used for this purpose. In these biopsies, each individual patient expressed a unique set of genes both in normal and tumour tissue. It is important to note that 5 striking patterns of tumour-related gene expression were obtained according to the 5 references used. Significant differences in 60%, 16%, 15% and 15% of the genes expressed were shown when autologous normal matched tissue biopsy references were compared to pooled cell lines, allogenic normal mixed cell types, tumours or allogenic normal matched cell type references, respectively. Thus, theoretically and our study suggested that patient autologous normal cells matching with the tumour type should be the most suitable reference in cDNA array for the identification of individual tumour gene profiles with clinical purpose.

Adult↗