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Biomedical subjects

J Waldron

Publications and source records attributed to J Waldron.

At least 19 recordsLinked to original sources
PubMed2005

Use of a ProSeal laryngeal mask airway and a Ravussin cricothyroidotomy needle in the management of laryngeal and subglottic stenosis causing upper airway obstruction.

We report the successful use of a ProSeal laryngeal mask airway (PLMA) as a dedicated airway to allow fibre-optic inspection and passage through a tightly stenosed glottic and subglottic lesion, before fibre-optic-guided transtracheal placement of a Ravussin needle and jet ventilation. The described technique avoided both tracheostomy and the potential of 'seeding' the tumour by passage of the needle through the mass. The PLMA may be a useful 'dedicated airway' and has several advantages over the classic LMA(double dagger) and intubating LMA when used for this purpose. These include improved airway seal and reduced risk of aspiration. Four other cases of use of the PLMA as a dedicated airway during management of difficult airways are discussed. double daggerLMA is the property of Intavent Ltd.

Aged↗
PubMed2001

The benefits and pitfalls of ipsilateral radiotherapy in carcinoma of the tonsillar region.

PURPOSE: Ipsilateral techniques designed to restrict treatment to the primary tumor and neck on the same side have been used in selected cases of cases of carcinoma of the tonsillar region at our institution for many years. The primary purpose of this study is to evaluate the risk of failure in the opposite neck in cases selected for unilateral radiotherapy over a 21-year period. METHODS AND MATERIALS: Ipsilateral radiotherapy techniques were used in 228 of 642 patients with carcinoma of the tonsillar region from 1970 to 1991. Local control, regional lymph-node control (including contralateral failure), and survival were calculated for different degrees of tumor extent treated with these techniques. RESULTS: Mean follow-up was 7 years. Cases tended to be T1 and T2, with N0 disease. The 3-year actuarial local control rate was 77% and cause-specific survival was 76%. Opposite neck failure was seen in 8 patients (crude rate of 3.5%). In the earlier period of the study, primary coverage was problematic in a proportion of cases and resulted in higher rates of local failure. CONCLUSION: Appropriately selected cases of carcinoma of the tonsil show minimal risk of failure in the opposite neck with ipsilateral techniques. Patients should undergo computed tomography planning to ensure adequate target coverage.

Adult↗
PubMed2001

Utility of a lung biopsy for the diagnosis of idiopathic pulmonary fibrosis.

It is not known if a surgical lung biopsy is necessary in all patients for the diagnosis of idiopathic pulmonary fibrosis (IPF). We conducted a blinded, prospective study at eight referring centers. Initially, cases were evaluated by clinical history and examination, transbronchial biopsy, and high-resolution lung computed tomography scans. Pulmonologists at the referring centers then assessed their certainty of the diagnosis of IPF and provided an overall diagnosis, before surgical lung biopsy. The lung biopsies were reviewed by a pathology core and 54 of 91 patients received a pathologic diagnosis of IPF. The positive predictive value of a confident (certain) clinical diagnosis of IPF by the referring centers was 80%. The positive predictive value of a confident clinical diagnosis was higher, when the cases were reviewed by a core of pulmonologists (87%) or radiologists (96%). Lung biopsy was most important for diagnosis in those patients with an uncertain diagnosis and those thought unlikely to have IPF. These studies suggest that clinical and radiologic data that result in a confident diagnosis of IPF by an experienced pulmonologist or radiologist are sufficient to obviate the need for a lung biopsy. Lung biopsy is most helpful when clinical and radiologic data result in an uncertain diagnosis or when patients are thought not to have IPF.

Biopsy↗
PubMed2001

Carcinoma-in-situ of the glottic larynx: results of treatment with radiation therapy.

