CD98 immunoreactivity in multinucleated giant cells of glioblastomas: An immunohistochemical double labeling study

CD98, which is identical to fusion regulatory protein‐1 (FRP‐1), has been reported to induce and regulate cell fusion and multinucleated giant cell formation. To investigate the association between CD98 and multinucleated giant cells (MNGCs) in glioblastomas, we investigate the CD98 immunoreactivity of MNGCs and the proliferative potential in CD98 immunoreactive MNGCs in paraffin‐embedded sections obtained from patients with glioblastomas. Double immunohistochemical staining for CD98 and Ki67 as a mitotic marker were performed in formalin‐fixed and paraffin‐embedded specimens obtained from 16 patients with primary glioblastomas including MNGCs. Most CD98 immunoreactive (CD98+) tumor cells were negative for Ki67. CD98+ MNGCs were identified in 15 cases. CD98+ Ki67– MNGCs were identified in 14 cases and ranged in number from one to 48 (6.7 ± 11.5). CD98– Ki67+ MNGCs were identified in 15 cases and ranged in number from one to 32 (11.1 ± 9.6). Mitotic index (MI) of CD98+ MNGCs (4.8 ± 2.7%) was significantly lower than that of CD98– MNGCs (91.1 ± 24.6%) (P < 0001). These results suggest that multinucleated giant cell formation may be developed by fusion among CD98– producing cells in glioblastomas.     

Voltage-clamp analysis of a transient potassium current in rat neostriatal neurons

Whole cell voltage-clamp recordings were made from cultured rat neostriatal neurons. Depolarizing voltage commands evoked transient and sustained outward K-currents. The transient K-current was activated by depolarizing commands beyond -50 mV; peak current was dependent upon holding potential. Bath application of 4-aminopyridine, but not inorganic calcium channel blockers (Cd, Co, Mn), attenuated the transient current. Reversal was near the K-equilibrium potential. These properties suggest that this transient K-current is similar to the A-current described in a number of other neurons.     

Intracellular study of nucleus parabrachialis and nucleus tractus solitarii interconnections

Responses of the nucleus parabrachialis (PBN) neurons to electrical stimulation of the nucleus tractus solitarii (NTS) were investigated by intracellular recording technique in anesthetized rats. Excitatory postsynaptic potentials (EPSPs) were evoked by ipsilateral NTS stimulation in 38 PBN neurons. They were considered monosynaptic because their latencies did not change with either variations in stimulus intensity or high-frequency repetitive stimulation. The latencies of EPSPs ranged from 1.2 to 6.9 ms. PBN neurons were also antidromically activated by NTS stimulation, giving a mean axonal conduction velocity of 4.6 m/s. Some of these neurons also responded with monosynaptic EPSPs to NTS stimulation. Direct stimulation of these neurons by depolarizing current pulses elicited repetitive firing with frequencies up to 350 Hz. The morphological analysis of 5 PBN neurons labeled with horseradish peroxidase (HRP) indicates that the soma were fusiform in shape, and the size varied from 163 to 783 microns 2. All neurons had 3-5 spiny primary dendrites which extended in a predominantly mediolateral direction. Axons arose from a proximal dendritic trunk, close to the soma. The results indicated that PBN is reciprocally connected with the NTS which elicits an excitatory effect on PBN neurons.     

The expression of gamma-aminobutyric acid and Leu-enkephalin immunoreactivity in primary monolayer cultures of rat striatum

Primary monolayer cultures of rat striatum were examined for gamma-aminobutyric acid (GABA) and leucine-enkephalin (L-ENK) immunoreactivity. Cultures were established on polycation-treated glass coverslips from the striata of gestational day 17 rat embryos using a serum and insulin-supplemented medium. The proportion of GABA-immunoreactive (GABA-IR) neurons increased during the first week in vitro from approximately one third to nearly one half and remained relatively constant thereafter. On the other hand, the proportion of L-ENK-IR neurons increased gradually over the culturing period, increasing from about one-fifth of the neurons initially to one-half after 3-4 weeks in vitro. The changes in the proportions of GABA- and L-ENK-IR neurons appeared to be largely a consequence of the death of non-immunoreactive neurons, not delayed expression or induction of GABA or L-ENK traits. Light microscopic analysis of somatic-proximal neuritic morphology led to a partitioning of the neuronal population into 4 groups. GABA- and L-ENK-IR groups were heterogeneous in this regard and differed only modestly.     

A case of a two-chambered right ventricle associated with aneurysm of the sinus of Valsalva

A 51-year-old male with a two-chambered right ventricle associated with an aneurysm of sinus of Valsalva, who underwent successful surgical repair without ventriculotomy, is reported. Preoperative right ventriculogram revealed that the right ventricle was divided by the anomalous muscle bundle, and the aneurysm of sinus of Valsalva growing from the right coronary sinus protruded just below the pulmonary valve. The right ventricular pressure was 107/10 mmHg and the pressure gradient between the right ventricle and the pulmonary artery was 88 mmHg. Trans-pulmonary arterial resection of the aneurysm of Valsalva sinus was performed and the anomalous muscle bundle was successfully removed through the pulmonary arteriotomy and the right atrial incision. Post-operative right ventricular pressure dropped to 42 mmHg, and there was no stenosis in the right ventricle.     

Regional cerebral blood flow during an attack of vertebrobasilar insufficiency

Using technetium-99m-labeled hexamethylpropyleneamineoxime [( 99mTc]HM-PAO) and single-photon emission computed tomography, we measured changes in regional cerebral blood flow in a 58-year-old man during an attack of vertebrobasilar insufficiency. Angiography demonstrated compression of the left vertebral artery by the osteophytes of cervical spondylosis when the patient turned his head to the left. Measured in the orthostatic position while turning his head to the left during a typical attack of vertebrobasilar insufficiency, regional cerebral blood flow was significantly reduced in the left cerebellum and the right occipital region. Our study illustrates the capability of [99mTc]HM-PAO single-photon emission computed tomography to measure transient reductions in regional cerebral blood flow and to relate these changes to the pathophysiology of vertebrobasilar insufficiency.