Refinement by linkage analysis in two large families of the candidate region of the third locus (SCA3) for autosomal dominant cerebellar ataxia type I

The autosomal dominant cerebellar ataxias (ADCA) are clinically and genetically heterogeneous. To date, several loci (SCAI-V) have been identified for ADCA type I. We have studied two large families from the northern part of The Netherlands with ADCA type I with a broad intra-familial variation of symptoms. In both families significant linkage is shown of the disease to the markers of the SCA3 locus on chromosome 14. Through recombinations, the candidate region for SCA3 could be refined to a 13-cM range between D14S256 and D14S81. No recombinations were detected with the markers D14S291 and D14S280, which suggests that the SCA3 gene lies close to these loci. This finding will benefit the individuals at risk in these two families who are seeking predictive testing or prenatal diagnosis.     

Mechanism of activation of the mouse c-mos oncogene by the LTR of an intracisternal A-particle gene.

In the mouse myeloma XRPC-24 the DNA of an intracisternal A-particle (IAP) is inserted within the coding region of c-mos. This insertion splits the c-mos into a 3' rc-mos and a 5' rc-mos separated by approximately 4.7 kb of IAP DNA. The insertion is in a head-to-head orientation and brings the 5' LTR of the IAP in juxtaposition to the 3' rc-mos such that the IAP and the 3' rc-mos are transcribed in opposite directions. The intact c-mos gene is usually dormant, whereas the 3' rc-mos is actively transcribed and is capable of transforming NIH3T3 cells. In an effort to understand the nature of this activation we mapped the 5' ends of the 3' rc-mos mRNA present in XPRC-24. We found two main mRNA start sites, one mapping to the junction of the 3' rc-mos and the 5' LTR, and the other located 10 nucleotides upstream to this junction, within the 5' LTR. This result indicates that the 3' rc-mos in XRPC-24 was activated by insertion of a promoter provided by the LTR of an IAP genome. Furthermore, the 5' LTR appears to possess promoter activities in two directions. This conclusion was confirmed by the fact that this 5' LTR, in both orientations, was able to activate the bacterial gene coding for chloramphenicol acetyltransferase (CAT) in the modular vector pSVOCAT.     

Electrophoresis of proteins and nucleic acids on acrylamide-agarose gels lacking covalent crosslinking

The preparation of acrylamide-agarose gels lacking covalent crosslinking with methylenebisacrylamide is described. These hybrid gels melt at 85 degrees C and, consequently, allow quantitative analysis of tritium-labeled protein after electrophoresis. Recovery of tritium-labeled ribonucleic acids extracted from hybrid gels is 20 to 25% greater than from standard acrylamide-methylenebisacrylamide gels. Standard curves of electrophoretic mobilities as a function of molecular weights of dissociated proteins and ribonucleic acids are compared for acrylamide-agarose gels and acrylamide-methylenebisacrylamide gels.     

Testicular histology of the dusky leaf monkey (presbytis obscura) as it relates to birth pattern in Peninsular Malaysia

The testicular histology of the dusky leaf monkey, Presbytis obscura,is described following a study of material from 16 adult males collected over a 13-month period in Peninsular Malaysia. The histological appearances were similar to those of the other cercopithecines studied so far. No seasonal variation in the height of the seminiferous epithelium was observed, and spermatogenesis was seen in all the adult testes. These findings suggest that males of this species are capable of breeding throughout the year. These results are discussed in relation to field observations of births of this species and to the birth patterns exhibited by other species of langur.     

Synthesis and gastrointestinal pharmacology of some 15- and 16- modified (±)-11-deoxyprostaglandins

The synthesis and gastrointestinal pharmacology of some 11-deoxyprostaglandin E₁ analogues are described with results analysed for selectivity from side effects. 11-Deoxygenation reduced potency relative to PGE₂ but, as has been reported for natural PGs, 15- or 16-methyl analogues were more potent than the unsubstituted parent compound in the order 16-methyl > 15-methyl > 16, 16-dimethyl. The results suggest that a complex interaction between C-15 and C-16 in methyl analogues affects their profile of activity, but that none of the modifications studied conferred a substantial potency or selectivity advantage over PGE₂.     

In vitro induction of tumor-specific immunity. III. Lack of requirement for H-2 compatibility in lysis of tumor targets by T cells activated in vitro to oncofetal and plasmacytoma antigens.

Many recent studies have demonstrated that cytotoxic T lymphocytes (CL) activated to various antigens other than those of the H-2 complex, will lyse target cells only when H-2 compatibility exists between the CL and target cell. From these observations, it has been inferred that T lymphocytes might only be capable of responding to H-2 antigen or antigens that become associated with H-2 region gene products. Our results suggest that this is not the case, and that in some situations, cytotoxic T lymphocytes can specifically lyse target cells of different H-2 types. Two in vitro systems are described where primary induction of cytotoxic T lymphocytes to oncofetal and plasmacytoma antigens results in CL capable of lysing suitable targets bearing these antigens, of either syngeneic or allogeneic derivation. Thus it is proposed that although interaction antigens involving H-2 components may preferentially activate T lymphocytes, this does not imply a restriction on the recognition potential of T lymphocytes.     

Broadly reactive murine cytotoxic cells induced in vitro under syngeneic conditions

Mouse spleen cells became cytotoxic in short-term 51Cr-release assays for a wide variety of target cells after 5 days of culture in vitro with polyinosinic acid in a system that was otherwise entirely syngeneic. This study characterizes these effector cells with respect to target specificity, effect of donor age, time course of their appearance, mouse strain differences, and expression of differentiation antigens Thy-1, Lyt-1, Lyt-2, NK-1, and asialo GM1. The combination of properties of this cytotoxic cell response that make it unique are that a) the broadly reactive cytotoxic activity developed from unprimed spleen cells in the absence of either foreign cells or foreign serum; b) the response did not peak until 4 to 5 days of culture in vitro; c) the broad reactivity pattern included freshly dispersed primary syngeneic sarcoma cells and cultured syngeneic fibroblasts but did not include syngeneic lymphoblast target cells; d) the response was largely monoclonal as defined by target cell binding; and e) cytotoxic cell activity was sensitive in complement-mediated treatments to both anti-NK and anti-theta but not to anti-Lyt-2, anti-Lyt-1, or anti-asialo GM1. Both high- and low-responding mouse strains have been identified.     

In Vivo Assay for the Synthesis of Hydroxyproline-rich Proteins

Simple methods are described for following in vivo the rate of peptidylproline hydroxylation and for determining what proportion of the total proline incorporated into protein is hydroxylated.