Capsaicin induced release of multiple tachykinins (substance P, neurokinin A and eledoisin-like material) from guinea-pig spinal cord and ureter

The release of tachykinins from isolated slice preparations of the guinea-pig spinal cord and ureter was studied in vitro. Capsaicin (10 microM) caused release of substance P, neurokinin A and an eledoisin-like component from both the spinal cord and ureter. The release of tachykinins induced by capsaicin or potassium (60 mM) was calcium dependent. No detectable release of neurokinin B or neuropeptide K, an N-terminally extended form of neurokinin A, was induced by capsaicin. No detectable release of tachykinins could be demonstrated after exposure to agents which are known to activate C-fibre afferents, such as histamine, bradykinin, serotonin, prostaglandins E1, E2 or acetylcholine. Protein extravasation in the ureter, as determined by the Evans Blue extravasation technique was used as a functional correlate to the tachykinin release. Protein extravasation was induced in vivo by local intraluminal injections of capsaicin at several hundred-fold lower concentrations than those required to induce a detectable release of tachykinins in vitro. The difference may, however, partly depend on the experimental conditions and the detection limit of the tachykinin assay used. The protein extravasation response to capsaicin was absent after systemic capsaicin pretreatment, which causes a marked depletion of tachykinins in the ureter. In conclusion, capsaicin evokes release of several tachykinins from both central and peripheral endings of primary afferent neurons. The peptides released from sensory nerves in the periphery may induce effects such as protein extravasation and smooth muscle contraction.     

The Effect of Dopa on the Spinal Cord. 8. Presynaptic and “Remote” Inhibition of Transmission from Ia Afferents to Alpha Motoneurones

In unanesthetized spinal cats, injected with l-DOPA, intra-axonal recording was used to investigate the primary afferent depolarization (PAD) evoked in different species of afferents by volleys in the flexor reflex afferents (FRA). It was confirmed that a late PAD is evoked in la afferents and usually not in Ib or cutaneous afferents. Some late PAD was observed in a few group II muscle afferents. Intracellular recording from motoneurones revealed a considerable depression of the Ia EPSP during the late PAD evoked from the FRA after DOPA, but it was diffkult to attribute this entirely to the PAD in Ia afferents since there was also a late postsynaptic conductance increase in the motoneurones. A further analysis was made on acute spinal cats not injected with DOPA, in which a late P.4D sometimes is evoked by FR24 volleys, without the late postsynaptic soma effects in motoneurones. The marked depression of the Ia EPSP evoked from the FRA under these conditions has a longer duration than the PAD in la afferent terminals. It is postulated that two mechanisms contribute to the Ia EPSP depression, presynaptic inhibition and “remote inhibition”; the latter action persisting after the repolarization of Ia afferents. The results are discussed in relation to reflex regulation of stepping.     

MICA4/HLA-DRB1*04/TNF1 haplotype is associated with mixed connective tissue disease in Swedish patients

In order to investigate major histocompatibility complex (MHC) class I chain-related gene A (MICA), tumor necrosis factor (TNFa), -308TNFA, and human leukocyte antigen (HLA-DR/DQ) polymorphisms in mixed connective tissue disease (MCTD), we analyzed 24 patients and 229 healthy controls from Sweden. MICA and TNFa typing was performed by polymerase chain reaction (PCR) and genotyping. HLA-DR and -DQ were genotyped using PCR-sequence specific primers (PCR-SSP) and PCR-sequence-specific oligonucleotide probe (PCR-SSOP), respectively. For analysis of -308TNFA polymorphisms we performed PCR with restriction endonuclease enzymes. We found that the MICA5.1-5.1 genotype was positively associated with MCTD. Shared epitope genes (DRB1*01 and DRB1*04) were also significantly positively associated with MCTD. Polymorphism of -308TNFA was not differently distributed in MCTD patients compared with controls. Furthermore, we demonstrated that frequencies of three estimated haplotypes were increased in MCTD patients compared with controls. Interestingly, the haplotype with MICA allele 4 together with DRB1*04 and TNF1 alleles gives the most specific pattern for MCTD patients compared with controls. Our study demonstrates a clear contribution of HLA loci in susceptibility to MCTD in the Swedish population. Susceptibility to MCTD may be linked to the MICA4/HLA-DRB1*04/TNF1 haplotype and MICA 5.1-5.1 genotype. Mixed connective tissue disease was also associated with shared epitope genes, which in RA has been associated with a more severe disease. Whether these genotypes affect the clinical phenotype of MCTD needs to be determined.     

