Search PubMed⌕ Search

Biomedical subjects

Y Roth

Publications and source records attributed to Y Roth.

At least 19 recordsLinked to original sources
PubMed2001

Monitoring response to convection-enhanced taxol delivery in brain tumor patients using diffusion-weighted magnetic resonance imaging.

Convection-enhanced drug delivery (CEDD) is a novel approach to enhance the delivery of drugs directly into brain tumors. We have used diffusion-weighted MRI (DWMRI) to monitor the effects of intratumoral CEDD in three brain tumor patients treated with Taxol. Clear changes in the images and the water diffusion parameters were observed shortly after the initiation of treatment. Initially, a bright area corresponding to decreased diffusion appeared, followed by the appearance of a dark area of increased diffusion within the bright area. The time to appearance of the dark area varied among the patients, suggesting different response rates. In this work, we have demonstrated the feasibility of using DWMRI as a noninvasive tool to achieve unique early tissue characterization not attainable by other conventional imaging methods.

Antineoplastic Agents, Phytogenic↗
PubMed2000

Noninvasive real-time monitoring of intracellular cancer cell metabolism and response to lonidamine treatment using diffusion weighted proton magnetic resonance spectroscopy.

We have used diffusion-weighted proton magnetic resonance spectroscopy (DWMRS) to noninvasively selectively observe only the intracellular metabolites of breast cancer and melanoma cell lines in vitro in real time. Breast cancer cell lines representing different stages in breast cancer progression were chosen for study. Intracellular biochemical profiles of six cell lines perfused in alginate beads were obtained. Spectral differences between groups of cell lines, including choline, lactate, and threonine peaks, were investigated. We also monitored response to the antineoplastic agent, lonidamine (LND), as a function of time and drug concentration in perfused cancer cells. Previous studies reported that this drug induced intracellular acidification and lactate accumulation. Diffusion weighted proton spectra demonstrated a 2- to 9-fold increase in the intracellular lactate signal as a response to LND treatment in several cancer cell lines. These results are consistent with the hypothesis that the principal mechanism of LND in some cancer cells is marked inhibition of lactate transport. Moreover, we have shown that there is a factor of two to three between the response of melanoma cells and that of some types of breast cancer cells. The higher sensitivity of the melanoma cells, as predicted by proton DWMRS, was correlated with changes in water-suppressed magnetic resonance spectra and confirmed by a biological assay. This study demonstrates the feasibility of using DWMRS for monitoring intracellular metabolism and for studying the effects and mechanisms of action of anticancer drugs. We believe that this method can be used for noninvasive clinical applications, such as the differentiation between benign and malignant tissue, real-time monitoring of response to therapy, dose response, and toxicity effects.

Animals↗
PubMed1999

Nasal nitric oxide does not control basal nasal patency or acute congestion following allergen challenge in allergic rhinitis.

Nasal nitric oxide (NO), a powerful vasodilator, could control the filling of nasal capacitance vessels, thus determining nasal patency and mediating the acute congestion accompanying allergen challenge. We examined the effect of topical N-nitro-L-arginine-methyl-ester (L-NAME; 100 to 200 mg), an NO synthase inhibitor, on nasal NO and on nasal patency assessed by acoustic rhinometry in 7 subjects with nasal allergy, and in 4 subjects we examined the effects of nasal allergen challenge on nasal NO before and after a short course of nasal steroid. After L-NAME, nasal NO fell to 42.1%+/-15.7% of baseline (p < .0001) with no significant change in minimal cross-sectional area. After allergen challenge, acute congestion was associated with a significant fall in nasal NO, which returned to baseline by 4 hours, when the congestion resolved. Repeat challenge after 2 weeks of nasal corticosteroid yielded similar findings. A role for NO in modulating vascular tone was not supported by the present study.

Acute Disease↗
PubMed1998

An objective analysis of the impact of lateral rhinotomy and medial maxillectomy on nasal airway function.

OBJECTIVE: The lateral rhinotomy and medial maxillectomy procedure, while known to interrupt nasal valve supports, has not previously been reported to adversely affect nasal airway function. The purpose of this study was to utilize state-of-the-art techniques to objectively analyze the impact of this procedure on nasal airway function. DESIGN: The study design was retrospective and subject controlled. METHODS: The study population was derived from an academic, tertiary-referral, otolaryngology-head and neck surgery department with an estimated catchment population of 4 million people. Subjects included 21 consecutive, long-term postoperative patients who had undergone lateral rhinotomy and medial maxillectomy for inverted papilloma. Objective measures included vestibular cephalometric measurements, airflow rhinomanometry, and acoustic rhinometry. RESULTS: Statistically significant results reveal that although lateral rhinotomy and medial maxillectomy are associated with alar collapse, both overall nasal airflow and valve areas are increased. CONCLUSION: Lateral rhinotomy and medial maxillectomy does not adversely affect nasal airway function. This appears to be the result of concomitant resection of the functionally dominant inferior turbinate. This suggests that lateral rhinotomy performed in conjunction with operations not requiring inferior turbinectomy, such as anterior craniofacial resection, may adversely affect nasal airway function.

Acoustics↗
PubMed1997

Distant metastases in terminal head and neck cancer patients.

