The role of volume-sensitive Cl- channels in the stimulation of chloride absorption by short-chain fatty acids in the rat colon

The short-chain fatty acids acetate, propionate and butyrate induced a concentration-dependent decrease in short-circuit current (Isc) of the rat colon in vitro. The decrease in Isc, being more pronounced in the distal than in the proximal colon, was dependent on the presence of Cl- ions and partly on the presence of HCO3-. In the distal colon, the fall in Isc could be inhibited by amiloride, indicating that the activity of the Na+/H+ exchanger is necessary for the induction of this response. The decrease in Isc was diminished by the Cl- channel blocker, 5-nitro-2-(3-phenylpropylamino)-benzoate, and the lipoxygenase inhibitor, nordihydroguaiaretic acid. In contrast, inhibitors of the leukotriene pathway or a Cl- channel blocker did not affect the Isc response in the proximal colon. Measurements of unidirectional fluxes revealed that butyrate caused a stimulation of the mucosa to serosa fluxes (Fms) of Na+ and Cl- in the distal, but only of FNams in the proximal colon. Unidirectional Rb+ fluxes were not altered. The stimulation of Fclms correlated with the degree of metabolism of the short-chain fatty acid. The increase in FClms was most pronounced for butyrate, smaller for acetate and not observed with the poorly metabolizable short-chain fatty acid, isobutyrate. Consequently, two factors seem to be responsible for the stimulation of Cl- absorption by short-chain fatty acids in the distal colon: (1) the intracellular production of HCO3- during the oxidation of short-chain fatty acids as substrate for the apical Cl-/HCO3- exchanger, and (2) the activation of volume-sensitive basolateral Cl- channels.

Tumour incidence, spectrum and ploidy in mice with a large deletion in the p53 gene

In human tumourigenesis the tumour suppressor gene most commonly affected by mutation, inactivation or allele loss is p53. Loss of p53 function is associated both with failure to maintain a normal diploid status and inability to delete cells by apoptosis following DNA damage. To investigate further the role of p53 we have generated mice carrying a large deletion within the gene. All animals homozygous for this deletion develop spontaneous tumours, predominantly lymphomas, by the age of 6 months. 10% of heterozygotes develop a range of neoplasms, with a lower predisposition towards lymphoma, by 9 months. Both tumour incidence and spectrum in heterozygotes differ from those previously reported in another p53 mutant stock, suggesting either difference in exposure to carcinogens between the two stocks, or a role for modulating genes within different genetic backgrounds. Tumours showed frequent loss of diploid status, and the majority of those arising in heterozygotes showed loss of the wild type allele. These findings are consistent with the concept that p53 acts as a tumour suppressor by preventing the propagation of DNA damage to daughter cells.

Promoter, enhancer and silencer elements regulate rearrangement of an immunoglobulin transgene

The chicken Ig lambda light chain locus is composed of a single V gene closely linked (1.8 kb) to a single J-C unit in its natural configuration. In mice transgenic for this locus, the transgene becomes rearranged in B cells and to a much lesser extent in T cells. Modifications were introduced in the transgene in order to characterize elements which target the recombinase to the Ig loci. In the absence of either the promoter or the enhancer located 3' of C lambda, rearrangement of the transgene is reduced 20- to 100-fold. Moreover, rearrangement is increased 5-fold when the DNA segment between V lambda and J lambda ('Uo segment'), which is deleted during the joining process, is replaced by a neutral DNA segment of equal length. The Uo segment behaved as a strong transcriptional silencer when tested in a CAT assay in vitro. Control transgenic mice harbouring only the two 3 bp mutations that introduced restriction sites at both ends of the Uo segment to allow for its replacement were also analysed. Rearrangement was reduced 10- to 100-fold in B cells from such transgenic lines. A model is proposed whereby the sites of these two mutations would function by counteracting transiently the repressing effect of the silencer, thus giving access of the chicken light chain locus to the recombinase.

