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K Bird

Publications and source records attributed to K Bird.

23 records · Page 2Linked to original sources

Testicular infarction secondary to acute inflammatory disease: demonstration by B-scan ultrasound.

Acute epididymitis can lead to obstruction of the adjacent testicular blood supply, resulting in focal or diffuse infarction of the testis or epididymis in the absence of torsion. Four cases are presented to demonstrate the spectrum of B-scan ultrasound findings, ranging from focal necrosis of the epididymis and ischemic infarction of the testis to diffuse testicular infarction. Epididymal enlargement and skin thickening are consistently seen on ultrasound as well as swelling and decreased echogenicity of the testicle. The authors suggest a protocol for acute scrotal symptoms, incorporating clinical findings and (where appropriate) radionuclide scans.

Acute Disease↗

Ultrasonography in testicular torsion.

Testicular torsion was evaluated by B-scan ultrasound in one experimental animal and in 12 patients. The clinical findings were categorized as acute, subacute, or chronic depending on the amount of time that had elapsed since the onset of pain (less than 24 hours, 1 to 10 days, and more than 10 days, respectively). A consistent pattern of sonographic parenchymal changes for each of these stages is described. The ultrasound textural changes were found to be diagnostically useful when correlated with the clinical findings. Scrotal ultrasound also complements radioisotope studies, locating the testicle when it cannot be found by palpation, and may detect testicular torsion that is not suspected clinically. When physiologic blood flow studies are normal in the clinical setting of possible torsion, ultrasound is more accurate than other imaging modalities in demonstrating pathology.

Adolescent↗

Crystallographic and molecular-orbital studies on the geometry of antifolate drugs.

In the common dihydrofolate reductase inhibitors an amino substituent replaces the pteridine carbonyl oxygen atom of folates, with altered hydrogen-bonding properties and size. Flexibility in the amino groups could facilitate enzyme binding. Studies of cycloguanil hydrochloride by neutron diffraction show both in-plane and out-of-plane deformation of amino groups. Molecular-orbital calculations ab initio on 2,4-diamino-5-methylpyrimidinium cation confirm that the 4-amino group is readily deformable. The 2,4-diaminoquinazoline structure is reported. Atomic co-ordinates, thermal parameters, bond distances and bond angles for cycloguanil and 2,4-diaminoquinazoline have been deposited as Supplementary Publication SUP 50108 (13 pages) at the British Library Lending Division, Boston Spa. Wetherby, West Yorkshire LS23, 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978) 169, 5.

Chemical Phenomena↗