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Biomedical subjects

D E Sanders

Publications and source records attributed to D E Sanders.

At least 19 recordsLinked to original sources

Canadian National Breast Screening Study: assessment of technical quality by external review.

Mammograms from the Canadian National Breast Screening Study (NBSS) were reviewed by three external experts to provide an objective evaluation of their technical quality, to establish a model for auditing mammograms in a screening program, and to assess whether NBSS mammograms improved over time. The sample reviewed included 10 randomly chosen mammograms from each of 15 screening centers for each calendar year of their operation between 1980 and 1987. All 830 mammograms were reviewed on two consecutive days in randomized sequence by each reader, and rated 0-3 for each of four criteria including positioning and image quality, with a total possible score of 0-12. Although the mammograms were not in temporal sequence when reviewed, the scores assigned by each reader were significantly higher for mammograms dating from later years. Subjects' ages at entry (40-49 vs 50-59 years) did not affect the score. The largest increase in scores was associated with a 1985 protocol change in which mediolateral oblique positioning replaced straight mediolateral positioning. This study reinforces the importance of monitoring technical quality in screening programs and establishes that the NBSS benefited from technical improvements during its operation. A retrospective review of NBSS mammography by three external reviewers confirmed that technical quality improved from 1980 to 1987. This improvement was associated with improved technology (film, processing, and units) and with the quality assurance programs operating during the NBSS, which identified problems and offered remedies.

Adult

Pulmonary infection with nontuberculous mycobacteria.

Nontuberculous mycobacterial infections (NTM) are being increasingly recognized as a cause of chronic pulmonary disease. We recently reviewed the clinical, radiologic, and bacteriologic presentation of 89 adult patients ill enough to have been hospitalized between 1981 and 1985 with the diagnosis of NTM. Preexisting lung disease was present in 82% and alcohol abuse in 40%. Although M. avium complex was identified in 51% of the patients, M. xenopi, which is usually reported to occur infrequently, accounted for 38% of our cases and M. kansasii for only 9%. Treatment was limited by a high incidence of associated disease, in vitro drug resistance, drug toxicity, and a mortality rate of 32% within 18 months of admission. Nevertheless, bacteriologic conversion occurred in 29% of those treated. M. xenopi appears to be an important pathogen in southern Ontario. It differs from the other NTM by having a different pattern of in vitro drug resistance but not by its clinical or radiologic presentation.

Adult

Cytologic diagnosis of bronchioloalveolar carcinoma by fine-needle aspiration biopsy.

From 1970 to June 1984, 275 patients with bronchioloalveolar carcinoma were admitted to the Toronto General Hospital. Of these, 181 (190 aspiration biopsies, including nine repeat samples) had this diagnosis made following the use of transthoracic fine-needle aspiration biopsy. Based on the cytomorphologic features observed in the aspiration preparations, the tumor was subclassified into three types: nonsecretory, secretory, and poorly differentiated. The cytologic features of these three types of bronchioloalveolar carcinoma are presented and illustrated. Cytomorphologically, the three types of this tumor are distinctly different and their features are sufficiently distinctive from those of bronchogenic adenocarcinoma and metastatic adenocarcinomas to be of diagnostic value. Transthoracic fine-needle aspiration biopsy appears to be a definitive minimally invasive means of establishing the diagnosis of bronchioloalveolar carcinoma preoperatively and especially to be of value for those small peripheral cancers which are relatively inaccessible to direct method of study and are potentially surgically curable.

Adenocarcinoma

Field management of neonatal diarrhea.

This article deals with the management and health factors involved in raising healthy calves. Practical considerations are given for veterinarians to implement a disease control program. Various management techniques concerning the feeding, housing, and ventilation of the neonate are also discussed.

Animal Husbandry

Progressive paresis in sheep due to delayed neurotoxicity of triaryl phosphates.

