Effect of ouabain and metabolic inhibitors on the Na and K movements and nucleotide contents of L cells

1. The general characteristics and Na and K movements of L cells (derived from mouse epithelium) have been measured. Both cells grown in suspension (LS cells) and as a monolayer (L cells) were used.2. The volume of L cells was 1.2 x 10(-9) cm(3) and of LS cells 3.5 x 10(-9) cm(3); of this 82% was water.3. Electron micrographs showed the presence of numerous protrusions (filopodia) from both forms of the cell. These had the effect of increasing the surface area of the cell by 2-4 times over smooth cells of the same volume. On changing from the flattened to the spherical shape during trypsinization, the filopodia altered to maintain a constant V/A ratio.4. These cells contain K, about 170 m-mole/l. intracellular water and Na, 9 m-mole/l. intracellular water (L cells only) at 20 degrees C. The K fluxes are 1.9 p-mole/cm(2) sec for LS cells and 0.8 p-mole/cm(2) sec for L cells and the Na fluxes are 1.8 p-mole/cm(2) sec for L cells (expressed as per total cell surface (including filopodia)). If expressed as p-mole/cell per sec then L and LS cells have the same K flux.5. 10(-4)M ouabain reduces the K influx to half, indicating an insensitivity to the glycosides common to the species. In the prolonged presence of ouabain the cells come into a new steady state with a [K](1), of 140 and a [Na](1) of 20-30 m-mole/l. intracellular water, but a constant [Na + K](1).6. Both DNP (10(-3)M) and IAA (10(-4)M) are required for maximum inhibition of K uptake, as both aerobic and anaerobic metabolic pathways may be used to drive the pump.7. K removal decreases the Na efflux, and Na removal (eventually) decreases the K influx providing evidence for Na/K coupling.8. The cells contain 7.5 m-mole/litre intracellular water of ATP, a level some 15 times that of ADP.9. The Na pump in these cells is very similar to that found in other tissues in that (a) it requires K to work, (b) it is blocked by ouabain and metabolic inhibitors and (c) it transports three molecules of Na for each two molecules of K.     

Novel neuritic clusters with accumulations of amyloid precursor protein and amyloid precursor-like protein 2 immunoreactivity in brain regions damaged by thiamine deficiency.

Experimental thiamine deficiency (TD) is a classical model of a nutritional deficit associated with a generalized impairment of oxidative metabolism and selective cell loss in the brain. In rats, TD-induced cell degeneration is accompanied by an accumulation of amyloid precursor protein (APP)/amyloid precursor-like protein 2 (APLP2) immunoreactivity in abnormal neurites and perikarya along the periphery of, or scattered within, the lesion. Prompted by these data and our previous findings of a genetic variation in the development of TD symptoms, we extended our studies to mice. C57BL/6, ApoE knockout, and APP YAC transgenic mice received thiamine-deficient diet and pyrithiamine injections. Unlike rats, APP/APLP2-immunoreactive neurites in all strains of mice were sparsely scattered within damaged areas and did not delimit the thalamic lesion. In addition, abnormal clusters of intensely immunoreactive neurites occurred only in areas of damage including the thalamus, mammillary body, and inferior colliculus. The clusters appeared as either irregular clumps or round or oval rosettes that strikingly resembled the neuritic component of Alzheimer amyloid plaques. However, immunostaining using various antisera to synthetic amyloid beta-protein (A beta 1-40) and thioflavine S histochemistry failed to show evidence of a component of A beta Neither APP/APLP2-immunoreactive clusters nor amyloid plaques were observed in the brain from patients with Wernicke-Korsakoff syndrome, the clinical manifestation of TD in man. Our results demonstrate species (i.e., genetic) differences in the response to TD-induced damage and support a role for APP and APLP2 in the response to brain injury. This is the first report that chronic oxidative deficits can lead to this novel pathology.     

