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Biomedical subjects

D Blackburn

Publications and source records attributed to D Blackburn.

7 recordsLinked to original sources
PubMed1990

Mitosis and histopathology in rat liver during methylclofenapate-induced hyperplasia.

Liver hyperplasia was induced in rats by daily administration of methylclofenapate (25 mg/kg by gavage). An increase in the incidence of colchicine-arrested metaphases was observed with peaks occurring at 40 h (1.3%), 64 h (6.4%) and 84 h (6.8%) after the start of treatment. This response contrasted with the much larger (21.3%) peak in arrested metaphases at 36 h after partial hepatectomy, but was still unexpectedly large in comparison with the S-phase response to methylclofenapate reported in a previous study. Progressive hypertrophic histopathological changes were apparent during the whole course of treatment.

Animals↗
PubMed1990

Noninvasive evaluation of the upper extremity.

Vascular problems of the arm and hand can be assessed by a number of noninvasive modalities that are chosen on the basis of the history and physical examination. For suspected upper-extremity ischemia, we begin with SLPs and velocity-waveform analysis. The former test will define the extent and approximate location of the disease process, and subjective assessment of the waveform will further determine the degree and location of occlusive disease. When digital ischemia is suspected, the Doppler examination combined with intermittent compression of the radial and ulnar arteries is valuable for defining the variable arterial anatomy of the hand and the patency of the common and proper digital arteries. The extent of distal ischemia can be assessed by digital pressures. Duplex scanning has been found to be of value in determining the source of upper-extremity micro-emboli, in imaging suspected aneurysmal changes, and for evaluating arteriovenous fistulae and bypass grafts. Cold testing is used to confirm the diagnosis of Raynaud's disease after excluding proximal occlusive disease. When symptoms suggest intermittent arterial obstruction, arterial compression at the thoracic outlet is assessed by monitoring the arterial waveform during a series of maneuvers that change the anatomy of the outlet. Although a combination of IPG and venous Doppler examination accurately identifies venous occlusion, we routinely use duplex scanning in this setting. In addition to providing both anatomic and hemodynamic information about the subclavian vein, the jugular vein and the junction of the innominate vein can also be studied. Because of its ability to image in a coronal plane, MRI scanning is another nonivasive study that we have found useful for evaluation of venous anatomy and patency of the subclavian, jugular, and innominate veins. Venous thrombosis, often the first manifestation of subclavian vein compression at the thoracic inlet, is best evaluated using duplex scanning.

Arm↗
PubMed1990

How postpartum women explain their lack of obtaining adequate prenatal care.

The quality of life for infants and children is often dependent on the adequacy of the prenatal care pregnant women receive. From July through to December 1985, 15% of pregnant women in one Midwestern county were identified as having inadequate prenatal care. The purposes of the study were to identify and analyse the reasons women in that county gave for not obtaining adequate prenatal care. In addition, chi-square was used to determine the relationship between the reasons given and the three variables, age, time between knowledge of pregnancy and making an appointment for care, and source of payment. A convenience sample (n = 44) was used in a study over a 5-month period at three locations. The Health Belief Model was the conceptual framework for this study. Insufficient money to pay for care was the primary reason given for not obtaining adequate prenatal care (81%). Other reasons included motivational issues (45%) and access or lack of transportation (19%). There was a significant relationship (P = 0.05) with four reasons to the variable of age and with three reasons to both the variables of time and source of payment. The following recommendations were identified as a result of this research: the need for subsidized prenatal care and the need for a community-wide education campaign regarding the need for adequate prenatal care and the consequences of inadequate care. Prenatal care is sometimes not available to all in the United States in spite of the relationship of infant mortality and the quality of life for infants and children to adequate prenatal care.

Attitude to Health↗
PubMed1989

Upper extremity arterial injury in athletes.

Between 1983 and 1986, 23 athletes were evaluated for arm and hand complaints. Eleven players had symptoms of thoracic outlet compression. Severe arm fatigue (eight patients) and finger ischemia (three patients) were the presenting symptoms. In the remaining 12 athletes, symptoms of hand ischemia were predominant. Noninvasive testing with Doppler ultrasonography and duplex scanning (positional testing and finger systolic pressure recording) and cold immersion were used to aid in diagnosis. In the 11 athletes with thoracic outlet compression, arteriography confirmed the finding with compression of the subclavian artery in five, the axillary artery in one, both subclavian and axillary arteries in two, posterior humeral circumflex artery in one, and subclavian aneurysm in two. Compression of the suprascapular artery was identified in four, the subscapular artery in two, and the posterior humeral circumflex artery in one. Thrombosis of a first baseman's ulnar artery and occlusion of the palmar arch in a frisbee player were documented by arteriography. Decompression of the thoracic outlet consisted of anterior scalenectomy in five, pectoralis minor muscle division in one, and resection of both muscles in two. Removal of cervical rib with interposed vein graft was performed in the two players with arterial aneurysm. Hand ischemia in the remaining athletes was treated conservatively with Dextran-heparin infusion for acute ischemia. Repeat noninvasive study of all players demonstrated absence of compression in their playing position, and all have resumed their playing careers. Hand ischemia in athletes can be evaluated noninvasively and treated conservatively. Resection of hypertrophied muscles to decompress the thoracic outlet together with release of branch artery compression in selected athletes promotes perfusion to arm and shoulder muscles and helps to avoid the catastrophic complication of repetitive trauma leading to sudden arterial thrombosis.

Adolescent↗