Spontaneous aberrant crypt foci in Apc1638N mice with a mutant Apc allele

The Apc1638N/+ mouse has a chain-terminating mutation in one allele of the adenomatous polyposis coli (Apc) gene that is similar to most mutations observed in the human familial adenomatous polyposis syndrome. Aberrant crypt foci (ACF), the earliest identified neoplastic lesions in the colon, are morphologically abnormal structures that are identifiedmicroscopically in the grossly normal colonic mucosas of rodents treated with colon carcinogens and of human patients. The colons and cecums of 62 Apc1638N/+ mice were evaluated for the spontaneous occurrence of ACF and tumors. Both male and female mice were killed at different times between 5 and 28 weeks of age. Wild-type littermates, ie, Apc(+/+) mice, at 22 to 26 weeks of age served as controls. ACF were identified in 97% of the Apc1638N/+ mice starting at 5 weeks of age and not in any wild-type littermates. Although the number of ACF increased with age (P < 0.0001), the average number of crypts per focus of the ACF did not increase significantly. In addition, wild-type Apc protein was detected by immunohistochemistry in all 22 ACF evaluated. Together these data suggest that heterozygous loss of Apc may be sufficient to initiate ACF in these mice and that these mice may be suitable models to study the interaction of environmental factors with an inherited mutation of the Apc gene that is associated with colon cancer.     

T cell developmental defects in 'viable motheaten' mice deficient in SHP-1 protein-tyrosine phosphatase. Developmental defects are corrected in vitro in the presence of normal hematopoietic-origin stromal cells and in vivo by exogenous IL-7

Defects in the gene that encodes SHP-1 protein tyrosine phosphatase result in multiple hematopoietic abnormalities and generalized autoimmunity in viable motheaten (me(v)) mice. These mice also exhibit early thymic involution and abnormalities in T cell development. Here, we describe the use of fetal thymic organ culture (FTOC) and bone marrow adoptive transfer to study the effects of SHP-1 deficiency on thymocyte development. Chimeric FTOC established with normal bone marrow placed onto deoxyguanosine-treated fetal thymic lobes or onto scid fetal thymic lobes generated T cells. Bone marrow from SHP-1-deficient me(v)/ me(v) mice generated decreased numbers of T cells in chimeric FTOC established using deoxyguanosine-treated thymi but generated normal numbers in chimeric FTOC established using scid thymi. However, scid fetal thymi seeded with me(v)/ me(v) bone marrow also exhibited morphological abnormalities and contained elevated numbers of macrophages. Addition of IL-7 to me(v)/ me(v) bone marrow-seeded scid FTOC led to increased cell numbers, particularly of macrophages. Intrathymic injection of IL-7 partially restored the ability of progenitor cells in me(v)/ me(v) bone marrow to populate the thymus of adoptive recipients. We conclude that abnormal T cell development in me(v)/ me(v) mice may in part be due to defects in the ability of bone marrow-derived accessory cells to provide bioavailable IL-7 to developing thymocytes.     

Effect of hypothermia on renal sodium reabsorption

Summary The relationship between sodium reabsorption and oxygen consumption was studied in an isolated rabbit kidney preparation perfused with blood at 37, 28 and 19° C. When the temperature was lowered from 37° C to 28° C and to 19°C the rate of oxygen consumption and of the maximal P.A.H. excretion (Tm P.A.H.) decreased more than that of sodium reabsorption.TheQ ₁₀ for sodium reabsorption is about 1.8, while that for maximal P.A.H. excretion is 2.5. Some hypothesis on the possible mechanisms of the lowQ ₁₀ of the Na⁺ reabsorption are forwarded.Preliminary reports have been published [Boll. Soc. Ital. Biol. Sper.43, 1019–1023 (1966) and44, 1784–1787 (1967);45, 860–862 (1969) and45, 863–865 (1969)].     

Age-related differences in novelty and target processing among cognitively high performing adults

Previous research on age-related changes in ERP components in response to novel and target stimuli has not carefully controlled for differences in level of cognitive status between age groups, which may have contributed to the common findings of increased P3 latency, decreased P3 amplitude, and altered P3 scalp distribution. Here, cognitively high-performing (top third based on published norms) old, middle-aged, and young adults matched for IQ, education, and gender participated in a novelty oddball paradigm. There were no age-associated differences in P3 latency. Older adults had a larger, more anteriorly distributed P3 amplitude to all stimulus types, even repetitive standards, suggesting they may rely on increased resources and effortful frontal activity to successfully process any kind of visual stimulus. However, after controlling for this non-specific age-related processing difference, the amplitude and scalp distribution of the P3 component to novel and target stimuli were comparable across age groups, indicating that for cognitively high functioning elders there may be no age-related differences specific to the processing of novel and target events as indexed by the P3 component.     

