Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Abstract: The cell surface receptors for insulin and epidermal growth factor (EGF) appear to share a common evolutionary origin, as suggested by structural similarity of cysteine-rich regions in their extracellular domains and a highly conserved tyrosine-specific protein kinase domain. Only minor similarity is found outside this catalytic domain, as expected for receptors that have different ligand specificities and generate different biological signals. The EGF receptor is a single polypeptide chain but the insulin receptor consists of distinct alpha and beta subunits that function as an alpha 2 beta 2 heterotetrameric receptor complex. Provoked by this major structural difference in two receptors that carry out parallel functions, we have designed a chimaeric receptor molecule comprising the extracellular portion of the insulin receptor joined to the transmembrane and intracellular domains of the EGF receptor to investigate whether one ligand will activate the tyrosine kinase domain of the receptor for the other ligand. We show here that the EGF receptor kinase domain of the chimaeric protein, expressed transiently in simian cells, is activated by insulin binding. This strongly suggests that insulin and EGF receptors employ closely related or identical mechanisms for signal transduction across the plasma membrane.
A chimaeric receptor allows insulin to stimulate tyrosine kinase activity of epidermal growth factor receptor.

Abstract: The evaluation and treatment of injuries of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb remain controversial. In a retrospective study that was done to assess our ability to determine whether displacement of the ligament (a Stener lesion) was present, we reviewed our accumulated experience with patients who had an injury of this ligament who were treated surgically between 1972 and 1984. Since our method of evaluation changed in 1977, we compared the preoperative and operative diagnoses in the twenty patients who were treated surgically from 1972 through 1976 with those in the twenty patients who were so treated from 1977 through 1984. Considering all forty patients who were treated operatively, sixteen (40 per cent) had a typical Stener lesion, and in two others (5 per cent) the ulnar collateral ligament was rolled up on itself and lying beneath the adductor aponeurosis. From 1972 through 1976, stability was tested with the metacarpophalangeal joint in complete extension or in varying amounts of flexion. Of the twenty thumbs that were evaluated by this technique and were treated surgically, 20 per cent had a Stener lesion. From 1977 through 1984, stability was tested with the joint in full flexion because of the findings in anatomical studies that were completed in 1977; the incidence of a Stener lesion in the twenty thumbs that were treated by repair or reattachment of the ligament during this time was 70 per cent.(ABSTRACT TRUNCATED AT 250 WORDS)
Rupture and displacement of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb. Preoperative diagnosis.

Abstract: The clinical features of 66 patients with histologically defined mitochondrial myopathy are described. The age of onset of symptoms ranged from birth to 68 years, but was before 20 years in 61%. Nineteen patients had similarly affected relatives. Three groups of cases could be identified clinically: a combination of progressive external ophthalmoplegia and weakness of the limbs induced or increased by exertion (55%); such limb weakness alone (18%); and those with clinical features, such as ataxia, dementia, deafness, involuntary movements and seizures, predominantly or exclusively arising from the CNS (27%). There was considerable overlap between these groups, and pigmentary retinopathy, present in 36% of patients, occurred in all three. At a mean disease duration of twenty years, 9 patients (all from Group 3) were severely disabled but 42 were still able to work. In vitro studies of mitochondrial metabolism, performed in 33 cases, most commonly showed deficiencies of the mitochondrial respiratory chain localized to complex I (18 patients) or complex III (9). No typical clinical picture emerged for any of the identifiable biochemical defects.
The clinical features of mitochondrial myopathy.