Observation method identifies that a lack of canonical babbling can indicate future speech and language problems.

AIM: We investigated how accurate observations of canonical babbling (CB) were and explored predictive babbling measures in children with and without medical diagnoses of conditions that can lead to speech and language problems. METHODS: From 2012 to 2014 this Stockholm-based study recruited 38 children aged nine months to 21 months with medical diagnoses and 30 children aged 10 months without diagnoses and included 21 previously studied 12-month-old children without medical diagnoses. CB and consonant sound production were directly observed by video recording natural play with a caregiver. The percentage of CB was calculated from each recording, and a validated observation form was used. How accurately the children with and without CB were classified was investigated with sensitivity and specificity. The groups were compared using predictive babbling variables. RESULTS: The observation method identified children with and without CB well, with a specificity of 0.89 and sensitivity of 0.93, respectively. Children with predictive babbling measures were identified in the clinical group (specificity 0.93-0.97), and a lack of these measures indicated a risk of being in the clinical group (odds ratios > 10). The sensitivity was low (0.32-0.42). CONCLUSION: Observation effectively identified a lack of CB and supported the importance of assessing babbling measures.

Perchlorate natural attenuation in a riparian zone.

Multiple lines of evidence were used to document the natural attenuation of perchlorate in a shallow alluvial aquifer. In the upgradient, aerobic portion of the aquifer, perchlorate did not biodegrade. However, natural flushing by groundwater flow is reducing perchlorate concentrations in the aquifer over time. Perchlorate concentrations in the source area are expected to meet cleanup criteria in 11 to 27 years without active remedial measures. At the distal end of the plume, perchlorate is rapidly degraded as it migrates upward through organic rich littoral zone sediments. Apparent first-order degradation rates in groundwater were about 0.20 d(-1) and are consistent with laboratory macrocosm rates (0.12 d(-1)). qPCR results show a distinct region of the littoral zone where perchlorate degraders are elevated. The Eh within this zone varies from +0.1 to +0.3 V indicating perchlorate degraders can thrive in moderately oxidizing conditions. The study has shown that (i) there was no apparent perchlorate biodegradation in aerobic aquifer; (ii) perchlorate declines over time in aerobic aquifer due to flushing; (iii) there was a rapid perchlorate attenuation in organic rich littoral zone; and, (iv) qPCR results show large increases in perchlorate degraders in the littoral zone.

Mutations in the glutathione synthetase gene cause 5-oxoprolinuria.

5-Oxoprolinuria (pyroglutamic aciduria) resulting from glutathione synthetase (GSS) deficiency is an inherited autosomal recessive disorder characterized, in its severe form, by massive urinary excretion of 5-oxoproline, metabolic acidosis, haemolytic anaemia and central nervous system damage. The metabolic defect results in low GSH levels presumably with feedback over-stimulation of gamma-glutamylcysteine synthesis and its subsequent conversion to 5-oxoproline. In this study, we cloned and characterized the human GSS gene and examined three families with four cases of well-documented 5-oxoprolinuria. We identified seven mutations at the GSS locus on six alleles: one splice site mutation, two deletions and four missense mutations. Bacterial expression and yeast complementation assays of the cDNAs encoded by these alleles demonstrated their functional defects. We also characterized a fifth case, an homozygous missense mutation in the gene in an individual affected by a milder-form of the GSS deficiency, which is apparently restricted to erythrocytes and only associated with haemolytic anaemia. Our data provide the first molecular genetic analysis of 5-oxoprolinuria and demonstrate that GSS deficiency with oxoprolinuria and GSS deficiency without 5-oxoprolinuria are caused by mutations in the same gene.

Ar+ and Xe+ velocities near the presheath-sheath boundary in an Ar/Xe discharge.

The velocities of Ar+ and Xe+ ions near the presheath-sheath boundary in an Ar/Xe discharge are studied by particle-in-cell Monte Carlo simulation. For a pure argon discharge the argon ion has almost the same velocity profile as it does in the mixture of argon and xenon. Similarly, for a xenon discharge the xenon ion has almost the same velocity profile as it does in the mixture of argon and xenon. The ion speed at the sheath-presheath boundary is the same for an ion in a pure argon or xenon discharge and for the same ion in a mixture of argon and xenon. We conclude that, in our simulation, each ion reaches its own Bohm speed at the presheath-sheath interface.

Children's word fluency strategies.

Two word fluency tasks, the FAS letter fluency task and the "animal" semantic fluency task, were administered to 130 healthy Swedish-speaking children between 6 and 15 years of age. The main aim was to gather normative data on these word fluency tasks for Swedish-speaking children. Another purpose was to examine the switching and clustering strategies used, along with the occurrence of erroneous responses, in relation to demographic data and number of words retrieved. Both phonological and semantic analyses of switching and clustering were conducted. Higher age was found to be related to a more effective use of phonological and semantic switching and clustering strategies. The reference data resulting from this study may be of clinical value in examinations of children with various diagnoses, including language impairment.