PURPOSE: Carcinoma-in-situ (CIS) of the vocal cords frequently progresses to invasive disease if untreated. Treatment approaches include vocal cord stripping, radiation therapy (RT), and laser excision. The purpose of this analysis was to assess the efficacy and safety of a standard RT regimen in the treatment of this condition. METHODS AND MATERIALS: Between January 1980 and December 1994, 67 patients (52 men, 15 women; median age, 65 years) with glottic CIS were treated with RT. The standard RT regimen was 51 Gy in 20 fractions given over 4 weeks (99% of patients). Prior to receiving RT, 21 patients (31%) had undergone 1 or 2 vocal cord stripping procedures, and 1 had been treated with laser. RESULTS: With a median follow-up of 6.5 years, 1 patient developed invasive glottic cancer, giving a 5-year actuarial local control rate of 98%. This patient recurred 14 months after treatment and was salvaged with laryngectomy. He is currently free of disease 2 years after surgery. There were no serious acute or late treatment complications. Sixteen patients (24%) developed subsequent malignancies, 8 of these being in the upper aerodigestive tract, although none were in the radiation field. CONCLUSIONS: Moderate-dose radiation therapy is an effective treatment for glottic CIS. It is well tolerated, produces no serious acute or long-term side effects, with an excellent cure rate.

Adult↗
PubMed2001

The organizational costs of preventable medical errors.

BACKGROUND: Preventable medical errors are associated with additional costs that tend to be borne by patients, but little is known about organizational costs associated with such errors. Two composite case studies (a fall and a delay in diagnosis) were used to identify the organizational costs of preventable medical errors. ANALYSIS: Legal, marketing, and organizational costs--direct, indirect, and long term--were associated with each of the preventable medical errors. A model was generated to examine the theoretical relationship between the costs and four determinants of corporate performance--price, wages, cost of capital, and efficiency. DISCUSSION: Organizations may also have a financial incentive to improve patient safety, for beyond patient and societal costs, preventable medical errors appear to account for significant legal, marketing, and operational costs for the organizations that deliver health care. Some of these costs are not so much the cost of the error but the costs of organizational responses to the error. Three broad areas of inquiry could be used to test the model and improve our understanding of the organizational costs of errors: market response to patient safety interventions, before/after studies of interventions, and case-control studies. SUMMARY AND CONCLUSION: Health care leaders have a moral imperative to implement systems that reduce medical errors and improve patient safety. An understanding of the costs associated with medical errors may help leaders understand the importance of patient safety from a financial perspective, develop measures to evaluate the impact of patient safety initiatives, and efficiently allocate resources to address this important health concern.

Female↗
PubMed2001

A DNA fingerprinting procedure for ultra high-throughput genetic analysis of insects.

Existing procedures for the generation of polymorphic DNA markers are not optimal for insect studies in which the organisms are often tiny and background molecular information is often non-existent. We have used a new high throughput DNA marker generation protocol called randomly amplified DNA fingerprints (RAF) to analyse the genetic variability in three separate strains of the stored grain pest, Rhyzopertha dominica. This protocol is quick, robust and reliable even though it requires minimal sample preparation, minute amounts of DNA and no prior molecular analysis of the organism. Arbitrarily selected oligonucleotide primers routinely produced approximately 50 scoreable polymorphic DNA markers, between individuals of three independent field isolates of R. dominica. Multivariate cluster analysis using forty-nine arbitrarily selected polymorphisms generated from a single primer reliably separated individuals into three clades corresponding to their geographical origin. The resulting clades were quite distinct, with an average genetic difference of 37.5 +/- 6.0% between clades and of 21.0 +/- 7.1% between individuals within clades. As a prelude to future gene mapping efforts, we have also assessed the performance of RAF under conditions commonly used in gene mapping. In this analysis, fingerprints from pooled DNA samples accurately and reproducibly reflected RAF profiles obtained from individual DNA samples that had been combined to create the bulked samples.

Animals↗
PubMed2001

Unusual eustachian tube mass: glomus tympanicum.

SUMMARY: A case of recurrent glomus tympanicum presenting with epistaxis is described. CT and MR imaging revealed a homogeneously enhancing mass extending along the entire course of the eustachian tube, with a portion protruding into the nasopharynx. Glomus tumors tend to spread along the path of least resistance and may extend into the eustachian tube. The unique imaging appearance should place a glomus tumor high on the list of differential diagnoses.

