Further studies on growth characteristics of epstein-barr virus (EBV) genome-positive and -negative epithelial hybrid cell lines

Differences in tumorigenicity between the Epstein-Barr virus (EBV) genome-negative and -positive epithelial A2L/AH hybrid cell lines have been described recently. Further differences in growth characteristics of the two epithelial hybrid cells have since been examined. Differences were found in doubling time and cloning efficiency in agarose of the two cell lines. In addition, the EBV genome-negative epithelial hybrid cell line (cl-654), unlike the EBV genome-positive epithelial hybrid cell line (cl-1), failed to grow in the unmanipulated nude mice, but was successfully transplanted in ⁶⁰Co-irradiated nude mice. The histopathologic findings of tumors induced by the inoculation of cl-654 cells in nude mice showed more differentiated carcinoma than the findings of tumors induced by cl-1 cells. The data suggest that EBV is associated with an alteration of cell differentiation in epithelial cells as well as tumorigenicity in nude mice.     

View from beneath: pathology in focus. Renal cell carcinoma metastasis to the tongue.

Metastases to the tongue from distant primaries are very rare. A case of renal cell carcinoma metastasis to the tongue, occurring in a 58-year-old man, is presented and previously reported cases are reviewed.     

Cranioplasty using the patient's autogenous bone preserved by freezing--an examination of post-operative infection rates

The current technique for cranioplasty using artificial bone requires further improvement with regard to infection, strength and comfort through good fitting. We have carried out cranioplasty using the patient's autogenous bone flap obtained during first surgery. It was immersed in 200 mg of Amikacin Sulphate, and frozen at -16 degrees C until its use in cranioplasty. From 1980 to 1998, cranioplasty has been carried out on 206 patients. They consisted of 118 males and 88 females, and their age ranged in our institute from 1 to 81; average age 51.1. Ruptured aneurysm (48%), head injury (14%), intracranial hemorrhage (23%) and cerebral infarction (12%) were the major causes requiring decompression surgery. We analyse the bone preservation period and the time between cranioplasty and the onset of infection. The infection rates per bone preservation periods, the causes of decompression and age groups are studied. Of the 208 case studies, infection necessitating bone removal or debridement was noted in 8 cases (3.88%). Average bone preservation period in the infected group was 31.1 days as compared with 54.9 days for the non-infected group (p < 0.05). Not patient age but the type of head injury is also a significant factor in post cranioplasty infection.     

The microvasculature of the cerebral white matter: arteries of the subcortical white matter

The microvascular architecture of the human cerebral subcortical white matter was studied. Most of the subcortical arteries ran straight through the cortex, but upon entering the white matter, they began to coil, loop, and spiral. Vascular stains showed wide spaces between the adventitial sheaths and blood vessels. The blood vessels coiled, looped, and spiraled within these wide adventitial spaces. This phenomenon was observed in the brains from persons ranging from the first to ninth decades of life and there were no statistically significant age-related correlations. Furthermore, there was no evidence of a reduction in the volume of white matter after fixation. Therefore, the observed tortuosity does not appear to be the result of shrinkage of brain tissue following fixation. While the mechanisms responsible for the subcortical arteries circuitry remain undetermined, this coiling architecture may serve as a trap for tumor cells and microorganisms passing through the blood stream, suggesting that these coiling arterial blood vessels may play a significant role in the pathogenesis of tumor metastasis and the brain abscess that frequently occurs in the gray-white matter junction.     

Novel surgical repair with bilateral gluteus muscle patching for intractable rectovaginal fistula

Abstract. We created a novel surgical repair for intractable rectovaginal fistula and treated four patients who had previously undergone unsuccessful surgery. An X-shaped skin incision was made on the perineum, and then the rectum was carefully divided from the vagina. Defects of both the rectum and the vagina were closed with vertical mattress sutures. The external sphincter muscle also was approximated. The gluteus muscle was identified through another skin incision to the buttock, and cut at the attachment to the femur. Bilateral gluteus muscles were approximated at the midline of the perineum so that the vagina was sufficiently separated from the rectum. Established anorectal angle was 92.5° (SD=6.4°). Mean resting pressure was 101.3 cm H₂O (SD=13.1). All patients retained complete anal function without soiling. The unusual problem of erosion of the posterior vaginal wall with fistulation in a sexually active woman justifies greater efforts, and this surgical technique offers good prospects in this small group of patients.     

Mutation (Ser284Leu) of neuronal nicotinic acetylcholine receptor alpha 4 subunit associated with frontal lobe epilepsy causes faster desensitization of the rat receptor expressed in oocytes

To date five mutations in two major constituents of neuronal nicotinic acetylcholine receptor (nAChR) in the brain, i.e. alpha4 and beta2 subunits, have been identified to be associated with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). Among them, only Ser284Leu, a point mutation in alpha4 subunit identified in ADNFLE as well as in a sporadic case with nocturnal frontal lobe epilepsy, remains to be characterized electrophysiologically. We examined the properties of rat nAChR harboring Ser284Leu reconstituted on Xenopus oocytes. Currents elicited in response to application of acetylcholine to oocytes expressing wild type or mutant nAChR were measured by a standard two-microelectrode voltage clamp method. Compared with wild-type nAChR, the mutant nAChR had a comparable EC(50) value for acetylcholine whereas it showed faster desensitization and lower Cs(+)/Na(+) permeability ratio. Ser284Phe, a putative mutation constructed for comparison, exhibited similar properties. These findings indicate that Ser(284) plays an important role in gating of nAChR along with Thr(276) and Ser(280), and suggest that mutation at Ser(284) could reduce nAChR activity similar to other mutations of alpha4 subunit found in ADNFLE.     

Molecular-feature domains with posterodorsal-anteroventral polarity in the symmetrical sensory maps of the mouse olfactory bulb: mapping of odourant-induced Zif268 expression

Individual glomeruli in the mammalian olfactory bulb presumably represent a single type of odourant receptor. Thus, the glomerular sheet provides odourant receptor maps at the surface of the olfactory bulb. To understand the basic spatial organization of the olfactory sensory maps, we first compared the spatial distribution of odourant-induced responses measured by the optical imaging of intrinsic signals with that detected immunohistochemically by expressions of Zif268, one of the immediate early gene products in juxtaglomerular cells. In the dorsal surface of the bulb, we detected a clear correlation in the spatial pattern between these responses. In addition, the molecular-feature domains and their polarities (spatial shifts of responses with an increase in carbon chain length) that were defined by the optical imaging method could be also detected by the Zif268 mapping method. We then mapped the Zif268 signals over the entire olfactory bulb using a homologous series of fatty acids and aliphatic alcohols as stimulus odourants. We superimposed the Zif268 signals onto the standard unrolled map with the help of cell adhesion molecule compartments. Each odourant typically elicited two pairs of clusters of dense Zif268 signals. The results showed that molecular-feature domains and their polarities were arranged symmetrically at stereotypical positions in a mirror-image fashion between the lateral and the medial sensory maps. The polarity of each domain was roughly in parallel with the posterodorsal-anteroventral axis that was defined by the cell adhesion molecule compartments. These results suggest that the molecular-feature domain with its fixed polarity is one of the basic structural units in the spatial organization of the odourant receptor maps in the olfactory bulb.