Signs of inflammation in both symptomatic and asymptomatic muscles from patients with polymyositis and dermatomyositis

OBJECTIVES

To determine whether muscle weakness is correlated with inflammation, expression of interleukin 1alpha (IL1alpha) and major histocompatibility complex (MHC) class I and II antigens on muscle fibres.

METHODS

Biopsy specimens from clinically symptomatic (proximal muscles) and asymptomatic (all distal but two proximal) muscles in eight patients with polymyositis, three patients with dermatomyositis and six healthy controls were analysed by immunohistochemistry for the presence of T cells and macrophages, and expression of IL1alpha and of MHC class I and II antigens.

RESULTS

were evaluated by conventional light microscopy and by computerised image analysis. Results: Inflammatory infiltrates with T cells and macrophages were observed to an equal degree in both symptomatic and asymptomatic muscle. The numbers of capillaries with IL1alpha expression were significantly higher (p<0.05) in the symptomatic and asymptomatic muscles of patients than in controls. The total IL1alpha expression per tissue section assessed by computerised image analysis was significantly higher in symptomatic muscles but not in asymptomatic muscles compared with that in controls. Neither the number of IL1alpha-positive capillaries nor the total IL1alpha expression differed significantly between symptomatic and asymptomatic muscles. Expression of MHC class I and II antigens on muscle fibres was detected in both symptomatic and asymptomatic muscles but rarely in healthy controls.

CONCLUSIONS

Presence of inflammatory infiltrates, T cells and macrophages, and expression of MHC class I and II antigens and of IL1alpha on muscle fibres were independent of clinical symptoms, and were present to an equal degree in both proximal and distal muscles. Thus, other factors seem to determine the development of clinical symptoms. One such factor could be variations in physical demands.

Increased endothelial expression of HLA-DQ and interleukin 1alpha in extra-articular rheumatoid arthritis. Results from immunohistochemical studies of skeletal muscle

OBJECTIVE

To investigate markers of endothelial activation in muscle biopsies from rheumatoid arthritis (RA) patients with and without extra-articular manifestations (ExRA).

PATIENTS AND METHODS

Nine consecutive ExRA patients were compared with nine RA controls without ExRA, matched for age, sex and duration of RA. Muscle biopsies were obtained from the lateral vastus or anterior tibial muscle. Macrophage and lymphocyte CD markers, HLA molecules, cytokines and adhesion molecules were investigated using immunohistochemistry, and stainings were evaluated using computer image analysis and conventional microscopy. Serum concentrations of soluble adhesion molecules, tumour necrosis factor alpha (TNF-alpha) and rheumatoid factor (RF) were determined using immunoassays.

RESULTS

The number of HLA-DQ-positive capillaries (P=0.039) and the expression of interleukin 1alpha (IL-1alpha) in endothelial cells (mean pairwise difference 0.26%; 95% confidence interval 0-0.52) were increased in ExRA patients compared with non-ExRA controls. There were no signs of inflammatory cell infiltrates or fibre degeneration. Serum levels of TNF-alpha, the soluble form of intercellular adhesion molecule 1, the soluble form of vascular cell adhesion molecule 1 and IgM RF were increased in the ExRA group.

CONCLUSION

The increased expression of HLA-DQ and IL-1alpha may indicate systemic endothelial activation in extra-articular RA, which could be of importance for cardiovascular comorbidity and mortality in such patients.

Skeletal muscle fibers express major histocompatibility complex class II antigens independently of inflammatory infiltrates in inflammatory myopathies

The aim of our study was to address the question of whether muscle fibers express major histocompatibility complex (MHC) class II in inflammatory myopathies. For this purpose we performed a systematic study of MHC class II antigen expression on muscle fiber membranes in muscle tissue from polymyositis and dermatomyositis patients in various stages of disease activity. Thirty-two patients with classical clinical signs of myositis were divided into subgroups depending on duration of clinical signs of myositis and presence or absence of inflammatory infiltrates in muscle tissue. Immunohistochemistry as well as double-immunofluorescence stainings were used to identify the presence of MHC class II in muscle tissue. MHC class I was included for comparison. Quantification of positive staining was performed using an image analysis system in addition to evaluation by manual microscopic scoring and laser confocal microscopy. It was demonstrated that a significant proportion of skeletal muscle fibers in inflammatory myopathies express MHC class II as well as MHC class I and that MHC antigen expression is independent of the inflammatory cell infiltration. Furthermore, there were no differences in staining pattern between polymyositis and dermatomyositis patients. Our results indicate that MHC class II and MHC class I molecules may be involved in initiating and maintaining the pathological condition in myositis rather than only being a consequence of a preceding local inflammation.