Epistaxis↗
PubMed2000

A phase II study of Biotene in the treatment of postradiation xerostomia in patients with head and neck cancer.

One of the major side effects of radical radiation therapy for head and neck malignancies is xerostomia, or dryness of the mouth. There is no clearly effective treatment for this condition, but we have observed that patients in our practice believe that their symptoms improve significantly when using two "over-the-counter" oral comfort products - Biotene (toothpaste, mouthwash and chewing gum) and Oralbalance gel. We decided to study these agents in a formal phase II study to evaluate their usefulness in patients with postirradiation xerostomia. Twenty-eight patients with post-irradiation xerostomia were entered on the study. All had biopsy-proven carcinoma of the nasopharynx, oropharynx, oral cavity, hypopharynx or larynx, and had received primary radiotherapy with curative intent (> or =50 Gy in 20 fractions) more than 4 months before study entry. More than 75% of both parotid glands were included in the primary radiation field. There was no clinical evidence of recurrent disease. Patients were provided with a 2-month supply of Biotene mouthwash, toothpaste, chewing gum and Oralbalance gel. Response was evaluated 1 and 2 months after study entry using a patient-completed visual analogue scale to assess the severity of xerostomia and its effects on quality of life. For analysis, the scored baseline was subtracted from the later scores to assess change. Patients with an increase of 10 mm from their baseline score on the visual analogue scale were classified as having responded to the treatment intervention, and those with an increase of > or =25 mm from their baseline score were classified as having experienced a major improvement in their symptoms. After 2 months of treatment, 15 patients (54%) reported an improvement in intraoral dryness and 10 of these patients (36%) reported a major improvement. Similar proportions of patients (46% some improvement, 25% major improvement) reported an improvement in their ability to eat normally. Seventeen patients (61%) reported an improvement in oral discomfort, and 12 of these (43%) had a major improvement in their symptoms. The results of this study suggest that the use of Biotene (mouthwash, toothpaste and chewing gum) and Oralbalance gel can improve many of the symptoms of radiation-induced xerostomia. A placebo effect could account for many of the observed improvements in symptoms, and in order to assess the role of these agents in the management of patients with postirradiation xerostomia a randomised phase III study is needed.

Administration, Oral↗
PubMed2000

An audit of asthma care in minor injury units.

Asthma was found to be one of the commonest reasons for attendance at nurse-led minor injury units in Cornwall. Care provided in these units should comply with BTS guidelines and local protocols. Ongoing education must be provided to ensure staff maintain the recommended standards of care.

Asthma↗
PubMed1999

Lymphomatoid granulomatosis following autologous stem cell transplantation.

Lymphomatoid granulomatosis (LYG) is a rare angio-destructive lymphoproliferative disorder (LPD) of uncertain etiology, with prominent pulmonary involvement. Recent studies indicate that LYG is an Epstein-Barr virus (EBV)-associated B cell LPD with large numbers of background reactive T lymphocytes (T cell-rich B cell lymphoma). Although the disease frequently, but not exclusively, occurs in various immunodeficiency states, it has not been reported in association with the transient immunosuppression following autologous bone marrow/peripheral stem cell transplantation (ABM/PSCT). We describe a patient who developed lymphomatoid granulomatosis of the lung approximately 2 weeks after high-dose chemotherapy and autologous peripheral stem cell transplantation for multiple myeloma. Although molecular studies showed no evidence of EBV genome in the biopsy material, the serologic profile with high IgM titers was suggestive of primary EBV infection. Complete radiologic remission occurred following reconstitution of the patient's immune response after a 2-week course of ganciclovir treatment. Despite the apparently low frequency of LPD (both LYG and EBV-associated post-transplant lymphoma) in the ABMT setting, we believe that it should be considered in the differential diagnosis of patients whose clinical course following ABMT is complicated by fevers, in the absence of an identifiable infectious process.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Diet and risk of ethanol-induced hepatotoxicity: carbohydrate-fat relationships in rats.

