Radiohumeral arthrodesis for salvage of failed total elbow arthroplasty

Ulnohumeral arthrodesis is the standard technique for elbow fusion. The geometry and surface area of the distal humerus and proximal ulna enhance the chances of fusion while maintaining some wrist motion. A case of a patient with multiple failed elbow procedures in which the standard ulnohumeral fusion was not possible is presented. A radiohumeral arthrodesis was performed in an attempt to obtain a stable, nonpainful elbow. After complete healing of the fusion, the patient was able to use the arm for most functions. This technique is presented as an option for salvage failed elbow arthroplasty in the face of significant bone loss.     

On the many faces of Leber hereditary optic neuropathy

Leber hereditary optic neuropathy (LHON) is a maternally inherited disorder, associated with mutations in the mitochondrial DNA, which is notorious for its aspecific presentations. Two pedigrees are described with cases that are atypical for LHON with respect to sex, age of onset, interval between the eyes becoming affected, course of the disease, concomitant disorders, additional test results, final visual acuity, and/or results of mtDNA analysis. Moreover, the pedigrees themselves did not suggest maternal inheritance. We analysed the diagnostic and clinical genetic difficulties related to the atypical aspects of these pedigrees. We conclude that mtDNA analysis is justified in every case of optic nerve atrophy with no clear cause. Identification of one of the three LHON specifically associated mtDNA mutations is essential to confirm the diagnosis.     

Interfollicular fibroblasts in the human thyroid gland: recognition of a CD34 positive stromal cell network communicated by gap junctions and terminated by autonomic nerve endings

While epithelial structure and functions have been substantially investigated in many organs, the mesenchymal elements have received less attention. Compared with follicular epithelial cells, there are a few morphological studies on the stroma of human thyroid gland. In order to characterize more fully and assess its possible functions, 15 samples of surgical and autopsy human thyroid tissue were studied by classical histology, immunohistochemistry, transmission electron microscopy, electron microscopic immunohistochemistry, and scanning electron microscopy. In human thyroid gland, the interfollicular connective tissue surrounding the follicles contained collagenous matrix, fibroblasts, unmyelinated nerve fibers with Schwann cells, small blood vessels, lymphatics, lymphocytes, plasma cells, macrophages, and mast cells. At the ultrastructural level, gap junctions between the cytoplasmic processes of interfollicular fibroblasts constituted a novel observation. Immunohistochemistry using a monoclonal antibody against Cx43 confirmed the distribution of gap junctions between stromal fibroblastic cells, which was compatible with the ultrastructural findings. The frequent and intimate association of fibroblastic processes with nerve terminals was also shown. Interfollicular stromal fibroblasts also stained with CD34. The main constituent of the human thyroid stromal tissue was a CD34 positive reticular network involving fibroblasts, mononuclear cells and nerve terminals. It represents a highly ordered stroma, with potential structural and functional similarities to the stroma of bone marrow (Yamazaki and Allen, 1990).     

Stroke therapy in children

OBJECTIVE: To evaluate the treatment modalities used in children (ages 1-18 years) with cerebral infarction. BACKGROUND: [corrected] Cerebrovascular disease in children is more common than once suspected but its treatment has not been rigorously studied. MATERIAL AND METHODS: We reviewed all cases of cerebral infarction at the James Whitcomb Riley Hospital for Children at the Indiana University Medical Center from 01.01.80 to 31.12.95. RESULTS: Ninety-three children who experienced ischemic strokes were followed over the past fifteen years. Fifty-seven males and thirty-six females comprised the sample. Mean age was 6.9 years at the time of stroke. No medication or surgical intervention was the therapeutic recommendation in 44% of patients. For cardioembolic strokes, warfarin was used later in the course for a few patients who went on to have atrial fibrillation or valve replacement. Aspirin was used in all patients with carotid artery dissections. Aspirin was used in most children with Moya-Moya, with calcium channel blockers and surgical intervention used in later cases. Exchange transfusion followed by monthly transfusion and chelation therapy has been the treatment of choice for children with cerebral infarction complicating sickle cell disease. CONCLUSIONS: In most instances, treatment was widely disparate, probably reflecting the lack of firm therapeutic guidelines for this age group, with a better understanding of the etiology and pathophysiology of strokes in children, multicenter, international, randomized therapeutic trials based strictly on an etiological basis should be organized in the future.     

VEGF mRNA induction correlates with changes in the vascular architecture upon spinal cord damage in the rat

The multiple cellular and molecular processes induced by injury to the central nervous system (CNS) are still poorly understood. In the present study, we investigated the response of the vasculature and the expression of mRNA for the angiogenic vascular endothelial growth factor (VEGF) following X-irradiation of the spinal cord in the newborn and following traumatic spinal cord injury in the adult rat. Both lesion models induced changes in the density and the distribution pattern of blood vessels: while X-irradiation led to a permanent local increase in vascular density in the fibre tracts of the exposed segments, a transient local sprouting of vessels was induced upon traumatic spinal cord injury. In situ hybridization showed that an increase of VEGF mRNA anticipated and overlapped with the vascular responses in both lesion models. In addition to the temporal correlation of VEGF expression and vascular sprouting, there was a clear correlation in the spatial distribution patterns. Following X-irradiation, the expression of VEGF mRNA was restricted to the fibre tracts, precisely the areas where the changes in the vasculature were observed later on. Upon transection in the adult animal, VEGF was mainly detectable at the border of the lesion area, where the transient increase in vascular density could be observed. Interestingly, according to the type of lesion applied, astrocytes (X-irradiation) or inflammatory cells (presumably microglial cells or macrophages; traumatic lesion) are the cellular sources of VEGF mRNA. Our results strongly indicate that VEGF is crucially involved in mediating vascular changes following different types of injury in the CNS.