Midline spikes.

Midline spikes are characterized by spike foci recorded at Cz, Fz, or Pz with amplitude ranging from 20 to 350 microvolts. Out of 7,929 EEGs performed at the Neurodiagnostics Laboratory, Kaiser Permanente Medical Center, Anaheim, California, between 1996 and 2006, 17 EEGs (0.21%) were identified as having interictal midline spikes with or without other epileptiform discharges. Eight EEGs showed midline spikes at Cz, 2 at Fz, 2 at Cz and Fz, 1 at Cz and C3, 1 at Cz, C3, and P3, 1 at Cz and F8, 1 at Cz and T4, and 1 at Cz with 2 Hz generalized spike and slow wave complex. Midline spikes were recorded in 10 males and 7 females. The age ranged from 4 days to 38-years-old with a mean age of 10.8 years. Twelve patients (70.6%) were children. Twelve patients (70.6%) had generalized tonic-clonic seizures and 5 had partial motor seizures. Of the 17 patients, 14 had no known causes, 1 had an agenesis of corpus callosum, 1 had a left frontal arteriovenous malformation, and 1 had a left frontal area stroke. We postulate that the mechanism for the genesis of midline spikes may be heterogeneous. Midline spikes may be triggered by thalamocortical network in a generalized tonic-clonic seizure, or may originate in the parasagittal cortex in a partial motor seizure.

Development of monoclonal antibodies to parathyroid hormone-induced resorptive factors from osteoblast-like cells.

Parathyroid hormone (PTH) induces osteoblast-like cells to secrete factors capable of increasing cellular bone resorption; these factors are extremely labile. We have partially isolated them from supernatants of PTH-stimulated ROS 17.2 cells using affinity chromatography. Products eluted from the matrix, carboxymethyl cellulose covalently linked to Cibacron Blue F3GA, (CM-AB) were used as immunogens in mice. Serum from these mice blocked the effect of PTH-stimulated supernatants in a bioassay for bone resorption (the bone rudiment system). Then, hybridomas were produced from spleen cells of these mice. Screening of these hybridoma cultures revealed a consistent blocking effect of supernatants at a dilution of 1:100 in the bioassay. At higher dilution (1:1000), however, fewer culture supernatants blocked this effect in the bioassay. Mixed hybridoma cultures have been cloned and subcloned. Evaluation of the resulting hybridoma supernatants revealed that supernatants from at least three clones were necessary to neutralize the effect of the PTH-induced, osteoblast-produced resorption factors in organ culture. Similarly, using sucrose density gradient analysis, it is necessary to use three antibodies to bind all the 35S-labeled protein from supernatants of PTH-stimulated ROS cultures (equivalent to the fraction used as immunogen in the mice). The effect of PTH in organ culture is blocked by this same group of hybridoma supernatants. The antibodies appear specific for osteoblast-like cell resorption factors, as they do not block the effect of PTH on cAMP accumulation in ROS cell cultures. On the other hand, they do block the effects of dibutyryl cAMP on resorption in organ culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Staphylococcus epidermidis meningitis and an intraspinal abscess associated with a midthoracic dermal sinus tract.

Congenital neuroectodermal defects are associated with meningitis that is unresponsive to conventional antibiotic therapy, recurrent bacterial meningitis, or meningitis due to an organism that is not usually the cause of this disease. Midthoracic dermoid and epidermoid cysts occur rarely and are easily overlooked. We report the case of a 13-month-old boy with meningitis that was unresponsive to antimicrobial therapy. We subsequently identified an intraspinal abscess, an infection due to Staphylococcus epidermidis, and a midthoracic dermoid cyst. We emphasize the need for clinicians to have a high index of suspicion and to make a careful physical examination when antibiotic treatment fails in patients with meningitis. We also provide a detailed anatomy of a midthoracic dermoid cyst and illustrate the usefulness of magnetic resonance imaging in preoperative diagnosis of congenital neuroectodermal defects.

Gonococcal abscess of the obturator internal muscle: use of new diagnostic tools may eliminate the need for surgical intervention.

Obturator internal muscle (OIM) abscess or pyomyositis, a poorly recognized intrapelvic infection, is characterized by limping, pain in the hip with limited movement, and the sciatic type of radiating leg pain. With the use of advanced diagnostic tools such as computed tomography (CT), magnetic resonance imaging, and radionuclide scans, several cases of OIM abscess have been diagnosed; these cases have recently been reported in the English-language literature. Staphylococcus aureus is the predominant organism isolated from OIM abscesses. Gonococcal abscess involving the OIM has not been reported. We describe a case of gonococcal OIM abscess in an adolescent female whose condition was successfully diagnosed and managed with the use of CT-guided needle aspiration and antibiotic therapy. We review the English-language literature regarding the use of newly developed tools in the diagnosis of OIM abscess.