This report describes the history, signs, histopathology, and diagnosis of a delayed neurotoxicity in Suffolk sheep caused by transmission oil. The signs of toxicity included hyperexcitability, a stiff gait, tetraparesis and inability to maintain sternal recumbency. The circumstances involved in exposure to the transmission oil were determined. Histopathology revealed widespread degeneration of axons in the spinal cord, especially their more distal portions.

Animals

Pulmonary atelectasis and other respiratory complications after cardiopulmonary bypass and investigation of aetiological factors.

Radiological evidence of pulmonary complications and possible aetiological factors were investigated in 50 consecutive patients after heart operations with cardiopulmonary bypass. Atelectasis was the most frequent pulmonary complication except for small pleural effusions, with an incidence of 64 per cent. Several types of atelectasis frequently co-existed, with a predominance of the less extensive plate and subsegmental forms. The incidence of atelectasis was the same on each side and the site of atelectasis was basal in three quarters of the patients. Preoperative clinical and catheter data were unrelated to the incidence of atelectasis. There was a significant positive correlation between a short cardiopulmonary bypass time and plate atelectasis, between a large fluid load after bypass and segmental atelectasis, between re-operation for bleeding and subsegmental atelectasis and between post-operative gastric dilation and atelectasis. The type of operation, the use of the intra-aortic balloon and the length of postoperative respiratory ventilation were unrelated to the incidence of atelectasis. The mechanism of development of atelectasis is discussed.

Adult

Unusual manifestations of pulmonary aspergillosis.

Pulmonary aspergillosis is being diagnosed with increasing frequency, particularly in larger referral centers. The spectrum of lung pathology can be classified into 3 major groups: A) non-invasive mycetoma; B) allergic bronchopulmonary aspergillosis and C) invasive aspergillosis. Five patients with pulmonary aspergillosis are presented, illustrating unusual features of each major group. Transthoracic needle aspiration biopsy was diagnostic in 3 patients. It is important to differentiate a mycetoma developing in a pre-existing cavity from a cavitating Aspergillus abscess. The radiologic appearances may be similar, but evolution of the 2 lesions is entirely different.

Adult

The Bartlett-Edwards incentive spirometer: a preliminary assessment of its use in the prevention of atelectasis after cardio-pulmonary bypass.

A preliminary assessment of the effectiveness of the Bartlett-Edwards incentive spirometer was made using it as part of the post-operative treatment of 34 patients after open-heart surgery. Its effects on atelectasis were assessed by measuring vital capacity, arterial oxygen tensions, clinical signs and radiological changes. It was found that vital capacity fell after surgery to 41.5 per cent of the pre-operative level, but this rose after the use of the incentive spirometer by an average of 15.5 per cent. Arterial oxygen tensions were unaltered by the use of the incentive spirometer. Temperature, pulse and respirations were of little help in the early diagnosis of atelectasis, but all patients who were still pyrexic four days after operation showed radiological evidence of atelectasis. The incidence of atelectasis demonstrated radiologically was total 84 per cent and plate 69 per cent, sub-segmental 34 per cent and segmental 9 per cent. The implications of these findings are discussed.

Adult

The radiologic diagnosis of malignant tumors of the salivary glands.

Radiologic investigation of possible salivary gland malignancy may answer in part questions concerning the lesion under study. Is it an invasive tumor, as evidenced by tissue destruction? Is the tumor intrinsic or extrinsic in origin to the salivary gland? Does the tumor extend into the deep portion of the salivary gland or beyond it into surrounding soft tissues? Sialography plays the major diagnostic role in consideration of the radiologic diagnosis of malignant tumors of the salivary glands. However, certain advanced radiologic modalities such as salivary gland scanning with sodium pertechnetate or 67Gallium citrate, as well as cervical ultrasound and computed tomography, may prove useful. This paper attempts to provide some answers to these questions.

Adult

Surgical treatment for pulmonary emphysema.

