The balance model of dyslexia and remedial training: an evaluative study.

The aim of this study was to test the validity of Bakker's (1983, 1990) theory and treatment paradigm of dyslexia. Twenty-one children (mean age = 9.9 years) categorized as P-type dyslexics (showing accurate but slow and fragmented reading) and 19 children (mean age = 9.7 years) categorized as L-type dyslexics (fast but inaccurate readers) were presented with hemisphere-specific stimulation (HSS) and hemisphere-alluding stimulation (HAS). HSS was produced by presenting words to either the left or the right visual half-field, or to the left or right hand of the participant. HAS training was achieved through the presentation of either semantically/phonetically demanding or perceptually demanding text. Participants were given either a treatment program that was specifically designed for their particular dyslexia subtype, or a program that had been deliberately chosen to be inconsistent with their subtype. Contrary to predictions, participants made gains on all of the reading measures, regardless of the type of treatment given. On the basis of these findings it is suggested that treatment gains made are due to nonspecific training effects and not to the specific nature of Bakker's remedial strategies.

Evaluation of dural closure techniques. Suture methods, fibrin adhesive sealant, and cyanoacrylate polymer.

A study was undertaken to investigate the relative strengths of dural repair using standard suture techniques, suture supplemented with tissue adhesive, and tissue adhesive alone. The efficacy of two tissues adhesives, fibrin adhesive sealant and cyanoacrylate polymer, as adjunctive or the sole means of effecting dural closure, was studied. In vitro analysis of repair techniques was accomplished using fresh human cadaveric dura. Uniform 4 mm defects were created, repaired using various techniques, and then subjected to pressurization testing. Defects repaired with suture alone leaked at pressurization levels within the physiologic range, while those supplemented with tissue adhesives failed at higher pressurization levels. In vitro testing, accomplished in white New Zealand rabbits, supported this conclusion. Histologic sections obtained from dura treated with fibrin adhesive sealant demonstrated minimal inflammatory response, while those sections obtained at the site of dural repair augmented with cyanoacrylate polymer featured significant inflammatory responses, including dural thinning, gliosis, and cortical necrosis. Results indicate that a new substance, fibrin adhesive sealant, appears to have application as an adjunctive means of effecting dural closure.

Traumatic atlantal anterior arch fracture with associated avulsion fracture of the transverse ligament attachment: a previously undescribed combined entity.

A case of an atlantal anterior arch burst fracture combined with an avulsion fracture of the transverse ligament attachment is presented. Similar cases have dealt with either isolated transverse ligament ruptures and avulsions or with Jefferson fractures associated with transverse ligament ruptures and avulsions. This case probably represents an entity in the spectrum of injury patterns to the atlanto-axial articulation.

Proximal interphalangeal joint arthroplasty.

Prosthetic implant arthroplasty of the proximal interphalangeal (PIP) joint has a limited role in the reconstruction of the rheumatoid hand. Ninety-three PIP joint arthroplasties, including 56 Flatt, 30 Swanson, and seven Niebauer implants, were reviewed with postoperative follow-up periods averaging 6.2 years. The average maximum extension/flexion for the prostheses were Flatt, 28 degrees/45 degrees; Swanson, 1 degree/40 degrees; and Niebauer, 3 degrees/26 degrees. The average active ranges of motion for the prosthetic groups were Flatt, 15 degrees; Swanson, 37 degrees; and Niebauer, 19.5 degrees. Analysis of active motion at intervals of up to ten years indicated gradually decreasing active motion for each prosthesis. Comparison of preoperative motion with motion three years after operation indicated a decrease in the Flatt prosthesis group, from 35 degrees to 20 degrees. Radiographically, cortical perforation by the prosthesis was common with the Flatt prosthesis (80%), and recurrent swan-neck deformity was frequent with the Swanson spacer (27%). Despite suboptimal clinical results, patient satisfaction was high, and the ability of patients to perform activities of daily living was acceptable.

The absent fifth metacarpal.

