Human-Type Blood Factors in Gibbons, with Special Reference to the Multiplicity of Serological Specificities of Human Type M Blood

The human-type blood groups of 20 gibbons of subspecies Hylobates lar lar and of four gibbons of subspecies Hylobates lar pileatus have been determined. Differences in distribution of the ABO blood groups and MN types were observed for the two subspecies, but all 24 gibbons were of Rh-Hr type Rh^Gi. All the animals also lack both factors I and i. By absorption experiments anti-M reagents were shown to contain antibodies of at least three distinct M specificities; one M specificity is shared by all gibbon red cells, a second is absent from all gibbon red cells, while a third is shared only by gibbons red cells of type (M)^Gi and type (MN)^Gi. The theoretical and practical significance of the multiplicity of M factors in human M blood are pointed out.     

The midsagittal area of the corpus callosum and total neocortical volume differ in three inbred strains of mice

Differences in the midsagittal area of the corpus callosum have been reported between human males and females, between handled and nonhandled rats, and both within and between various strains of mice. This measure has, in addition, been related to handedness in humans and "pawedness" in certain strains of mice. The present study investigated the between- and within-strain differences in three inbred strains of mice, two with autoimmune disorders and spontaneously occurring developmental neuropathology, in the midsagittal area of the corpus callosum, the total neocortical volume, and the asymmetry of the neocortex. These morphometric measures were obtained from coronally sectioned celloidin-embedded material from New Zealand Black (NZB/BINJ), BXSB/MpJ, and DBA/2J mouse strains. NZB mice had a total neocortical volume larger than that of either the BXSB or DBA strains, whereas the BSXB mice had a midsagittal area of the corpus callosum larger than that of either of the other two strains. In addition, there was a positive correlation between these two measures. There was no correlation between total neocortical asymmetry and midsagittal area of the corpus callosum in any of the three strains. Finally, there were no differences in any morphometric measure between animals with or without developmental neuropathology in any given strain.     

Immunological characterization and localization of the Na+/Ca2(+)-exchanger in bovine retina

The sodium/calcium exchanger was purified from bovine retinal rod outer segment membranes and used for the immunization of New Zealand White rabbits. A polyclonal antibody was produced which was found to bind specifically to the 230 kDa Na+/Ca2(+)-exchanger protein as assessed by Western blotting. The antibody did not bind to the high-molecular-weight "rim protein," thereby demonstrating that this protein is distinct from the rod outer segment of Na+/Ca2(+)-exchanger. We used the polyclonal antibody for immunohistochemically localizing the exchange protein in bovine retina. Fluorescent light microscopy revealed intensive immunolabeling of the photoreceptor outer segments, whereas other retinal cell layers exhibited minimal binding. Using the electron microscopic immunogold method, we found specific antibody binding to the extracellular side of rod outer segment plasma membrane. Rod disk membranes, rod inner segments, and cone photoreceptors displayed no significant labeling. We therefore conclude that the Na+/Ca2(+)-exchanger is localized primarily in the rod outer segment plasma membrane, the most appropriate localization considering its proposed role in the process of vertebrate phototransduction.     

Comparison of 99Tcm dimercaptosuccinic acid scans and intravenous urography in children

A retrospective comparison of 99Tcm dimercaptosuccinic acid (DMSA) scans and intravenous urograms (IVUs) was performed on a large, unselected paediatric population to assess critically the relative merits of these two techniques. A total of 205 children were studied, providing 388 kidneys for comparison. The studies agreed in 81%, both being normal in 39%, and both abnormal in 42%. In 28 kidneys (7%), the IVU was abnormal when the 99Tcm DMSA was normal. There was a collecting system abnormality in 27 kidneys, but 10 kidneys also showed a parenchymal abnormality. In all these the parenchymal abnormality was global thinning on the IVU, and the contralateral kidney was small. In 40 kidneys (10%) the 99Tcm DMSA was abnormal when the IVU was normal: the abnormalities demonstrated were predominantly focal defects. After excluding IVUs of poor diagnostic quality, only 14 kidneys (3.6%) showed this disparity. The important clinical subgroups are infection, with or without reflux (27 kidneys), hypertension (4) and neonates with poor renal function (2). The one false positive 99Tcm DMSA was a result of an anatomical variant. Global thinning in a "normal" kidney on a 99Tcm DMSA scan may be overlooked when the contralateral kidney is poorly functioning and small.     

Evidence that the Rate of Wallerian Degeneration is Controlled by a Single Autosomal Dominant Gene

In a substrain of C57BL mice, C57BL/Ola, Wallerian degeneration in the distal segment of the severed sciatic nerve is extremely slow when compared to other mice. Despite this very slow degeneration in the distal segment regeneration of the motor nerves is not impaired. From suitable genetic outcrosses and backcrosses, the authors provide evidence that the rate of Wallerian degeneration in this strain is controlled by a single autosomal gene product. The authors have also shown that the rate of degeneration, in C57BL/Ola mice, is influenced by the environment in which the animals were bred and housed. Wallerian degeneration in the sciatic nerves of mice raised in isolators is slower than in those raised in a conventional animal house. This strain of mouse may prove to be of value in the understanding of nerve degeneration and regeneration.     

