Mature, long-lived CD4+ and CD8+ T cells are generated by the thymoma in myasthenia gravis

Antibodies to muscle acetylcholine receptors, to other muscle antigens, and to some cytokines are found in the majority of patients with thymic tumors (thymomas) and myasthenia gravis (MG). The role of the tumor in initiating autoimmunity, however, is unclear; in particular, it is not known whether the thymoma exports mature and long-lived T cells, which could provide help for antibody production in the periphery. Here, we quantified recently exported thymic T cells using the approach of measuring episomal DNA fragments [T-cell receptor excision circles (TRECs)], generated by T-cell receptor gene rearrangement. Compared to values in healthy individuals (n = 10) or in patients with late-onset MG (n = 8), TREC levels were significantly raised in both the CD4+ and CD8+ peripheral blood compartments of patients with thymoma and MG (n = 14, p = 0.002 and p = 0.0004 compared to healthy controls) but only in the CD8+ compartment of the three patients with thymoma without MG (p = 0.4 and p = 0.01 for CD4+ and CD8+). TREC levels decreased following thymectomy to values similar to controls but were substantially raised in patients who had developed tumor recurrence (n = 6, p = 0.04 and p = 0.02 for CD4+ and CD8+); this was associated with increased antibodies to interferon-alpha and interleukin-12 in the one case studied serially. Collectively, these results support the hypothesis that the neoplastic thymoma tissue itself can generate and export mature, long-lived T cells and that these T cells reflect the thymic pathology and are likely to be related to the associated autoimmune diseases. The results also provide a new approach for early diagnosis of thymoma recurrence.

Scabies management in the community

BACKGROUND

Unidentified and undertreated cases of scabies are the source of continued spread.

AIMS

To evaluate management of scabies in the community.

METHODS

Eighty-six outpatient and ward referrals were reviewed. Fifty-six had previously applied scabicidal treatments (Group 1), whilst in 30 patients the diagnosis was made de novo (Group 2). Treatment failure was identified by a detailed questionnaire. In both groups, patients were reviewed at four to six weeks.

RESULTS

Sixty-four per cent of Group 1 was initially correctly diagnosed. Seventy per cent of Group 1 patients had received verbal and written instruction as part of previous unsuccessful treatments. The clearance rate in the combined group treated according to protocol was 96%; 100% clearance was ultimately achieved.

CONCLUSION

Inconsistency in diagnosis and treatment of patients is common. A treatment protocol should be made available to family practitioners.

Nativity and older women's health: constructed reliance in the health and retirement study

Gender and nativity are known risk factors for physical and economic dependency. Immigrant women are particularly disadvantaged because of their greater lack of social and economic resources. In this study, we investigate how women immigrants coordinate and utilize various support systems as they approach retirement age, as well as how choices and constraints affect their physical wellbeing. Experiences throughout the life course play a role in the maintenance of health, but the pre-retirement years are particularly crucial to the establishment of patterns of reliance to be used in later life. We examine the effects of economic resources, social support, and family ties (as well as several exogenous variables) on women's physical health using data from the Health and Retirement Survey. For the women in this study, demographic characteristics, such as Hispanic ethnicity and low education are strong risk factors for poor health. Findings also indicate that reliance patterns across resource domains do not differ significantly by nativity and that both economic and familial resource access significantly lessens the risk of poor health for both native and foreign born women.

Methanogenic activity measurements by the MAIA biosensor: instructions guide

The MAIA (Methanogenic Activity and Inhibition Analyser) is a titration (pH-stat) biosensor designed to determine the activity and inhibition related to acetoclastic methanogens. The main operational problems encountered in using this instrument are described.

Illumination for coherent soft X-ray applications: the new X1A beamline at the NSLS

The X1A soft X-ray undulator beamline at the NSLS has been rebuilt to serve two microscopy stations operating simultaneously. Separate spherical-grating monochromators provide the resolving power required for XANES spectroscopy at the C, N and O absorption edges. The exit slits are fixed and define the coherent source for the experiments. The optical design and the operational performance are described.

Gianotti-Crosti syndrome in an infant following immunization

Gianotti-Crosti syndrome (GCS) is a distinctive, self-limiting acropapular or papulovesicular eruption. Typical clinical presentation is that of a monomorphic, nonpruritic eruption most commonly involving the face, neck, buttocks, and extremities. It tends to occur in childhood, though infrequently it has been reported in adults. We report GCS occurring in an infant following immunization.

High cell density provides potent survival signals for resting T-cells

Activated T-cells are susceptible to apoptosis through two particularly important pathways: ligation of CD95 (Fas/Apo-1) or cytokine deprivation. Resting T-cells have until recently been considered to be relatively resistant to apoptosis. In this report we show that resting T-cells die rapidly by apoptosis when deprived of serum or cell contact. Primed CD45RO+ cells were more susceptible than naive CD45RA+ cells, consistent with their relative expression of Bcl-2. CD4+, CD8+ and gammadelta T-cells were equally prone to apoptosis under all studied conditions. A linear relationship between cell survival and serum concentration was observed for cells cultured between 0.5-2x10(6)/ml. T-cells cultured at low density died even in high concentrations of serum. However, resting T-cells cultured at high cell density (4x10(6)/ml) survived for extended periods in the absence of serum or other survival factors. This effect was mediated by the production of soluble factors and independent of integrin mediated signals. These results suggest that T-cells at sites of high density such as the lymph node paracortex are independent of external survival factors, while those trafficking through the peripheral circulation are highly dependent on serum derived factors for survival.

