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Biomedical subjects

J E Harvey

Publications and source records attributed to J E Harvey.

At least 19 recordsLinked to original sources

A novel and simple colorimetric method for screening Giardia intestinalis and anti-giardial activity in vitro.

A new and simple colorimetric method has been developed for determining activity in vitro against Giardia intestinalis. The microtitre plate assay is based upon the nucleoside hydrolase activity released from G. intestinalis by lysis. Action of the nucleoside hydrolase on the substrate analogue, 4-nitrophenyl beta-D-ribofuranoside (NPR), gives rise to a coloured product which may be determined directly by the change in absorbance. A number of other such nucleoside analogues can be similarly used, but NPR is the preferred substrate, since it gives high enzymic activity at a relatively low substrate concentration. The IC50 values determined using this method for the known anti-giardials metronidazole, tinidazole and furazolidone were consistent with previously published values. The method is simple, does not involve radioisotopes or complex instrumentation, and thus provides a convenient method for screening potential anti-giardial agents.

Animals

Three cases of meningococcal pneumonia.

Three cases of pneumonia due to Neisseria meningitidis are described. In all three cases the organism was isolated only from blood cultures, but in the presence of good clinical and radiological evidence of pneumonia. The isolates belonged to three different serogroups: B type 2b, C, and Y. The cases illustrate the fact that N meningitidis can cause pneumonia and that culture of blood plays an important part in the diagnosis. Clinically there is nothing to differentiate meningococcal pneumonia from other causes of community acquired pneumonia. Predisposing factors include aspiration, immunosuppression, influenza, and adenovirus infections. When diagnosed, pneumonia due to N meningitidis should be notified and prophylaxis given as for meningitis or septicaemia.

Adult

Comparison of clinical evaluation and computed tomographic diagnostic accuracy for tumors of the larynx and hypopharynx.

Ninety-five patients with laryngeal and hypopharyngeal cancer were examined and staged preoperatively by clinical evaluation (CE) and computed tomography (CT). The CE and CT staging were compared to each other and to the pathologic (PT) staging of the tumors. The CT staging showed high accuracy in staging transglottic (88%), supraglottic (68%), and oropharyngeal tumors invading the larynx (68%) when compared to the PT findings. The CT staging was less effective in evaluating glottic tumors (46%), both overstaging (12%) and understaging (20%) cases. Combined CE-CT evaluation showed higher accuracy in staging all tumors (84%) compared to CE alone (52%) or CT alone (68%). The findings suggest that combined CE-CT should be used to evaluate laryngeal and hypopharyngeal tumors.

Diagnostic Errors

Demonstration of supernumerary tracheal bronchus by computed tomographic scanning and magnetic resonance imaging.

A bronchus arising directly from the trachea is an infrequent congenital anomaly which usually represents the displaced origin of a normal bronchus. Rarely, a true supernumerary tracheal bronchus occurs supplying an associated tracheal lobe. The case is described of a patient in whom a supernumerary tracheal bronchus and tracheal lobe was demonstrated by computed tomographic scanning and magnetic resonance imaging.

Bronchi

Prediction of occult neck disease in laryngeal cancer by means of a logistic regression statistical model.

The ability to accurately predict the presence of subclinical metastatic neck disease in clinically N0 patients with primary epidermoid cancer of the larynx would be of great value in determining whether to perform an elective neck dissection. We describe a statistical approach to estimating the probability of occult neck disease given pretreatment clinical parameters. A retrospective study was performed involving 736 clinically N0 patients with primary laryngeal cancer who were treated surgically with primary resection and ipsilateral neck dissection. Nodal involvement was determined histologically after surgical lymphadenectomy. A logistic regression model was used to derive an equation that calculated the probability of occult neck metastasis based on pretreatment T stage, tumor location, and histologic grade. The model has a sensitivity of 74%, a specificity of 87%, and can be entered into a programmable calculator.

Adult

Guidelines for the management of spontaneous pneumothorax. Standards of Care Committee, British Thoracic Society.

Simple flow diagrams, with explanatory notes, have been devised to assist in the immediate and subsequent management of patients presenting to casualty departments with spontaneous pneumothorax. They cover decision making about which patients require admission; whether a drainage procedure is necessary; if so, the appropriate method, including technical details; inpatient treatment; referral of inpatients to a respiratory specialist; and follow up arrangements. The guidelines, designed for incorporation into casualty and ward handbooks, have already proved valuable in several district general hospitals, and can be used as a basis for audit.

Humans

Mycobacterial contamination of fibreoptic bronchoscopes.