T-cell lymphoma induction by radiation leukemia virus in athymic nude mice.

We report the development of extrathymic lymphoblastic lymphomas in RadLV-inoculated congenitally athymic nude mice. Thus, a leukemogenic virus which appears to require the presence of a thymus for its replication in normothymic mice can infect and transform target cells in the absence of this organ in the athymic host. The cells of one of these lymphomas have been established in vitro as a permanent cell line, BALB/Nu1. This cell line as well as a lymphoma induced in NIH/Swiss nude mice exhibit several T-cell markers, including terminal deoxynucleotidyl transferase activity, Thy-1.2, and Ly-2.2, but not Ly-1.2 nor TL. Ig determinants were not detected. The characteristics of the tumor cells support the view that cells with T-cell markers may normally exist in nude mice and undergo neoplastic transformation and clonal expansion after infection with a leukemogenic virus. The alternative possibility that virus-induced differentiation of prothymocytes may lead to the expression of Thy-1.2 and Ly-2.2 antigens is also considered. BALB/Nu1 cells release large numbers of type C viral particles. The virus, designated radiation leukemia virus (RadLV)/Nu1, has RTase activity and the protein profile characteristic of murine leukemia virus (MuLV). In radioimmunoassays, it cross-reacts completely with RadLV/VL3, a virus obtained from RadLV-induced C57BL/Ka thymic lymphoma cells in culture, and slightly with a xenotropic virus (BALB:virus-2) and with AKR MuLV. On inoculation into C57BL/Ka mice it has thymotropic and leukemogenic activity. In vitro it is B-tropic, poorly fibrotropic, and has limited xenotropic activity. Thus, RadLV/Nu1 appears to be biologically and serologically similar or identical to its parent virus, RadLV.

Genetic control of radiation leukemia virus-induced tumorigenesis II. Influence of Srlv-1, a locus not linked to H-2.

A single locus, tentatively denoted Srlv-1 (susceptibility to radiation leukemia virus [RadLV]-1), confers dominant susceptibility to RadLV-induced leukemogenesis. Srlv-1 is not linked to H-2, and appears to be distinct from Fv-1 and Fv-2. Preliminary data suggest that Srlv-1 affected virus proliferation. A striking feature of this system is that Srlv-1 overrides the protection afforded by the H2D-associated dominant resistance to RadLV-induced neoplasia.

Unexpected effects of the severe combined immunodeficiency mutation on murine lymphomagenesis.

Strain C.B17 scid/scid (SCID) mice, which lack functional T and B lymphocytes, show heightened susceptibility to the induction of thymic lymphomas by x-irradiation. Susceptibility is highest in thymus-chimeric SCID-BL mice (thymectomized SCID mice bearing a C57BL thymus graft). All SCID-BL lymphomas originate in the cells of the thymic graft (C57BL type) and lack murine leukemia virus expression. Both SCID and SCID-BL lymphomas are phenotypically CD4-8+ and/or CD4+8+, but only the SCID-BL tumors express CD3. Injection of C57BL or BALB/c bone marrow into irradiated SCID-BL mice prevents lymphoma development, but SCID marrow is completely ineffective. The results suggest that the scid condition enhances the activity of a putative lymphomagenic agent induced in the bone marrow by x-irradiation and that C57BL thymic cells are highly sensitive targets. Moreover, the failure of SCID bone marrow to protect against lymphomagenesis vs. the efficacy of marrow from immunocompetent donors points to involvement of T or B lineage cells in this process.

Differentiation of CD3-4-8- thymocytes in short-term thymic stromal cell culture.

We have investigated the ability of a heterogeneous thymic stromal cell (HTSC) culture system to promote in vitro differentiation of CD3-4-8- thymocytes. Culture of purified murine CD3-4-8- thymocytes on HTSC for 1 d resulted in the appearance of CD4+8+ cells, which did not occur when the sorted cells were maintained in medium alone. It is remarkable that when the culture period was extended to 2 d, CD3-4-8- progenitors differentiated further to CD4+8- and CD4-8+ cells, which also expressed high levels of TCR-CD3. This rapid differentiation on stroma in vitro appears to outpace parallel development in vivo. The differentiation potential of a subset of CD3-4-8- thymocytes that express high levels of a marker of normal and neoplastic thymic progenitors, the 1C11 antigen, was examined next. 1C11hiCD3-4-8- cells also gave rise to CD4-8+ and CD4+8+ populations after 1 d of culture on HTSC. Extending the culture period to 2 d resulted in a significant percentage of CD3-expressing cells that were CD4+8+, CD4+8- and CD4-8+ cells. These results suggest that in the in vitro HTSC culture system, various subsets of immature thymocytes can differentiate into all the mature phenotypes of cells normally found in the adult mouse thymus. This may provide a novel and rapid assay for thymic progenitors.