Cerebral proton and phosphorus-31 magnetic resonance spectroscopy in patients with subclinical hepatic encephalopathy

BACKGROUND/AIMS

In vivo magnetic resonance spectroscopy can be used to study cerebral metabolism non-invasively. We aimed to correlate 1H and 31P magnetic resonance spectral abnormalities in the brains of patients with subclinical hepatic encephalopathy.

METHODS

Eighteen patients were studied at 1.5T, with combined 1H and 31P magnetic resonance spectra obtained from multiple voxels in the cerebral cortex and basal ganglia. Peak area ratios of choline, glutamine/glutamate, relative to creatine in the 1H spectra and percentage phosphomonoesters, phosphodiesters and betaNTP signals relative to total 31P signals in the 31P spectra were measured.

RESULTS

Six patients did not complete the full examination - 31P results are available from 12 patients only. Relative to creatine, there were reductions in choline and elevations in glutamine/glutamate, varying across the brain with choline significantly reduced in occipital cortex (p<0.05) and glutamine/glutamate most significantly elevated in temporo-parietal cortex (p<0.0001). Percentage phosphomonoester (p<0.05), phosphodiester (p<0.05) and betaNTP (p<0.005) signals were significantly decreased in basal ganglia spectra. No correlation was found between the magnitude of 1H and 31P MRS changes, except between percentage phosphodiester decrease and glutamine/glutamate to creatine increase in occipital cortex.

CONCLUSION

The results of this study point to a multifactorial aetiology for this condition.

An MRI study of the effect of treadmill training on bone morphology of the central and third tarsal bones of young thoroughbred horses

Training results in marked modelling of the subchondral bone of the carpus, but the effect of training on the subchondral bone of the distal tarsal joints is unknown. The aim of this study was to determine whether training influenced modelling of the third and central tarsal bones in Thoroughbred horses. Twelve untrained Thoroughbred horses were divided into 2 groups. Group 1 underwent a 19 week progressive training regimen on a high speed treadmill. Group 2 were walked for 40 min daily. Images of left tarsi were obtained by magnetic resonance imaging (MRI) with a 0.5 Tesla superconducting magnet using a spin echo sequence. Sagittal and oblique sagittal slices were made perpendicular to the articular surfaces of the intertarsal joints and were analysed using image analysis software to measure the proportion of dense subchondral bone in the dorsal facet of each bone. Mean +/- s.d. percentage area of dense subchondral bone in the dorsal facet of the central tarsal bone in Group 1 was 47 +/- 8 medially, 46 +/- 4 sagitally and 50 +/- 11 dorsolaterally, whereas in Group 2 it was 39 +/- 16 medially, 43 +/- 8 sagitally and 53 +/- 7 dorsolaterally. For the third tarsal bone mean +/- s.d. percentage area of dense subchondral bone in Group 1 was 32 +/- 10 medially, 39 +/- 11 sagitally and 44 +/- 8 dorsolaterally, whereas in Group 2 it was 28 +/- 8 medially, 37 +/- 6 sagitally and 41 +/- 9 dorsolaterally. There was no significant difference in percentage area of dense subchondral bone between the trained and untrained horses. An effect of treadmill training of Thoroughbred horses on modelling of the central and third tarsal bones could not be demonstrated.

Localized bowel vasculitis: postoperative cyclophosphamide or not?

We describe 2 patients with necrotizing vasculitis localized to the bowel, who were treated by excision of the involved tissue. Postoperatively, there was no evidence of active vasculitis, and both patients remain in remission on followup, without the use of immunosuppressive treatment. Evidence that an abnormal local microenvironment is necessary to sustain chronic inflammation may explain why surgical excision can be an important tool in the treatment of vasculitis.

A missense mutation in the zinc-finger domain of the human hairless gene underlies congenital atrichia in a family of Irish travellers

Congenital atrichia is a rare, recessively inherited form of hair loss affecting both males and females and is characterized by a complete absence of hair follicles. Recently, a mutation in the human hairless gene was implicated in the pathogenesis of congenital atrichia. The human hairless gene encodes a putative single zinc-finger transcription-factor protein with restricted expression in brain and skin, which is believed to regulate catagen remodeling in the hair cycle. In this study, we report the identification of a missense mutation in the zinc-finger domain of the hairless gene in a large inbred family of Irish Travellers with congenital atrichia. The mutated arginine residue is conserved among human, mouse, and rat, suggesting that it is of significant importance to the function of the zinc-finger domain.

