Is functional hemispheric lateralization guided by structural cerebral asymmetry?

"Lateralized hemispheric function is guided by structural cerebral asymmetry" remains an attractive hypothesis. It is plausible that genetically determined events lead to structural asymmetry that in turn guide lateralized functional development. However, hemispheric specializations are neither inevitable consequences of early local cytoarchitectural differences nor immutably fixed in structure. The human brain possesses dynamic plasticity as its primary mission and can override and transcend hemispheric differences for preservation of higher cognitive functions such as speech and language.

Omental angiogenic lipid fraction and bone repair. An experimental study in the rat.

A lipid material extracted from the omentum has previously been shown to contain a potent angiogenetic activator (20), capable of creating intense vasoproliferation in traumatized tissues (19). This study was undertaken to analyze the efficacy of local administration of this omental lipid fraction on osseous vascularization and bone repair. An osteoperiosteal segmental femoral defect in the rat was replaced by a demineralized allogenic bone graft exposed to continuous local delivery of omental lipid via an implanted miniosmotic pump. Saline solution delivered in the same way served as a control. Neovascularization and bone formation in the transplant were quantitatively evaluated by means of dynamic radioisotopic bone imaging, radiographic photodensitometry, microangiography, and biomechanical testing. Compared with the control group, the omental lipid angiogenic fraction-treated specimens showed an 80% overall increase (p less than 0.001) in bone density as well as a twofold increase (p less than 0.001) in regional blood perfusion, maximal at 2 weeks following surgery. At 12 weeks, biomechanical testing demonstrated significantly higher union rate (p less than 0.05) and strength (p less than 0.01) in the treated specimens as compared with the controls. These data demonstrate that the omental lipid fraction factor has potent angiogenic properties that enhance bone blood perfusion and bone regeneration.

Subacute osteomyelitis presenting as bone tumors.

The problem of the differential diagnosis between subacute osteomyelitis and primary bone tumors is a difficult one. Presenting symptoms, duration of disease, laboratory data, and location of the pathologic process are of little assistance. The authors reviewed eight typical cases. Preoperative diagnosis included benign and malignant bone tumors, as well as osteomyelitis; but the final diagnosis of osteomyelitis was made only after open biopsy and culture. The presenting symptoms and signs included: pain, usually dull; soft tissue mass; and, rarely, low grade fever. The radiographic features were usually a lytic area with various degrees of sclerotic reaction. White blood count and sedimentation rate were not helpful. The treatment, including surgical curettage and appropriate antibiotic therapy, resulted in resolution of the process and healing of the bony defects.

Nine-year follow-up of the Mathys uncemented acetabular cup: a radiological evaluation.

Radiological studies were performed in patients who underwent hip arthroplasty using the Mathys acetabular cup. The development of radiolucent and sclerotic lines, subsidence, changes in position of the implants, changes in bone density, and the significance of these findings are discussed.

Callosal bisection and transcallosal secondary antiepileptogenesis.

More than 28,000 neuroscientists and 3,000 epileptologists gathered at their respective 2001 meetings of the Society for Neuroscience and the American Epilepsy Society. Yet only six articles, one directly and five indirectly, discussed the corpus callosum (CC). Is not this in itself a remarkable finding? Are there no mysteries left? The reality is that considerable uncertainties exist regarding the rationale for callosal bisection (CCB) that causes contrasting effects (i.e., amelioration of generalized seizure, at times leading to freedom from seizure, and intensification of postoperatively fragmented seizure, at times leading to status epilepticus). Similarly, the clinical relevance of EEG mirror focus formation, an experimentally well-established transcallosal consequence of partial cortical epileptogenesis, continues to be debated. This presentation revisits these unresolved issues (a) to gain insight into the dynamic role played by the CC in medically refractory epilepsy, and (b) to promote the development of antiepileptogenic tools that are currently unavailable.

Intertrochanteric fracture of the hip. Comparison of nail-plate fixation and Ender's nailing.

Between April 1979 and August 1983, 201 patients with intertrochanteric fractures of the hip were admitted to Haife Medical Center (Rothschild), Israel. These patients were randomely divided into two groups: 104 patients underwent fixation with a compression screw and plate (Richard's Co.) and 97 patients underwent fixation with Ender's nails. The results of both groups were analyzed and evaluated clinically, economically, and socially. There were differences in operative time, incidence of infection, local complications, and functional capacity, but, on the other hand, no difference in the length of hospital stay. The perioperative mortality was significantly higher in the group that underwent fixation with Ender nails (seven to one), but the overall mortality was the same for both groups. The advantages of the Ender method are a quicker surgical procedure, diminished blood loss, and practically no risk of deep infection. The fixation with compression screw and plate assures a better anatomical reduction of the hip with fewer local complications and a better functional result, but carries a higher risk of infection.

Lasting secondary antiepileptogenesis induced by cingulate kindling.

PURPOSE: To test the validity of a hypothesis that kindling-induced enduring kindling inhibition of the homotopic secondary site is not a primate species-specific effect but occurs also in feline species. METHODS: Five mature male cats were kindled at the anterior (AC) and posterior (PC) cingulate cortex followed by secondary-site kindling and primary-site retest. RESULTS: Kindling was characterized by a marked seizure-stage instability and a progressive afterdischarge threshold elevation in all the animals. A protracted nonconvulsive seizure stage was followed by convulsive evolution and rapid generalization. At the secondary site, positive transfer effect was absent, and kindling did not occur. Primary-site retest activated kindled seizure within three stimulations. Recurrent spontaneous seizures, identical to the primary-site kindled seizure, occurred in two AC-kindled animals. Subsequent to this, a markedly elevated afterdischarge threshold also was found at some distant cortical and subcortical sites, to which the afterdischarge propagated. Kindling of the amygdala ipsilateral to the kindled AC or PC was tardy, with no positive transfer effect. However, it was associated with afterdischage threshold reduction. CONCLUSIONS: Cingulate kindling-induced enduring kindling inhibition at a homotopic secondary site is not a primate species-specific effect and occurs also in feline species. It is not limited to a homotopic site and represents a lasting secondary antiepileptogenesis, presumably due to enhanced intrinsic inhibitory mechanism(s) available to the mammalian brain. A selective afterdischarge threshold elevation concurrently observed is suspected to be a feline species-specific effect.