Contamination of bronchoalveolar lavage specimens by environmental mycobacteria in hospital water supplies may lead to diagnostic confusion, particularly in immunocompromised patients. Mycobacteria may become concentrated in the tubing of bronchoscope disinfecting machines. It is very difficult to eradicate these organisms once contamination has occurred.

Adult

Epidermoid carcinoma of the oral cavity and oropharynx: validity of the current AJCC staging system and new statistical tools for the prediction of subclinical neck disease.

The 1983 and 1988 AJCC T- and N-staging systems were compared using the case records of 531 patients with primary epidermoid malignancies of the oral cavity. All patients had a minimum followup of 5 years. There were 390 patients with early stage (T1, T2) disease and 141 with advanced stage (T3, T4) lesions according to both the 1983 and 1988 T-definitions: 342 patients manifested no clinical nodes (NO), 189 had clinically evident nodes (N1-N3), and none had metastatic disease. Cox regression analysis demonstrated that the 1983/1988 T-stage definitions differentiated survival successfully (p < 0.001). The 1988 staging system for nodal disease showed a highly significant separation of N2 and N3 when compared with the 1983 system (p < 0.001). Of the 342 patients who were staged N0, 154 had primary neck dissection. Logistic regression predicted the incidence of subclinical disease according to the site and the T-stage of the primary tumor with a sensitivity of 78% and a specificity of 95%. We conclude that the 1988 N-stage definition is a better prognosticator of survival than the 1983 definition. Furthermore, a logistic regression model can be used to predict the probability of subclinical disease in primary oral cavity cancers.

Adolescent

Clinical staging for primary malignancies of the supraglottic larynx.

A study of 520 patients with primary supraglottic cancer was conducted. The tumors were staged according to the 1983 and 1988 American Joint Committee on Cancer (AJCC) T- and N-stage definitions. There were 293 patients with early stage (T1, T2) tumors, 227 with advanced stage (T3, T4) tumors and 428 with early nodal disease (N0, N1) in both systems. In the 1983 N-staging, there were 44 N2 and 48 N3 lesions; in the 1988 N-staging, there were 62 N2 and 30 N3 lesions. Cox regression analysis showed that the 1983 and 1988 T-stage (T1 through T4) definitions successfully prognosticate for survival when patients were without neck node involvement. In contrast, when neck nodes were present, the N-stage (N0 through N3) of the disease prognosticated survival better than T-stage. Further analyses showed that the 1988 N-stage definition provided a better separation between N2 and N3 lesions compared to the 1983 version. Combined-modality treatment (surgery and radiation) significantly improved survival compared to single-modality treatment (surgery or radiation alone) when patients were staged T4 and N0 through N3 neck disease, but not when patients advanced from T1 to T3. Comparison of treatment efficacy over the last four decades for single- and combined-modality treatment did not reveal statistically significant differences in survival rates in our patient population. This was consistent with cumulative results of various institutions over the last four decades. We conclude that the 1988 AJCC T- and N-stage definitions successfully prognosticate for T-stage (T1 through T4) and N-stage (N0 through N3) with better separation of N2 and N3 lesions compared to the 1983 version.

Adenocarcinoma

The effects of carbamazepine on stuttering.

No pharmacological treatment protocol has proven generally useful for all patients who stutter. Various medications, behavior therapy, relaxation, suggestion, and social-based therapies have been used. For this drug treatment study, two groups of adult stutterers were followed in an 8-week open label protocol. All subjects had in the past received speech therapy; none had been treated previously with medication for stuttering. The first group (N = 12) received a maximum dose of 800 mg of carbamazepine; the second group (N = 8) received a maximum dose of 400 mg of carbamazepine. Each patient served as his or her own control. A series of systematic speech tests was given weekly to determine the variability of fluency for each subject. A statistically significant change occurred for a number of "expectancy to stutter" characteristics. Subjects felt that they stuttered less often while taking carbamazepine. Subjective effects began before medication and continued after patients discontinued the medication. Struggle characteristics also subjectively decreased. However, no objective improvement was found. No change was found in percentage of words stuttered, reading improvement, or improvement in spontaneous speech rate. Interrater reliability showed a correlation of .996. Three carbamazepine serum level therapeutic windows were inspected with negative results. Interestingly, naive listener ratings did show a statistically significant improvement on carbamazepine versus placebo. Future anecdotal reports of pharmacological improvement of stuttering should be subjected to rigorous objective testing before general acceptance.

Adult

Surgical pathology of cancer of the oral cavity and oropharynx.

