Evidence for Linkage of Bipolar Disorder to Chromosome 18 with a Parent-of-Origin Effect

A susceptibility gene on chromosome 18 and a parent-of-origin effect have been suggested for bipolar affective disorder (BPAD). We have studied 28 nuclear families selected for apparent unilineal transmission of the BPAD phenotype, by using 31 polymorphic markers spanning chromosome 18. Evidence for linkage was tested with affected-sib-pair and LOD score methods under two definitions of the affected phenotype. The affected-sib-pair analyses indicated excess allele sharing for markers on 18p within the region reported previously. The greatest sharing was at D18S37: 64% in bipolar and recurrent unipolar (RUP) sib pairs (P = .0006). In addition, excess sharing of the paternally, but not maternally, transmitted alleles was observed at three markers on 18q: at D18S41, 51 bipolar and RUP sib pairs were concordant for paternally transmitted alleles, and 21 pairs were discordant (P = .0004). The evidence for linkage to loci on both 18p and 18q was strongest in the 11 paternal pedigrees, i.e., those in which the father or one of the father's sibs is affected. In these pedigrees, the greatest allele sharing (81%; P = .00002) and the highest LOD score (3.51; θ = 0.0) were observed at D18S41. Our results provide further support for linkage of BPAD to chromosome 18 and the first molecular evidence for a parent-of-origin effect operating in this disorder. The number of loci involved, and their precise location, require further study.     

Characterization of midgut proteinase activities of white grubs: Lepidiota noxia,Lepidiota negatoria,and Antitrogus consanguineus (scarabaeidae,melolonthini)

The proteinases in the midguts of three scarab white grub species, Lepidiota noxia, L. negatoria, and Antitrogus consanguineus, were investigated to classify the proteinases present and to determine the most effective proteinase inhibitor for potential use as an insect control agent. pH activity profiles indicated the presence of serine proteinases and the absence of cysteine proteinases. This was confirmed by the lack of inhibition by specific cysteine proteinase inhibitors. Trypsin, chymotrypsin, elastase, and leucine aminopeptidase activities were detected by using specific synthetic substrates. A screen of 32 proteinase inhibitors produced 9 inhibitors of trypsin, chymotrypsin, and elastase which reduced proteolytic activity by greater than 75%. © 1995 Wiley-Liss, Inc.     

An in situ assay for induced diphtheria-toxin-resistant mutants of diploid human fibroblasts

The sensitivity of diploid human fibroblasts to the cytotoxic effects of diphtheria toxin (DT) depended on the cell growth status. Exponentially growing cells treated with 10^?3-1 lethal flocculating units (LF) of DT/ml for 4 days survived with a frequency of 4 × 10^?4. However, the DT-resistant phenotype of colonies isolated under these conditions was not stable. When the growth of the cells had been arrested by confluence or deprivation of serum growth factors prior to treatment with DT (4 days, 10^?3-0.6 LF/ml), the survival decreased to 2 × 10^?6 and the resistance of isolated colonies was stable. An in situ assay for induced DT-resistant mutants was developed in order to avoid problems associated with the possible reduced viability of the mutants relative to that of wild-type cells. A reproducible and linear dose response was obtained for the induction of DT-resistant mutants by ethylnitrosourea. The mutants were induced with high frequency by this compound (e.g., 10^?3 mutants/viable cell at a 37% survival dose); complete expression of the mutant phenotype occurred after 6 generations of growth under nonselective conditions. Isolated mutant colonies showed stable resistance to DT and were cross-resistant to Pseudomonas aeruginosa exotoxin A.     

Comparative Study of Wastewater Lagoon with and without Water Hyacinth

A 3-year study was conducted on an existing, one-cell, facultative sewage lagoon having a total surface area of 3.6 ha and receiving a BOD₅ loading rate of 44 kglhald (40 Iblald). The comparative experimental periods ran from July through November for 3 consecutive years. During the first period, water hyacinths completely covered the lagoon. The water hyacinth coverage was reduced to 33% of the total surface area the second year. The lagoon, free of all vascular aquatic plants the third year, was monitored for comparative purposes. The most significant improvement overall in the effluent quality occurred when water hyacinths covered the entire lagoon. During this period the effluent BOD₅ and TSS were 23 and 6 mgll, respectively. Without water hyacinths, the effluent BOD₅ and TSS were 52 and 77 mgll, respectively. The effluent total organic carbon concentration with water hyacinths averaged 40 mgll, and without water hyacinths, 72 mgll. A discussion of the results from this 3-year study is presented in this paper along with associated problems that were observed when water hyacinths were introduced into the lagoon and altered its behavior from that of a normal facultative lagoon.     

The Chicago variant of clinical galactosemia

Summary A new variant of clinical galactosemia with two hitherto unidentified alleles on the transferase locus in one family is described. This new clinical variant of transferase has 25% of normal control activity in blood and in skin fibroblasts, and the patient accumulates galactose-1-phosphate in blood on an unrestricted galactose diet. Using starch gel electrophoresis on the hemolysate of the family members, a fast-moving transferase with mobility in between those of the normal control and of the Duarte variant is identified. This new allele is designated as (fast-moving Chicago variant). In addition, a second new allele was documented in this family by studying the instability of the transferase enzyme in hemolysates of family members at 50°C for various time intervals. This new allele is designated as (heat-labile Chicago variant). On the basis of the studies, the transferase genotype of this patients is thought to be a double heterozygote compound, /GALT^G.     