Nutritional status is a primary factor in the effects of xenobiotics and may be an important consideration in development of safety standards and assessment of risk. One important xenobiotic consumed daily by millions of people worldwide is alcohol. Some adverse effects of ethanol, such as alcohol liver disease, have been linked to diet. For example, ethanol-induced hepatotoxicity in animal models requires diets that have a high percentage of the total calories as unsaturated fat. However, little attention has been given to the role of carbohydrates (or carbohydrate to fat ratio) in the effects of this important xenobiotic on liver injury. In the present study, adult male Sprague-Dawley rats (8-10/group) were infused (intragastrically) diets high in unsaturated fat (25 or 45% total calories), sufficient protein (16%) and ethanol (38%) in the presence or absence of adequate carbohydrate (21 or 2.5%) for 42-55 days (d). Animals infused ethanol-containing diets adequate in carbohydrate developed steatosis, but had no other signs of hepatic pathology. However, rats infused with the carbohydrate-deficient diet had a 4-fold increase in serum ALT levels (p < 0.05), an unexpectedly high (34-fold) induction of hepatic microsomal CYP2E1 apoprotein (p < 0.001), and focal necrosis. The strong positive association between low dietary carbohydrate, enhanced CYP2E1 induction and hepatic necrosis suggests that in the presence of low carbohydrate intake, ethanol induction of CYP2E1 is enhanced to levels sufficient to cause necrosis, possibly through reactive oxygen species and other free radicals generated by CYP2E1 metabolism of ethanol and unsaturated fatty acids.

Alcohol Drinking↗
PubMed1998

T1/T2 glottic cancer managed by external beam radiotherapy: the influence of pretreatment hemoglobin on local control.

PURPOSE: Pretreatment hemoglobin (Hb) level has been reported to be an important prognostic factor for local control and survival in various malignancies. However, in many settings, the adverse effect of a low Hb may be related to more advanced disease. The purpose of this analysis was to assess the influence of pretreatment Hb on local control in a large series of patients with a localized cancer (T1/T2 glottic cancer, AJCC 1992) treated in a standard fashion. MATERIALS AND METHODS: Between January 1981 and December 1989, 735 patients (median age 63; 657 males, 78 females) with T1/T2 glottic cancer were treated with radiation therapy (RT). The standard RT prescription was 50 Gy in 20 fractions over 4 weeks (97% of patients). Factors studied for prognostic importance for local failure included pretreatment Hb, age, sex, T category, anterior commissure involvement, subglottic extension, and tumor bulk (presence of visible tumor vs. subclinical disease). RESULTS: With a median follow-up of 6.8 years (range 0.2-14.3), 131 patients have locally relapsed for an actuarial 5-year relapse-free rate of 81.7%. The 5-year actuarial survival was 75.8%. The mean pretreatment hemoglobin level was 14.8 g/dl and was similar in all prognostic categories. On multivariate analysis, using the Cox proportional hazards model, pretreatment Hb predicted for local failure after RT. The hazard ratio (HR) for relapse was calculated for various Hb levels. For example, the HR for a Hb of 12 g/dl vs. a Hb of 15 g/dl was 1.8 (95% confidence interval 1.2-2.5). Previously established factors, including gender, T category, subglottic extension, as well as tumor bulk, were also prognostically important for local control. CONCLUSIONS: This analysis, in a large number of similarly treated patients, indicates that pretreatment Hb is an independent prognostic factor for local control in patients with T1/T2 carcinoma of the glottis treated with RT. The underlying biology of this observation needs to be explored, and using this information, it may be possible to develop strategies to improve treatment outcome.

Carcinoma, Squamous Cell↗
PubMed1998

Surgical salvage after failed radiation for paranasal sinus malignancy.