Investigation into the effects of amyloid (1-42) beta-peptide upon basal and antigen-stimulated hexosaminidase and serotonin release from rat RBL-2H3 basophilic leukemia cells

There is evidence that beta-amyloid (A beta) peptide infusion in vivo produces a degranulation of vascular mast cells. It would be useful to investigate the interaction between A beta and mast cells in a simple in vitro model system in order to determine the cellular mechanism by which exposure to A beta peptides results in mast cell degranulation. In the present study, the effect of A beta(1-42) upon the release of granular hexosaminidase and serotonin has been investigated using the cognate rat mast cell line, RBL-2H3. Sensitization of these cells for 1 h with anti-DNP IgE (monoclonal anti-dinitrophenyl) results in a large release of hexosaminidase and serotonin due to degranulation when the cells are exposed to DNP-HSA (albumin, human dinitrophenyl). Pretreatment overnight with A beta(1-42) (10 and 30 microM) did not affect either the basal or antigen-stimulated release of hexosaminidase or serotonin. A similar lack of effect of A beta(25-35) and the lipid peroxidation product HNE upon antigen-stimulated release of hexosaminidase or serotonin was also found. It is concluded that RBL-2H3 cells are not a useful model for mechanistic studies into the effects of beta-amyloid peptides upon vascular mast cells.

Oviductal isthmic motility patterns as monitored by polyview in unrestrained sows around ovulation

A method for monitoring oviductal isthmic motility in sows incorporating a computer programme (Polyview) was developed. This method was found to be reliable and easy for recording and analysing data. Isthmic motility patterns were monitored from 11 h prior to and up to 36 h after ovulation in 13 unrestrained multiparous sows during their second oestrus after weaning. The amplitudes and frequencies of phasic pressure fluctuations in relation to the hormonal profiles were also calculated. The isthmic motility patterns were regular before ovulation changing to wave patterns during the peri-ovulatory period and eventually to irregular patterns after ovulation. The amplitudes and frequencies of phasic pressure fluctuations were significantly higher (p<0.05) prior to and soon after ovulation than afterwards. Plasma oestradiol-17beta levels significantly (p<0.05) decreased before ovulation while plasma progesterone levels increased significantly (p<0.05) after ovulation. Despite a significant decrease in the plasma levels of oestradiol-17beta prior to ovulation, the amplitudes and frequencies of phasic pressure fluctuations remained high until shortly after ovulation. This could have been due to the endogenous levels of oestradiol-17beta bound to the nuclear oestradiol-17beta receptors that might still have been present in the isthmus. Conversely, the irregular isthmic motility patterns, the decline in the frequencies of phasic pressure fluctuations and amplitudes seen after ovulation may have been due to the rising plasma levels of progesterone. The amplitudes and frequencies of phasic pressure fluctuations were highest at the time when oestradiol-17beta levels were highest and when progesterone levels were low. It can be concluded that the changes in the isthmic motility patterns, amplitudes and frequencies of phasic pressure fluctuations in relation to the changes in the plasma levels of oestradiol-17beta and progesterone seen in the present study prior to and after ovulation indicate a possible role of the oviduct in regulating gamete transport.