Mitogens for murine embryo cell lines

The growth-promoting activities of fetal bovine serum, cortisol, phorbol myristate acetate, prostaglandin F2α, insulin, epidermal growth factor, and fibroblast growth factor were evaluated on four murine embryo cell lines (Swiss 3T3, Balb 3T3, M2, and C3H10T1/2). Each cell had an unique response spectrum to this collection of reported mitogens. Phorbol myristate acetate and prostaglandin F2α were active only on selected cell lines; cortisol was inactive on all four lines. Serum, epidermal growth factor, and fibroblast growth factor were able to stimulate cell division in all four lines, albeit to varying degrees for the different target cells.     

The activation of bovine Factor X by bovine Factor Xa

A steady-state kinetic analysis of the activation of bovine Factor X, by bovine Factor X_a, was undertaken. The activation was found to be dependent on the presence of divalent cations; Ca²⁺ showing the greatest stimulatory effect and Mn²⁺ exhibiting a lower degree of activity for this reaction. Although Sr²⁺ and Mg²⁺ were ineffective when present alone, each contributed synergistically to the activation rate at suboptimal levels of Ca²⁺. The effect of phospholipid (phosphatidylcholine:phosphatidylserine, 4:1, w:w) on the rate of activation and on the activation pathway was investigated. Phospholipid (PL) concentrations of up to 40 μm had no effect on the activation rate; whereas, concentrations of 40–180 μm were slightly inhibitory. In the absence of PL, the major product of the activation was Factor α-X_a, while in the presence of PL, lower-molecular-weight forms of Factor X (Factor β-X) and Factor X_a (Factor β-X_a were produced. At saturating levels of Ca²⁺, the K_{m app} for the activation, at pH 7.4 and 37 °C, in the absence of PL, was found to be 0.6 ± 0.1 μm and the V was 1.7 ± 0.3 mol Factor X cleaved min^?1 mol^?1 Factor X_a. The corresponding values, in the presence of 90 μm PL, were 1.4 ± 0.2 μm and 2.2 ± 0.2 mol Factor X cleaved min^?1 mol^?1 Factor X_a.     

Two distinct regulatory steps in cartilage differentiation

The effect of developmental stage on chondrogenic capacity in high-density cell cultures of chick embryonic wing bud mesenchyme is examined. Mesenchyme from stage 19 embryos forms aggregates of closely associated cells which do not form cartilage matrix, nor contain significant levels of type II collagen that are detectable by immunofluorescence, unless they are treated with dibutyryl cyclic AMP. Mesenchyme from stage 24 embryonic wing buds in high-density cell cultures will spontaneously form cartilage, as defined by electron microscopy and immunofluorescence with antibody to type II collagen. Cultures prepared from stage 26 wings form numerous aggregates which fail to accumulate an Alcian blue-staining matrix and which resemble mesenchyme cells morphologically. However, because these cells show considerable intracellular immunofluorescence for type II collagen, they are actually unexpressed cartilage cells. Several treatments, including exposure to dibutyryl cyclic AMP, ascorbic acid and an atmosphere of 5% oxygen, or mixture with small numbers of stage 24 wing mesenchyme cells, stimulate expression, as determined by the accumulation of an Alcian blue-staining matrix and an ultrastructurally recognizable cartilage matrix. Since the addition of similar numbers of differentiated cartilage cells does not stimulate expression of stage 26 cells, it is proposed that initial cartilage expression is dependent on a mesenchyme-specific influence which might be removed by cell dissociation. These studies demonstrate that there are at least two distinct transitions in cartilage differentiation: one involves the conversion of mesenchyme to unexpressed chondrocytes and the second involves mesenchyme-dependent expression of chondrogenic differentiation.     

Mitogenic property of the apical ectodermal ridge

While the apical ectodermal ridge (AER) is well known for its required role in the development of distal parts of the limb and for its ability to stimulate limb duplications, the mechanism of its action is unknown. In this study we use a culture system previously developed by M. Globus and S. Vethamany-Globus (1976, Differentiation6, 91–96) in which an AER grafted onto a high-density cell culture of limb mesenchyme stimulates the formation of an outgrowth. Time-lapse movies taken during the outgrowth period demonstrated no cellular activities other than cell division. Both the mitotic index and labeling index in the mesenchyme were significantly elevated under the AER as compared to that without AER, indicating that the AER provides a growth-promoting stimulus which increases the proportion of dividing cells. On the other hand, nonridge ectoderm had no detectable effect on the mitotic index. Treatment of cultures with cytosine arabinoside both inhibited DNA synthesis and prevented AER-induced outgrowth. These results demonstrate a mitogenic capacity of AER tissue and suggest that mesenchymal outgrowth requires this activity. The mitogenic property of the AER is considered in relation to limb outgrowth in situ.