OBJECTIVE: To comment on the role of surgical salvage following failed initial treatment for paranasal sinus malignancy. DESIGN: A retrospective analysis of one hundred eighty patients treated at The Princess Margaret Hospital, Toronto, from 1976 to 1993. MATERIALS AND METHODS: Thirty-four of 95 patients (36%) who failed initial treatment underwent surgical salvage. Initial therapy in this group was radiation only (n = 27) and combined therapy (n = 7). Patient, tumor, and surgical data were recorded. There were 23 T4, three T3, six T2, and two T1 carcinomas. Survival, recurrence rates, and the influence of a variety of variables on outcome were analyzed. RESULTS: Two- and 5-year overall actuarial survival calculated from the date of diagnosis was 54% and 35%, respectively. Two- and 5-year overall actuarial survival calculated from the date of salvage surgery was 44% and 22%, respectively. Advanced age (P < .004), patients with T4 category disease (P < .04), and squamous cell carcinomas (P < .049) correlated with poorer outcome on univariate analysis. Local failure was the most common cause of death (n = 13; 65%). CONCLUSION: Salvage surgery has a limited role in the management of persistent or progressive disease following failure of initial treatment. Careful postradiation surveillance with endoscopic biopsy under general anesthesia and immediate surgical resection when appropriate may improve the salvage rate.

Actuarial Analysis↗
PubMed1996

The rate and characteristics of suicide attempters in the native Hawaiian adolescent population.

Native Hawaiian high school students, N = 1779, were surveyed for symptoms of psychopathology and suicide attempts in the previous 6 months. Seventy-seven (4.3%) of the students reported making a suicide attempt. There were no significant differences in prevalence rates for males and females. Depression, anxiety, aggression, substance abuse symptoms, and low family support, but not peer support, were significantly correlated with suicide attempts. On logistic regression, depression, substance abuse, and family support independently predicted attempts. The lack of gender difference may indicate a cultural characteristic of the Hawaiian population that differentiates it from mainstream American populations but likens it to the Native American population.

Adolescent↗
PubMed1992

Comparison of plain radiographs and computed tomographic scanning in nasopharyngeal carcinoma.

Plain radiographs, computed tomographic (CT) scans and clinical records of 100 patients with nasopharyngeal carcinoma were studied. CT scans and plain radiographs provided similar information in 46 patients. There were 54 cases in which the two techniques disagreed. In 45 cases CT demonstrated abnormalities not seen in plain radiographs and in nine cases plain radiographs demonstrated abnormalities not seen with CT scanning. Based on the total information gained from clinical examination, the imaging investigations, biopsies, and subsequent clinical course and investigations it appeared that none of the abnormalities predicted by plain radiographs alone could be substantiated. Conversely the CT abnormalities could be supported as being correct. We conclude that CT alone is the undoubted investigation of choice where this is available. Plain films provide less information, are unreliable and, where CT is available, superfluous.

Bone and Bones↗
PubMed1992

Complications following fast neutron therapy for head and neck cancer.

Serious complications resulting from the use of fast neutrons to treat head and neck malignancies are reported in 38 patients. The average interval between treatment and onset of complications was 5.5 years. Significant airways obstruction, requiring a tracheostomy, occurred in two patients, and a gastrostomy or pharyngostomy was performed for intractable dysphagia in six. Eight patients developed osteoradionecrosis: carotid artery rupture occurred in three patients following surgery for residual or recurrent disease. Our experience suggests that complications following fast neutron therapy for head and neck tumours are more severe, more common and occur after a longer time interval than those seen following conventional radiotherapy. Subsequent surgery in the irradiated area is compromised by severely impaired wound healing. When radical surgery is necessary for residual or recurrent disease the entire volume of irradiated tissue must be removed if healing is to be achieved.

Airway Obstruction↗
PubMed1992

Tuberculosis of the nasopharynx: clinicopathological features.

The clinicopathological features of 10 adult patients with nasopharyngeal tuberculosis (TB) are presented. 9 patients had no evidence of chest or systemic disease. 7 patients presented with cervical lymphadenopathy, and only 4 had nasal symptoms. Examination of the nasopharynx showed no abnormality in 2 patients, lymphoid hyperplasia in 4 patients, and a tumour-like mass in 4 patients. These findings suggest that nasopharyngeal TB may occur more frequently as part of an isolated upper respiratory tract infection than as secondary to pulmonary infection. The nasopharynx may be a portal of entry for tubercle bacilli in patients who develop cervical lymphadenitis. Involvement of the nasopharynx by TB may be underdiagnosed because it does not produce obvious symptoms or physical signs in all cases.

Adult↗