With improved control of cancer above the clavicles, distant metastases (DM) are frequently more seen and are becoming a more common cause of morbidity and mortality. The present study defined the incidence of distant metastases in a cohort of terminal head and neck cancer patients (HNCP) and compared it to current reported data. The incidence of distant metastases in relation to the primary tumour was evaluated and their impact on survival was assessed. A retrospective survey of patient charts was made, based on the hospice database and original referring hospital charts. Data of 59 patients admitted to the hospice were evaluated. The incidence and location of locoregional and distant disease were studied and effects on survival analyzed. The overall survival from diagnosis to demise was 42.7 months. Thyroid cancer was seen in 20.3 per cent of cases and squamous cell cancer was seen in 59.3 per cent. Distant metastases were found in 83 per cent and 48.6 per cent of patients respectively. Laryngeal cancer patients had a 54.5 per cent incidence of distant metastases. Locoregional disease was seen in 47 per cent of cases and 35.7 per cent of them had distant metastases while a 64.3 per cent incidence of distant metastases was found in cases without locoregional disease. Mean survival was 47.3 months with distant metastases vs 36.5 months without metastases. The difference was not statistically significant. The incidence of distant metastases in squamous cell cancer in terminal HNCP was 48.6 per cent. This is the highest reported incidence of metastases in a clinical series. Patients without locoregional disease had almost a two-fold incidence of metastases. Survival was not affected by metastases in this series.

Aged↗
PubMed1996

An international comparison of characteristics of the sensation of nasal obstruction between Canadian and Japanese patients.

To determine differences in perception of nasal obstruction in Canadians and Japanese, we assessed subjective and objective nasal patency of 48 patients in Canada and 43 patients in Japan. Mean severity of the sensation of nasal obstruction in Canadian patients was significantly higher than in Japanese patients, while no significant differences in nasal resistances were found. Complaints of nasal obstruction in Canadian patients were directly concerned with nasal breathing, while Japanese patients complained of indirect matters, such as "unable to concentrate on job or study" or "nasal obstruction or nasal speech pointed out by other persons." The differences might be due to national characteristics.

Adult↗
PubMed1995

Care of the terminal head and neck cancer patient in the hospice setting.

The ratio of incidence to mortality is somewhat less than 3:1 for head and neck cancer, and the 5-year relative survival rate is 50%. Despite the high mortality rate, few reports have focused on patients with terminal head and neck cancer. A growing number of these patients end their lives in a hospice facility. A retrospective analysis was undertaken of 67 patients with terminal head and neck cancer who were admitted to the Tel Hashomer Hospice between 1988 and 1992. Patient data were reviewed and analyzed, and the particular characteristics of this population were defined. This study found that terminal head and neck cancer patients seem to receive better support in a hospice than in a general hospital or some family settings.

Aged↗
PubMed1994

Hyponatremia associated with laryngeal squamous cell carcinoma.

An association between laryngeal squamous cell carcinoma and inappropriate antidiuresis is described in a 76-year-old man. Even though all accepted diagnostic criteria for the syndrome of inappropriate secretion of antidiuretic hormone were fulfilled, abnormal levels of antidiuretic hormone were not demonstrated, leaving the mechanisms of this hyponatremia unclear.

Aged↗
PubMed1994

The effect of prostaglandins E2 and F2a on brain and tracheal ciliary activity.

Prostaglandins E2 and F2a have a mild stimulatory effect (+11% to 18% from baseline) on the in vitro ciliary beat frequency in tracheal rings, which contain mucus-producing cells, and in brain slices, which are devoid of mucus. Results are compared with previous studies and the merits of the used experimental models are discussed.

Animals↗
PubMed1993

Cerebrospinal fluid (CSF) otorhinorrhoea following vestibular schwannoma surgery treated by extended subtotal petrosectomy with obliteration.

Extended subtotal petrosectomy as a treatment for persistent cerebrospinal fluid (CSF) otorhinorrhoea is presented. Four patients were successfully operated on by this technique, all previously having undergone suboccipital removal of vestibular schwannoma: other interventions used had failed to seal the fistulae. The internal auditory canal was the usual pathway for CSF leakage as well as retrosigmoid, retrolabyrinthine, retro- or perifacial cells. Total exenteration of middle ear and mastoid cell tracts, skeletonization of sigmoid sinus, jugular bulb and facial nerve, drilling out of semicircular canals, vestibule, and cochlea, and skeletonization of the internal auditory canal, followed by obliteration, are the main steps of this approach.

Cerebrospinal Fluid Otorrhea↗
PubMed1993

Cimetidine improves GERD symptoms in patients selected by a validated GERD questionnaire.

A questionnaire was constructed and validated to improve the accuracy of symptom assessment in diagnosing gastro-oesophageal reflux disease (GERD). The GERD questionnaire consisted of four questions describing an upward moving, uncomfortable feeling in the chest frequently accompanied by retrosternal burning that is improved with antacids. It was found that if a patient answered yes to all four questions the likelihood was 85% that erosive oesophagitis would be detected on endoscopy or that pathological gastro-oesophageal reflux on 24-hour pH-monitoring would be documented, or both. The GERD questionnaire was used to identify 269 patients with probable GERD who after one week on placebo entered a 2-week double-blind placebo-controlled study which was completed by 251 patients. Cimetidine (400 mg) b.d. was given to 124 patients and placebo to 127 patients. On diary cards the patients noted the number, the mean duration and the mean severity of GERD symptoms episodes. Cimetidine was significantly superior to placebo in increasing the percentage of symptom-free days, and in reducing the median number of daily symptom episodes. This trial demonstrates that 400 mg cimetidine b.d. is effective in improving GERD symptoms in patients identified by a descriptive, validated GERD questionnaire.

Adult↗
PubMed1992

Nasal ciliary motility in retinitis pigmentosa.

Normal in-vitro ciliary beat frequency is reported in a patient with retinitis pigmentosa. The significance of electromicroscopic ciliary defects in this condition is appraised.

Ciliary Motility Disorders↗