Isolation and characterization of two European strains of Ehrlichia phagocytophila of equine origin

We report the isolation and partial genetic characterization of two equine strains of granulocytic Ehrlichia of the genogroup Ehrlichia phagocytophila. Frozen whole-blood samples from two Swedish horses with laboratory-verified granulocytic ehrlichiosis were inoculated into HL-60 cell cultures. Granulocytic Ehrlichia was isolated and propagated from both horses. DNA extracts from the respective strains were amplified by PCR using primers directed towards the 16S rRNA gene, the groESL heat shock operon gene, and the ank gene. The amplified gene fragments were sequenced and compared to known sequences in the GenBank database. With respect to the 16S rRNA gene, the groESL gene, and the ank gene, the DNA sequences of the two equine Ehrlichia isolates were identical to sequences found in isolates from clinical cases of granulocytic ehrlichiosis in humans and domestic animals in Sweden. However, compared to amplified DNA from an American Ehrlichia strain of the E. phagocytophila genogroup, differences were found in the groESL gene and ank gene sequences.     

Thiols decrease cytokine levels and down-regulate the expression of CD30 on human allergen-specific T helper (Th) 0 and Th2 cells

The thiol antioxidant N-acetyl- L-cysteine (NAC), known as a precursor of glutathione (GSH), is used in AIDS treatment trials, as a chemoprotectant in cancer chemotherapy and in treatment of chronic bronchitis. In vitro, GSH and NAC are known to enhance T cell proliferation, production of IL-2 and up-regulation of the IL-2 receptor. The 120-kD CD30 surface antigen belongs to the tumour necrosis factor (TNF) receptor superfamily. It is expressed by activated T helper (Th) cells and its expression is sustained in Th2 cells. We have analysed the effect of GSH and NAC on the cytokine profile and CD30 expression on human allergen-specific T cell clones (TCC). TCC were stimulated with anti-CD3 antibodies in the presence of different concentrations of GSH and NAC. Both thiols caused a dose dependent down-regulation of IL-4, IL-5 and IFN-gamma levels in Th0 and Th2 clones, with the most pronounced decrease of IL-4. Furthermore, they down-regulated the surface expression of CD30, and the levels of soluble CD30 (sCD30) in the culture supernatants were decreased. In contrast, the surface expression of CD28 or CD40 ligand (CD40L) was not significantly changed after treatment with 20 m M NAC. These results indicate that GSH and NAC favour a Th1 response by a preferential down-regulation of IL-4. In addition, the expression of CD30 was down regulated by GSH and NAC, suggesting that CD30 expression is dependent on IL-4, or modified by NAC. In the likely event that CD30 and its soluble counterpart prove to contribute to the pathogenesis in Th2 related diseases such as allergy, NAC may be considered as a future therapeutic agent in the treatment of these diseases.     

Hand and finger skin temperatures in convective and contact cold exposure

The present study aimed at investigating the spatial variability of skin temperature (T _sk) measured at various points on the hand during convective and cold contact exposure. A group of 8 subjects participated in a study of convective cooling of the hand (60 min) and 20 subjects to contact cooling of the finger pad (5 min). Experiments were carried out in a small climatic chamber into which the hand was inserted. For convective cold exposure,T _sk was measured at seven points on the palmar surface of the fingers of the left hand, one on the palmar surface and one on the dorsal surface of the hand. The air temperature inside the mini-chamber was 0, 4, 10 and 16°C. With the contact cold exposure, the subjects touched at constant pressures an aluminium cube cooled to temperatures of –7, 0 and 7°C in the same mini-chamber. ContactT _sk was measured on the finger pad of the index finger of the left hand. TheT _sk of the proximal phalanx of the index finger (on both palm and back sides), and of the middle phalanx of the little finger was also measured. The variation ofT _sk between the proximal and the distal phalanx of the index finger was between 1.5 to 10°C during the convective cold exposure to an air temperature of 0°C. Considerable gradients persisted between the hand and fingers (from 2 to 17°C at 0°C air temperature) and between the phalanges of the finger (from 0.5 to 11.4°C at 0°C air temperature). The onset of cold induced vasodilatation (CIVD) on different fingers varied from about 5 to 15 min and it did not always appear in every finger. For contact cold exposure, whenT _sk on the contact skin cooled down to nearly 0°C, the temperature at the area close to the contact skin could still be 30°C. Some cases of CIVD were observed in the contact skin area, but not on other measuring points of the same finger. These results indicated that local thermal stimuli were the main determinents of CIVD. Representative hand skin temperature may require five or more measuring points. Our results strongly emphasised a need to consider the large spatial and individual variations in the prediction and modelling of extremity cooling.     