Increased synthesis and expression of H-2 antigens on thymocytes as a result of radiation leukemia virus infection: a possible mechanism for H-2 linked control of virus-induced neoplasia.

Previous studies from this laboratory have mapped resistance and/or susceptibility to radiation-induced leukemia virus (RadLV)-induced neoplasia to the H-2D region. H-2 linked effects on virus replication can be detected subsequent to the initial virus infection, and clear-cut differences in numbers of virus infected thymus cells can be detected as early as 5 wk after RadLV inoculation. Rapid increases in cellular synthesis and cell surface expression of H-2 antigens are detectable immediately after virus inoculation. These changes have been studied by immunofluorescence, absorption, cell surface iodination followed by sodium dodecyl-sulfate-polyacrylamide gel electrophoresis, and two dimensional gel electrophoretic analysis of internally labeled lymphocyte proteins. Expression of H-2K molecules is significantly increased in cells of susceptible and resistant animals. However, significant increases in expression of H-2D antigens occurs only on thymus cells from resistant strains (H-2Dd). Transformed cells of resistant and susceptible H-2 haplotypes adapted to tissue culture lack detectable H-2 antigens as determined by serological absorption studies. It is argued that altered expression of H-2 antigens plays a very significant role in the mechanism of host defense to virus infection.

Indirect induction of radiation lymphomas in mice. Evidence for a novel, transmissible leukemogen.

The transmission of a lymphomagenic agent(s) from the bone marrow of irradiated mice to thymic target cells has been demonstrated by: (a) the induction of T cell lymphomas in nonirradiated thymic grafts implanted in irradiated, Thy-l-congenic mice, (b) the induction of T cell lymphomas of host origin in mice infused with bone marrow from irradiated, Thy-l-congenic donors. The latter procedure also yields an appreciable number of pre-B cell lymphomas of uncertain origin. The results confirm Kaplan's theory that radiation induces thymic lymphomas in mice by an indirect mechanism. However, the previously described radiation leukemia virus is clearly not involved in the majority of transferred lymphomas. We propose that the mediating agent in radiation lymphomagenesis is a novel, transmissible agent induced in the bone marrow, but exerting its transforming activity on cells in the thymus. The nature and mode of action of the agent are under investigation.

Distribution of binding sites for human chorionic gonadotropin in the preovulatory follicle of the rat.

The distribution of binding sites for human chorionic gonadotropin (hCG) in the preovulatory follicle was studied by autoradiography. An ovulatory dose (10 IU/rat) of [125I]hCG (1.4 muCi/IU) was administered intravenously, and large Graafian follicles were isolated 3 h later by microdissection. Injection of excess unlabeled hCG (500 IU/rat) prevented uptake of radioactivity by the follicle, indicating that binding of iodinated hormone was confined to specific and saturable receptor sites. The density of bound hormone molecules was highest in the theca interna and in three to four layers of mural granulosa cells adjacent to the basement membrane; labeling was chiefly associated with the cell borders. No significant binding could be detected either on the oocyte or on the cumulus cells surrounding the oocyte. We therefore suggest that the induction of ovum maturation does not require attachment of the hormone to the oocyte itself or to follicle cells in its immediate vicinity.

Inhibition of lymphocyte proliferation by detergent-solubilized mouse liver membranes.

The role of phenomena analogous to fibroblast contact inhibition in lymphocyte growth regulation is controversial, although it is clear that direct cell-cell contact is vital to immunoregulation and accessory cell function. An extract of mouse liver plasma membrane proteins, referred to as suppressive liver extract (SLE), that suppresses the growth of 3T3 fibroblasts also inhibited the mitogen-induced proliferation of murine lymphocytes. A dose of 20 micrograms/ml SLE was less than 95% suppressive of proliferation in both mouse T and mouse B cells treated with a variety of mitogens. B cell growth factor, while increasing DNA synthesis overall in mitogen-stimulated B cells, did not change the extent of SLE suppression, which suggests that the SLE does not interfere with lymphocyte-growth factor interactions. In exploring a sequence of B cell activation events, we discovered that SLE had no effect on the early activation event of increased phosphatidylinositol turnover. Blastogenesis, however, was inhibited in mitogen-stimulated, SLE-treated B cells. The maximum suppressive effect was observed if the SLE was added within 8-12 h of the mitogenic stimulus. SLE did not affect the viability of cells in culture. These results point to a possible unity of regulatory mechanisms between contact inhibition in fibroblasts and the processes of immunoregulation.

Formation and distribution of nuclear pore complexes in interphase.