[The patient with chronic low back pain in a thermal spa]

We have made our study over a period of five months. Out of 553 patients admitted to the Thermal Clinic at Lavey-les-Bains, we observed 111 patients suffering from chronic low-back pain, noting the changes, both subjective and objective, during their three-week stay at the clinic. From the physical aspect, they were encouraged to increase lumbothoracic mobility. From the subjective aspect, an evaluation of pain and handicap level, was made using a visual comparison scale and the completion of a questionnaire. We concluded that, in the short term, thermal treatment resulted in an appreciable relief of pain for these patients. In the long term, however, in view of the changing developments in clinical measuring techniques it is not possible to estimate in advance the functional effectiveness of treatment.

New simplified molecular design for functional T cell receptor

We have produced a chimeric single-chain T cell receptor (TcR) that combines the specific antibody recognition function and TcR/CD3 signaling properties within the same polypeptide chain. This hybrid molecule consisted of a single-chain antibody combining site that was connected over a short spacer to the transmembrane and cytoplasmic region of CD3 zeta. When expressed on TcR- or TcR+ T cell hybridomas it could mediate recognition of relevant target cells and subsequent production of lymphokines; i.e. it could functionally replace the TcR/CD3 complex. Therefore, the single-chain TcR model presented here represents an interesting and useful means for the creation of T cells with new specificities.

Practice nursing in Glasgow after the new general practitioner contract

Six months after the implementation of the new general practitioner contract in April 1990, practice nurses employed in greater Glasgow were surveyed using a self completed postal questionnaire. Of the 165 practice nurses employed in greater Glasgow 153 (93%) were identified and surveyed. Of these, 131 responded to the questionnaire (86%). The practice nurses were well qualified and experienced. Sixty per cent were under 40 years of age, 68% had been recruited within the previous year and 70% were employed for five sessions or more per week. Many carried out extended nursing duties, including health promotion activities. Many described inadequacies of their employment contract, practice facilities and the functioning of the primary health care team. If service quality is to be assured in practice nursing and practice nurses are to function as key primary health care team workers, then it is important that their role, professional skills, and working facilities are defined, supported and monitored. This should be addressed by general practitioners, practice nurses, and their professional bodies, in collaboration with the health board.

Evidence for the extralenticular expression of members of the beta-crystallin gene family in the chick and a comparison with delta-crystallin during differentiation and transdifferentiation

The beta-crystallins are major water soluble proteins of vertebrate lens fibre cells and have previously been regarded as lens-specific proteins: however beta B2-and beta A3/A1-crystallin RNAs are transcribed and beta-crystallin polypeptides are detectable in the developing chick retina. The beta-crystallin RNA is transcribed in a subpopulation of retina cells and the number of transcribing cells and the level of beta-crystallin polypeptides increase during the differentiation of the retina. Several tissues express beta-crystallin polypeptides, but individual tissues are characterised by qualitative and quantitative differences in the beta- and delta-crystallin polypeptides expressed. The expression of beta-crystallins appears to be non-random as defined by tissue distribution, cellular localisation and ontogeny, implying a function for extralenticular beta-crystallins and a complex mechanism for the regulation of their expression.

Catecholamine regulation of adipocyte lipolysis after surgery

The effect of surgical trauma on the regulation of lipolysis was studied in isolated fat cells obtained before and 24 hours after elective cholecystectomy in 12 patients who were not obese and who were healthy otherwise. Surgery was accompanied by a twofold increase of the basal rate of lipolysis and by a significant 50% elevation of the lipolytic effect of catecholamines. The actions of various agents that selectively stimulate lipolysis at different early or late steps in the cyclic adenosine monophosphate system beyond the adrenoreceptors were also increased about 50% after surgery (p less than 0.01). The properties of the beta-adrenoceptors were not altered by surgery, as assessed by radioligand binding and isoprenaline sensitivity. The antilipolytic properties of catecholamines (mediated by alpha 2-adrenoreceptors) were not influenced by cholecystectomy. Lipolysis was not altered in four subjects who had no surgery and who served as control subjects 24 hours after being given the same type of postoperative nutrition as patients who underwent cholecystectomy. We concluded that moderate surgical trauma is associated with increased lipolytic activity of fat cells. This is secondary to an enhanced ability of catecholamines to stimulate lipolysis because of a modification at the most distal steps in the cyclic adenosine monophosphate system, which may involve the protein kinase/hormone sensitive lipase complex.