Effects of post-ovulatory food deprivation on the hormonal profiles, activity of the oviduct and ova transport in sows

The objective of the present study was to investigate the effect of post-ovulatory food deprivation on the hormonal profiles and consequently on the activity of the oviduct and ova transport in sows. Sows were randomly allocated to the control (C-group, n=6) or fasted (F-group, n=5) group. The F-group sows were fasted for four meals starting with the morning meal after detection of ovulation in the second oestrus after weaning. Ovulation was checked by transrectal ultrasonography. Blood was collected for the analyses of progesterone, oestradiol-17beta, prostaglandin F(2 approximately ) metabolite, insulin, free fatty acids and triglycerides. Oviductal isthmic motility was monitored on Polyview before and after ovulation until the time of slaughter. After slaughter, the isthmus opposite the side with transducer was divided into three equal segments and flushed separately and a third of the uterine horn part from the utero-tubal-junction (UTJ) was also flushed. A high proportion of ova in the F-group was found in the first and second parts of the isthmus. In the C-group, a high proportion of ova was found in the third part of the isthmus and the uterus. The mean isthmic pressure in the C-group decreased significantly (P<0.05) during the period immediately after ovulation while in the F-group mean pressure remained unchanged. The frequency of phasic pressure fluctuations were significantly (P<0.05) higher in the F- than in the C-group 13 to 24 h after ovulation. No significant differences in progesterone concentrations were seen between the two groups of sows. Prostaglandin metabolite levels were significantly (P<0.05) higher in the F-group than in the C-group. Oestradiol-17beta levels significantly (p<0.05) decreased earlier in the F- than in the C-group. Serum insulin levels were significantly (p=0.05) lower in the F- than in the C-group while free fatty acids were significantly (p<0.01) higher in the F- than in the C-group. There were no significant differences in the serum levels of triglycerides between the F- and the C-group. Therefore, it can be concluded in the present study that food deprivation is associated with changes in the hormonal profiles, activity of the oviduct and a delay of ova transport in sows.

The influence of inhibited prostaglandin biosynthesis on post-ovulatory oviductal ova transport in sows

Changes in prostaglandin and progesterone concentrations after ovulation seem to affect reproductive functions in the sow. The influence of lowered prostaglandin levels on ova transport velocity through the isthmus part of the oviduct, and on progesterone concentrations, was studied during the second estrus after weaning in thirteen purebred Yorkshire multiparous sows. To determine the time of ovulation transrectal ultrasonographic examination was performed. In the second estrus, six sows were given intravenous injections of flunixin meglumine (2.2 mg/kg body weight) every sixth hour from 4 to 8 h after time of ovulation until about 48 h after ovulation, at which time the sows were slaughtered. Blood samples were collected every second hour from about 12 h before ovulation until slaughter. Progesterone and prostaglandin F2alpha (PGF2alpha) metabolite levels were determined. Immediately after slaughter the isthmus part of the oviducts were cut into 3 equally long segments and the number of ova in each segment, and in the upper part of the uterine horns, was determined. Before start of treatment, PGF2alpha metabolite levels were similar in the 2 groups (P=0.84). In the treatment group, PGF2alpha values dropped to below the detection limit immediately after start of treatment, whereas in the control group the concentrations were quite stable throughout the sampling period (P=0.005). Ova recovery rate was 94% in the treatment group and 95 % in the control group. At time of slaughter, in the treatment group ova had on average passed 2.1 segments whereas in the control group the ova had passed 2.5 segments (P=0.57). The progesterone levels increased continuously in both groups after ovulation but there was no difference in the mean progesterone concentrations between the two groups before (P=0.96) or after (P=0.58) ovulation. It can be concluded that the transport of ova through the isthmus part of the oviduct is unaffected by an inhibition of prostaglandin synthesis immediately after ovulation. Furthermore, the post-ovulatory progesterone profile seems unaffected by lowered PGF2alpha levels.

Cryopreservation of Papaver somniferum Cell Suspension Cultures*

The effect of culture age and various cooling rates on the survival and regrowth of cryopreserved cell cultures of PAPAVER SOMNIFERUM L. is described. Survival and regrowth following cryopreservation, in liquid nitrogen, occurred only with 4 and 5 day old cultures. No regrowth was observed in 3 or 6 day old cultures. Cooling rate had a significant effect on survival following cryopreservation with an optimum cooling rate of 0.5 degrees C min (-1).