Three in-vivo observations stimulated interest in surgical treatment for emphysema: (a) the destructive changes are rarely generalized, (b) the central portions of the lungs are frequently less seriously affected, and (c) marginal folding produces obstructive change in the more normal lung tissue. If destroyed avascular space-occupying areas can be removed, the compressed lung tissue may be stretched to fill pleural space in a functionally effective fashion. Residual elastic tissue will them maintain patency of terminal bronchioles. Preoperatively the extent of the destructive change can be defined most accurately by pulmonary angiography, and zones of functioning capilary circulation can be identified. Forty-seven patients with multifocal space-occupying emphysematous change have been treated surgically. The postoperative mortality was 21% but worthwhile long-term improvement has been obtained in 45% of patients presenting with disabling dyspnea. In these patients, surgical treatment warrants consideration if significant space occupation accompanies the bullous disease, provided alveolar vascularization can be demonstrated in the compressed adjacent normal lung tissue. Limited resections that preserve all vascularized and potentially functioning lung tissue are preferable. It is essential that obliteration of the hemithorax be obtained promptly in view of the high incidence of postoperative complications requiring secondary operative procedures, if 'leaks' and residual spaces are allowed to persist. Postoperative care in a respiratory intensive care unit is mandatory.

Adult

The radiologic diagnosis of malignant tumors of the larynx.

A variety of radiologic examinations are used to assess malignant tumors of the larynx. The primary role of radiographic examination is the pretreatment classification of laryngeal cancer, necessary to select the appropriate modality of treatment. The major radiologic modalities comprise conventional lateral radiography, anterior-posterior tomography, laryngography, xeroradiography, and high KV selective filtration radiography. Advanced radiologic modalities such as CT scanning and transverse B-mode gray scale ultrasound may also prove useful. It is the purpose of this presentation to define the role of these modalities in pretreatment definition of laryngeal cancer. Additionally, some comment is made as to the role of radiology in the diagnosis of post-radiation therapy recurrence of laryngeal cancer.

Adult

Intrathoracic manifestations of amyloid disease.

Nine cases of intrathoracic amyloid disease have been reviewed. A brief summary of historical material is presented along with detailed descriptions of the more pertinent cases. Observations suggest that a classification of the radiographic manifestations is needed with stress on massive calcific lymph node enlargement and a pulmonary lesion characterized by aggregations of small nodules.

Adult

The small bowel enema: experience with 150 examination.

Clinical application of the small bowel enema has received waxing and waning enthusiasm since it was first described in 1929. Our experiences with 150 small bowel enema studies is presented. The Sellink method was used for patients without ileostomy, (140), and retrograde studies for those with ileostomy. The merits of the small bowel enema compared to the conventional technique are discussed. The small bowel enema is the preferred method for radiologic assessment of the small bowel in patients whose clinical picture suggests small bowel disease.

Adult

Percutaneous aspiration lung biopsy.

A total of 182 percutaneous trans-thoracic aspiration biopsies were performed in 164 patients over a three-year period. In malignant neoplasms arising in the lung the diagnostic accuracy rate was 84%. In the non-malignant localized parenchymal lesions the accuracy drops considerably unless the lesion is cystic or cavitary. Some patients with non-parenchymal lesions were selected to assess further the value of this procedure. It proved much less rewarding in lesions of the chest wall, diaphragm and also in diffuse parenchymal disease. These lesions may be more accurately identified by other methods of biopsy. Lesions presenting as a mediastinal mass are an intermediate group and in selected cases helpful information can often be obtained by small-bore needle aspiration, particularly if a pericardial, bronchogenic or thymic cyst is suspected. Recent reports have shown that the aspiration of pulmonary lesions can be utilized to obtain viable tumour cells for chemosensitivity testing. The aspiration of nodular pulmonary lesions should be considered when a diagnosis is not forthcoming from the usual investigative means, since there has been little morbidity and no mortality in the series.

Biopsy