Differential effects of prenatal exposure to phenobarbital on the behaviour and neurochemistry of CBA and C57BL/6J mice

Pregnant C57BL/6J and CBA mice were administered 60 mg/kg phenobarbital intraperitoneally from days 10 to 16 of gestation. On day 18 of pregnancy half of the control and drug-treated mice were killed and the embryonic brains removed for cell cultures. The remaining mice were allowed to have their litter. After cross-fostering the mice were used for behavioural studies. Pups born to drug-treated CBA mice had birth-weights similar to controls, but their weights had fallen behind controls by day 18 after birth. They were slower at attaining mature responses in tests for sensory motor development and became progressively more hyperactive (three times more active at day 18) compared to controls. Drug-exposed C57 pups also had birth weights similar to controls. After cross-fostering, 19% of control and 31% of drug-exposed pups died, but the remaining drug-exposed pups showed no deficits in weight gain. In contrast to drug-treated CBA pups, drug-exposed C57 pups were slightly quicker in attaining mature responses in some tests. There was no difference in activity between them and their controls. In neurochemical analyses, uptake of neurotransmitters by cerebral cultures from CBA showed that uptake of GABA was increased by 5%, choline by 95%, dopamine 120%, serotonin 165% and noradrenaline by 160% in cultures from drug exposed embryos compared to controls. In cerebral cultures from C57, GABA uptake was reduced by 18%, choline 33%, dopamine 35% and noradrenaline by 25%. Only serotonin uptake was increased by 182% compared to controls. Differences between C57 and CBA were also apparent in the uptake of neurotransmitters by neuronal cultures from the mesencephalon.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of flumazenil on global cerebral blood flow and on intracranial pressure in the reperfusion phase following incomplete global cerebral ischemia]

Sedation with benzodiazepines in intensive care patients with head injuries has become part of a standard concept in controlling intracranial pressure (ICP) and metabolic demands of an injured brain. The specific benzodiazepine antagonist flumazenil, which is supposed to exert no direct effect on cerebral blood flow (CBF) in healthy volunteers, suggests that rapid reversal from midazolam sedation might be achieved without any deleterious side effects. It remains however ambiguous if the same holds true in subjects with head trauma. This study describes the effect of flumazenil on CBF, ICP and cerebral perfusion pressure (CPP) during the reperfusion period after incomplete global ischemia in 10 goats. After preparation progressively decreasing CBF in 7 goats was achieved by stepwise external occlusion of the a. max. interna. 90-120 min after reestablishment of CBF 15 mg midazolam i.v. were given followed by 0.5 mg flumazenil i.v. 5 min later. Within 60 sec after application of the antagonist an increase of CBF by 30-165% and of ICP by 25-310% was noted in 5 goats. Simultaneous changes in arterial pressure, CBF and ICP suggest a severe impact of the benzodiazepine antagonist after midazolam sedation on ICP and CBF during periods of impaired cerebral autoregulation. Until the cerebrovascular and cerebral metabolic effects of flumazenil have been elaborated in detail, it is recommended to titrate the effect of flumazenil over long intervals in head injured patients.

[Reactive dynamics of immunologic parameters in healthy humans and in patients with rheumatoid arthritis]

Investigations of three immune components (IgG, CRP, alpha 1 sGP) in 500 patients with rheumatoid arthritis at the beginning and the end of a spa treatment lasting 4 or 6 weeks as well as in 29 healthy test persons in monthly intervals over 2 years make clear that these immune components represent biorhythmologically regulated functions which underly a different dynamics related to the initial value. By means of the so-called "cross-over-point method" the adequate conditions can be figured. In these cases under the influence of the spa therapy a significant decrease of the dispersion at the end of the significant decrease of the dispersion at the end of the cure develops for the parameters CRP and IgG. These findings as well as the typicality of the course of the empiric regression between the beginning of the cure and the end of the cure represent criteria which are of importance for the demarcation of the dependence of the initial value to a statistical a: (a-b) effect. It is shown that the pathologically reactive dynamics of the immune components can be demarcated from the biorhythmically undisturbed dynamics.