A double-blind, placebo-controlled, efficacy, safety, and pharmacokinetic study of INN 00835, a novel antidepressant peptide, in the treatment of major depression

BACKGROUND: INN 00835 is a synthetic pentapeptide with a potential for rapid onset of action as an antidepressant. Its efficacy was investigated in a pilot study in patients diagnosed with major depression. METHODS: Fifty two patients received either active drug - INN 00835 (26 patients) - or placebo (26 patients), subcutaneously at 0.2 mg/kg for 5 consecutive days. The patients were evaluated for an additional 4 weeks after treatment. Efficacy was evaluated by the following psychiatric rating scales: HAMD, MADRS, CSRS, CGI, and VAS. The effect of treatment was also evaluated by using a biochemical marker: changes in blood platelet serotonin (5HT) uptake rates in drug-treated patients compared to those in the placebo group. Plasma concentrations of INN 00835 were measured by LC/MS. RESULTS: Statistical analysis indicated a strong pharmacodynamic correlation between plasma drug concentrations at 1 h after dosing and the reduction in the severity of depression as measured by the psychiatric rating scales. A minimum effective plasma concentration (MEC) of INN 00835 was 5 ng/ml. Statistically significant differences in response to treatment (P<0.05) were found between patients with plasma concentrations above MEC and those in the placebo group, as well as between subjects with plasma concentrations above and below the MEC. The peak effect was observed after the 5-day treatment and the response to treatment persisted during the 4-week follow-up period. The change of 5HT uptake rates after treatment was significantly larger in the drug-treated group than in the placebo group. Limitations: This was a pilot study conducted in a relatively small population (52 patients) and the limited number of blood sampling times did not allow a comprehensive pharmacokinetic analysis. There was a relatively large placebo response. The results have to be confirmed in future, large scale studies. CONCLUSIONS: INN 00835 appears to be a promising drug for the treatment of major depression.     

Autosomal dominant inheritance of spondyloenchondrodysplasia

Spondyloenchondrodysplasia comprises generalized enchondromatosis with platyspondyly and is thought to be inherited as an autosomal recessive condition. A mother and son are reported with typical features of spondyloenchondrodysplasia. Their similar radiographic and MRI findings are presented. The radiologic appearance of the spine changed over time, illustrating the evolving phenotype of this condition. Transmission from mother to son suggests that dominant pattern of inheritance is possible. A classification of the enchondromatoses is discussed.     

Inhibition of Pseudomonas aeruginosa by Hyperbaric Oxygen II. Ultrastructural Changes

The ultrastructure of Pseudomonas aeruginosa cells treated with hyperbaric oxygen for 20 to 24 hr was examined by electron microscopy. A marked difference in the morphology of the nuclear area and cytoplasm of experimental cells was noted when compared to control cells grown under normobaric conditions. This difference was characterized by the absence of a definitive nuclear area and a reduced granularity of the cytoplasm.     

Development of a real-time fluorescence PCR assay for rapid detection of the diphtheria toxin gene

We developed and evaluated a real-time fluorescence PCR assay for detecting the A and B subunits of diphtheria toxin (tox) gene. When 23 toxigenic Corynebacterium diphtheriae strains, 9 nontoxigenic C. diphtheriae strains, and 44 strains representing the diversity of pathogens and normal respiratory flora were tested, this real-time PCR assay exhibited 100% sensitivity and specificity. It allowed for the detection of both subunits of the tox gene at 750 times greater sensitivity (2 CFU) than the standard PCR (1,500 CFU). When used directly on specimens collected from patients with clinical diphtheria, one or both subunits of the tox gene were detected in 34 of 36 specimens by using the real-time PCR assay; only 9 specimens were found to be positive by standard PCR. Reamplification by standard PCR and DNA sequencing of the amplification product confirmed all real-time PCR tox-positive reactions. This real-time PCR format is a more sensitive and rapid alternative to standard PCR for detection of the tox gene in clinical material.     