A study was designed to determine the influence of certain surgical pathologic findings on tumor spread and survival in patients with cancer of the oral cavity and oropharynx. All patients with the histopathological diagnosis of carcinoma of the oral cavity or oropharynx from 1955 to 1983 were included in the study. Using the Head and Neck Tumor Registry of the department of otolaryngology of the Washington University School of Medicine, information was obtained regarding preoperative evaluation, staging, classification, diagnosis, treatment, surgical pathology parameters, and outcome results. The patient populations consisted of 545 patients with oral cavity cancer and 224 patients with oropharynx cancer, all of whom were eligible for 3-year follow-up. Information from a retrospective analysis of the pretreatment examination records regarding site and size of the primary tumor and neck dissection, and specific treatment, and from surgical pathology reports regarding site, size, tumor spread and resection margins, was correlated with treatment outcome. The database file was analyzed using dbase III and its companion program Framework, and SAS PC (Statistical Analysis Systems for personal computers).

Cause of Death

The pharmacokinetics and sputum penetration of ampicillin and amoxycillin following simultaneous i.v. administration.

Five patients with exacerbation of chronic bronchitis received as a single iv injection 500 mg of ampicillin and 500 mg of amoxycillin. Blood and sputum samples were collected at timed intervals following dosing and the concentrations of the two antibiotics present in the samples were determined by HPLC analysis. No statistically significant differences were observed between the serum concentrations of ampicillin and amoxycillin, and the pharmacokinetics of the two drugs were almost identical, with half lives of 93 min (amoxycillin) and 103 min (ampicillin). Sputum amoxycillin concentrations were significantly higher (Student's paired t-test; P less than 0.001) than those of ampicillin, with mean levels two hours after dosing of 2.9 mg/l (range 1.9-4.0) for amoxycillin and 1.4 mg/l (range 0.8-2.4) for ampicillin.

Amoxicillin

Clinical classification and staging for primary malignancies of the maxillary antrum.

A study of 51 patients with primary malignant maxillary sinus neoplasms was conducted. None of the patients had neck nodes and/or metastases, and each had 5-year follow-up. The tumors were staged according to the 1983 and 1988 American Joint Committee on Cancer staging systems for maxillary sinus cancers. There were 13 early stage (T1, T2) and 38 advanced (T3, T4) tumors in both systems. Cox regression analyses of survival curves showed increasingly worse prognoses for advanced tumors in both T-staging systems. Further analyses showed a significant difference in survival between T3 and T4 in the 1988, but not in the 1983 system. There were no significant differences in survival according to treatment modality or histological type of malignancy. We conclude that the 1988 system prognosticates successfully for T-stage (1 to 4) and demonstrates significant improvement in detecting T3 versus T4 differences compared to the 1983 system. The 1988 system applies equally for epidermoid cancer and other malignancies of the antrum.

Adult

Distribution of LCA protein subspecies and the cellular adhesion molecules LFA-1, ICAM-1 and p150,95 within human foetal thymus.

The distribution of leucocyte common antigen (LCA) protein subspecies and the cellular adhesion molecules LFA-1 (CD11a), ICAM-1 (CD54) and p150,95 (CD11c) has been established within frozen sections of human foetal thymus. Whereas over 95% of foetal cortical thymocytes and approximately 85% of medullary thymocytes were CD45RO positive, CD45RA was only expressed by approximately 29% of medullary thymocytes. The majority of foetal thymocytes also expressed CD11a, whereas CD54 was expressed by thymic epithelial and accessory cells and also apparently by some cortical thymocytes adjacent to epithelial cells. The distribution of CD54 and the major histocompatibility complex (MHC) class II molecule HLA-DR, demonstrated with a monoclonal antibody to a monomorphic determinant, was similar. The CD11c molecule was present on a population of dendritic-type accessory cells, but was absent from the large, scavenger, KiM8-positive macrophages occurring throughout the thymic cortex.

Antibodies, Monoclonal

Natural history of treated T1N0 squamous carcinoma of the glottis.

The records of 373 patients with T1N0 squamous carcinoma of the glottis were examined. Of these, 271 underwent initial hemilaryngectomy; 102 had full-course irradiation for cure. While the overall survival rates of the two initial therapies were similar, failure of the initial treatment modality was approximately twice as frequent in the irradiated patients (34.4%) as in the patients undergoing hemilaryngectomy (16.9%). The effect of this difference in initial failure rate on quality of life and on cost of overall therapy will be discussed.

Carcinoma, Squamous Cell