Macrophage migration inhibitory factor (MIF) gene polymorphism is associated with susceptibility to but not severity of inflammatory polyarthritis

The aim of the study was to investigate whether polymorphisms of macrophage migration inhibitory factor (MIF) determine susceptibility to or severity of inflammatory polyarthritis (IP). Genotypes for a single-nucleotide polymorphism (MIF-173*G/C) and a tetranucleotide (CATT)(n) repeat mapping to the promoter region of the MIF gene were compared between UK Caucasian IP cases (n=438) and controls (n=343). Both polymorphisms were also investigated for association with features of disease activity and severity at baseline and by 5 years. The MIF-173*C allele (OR 1.7, 95% CI 1.3-2.4, P=1.8 x 10(-4)) and the CATT(7) allele (OR 1.5, 95% CI 1.0-2.1, P=0.02) were found to be associated with increased susceptibility to IP. Furthermore, presence of the haplotype containing both associated polymorphisms was associated with a three-fold increase risk of developing IP. No association with disease severity or activity either at baseline or by 5 years was detected for either of the promoter polymorphisms studied. In conclusion, MIF is a susceptibility gene for the development of IP. The same alleles previously reported to be associated with susceptibility to juvenile idiopathic arthritis account for the increased risk. The promoter polymorphisms of MIF, investigated in this study, do not influence the severity of disease outcome by 5 years.     

Infliximab

Infliximab is a chimaeric monoclonal antibody which binds to and inhibits the activity of tumour necrosis factor-alpha (TNFalpha), a cytokine which is involved in the development of both Crohn's disease and rheumatoid arthritis. In patients with treatment-resistant Crohn's disease, infliximab was significantly more effective than placebo in the relief of symptoms. 50 to 89% of patients responded to infliximab and most of them also achieved remission. Patients showed signs of relapse 8 to 12 weeks after a single infusion but responded to additional infusions of the drug. Infliximab was also effective in closing the fistulae in 68% of patients with fistulising Crohn's disease; the response rate with placebo was 26%. Infliximab achieved a clinical response in 44 to 81% of patients with refractory rheumatoid arthritis. Following a single infusion, symptom recurrence was evident after 6 to 12 weeks, but subsequent infusions re-established a clinical response. Concurrent methotrexate appeared to prolong the effects of infliximab in this patient group. Anti-infliximab and anti-double-stranded DNA antibodies developed in some patients, particularly those who received multiple infusions of infliximab. Acute adverse events consistent with hypersensitivity occurred in some patients who received multiple infusions of infliximab. Infection occurred slightly more frequently with infliximab than with placebo. CONCLUSIONS: Infliximab appears to be an effective therapy for patients with treatment-resistant or fistulising Crohn's disease or refractory rheumatoid arthritis. The tolerability, long term efficacy and optimal dosage regimen need to be further defined in comparative trials before the full potential of infliximab is realised in these patients.     

Inhibition of TCR-mediated shedding of L-selectin (CD62L) on human and mouse CD4+ T cells by metalloproteinase inhibition: analysis of the regulation of Th1/Th2 function

The generation of a productive primary immune response is dependent on the ability of na?ve T lymphocytes to recirculate through peripheral lymph organs to encounter specific antigen. The process of na?ve CD4(+) T cell entry into lymph nodes correlates with cell surface expression of L-selectin (CD62L), which mediates early tethering and rolling events to endothelium prior to entry. Here, we demonstrate that surface expression of CD62L enhances CD4(+) T cell activation in vitro. The synthetic hydroxamate metalloproteinase inhibitor (BB-3103), specifically inhibits activation-induced shedding of CD62L from CD4(+) T cells by TCR cross-linking and lowers proliferation in part by reducing rapid tyrosine phosphorylation of zeta-associated protein 70 kDa (ZAP-70) and by increasing cytosolic free Ca(2+) concentration mobilization. BB-3103 also inhibited the proliferative response of both murine CD4(+) Th1 and Th2 subsets in vitro but the inhibitory effects were sustained only in Th2-type cells. Similarly, BB-3103 mediated prolonged inhibition of allergen-dependent peripheral T cell proliferation in atopic dermatitis patients but not in healthy controls. Analysis of CD62L expression on murine CD4(+) T cell subsets revealed that surface expression was maintained on Th1 cells but not Th2 cells. The differential effects of BB-3103 on primed effector CD4(+) T cells may provide new insights into generating therapeutic agents capable of redressing the Th2/Th1 imbalance in allergic diseases.     