The possibility of nuclear pore formation in the interphase nucleus was investigated in control and phytohemagglutinin (PHA) stimulated lymphocytes by the freeze-etching technique. 48 hr after the addition of PHA, the newly formed blasts which had not as yet divided had at least twice the number of pores per nucleus as controls. This clearly demonstrates that in lymphocytes nuclear pore formation can take place during interphase. It has generally been assumed that the distribution of nuclear pore complexes in somatic animal cells is random. However, we have utilized freeze etched rat kidney cells and a computer program to evaluate pore distribution. We find a minimum pore center-to-center spacing of approximately 1300 A and multiples thereof with high frequency. This is strong evidence for a nonrandom distribution of nuclear pores. The nonrandomness may be related to an underlying chromosomal organization in interphase. Using three criteria for identifying prospective pore sites (membrane specialization, nonrandomness, and alteration of heterochromatin distribution), we have found forming pores in sectioned material from cultured human melanoma cells. While nuclear pore formation may take place in conjunction with reformation of the nuclear membrane, a mechanism also exists for their formation during interphase.

Time sequence of nuclear pore formation in phytohemagglutinin-stimulated lymphocytes and in HeLa cells during the cell cycle.

The time sequence of nuclear pore frequency changes was determined for phytohemagglutinin (PHA)-stimulated human lymphocytes and for HeLa S-3 cells during the cell cycle. The number of nuclear pores/nucleus was calculated from the experimentally determined values of nuclear pores/micro(2) and the nuclear surface. In the lymphocyte system the number of pores/nucleus approximately doubles during the 48 hr after PHA stimulation. The increase in pore frequency is biphasic and the first increase seems to be related to an increase in the rate of protein synthesis. The second increase in pores/nucleus appears to be correlated with the onset of DNA synthesis. In the HeLa cell system, we could also observe a biphasic change in pore formation. Nuclear pores are formed at the highest rate during the first hour after mitosis. A second increase in the rate of pore formation corresponds in time with an increase in the rate of nuclear acidic protein synthesis shortly before S phase. The total number of nuclear pores in HeLa cells doubles from approximately 2000 in G(1) to approximately 4000 at the end of the cell cycle. The doubling of the nuclear volume and the number of nuclear pores might be correlated to the doubling of DNA content. Another correspondence with the nuclear pore number in S phase is found in the number of simultaneously replicating replication sites. This number may be fortuitous but leads to the rather speculative possibility that the nuclear pore might be the site of initiation and/or replication of DNA as well as the site of nucleocytoplasmic exchange. That is, the nuclear pore complex may have multiple functions.

Ethylene formation in rat liver microsomes.

Reduced triphosphopyridine nucleotide and pyrophosphate-dependent peroxidation of lipids in rat liver microsomes were coupled to the generation of ethylene in the presence of cuprous ions. This system suggests a model for the biogenesis of ethylene in cells.

Ethane evolution: a new index of lipid peroxidation.

Homogenates of mouse liver and brain at 37 degrees C spontaneously formed lipid peroxides and simultaneously evolved ethane. alpha-Tocopherol, a lipid antioxidant, blocked ethane formation. When mice were injected with carbon tetrachloride (a liquid prooxidant for liver), the animals produced ethane. Ethane evolution in vivo was stimulated by prior administration of phenobarbital and it was diminished by prior injection of alpha-tocopherol. These data suggest that ethane production may be a useful index of lipid peroxidation in tissue homogenates and in intact animals.

Interferon administered orally: protection of neonatal mice from lethal virus challenge.

Interferon was identified in the milk of mice injected with an interferon inducer. The kinetics of interferon appearance in serum and in milk were similar, but maximum concentrations in milk were 10 to 20 percent of those in serum. Interferon administered orally to neonatal mice was detected in their serums. Significantly more newborns survived an oral challenge with vesicular stomatitis virus when interferon had been induced in the lactating mothers.

Infection of the SCID-hu mouse by HIV-1.

SCID-hu mice with human fetal thymic or lymph node implants were inoculated with the cloned human immunodeficiency virus-1 isolate, HIV-1JR-CSF. In a time- and dose-dependent fashion, viral replication spread within the human lymphoid organs. Combination immunohistochemistry and in situ hybridization revealed only viral RNA transcripts in most infected cells, but some cells had both detectable viral transcripts and viral protein. Infected cells were always more apparent in the medulla than in the cortex of the thymus. These studies demonstrate that an acute infection of human lymphoid organs with HIV-1 can be followed in the SCID-hu mouse.

Synthetic strands of cardiac muscle: growth and physiological implication.

Cardiac muscle cells obtained fronm disaggregated embryonic chick hearts were cultured on difjerentially treated oriented substrata. Subsequent cell reaggregation, growth, and attachmwent produced linearly organized strands of cardiac muscle with dimensions suitable for electrophysiological analysis. Along the strand, areas that contained few muscle cells demonstrated reduced conduction velocity and were subject to propagation failure.