Serotonergic inhibition of action potential evoked calcium transients in NOS-containing mesopontine cholinergic neurons

Nitric oxide synthase (NOS)-containing mesopontine cholinergic (MPCh) neurons of the laterodorsal tegmental nucleus (LDT) are hypothesized to drive the behavioral states of waking and REM sleep through a tonic increase in firing rate which begins before and is maintained throughout these states. In principle, increased firing could elevate intracellular calcium levels and regulate numerous cellular processes including excitability, gene expression, and the activity of neuronal NOS in a state-dependent manner. We investigated whether repetitive firing, evoked by current injection and N-methyl-D-aspartate (NMDA) receptor activation, produces somatic and proximal dendritic [Ca(2+)](i) transients and whether these transients are modulated by serotonin, a transmitter thought to play a critical role in regulating the state-dependent firing of MPCh neurons. [Ca(2+)](i) was monitored optically from neurons filled with Ca(2+) indicators in guinea pig brain slices while measuring membrane potential with sharp microelectrodes or patch pipettes. Neither hyperpolarizing current steps nor subthreshold depolarizing steps altered [Ca(2+)](i). In contrast, suprathreshold currents caused large and rapid increases in [Ca(2+)](i) that were related to firing rate. TTX (1 microM) strongly attenuated this relation. Addition of tetraethylammonium (TEA, 20 mM), which resulted in Ca(2+) spiking on depolarization, restored the change in [Ca(2+)](i) to pre-TTX levels. Suprathreshold doses of NMDA also produced increases in [Ca(2+)](i) that were reduced by up to 60% by TTX. Application of 5-HT, which hyperpolarized LDT neurons without detectable changes in [Ca(2+)](i), suppressed both current- and NMDA-evoked increases in [Ca(2+)](i) by reducing the number of evoked spikes and by inhibiting spike-evoked Ca(2+) transients by approximately 40% in the soma and proximal dendrites. This inhibition was accompanied by a subtle increase in the spike repolarization rate and a decrease in spike width, as expected for inhibition of high-threshold Ca(2+) currents in these neurons. NADPH-diaphorase histochemistry confirmed that recorded cells were NOS-containing. These findings indicate the prime role of action potentials in elevating [Ca(2+)](i) in NOS-containing MPCh neurons. Moreover, they demonstrate that serotonin can inhibit somatic and proximal dendritic [Ca(2+)](i) increases both indirectly by reducing firing rate and directly by decreasing the spike-evoked transients. Functionally, these data suggest that spike-evoked Ca(2+) signals in MPCh neurons should be largest during REM sleep when serotonin inputs are expected to be lowest even if equivalent firing rates are reached during waking. Such Ca(2+) signals may function to trigger Ca(2+)-dependent processes including cfos expression and nitric oxide production in a REM-specific manner.     

Cytomegalovirus (CMV): specific lymphokine production in congenital CMV infection.

The studies reported here were designed to examine cytomegalovirus (CMV)-specific lymphokine production in infants with congenital CMV infection to elucidate the role of the efferent limb of the immune response to this virus. Mononuclear cells (MNC) from adult control donors and congenitally infected infants were stimulated with mitogen (PHA) or antigens (CMV, mumps), and the supernatants were assayed for production of migration inhibitory factor (MIF) and interferon (IFN). Concordance was observed between lymphocyte proliferative responses to CMV antigen and production of MIF in both control donors and congenitally infected infants. PHA-stimulated cultures from both controls and patients resulted in immune-specific IFN-gamma production in all cases. CMV-stimulated MNC from controls produced IFN when lymphocyte proliferation responses to the antigen were present, whereas those with absent proliferation did not produce IFN. CMV-induced IFN was detected in several patients who had reduced lymphocyte proliferative responses to CMV. The predominant species of IFN stimulated by CMV was neutralized by anti-IFN-gamma, suggesting that CMV induced primarily immune-specific IFN-gamma. In some cases, IFN activity was also reduced to a lesser degree by anti-IFN-alpha, suggesting either the presence of IFN-alpha or of cross-reacting antigenic determinants shared by the two species of IFN. Mumps viral antigen induced primarily IFN-alpha regardless of the immunological status of the donor. We conclude that lymphokine production in congenital CMV reflects the state of activation and/or proliferation of CMV-specific T helper cells rather than an intrinsic defect in the efferent limb of the immune response.