Enhancement of peroxisomal enzymes, cytochrome P-452 and DNA synthesis in putative preneoplastic foci of rat liver treated with the peroxisome proliferator nafenopin

The peroxisome proliferator (PP) nafenopin (NAF) enhanced tumordevelopment in rat liver through promotion of a subtype of putativepreneoplastic cell foci, characterized by weak cytoplasmic basophilia(1,2). In order to elucidate the selective growth advantageof these weakly basophilic foci (WBF) we investigated the effectsof NAF on their metabolic phenotype and DNA synthesis. In WBF,as well as in other foci subpopulations and in hepatocellularcarcinomas the occurrence of five NAF-inducible enzymes, i.e.of peroxisomal ß-oxidation (acyl-CoA oxidase, bifunctionalprotein and thiolase), catalase and cytochrome P-452 was studiedby immunohistochemical methods. In untreated livers almost allfoci were stained with the same intensity as the surroundingtissue. When NAF was applied, most of the liver foci showedconsiderably less staining than the non-focal parenchyma inwhich pronounced enzyme induction had occurred. However, thesubpopulation of WBF showed a more heterogeneous pattern ofenzyme expression varying from less to even more than in theadjacent tissue. A similarly broad range of expression of peroxisomalenzymes was found in hepatocellular carcinomas. On average,however, the tumors exhibited less staining and lower activityof peroxisomal ß-oxidation than the surrounding parenchyma.WBF always showed higher rates of DNA synthesis than other focisubtypes and unaltered liver. In     

Does epidural analgesia influence the mode of delivery in primiparae managed actively? A preliminary study of 1250 women

We studied 1250 primiparous women with a singleton pregnancy, gestational age at delivery of 37-42 weeks, with a single live fetus, vertex presentation whose first and second stages of labour were managed according to strict criteria for the active management of labour. 568 (45%) received epidural analgesia (bupivacaine 0.25%) during labour, and the other 682 (55%) received either Entonox, pethidine or no analgesia. The spontaneous vaginal delivery rate in the epidural group was 67% (95% confidence interval [CI] 63-71%), lower than that in the non-epidural group (87%, 95% CI 84-90%). All instrumental delivery rates were higher in the epidural group. However, the rotational forceps rate in the epidural group (2.5%, 95% CI 1.4-4.1%) was only marginally higher than in the non-epidural group (0.9%, 95% CI 0.3-1.9%). Women who were induced were more likely to request an epidural (56%: 95% CI 50-61%) than those with spontaneous onset of labour (41%: 95% CI 38-45%). Whether labour was spontaneous or induced, a higher proportion of women who received epidural required oxytocin augmentation. The effects of combinations of epidural analgesia, the need for oxytocin augmentation and induction of labour on mode of delivery were additive. This preliminary study suggests that a high rate of spontaneous vaginal delivery can be achieved with epidural analgesia when labour is actively managed.     

Learning by Selection in the Trion Model of Cortical Organization

The basic issue of whether mammalian learning in cortex proceedsvia a selection principle, as stressed by Edelman, versus aninstructional one is of major importance. We present here arealization of selection learning in the trion model, whichis based on the Mountcastle columnar organizational principleof cortex. We suggest that mammalian cortex starts out withan a priori connectivity between minicolumns that is highlystructured in time and in space, competing between excitationand inhibition. This provides a "naive" repertoire of spatial-temporalfiring patterns that stimuli and internal pro-cessing map onto.These patterns can be learned with small modifications to theconnectivity strengths determined by a Hobbian learning rule.As various patterns are learned, the repertoire changes somewhatin order to respond property to various stimuli, but the majorityof all possible stimuli still map onto spatial-temporal firingpatterns of the original repertoire. In order to show that theexample presented here is showing true selectivity and is notan artifact of more stimuli evolving into the learned pattern,we develop a selectivity measure. We suggest that some formof instructional learning (in which connectivities are finelytuned) is present for difficult tasks requiring many trials,whereas very rapid learning involves selectional learning. Bothtypes of learning must be considered to understand behavior.     

Technology update: computer-assisted video instruction in hospitals

Interactive videodisks are state-of-the-art technology, and their potential is rapidly beginning to be recognized in the health care industry. A recent survey of 169 health institutions found that 79% planned the purchase of videodisks within the next year, and 72% planned to develop a videodisk program. As the role of the medical records practitioner increasingly includes acting as a hospitalwide information manager, CAVI provides the medical records professional a unique opportunity to both provide effective training within the department and hospital and be the leader in bringing the advantages of CAVI to the institution.