Husbands' and wives' adjustment to pregnancy and first parenthood

There are conflicting reports regarding type and extent of the change in couples' lives due to the arrival of a 1st baby. The present short-term longitudinal study of 39 volunteer couples had 2 major objectives: 1) to examine changes in couples' division of labor during the transition to parenthood; and 2) to investigate husband-wife differences in the associations between indices of marital and parental adjustment during the early postpartum months. Individual questionnaires and interviews were administered in couples' homes on 3 occasions: early pregnancy, late pregnancy, and 3-4 months postpartum. The major findings were that changes in household division of labor from early pregnancy to late pregnancy to 3-4 months postpartum demonstrated a curvilinear pattern, such that late pregnancy was characterized by more egalitarian household roles than was found in early pregnancy or postpartum. Marital adjustment mean scores suggested that marriages were functioning well at 3-4 momnths postpartum. Fathers' greater involvement with the baby was associated with better marital and parental adjustment, whereas fathers' postpartum participation in feminine household tasks was correlated with lower adjustment. In contrast to father, mothers' greater participation in baby care tasks was associated with lower marital adjustment. Mothers usually perceived changes in marriage and lifestyle due to the baby as more bothersome than did fathers. Adjustment to parenthood and marital adjustment measures were more interrelated more frequently for fathers than mothers. These findings underscore the complex associations among husbands' and wives' household roles, marital adjustment, involvement with baby, and adjustment to parenthood.     

Religious and Spiritual Development from Adolescence to Early Adulthood in the U.S.: Changes over Time and Sexual Orientation Differences

Archives of Sexual Behavior - Adolescence is a critical time in the U.S. for religious development in that many young people eschew their religious identity as they enter adulthood. In general,...     

No evidence for paternal mtDNA transmission to offspring or extra-embryonic tissues after ICSI

There is a risk that ICSI may increase the transmission of mtDNA diseases to children born after this technique. Knowledge of the fate and transmission of paternal mitochondrial DNA is important since mutations in mitochondrial DNA have been described in oligozoospermic males. We have used an adaptation of solid phase mini-sequencing to exclude the presence of levels of paternal mtDNA >0.001% in ICSI families. This method is more sensitive than those used in previous studies and is sufficient to detect the likely paternal contribution (approximately 0.1-0.5% from simple calculations of expected dilution during fertilization). Using this method, we were able to detect concentrations as low as 0.001% paternal mtDNA in a maternal mtDNA background. No paternal mtDNA was detected in the embryonic (blood or buccal swabs) tissue of children born after ICSI nor in extra-embryonic tissue (placenta or umbilical cord). In conclusion, we did not detect paternal mtDNA in blood, buccal swabs, placenta or umbilical cord of children born after ICSI. We have found no evidence that ICSI increases the risk of paternal transmission of mtDNA and hence of mtDNA disorders.     

The association of atopic diseases with endometriosis

Comparisons of the incidence of health-related problems were conducted between women with demonstrable endometriosis (N = 88) and a control group (N = 88). Increased incidence of respondents' reports of allergic manifestations (p less than .005) were found. Directions for further research are suggested.     

Danish ethics council rejects brain death as the criterion of death -- commentary 1: wanting it both ways

In this commentary on the recommendations of the Danish Council of Ethics (DCE) concerning criteria for death it is argued that whilst the DCE is correct in stressing the cultural aspects of death, its adoption of cardiac-oriented criteria raises several problems. There are problems with its notion of a 'death process', which purportedly begins with brain death and ends with cessation of cardiac function, and there are serious problems regarding its commitment to a cardiac-oriented definition whilst permitting transplantation when the heart is still beating.