IV N-acetylcysteine treatment of hematologic reactions to chrysotherapy

Twelve patients with adverse hematologic reactions to chrysotherapy received intravenous N-acetylcysteine (IV NAC) to achieve removal and/or redistribution of gold. Urine gold excretion while on IV NAC doubled that predicted from control measurements. Treatment within 20 days of the last gold injection was associated with better recovery of hematologic parameters. No untoward reactions from IV NAC were encountered. The pathogenesis of gold induced hematologic reactions is examined from both toxic as well as immunological perspectives.

[Changes in the immunological components of the blood during balneotherapy in patients with rheumatoid arthritis]

The changes of the immunoglobulin G, the C-reactive protein and the acid alpha 1-glycoprotein which were observed under spa therapy in patients with rheumatoid arthritis. In these cases was shown that these parameters undergo regulative influences which in typical relationship to the initial tissue lead to a cross-over-phenomenon with demarcation of a regulatory zero- (or normal) region. Here patients with rheumatoid arthritis show the tendency to maintain a slightly increased defensive condition under the cure. On the basis of a narrowing of the dispersion of the immune components to the end of the cure compared with the beginning of the cure is concluded that the changes of defensive components to the blood which are to be observed in different initial values are not only based on the endogenic rhythmicity but partly also on the effects of the spa therapy.

[Synovial membrane permeability for plasma proteins and protein syntheses in rheumatic diseases]

1. The permeability of the synovial membrane for proteins is larger in rheumatoid arthritis than in osteoarthrosis, in rheumatoid arthritis with high CRP activity larger than in rheumatoid arthritis with low CRP activity. 2. The diffusion by the synovial membrane in most plasma proteins takes place depending on their molecular weight. Of the 14 proteins tested only haptoglobin and fibrinogen did not follow this regularity. 3. While the non-immune proteins proved in the synovial fluid only come from the blood plasma, the immune globulins IgG, IgA, and IgM as well as lysozyme are partly also locally synthetized and enriched in rheumatoid arthritis. In rheumatoid arthritis lysozyme is present in the synovia not only in free, but in most cases also in cell-bound form.

Chrysotherapy. Suppression of immunoglobulin synthesis

Forty-four subjects with classic or definite rheumatoid arthritis who were on individualized chrysotherapy were observed for changes in serum protein electrophoresis, immunoglobulins, and circulating lymphocyte counts. By paired variate analysis, significant declines from pretreatment values were recorded for the following--electrophoretic protein fractions: gamma, alpha-1, alpha-2, (P less than 0.05); immunoglobulins: IgM--53% (P less than 0.001), IgG--37% (P less than 0.01), IgA--34% (P less than 0.001). Rheumatoid factor decreased in 29 of 39 subjects, 15 becoming seronegative (P less than 0.001); circulating lymphocytes decreased by 27% (P less than 0.001). The maximal suppressive effect on IgG and IgM was not achieved until the third and fourth years of therapy by sustained weekly administration of gold sodium thiomalate (one year cumulative dosage, mean 2106 mg, range 1065-2,885; greater than or equal to 4 year cumulative dosage, mean 8747 mg, range 5,385-15,160 mg). An immunosuppressive effect is suggested by these results.

[Refined diagnosis of C-reactive protein for the detection and course control of chronic inflammatory rheumatic processes]

When different methods of demonstration of C-reactive protein are used, results much deviating one from another may be observed. An exact diagnostics based on radial immunodiffusion with large range of recognition allows a quantitative registration of changes of C-reactive protein. The exact diagnostics of C-reactive protein seems to be of advantage especially with regard to comprehension and control of the course of subclinical processes. Together with the blood sedimentation rate the exact diagnostics of C-reactive protein gives the possibility of an improved objectivation of the process activity in chronic inflammatory rheumatic diseases.