Functional reactivation of the deafferented hippocampus by embryonic septal grafts as assessed by measurements of local glucose utilization

Summary Transection of the septo-hippocampal connections through fimbria-fornix damage in the rat results in profound hippocampal cholinergic deafferentation, and, when applied bilaterally, leads to severe and long-lasting impairments in learning and memory. Previous studies have shown that intrahippocampal septal grafts can reestablish a new cholinergic innervation in the inititally denervated hippocampal formation and at least partly compensate for the lesion-induced learning impairments in fimbria-fornix lesioned rats. The purpose of the present study was to determine the magnitude of lesion-induced alterations in cerebral function as reflected in local glucose use measured by (¹⁴C)-2-deoxyglucose (2-DG) autoradiography, and the degree to which this index of functional activity could be normalized following reinnervation from transplants of fetal cerebral tissue from the primordial septal region. Six months after unilateral fimbriafornix transection the rate of glucose utilization was reduced markedly throughout the ipsilateral hippocampus when compared to the intact contralateral side, while in the neocortex only the cingulate cortex showed long-lasting reductions in glucose use. Rats that received a transplant of fetal septal-diagonal band tissue at the time of fimbria-fornix transection, and were sacrificed 6 months later, displayed significantly greater glucose utilization in the ipsilateral hippocampus and cingulate cortex than was measured in these areas in rats with lesion alone. The recovery in glucose use was paralleled by a significant increase in acetylcholinesterase (AChE) staining in several areas of the ipsilateral hippocampal formation and cingulate cortex. This index of graft-induced cholinergic reinnervation was, moreover, significantly correlated with the rate of glucose use. Thus, in the fimbria-fornix transected animals the magnitude of glucose depression correlated with the extent of reduction in AChE staining, and in the grafted animals the degree of normalization of glucose use was correlated with the graft-induced increase in AChE-staining density. These results thus indicate that the 2-DG autoradiographic technique can provide a unique opportunity to map both altered functional activity in localized areas of the brain following specific lesions and the extent to which transplant-derived reinnervation of the host may induce a return to normal functional levels in the target site.ETP and Royal Society (London) visiting fellow     

Occurrence of neuropeptide Y (NPY)-like immunoreactivity in catecholamine neurons in the human medulla oblongata

We report here the coexistence of a neuropeptide and catecholamines in neurons of the human brain. Using indirect immunofluorescence histochemistry, combined with elution and restaining experiments, neurons in the medulla oblongata of man were demonstrated to contain both a neuropeptide Y-like peptide and the catecholamine synthesizing enzyme tyrosine hydroxylase.     

Local versus regional cerebral blood flow in the rat at high (hypoxia) and low (phenobarbital anesthesia) flow rates.

Local cerebral blood flow (CBF) was measured in rats, using an autoradiographic technique with 14C-iodoantipyrine as diffusible tracer, in situations with low, normal and high flow rates (phenobarbital anesthesia, analgesia with 75% N2O, and hypoxia, respectively). A comparison of the results with previous data obtained in conscious rats (Sakurada et al. 1978) demonstrates that 75% N2O moderately reduces local CBF in some, but not all, cortical and subcortical areas, that phenobarbital anesthesia reduces local CBF to between 30 and 65% of (conscious) control, and that pronounced hypoxia (arterial P02 about 25 mmHg) increases local CBF 3- to 4-fold. A comparison of the values obtained for cortical structures with those previously measured with a technique based on the Fick principle shows that the autoradiographic technique gives similar values at low and normal flow rates but that it moderately underestimates CBF at high flow rates, probably due to diffusion limitation.     

Familial partial trisomy 5p resulting from segregation of an insertional translocation

A case of duplication of segment p13-p15 of the short arm of chromosome 5 as the result of an insertional translocation in a mentally retarded girl with congenital anomalies is reported. Some of the apparently balanced carriers of the inverted insertion showed minor congenital anomalies.