Mutants of Arabidopsis thaliana with altered phototropism.

Thirty five strains of Arabidopsis thaliana (L.) Heynh. have been identified with altered phototropic responses to 450-nm light.

Mutants of Arabidopsis thaliana with decreased amplitude in their phototropic response.

Two mutants of Arabidopsis thaliana have been identified with decreased phototropism to 450-nanometer light. Fluence-response relationships for these strains (ZR8 and ZR19) to single and multiple flashes of light show thresholds, curve shapes, and fluence for maximum curvature in first positive' phototropism which are the same as those of the wild type. Similarly, there is no alteration from the wild type in the kinetics of curvature or in the optimum dark period separating sequential flashes in a multiple flash regimen.

Influence of hook position on phototropic and gravitropic curvature by etiolated hypocotyls of Arabidopsis thaliana.

Phototropic and gravitropic curvature by hypocotyls of Arabidopsis thaliana is minimal when the side of the hook with the cotyledons attached is positioned toward the direction of tropistic curvature, and maximal when that side of the hook is positioned away from the direction of tropistic curvature. Based on these data, it is proposed that the position of the hook with attached cotyledons affects curvature and not stimulus perception. A randomly oriented population of plants exhibited considerable heterogeneity in tropistic curvature.

Pyogenic vertebral osteomyelitis of the posterior elements.

Three cases of pyogenic vertebral osteomyelitis involving only the posterior elements are presented. This unusual location creates difficulty in distinguishing vertebral osteomyelitis from neoplasms and arthridites. All three patients had involvement of the articular facet, a helpful indication against neoplasms.

Aggressive posttraumatic osteoporosis of the humerus simulating a malignant neoplasm.

Eleven patients with an unusual, moth-eaten, destructive lesion in the humerus simulating a malignant neoplasm are presented. The radiographic changes developed over an extended period after trauma. This pattern of posttraumatic osteoporosis can easily be mistaken for a malignancy.

Circulating levels of sialic acid and glycosaminoglycans: a diagnostic test for ankylosing spondylitis.

The circulating levels of sialic acid (N-acetylneuraminic acid) and glycosaminoglycans (GAGs) were measured in 69 patients with spinal disorders of orthopaedic interest (ankylosing spondylitis 17, osteofluorosis 6, idiopathic backache 10, osteoarthrosis 16, osteoporosis 20). The serum GAG levels showed no statistically significant change from control values in the five disorders investigated in the present study. Although osteoporosis and osteoarthrosis showed a decrease in serum sialic acid (SA) levels, the mean ratio (SA/GAG) demonstrated no change from control values.

Galeazzi injury with an associated fracture of the radial head.

A 36-year-old man sustained an injury that was a combination of Essex-Lopresti and Galeazzi fractures. His injuries consisted of a distal radial shaft fracture, a radial head fracture, and disruption of the distal radioulnar joint. These injuries are uncommon and this combination seems not to have been reported.

Floral Induction in a Photoperiodically Insensitive Duckweed, Lemna paucicostata LP6 : Role of Glutamate, Aspartate, and Other Amino Acids and Amides.

The effects of 20 amino acids and two amides were studied on the flowering of a photoperiodically insensitive duckweed, Lemna paucicostata LP6. Alanine, asparagine, aspartate, cystine, glutamate, glutamine, glycine, lysine, methionine, proline, serine, and threonine induced flowering under a photoperiodic regime of 16 hours light and 8 hours darkness. Among these, glutamate and aspartate were found to be the most effective for flower induction.

Role of Catecholamines in Promotion of Flowering in a Short-Day Duckweed, Lemna paucicostata 6746.

l-Epinephrine, l-norepinephrine, and l-isoproterenol substantially promote flowering under a photoperiodic regime of 8 hours light and 16 hours darkness in Lemna paucicostata 6746 when grown on the modified Bonner-Devirian medium devoid of ethylenediaminetetraacetic acid. If catecholamines are provided to plants at 10(-4) molar level prior to transferring them to the short-day regime, they not only induce more floral primordia but also significantly improve flower development and sustain the flowers for a longer period. Propranolol (10(-4) molar), a beta-adrenergic blocking agent, partially suppresses flowering and the inhibition of flowering is relieved by catecholamines.

Bony ankylosis of the elbow after burns.

Ten patients with 13 ankylosed elbows after burns are described. Six elbows, fixed in nearly full extension, had almost total functional disability; the other seven had varying amounts of deformity. In five of the 13 elbows there was a continuous bony mass with loss of the joint space; these were treated by a modified excision arthroplasty which restored good movement and useful function, though there was some lateral laxity.