Although many patterns of metacarpal abnormalities have been described, the congenital anomaly of complete or partial absence of the fifth metacarpal has not been well defined. This article reports on seven patients with longitudinal partial or complete absence of the fifth metacarpal with the ulna and the three phalanges of the little finger present.

Hinged total elbow replacement.

Total elbow arthroplasty using a hinged prosthesis was performed on 17 elbows in 12 patients. Clinical follow up ranged from 18 to 85 months, and averaged 56 months. Indications for surgery included disabling pain, restricted motion of the elbow, and roentgenographic evidence of joint destruction. We did not use this prosthesis in patients with restricted shoulder motion or in those with demanding occupational or recreational activities. Fifteen elbows showed good results; one elbow was complicated by ectopic ossification, and one prosthesis was removed for a deep wound infection. No other instances of symptomatic loosening were found, although radiographs demonstrated a lucent line around the cement in four elbows and a cement fracture in one elbow. All patients were relieved of their pain. The low incidence of loosening may be explained by the selective use of the hinged prosthesis. Index Terms: elbow, arthroplasty, hinged prosthesis.

S-acetonyl-CoA. A nonreactive analog of acetyl-CoA.

We have synthesized S-acetonyl-CoA from CoASH and 1-bromoacetone. This thioether-containing structural analogue of acetyl-CoA is a potent competitive inhibitor, with respect to acetyl-CoA, of citrate synthase, phosphotransacetylase, and carnitine acetyltransferase. This analog will not activate Escherichia coli phosphoenolpyruvate carboxylase or rat liver pyruvate carboxylase, two enzymes which require acetyl-CoA as an obligate activator. Furthermore, acetonyl-CoA will not compete with acetyl-CoA for binding to these enzymes showing the apparent absolute requirement of these two enzymes for a thioester group on the activating ligand. S-Acetonyl-CoA should be a useful reagent in the investigation of acetyl-CoA-requiring processes.

Treatment of chronic elbow instability.

Four patients developed chronic elbow instability following closed traumatic dislocations. All patients had disruption of the anterior capsule of the elbow joint with avulsion of the brachialis from its insertion on the coronoid process. Repair of the anterior soft tissues restored elbow stability with minimal difficulty and no significant complications.

Mitochondrial metabolism of (D,L)-threo-9, 10-dibromo plamitic acid.

Bromination of palmitoleic or palmitelaidic acid proceeds by trans addition and yields dibrominated products which cannot undergo beta-oxidation when incubated with mitochondria isolated from hamster brown adipose tissue. These mitochondria were selected because they have a high capacity for oxidation of C16 fatty acids and because they are readily uncoupled by an excess of free fatty acids of this chain length. The only metabolites which could be recovered from the incubation mixtures were dibromopalmitoylcarnitine and dibromopalmitoyl CoA. Free fatty acid was also recovered. Addition of synthetic carnitine or CoA esters of brominated fatty acids did not interfere with subsequent oxidation of palmitoylcarnitine. Addition of the free brominated fatty acids did not significantly increase the rate of oxidation of subsequent additions of palmitoylcarnitine, as did other known synthetic uncouplers. These results are consistent with observations by others that feeding brominated oils leads to brominated fatty acid incorporation into tissue lipids, and indicate why this is so. They also provide a possible explanation for the hepatic damage noted in feeding experiments.

Lyme arthritis in Wisconsin.

Rash, severe constitutional symptoms, and arthritis developed in three persons who were bitten by ticks in Wisconsin. On comparison with other reports of arthritis related to tick bites, we found that the illness of our patients had clinical features consistent with Lyme arthritis. Lyme arthritis appears not to be restricted to New England as has been previously reported.

Pentasomy X with multiple dislocations.

We describe a pentasomy X (49,XXXXX) patient whose multiple dislocations led to a consideration of the Larsen syndrome. Review of the 11 reported cases of pentasomy X showed that elbow dislocations are known to occur in this syndrome. Our patient is the first to present hypoplasia of the glenoid process with consequent should dislocation. Clinical and radiologic findings of previously reported cases of pentasomy X are reviewed.