Neutrophils rolling on immobilised platelets migrate into homotypic aggregates after activation

Interactions between platelets and leucocytes are implicated in the pathology of thrombotic vascular disease. Using a flow-based adhesion assay we have investigated a novel route for the formation of neutrophil aggregates on the surface of immobilised activated platelets. Neutrophils perfused over a platelet monolayer formed numerous rolling attachments but rapidly stopped and spread after the superfusion of N-formyl-methionyl-leucyl-phenylalanine or platelet-activating factor (both at 10(-7) M). Subsequent integrin-mediated migration across the platelet monolayer enabled formation of homotypic neutrophil aggregates, which was significant within 2.5 min of receipt of either stimulus. Aggregates increased in size with time and had an average projected area of approximately 500 microm2 after 10 min. Increasing size was correlated with an increasing tendency for movement downstream and large aggregates sometimes tumbled in that direction. The formation and stability of homotypic aggregates was dependent on several adhesive mechanisms. Antibody blockade demonstrated that interactions involving CD11a/CD18 and ICAM-3, between alpha(v)beta3-integrin and CD31 and between L-selectin and an unidentified counter-ligand were all required for the complete aggregatory response. Furthermore, blockade of L-selectin allowed initial aggregation which then reversed, suggesting that this receptor might regulate the interactions between other adhesion molecules that directly supported cell-cell adhesion. We propose that this novel route for leucocyte aggregation could promote vascular occlusion in thrombotic vessels or at distal sites in the event of embolisation.

The diagnosis of lameness associated with distal limb pathology in a horse: a comparison of radiography, computed tomography and magnetic resonance imaging

A cadaver limb from an eight-year-old horse with right forelimb lameness that was relieved with an intra-articular distal interphalangeal joint block was imaged with radiographs, spiral computed tomography (CT) and magnetic resonance imaging (MRI). Spiral CT demonstrated several lucencies within the deep digital flexor tendon immediately proximal to the navicular bone. On MRI these areas had increased signal and there was enlargement of the tendon at this site. Effusion in the proximal interphalangeal joint and navicular bursa and thinning of the fibrocartilage of the navicular bone were also observed on MRI images. These changes were not detected on radiographs. Histopathology confirmed that there were focal areas of collagen necrosis within the deep digital flexor tendon with thinning and degenerative changes in the fibrocartilage of the navicular bone.

Mobile atheroma of the aortic arch is an underestimated source of embolization

BACKGROUND

Mobile atheroma are associated with increased perioperative strokes in patients undergoing coronary artery bypass surgery. Peripheral embolization is an additional risk. Transesophageal echocardiography (TEE) accurately identifies mobile atheroma. Recent reports have discussed the possible influence of anticoagulant therapy in promoting peripheral cholesterol embolization.

METHODS

Fourteen patients with mobile atheroma were treated with anticoagulation. A review of literature reporting results and complications of anticoagulation in the treatment of this condition was compared with our recent experience.

RESULTS

Between 1994 and 1996, 14 patients with peripheral embolization and mobile atheroma confirmed by TEE were anticoagulated. Clinical follow-up between 6 to 30 months has demonstrated no further evidence of systemic embolization since anticoagulation. Furthermore, repeat TEE in 3 of 14 patients no longer visualized mobile atheroma.

CONCLUSIONS

Mobile atheroma are recognized sources for embolization. Patients with generalized atherosclerosis should be screened for this condition in cases of systemic embolization. Anticoagulation may have therapeutic considerations in the management of this condition.

Intensive nutritional counselling in bulimia nervosa: a role for supplementation with fluoxetine?

OBJECTIVE

The aims of the paper are to determine whether nutritional counselling is associated with an improvement in bulimic symptomatology, whether this improvement is maintained during post-treatment follow-up, and whether the addition of fluoxetine 3 x 20 mg/day confers additional benefit.

METHOD

Psychological, pharmacological and combined psychopharmacological treatments of bulimia nervosa were reviewed briefly. Sixty-seven patients referred to specialist eating disorder services who fulfilled strict diagnostic criteria were treated with intensive nutritional counselling and randomly assigned to either fluoxetine 3 x 20 mg/day or placebo. After a 1-week 'wash-out', active treatment was given over 8 weeks, followed by post-treatment interviews at 12 and 20 weeks.

RESULTS

Both groups of patients improved significantly during treatment. In some respects, the fluoxetine group did slightly better as demonstrated by the items 'restraint', 'weight concern' and 'shape concern' (p < 0.05 vs p < 0.0001) on the Eating Disorder Examination (EDE). Fluoxetine patients decreased their energy intake and lost a modest amount of weight. They went on to regain weight during the follow-up period, returning to levels higher than they were initially. These patients also appeared more likely to have a recurrence of symptoms, as shown by the fall in percentage of binge-free patients and by changes in the EDE.

CONCLUSION

Nutritional counselling is an effective means of treating bulimia nervosa, with improvement maintained up to 3 months follow-up. The addition of fluoxetine may confer some benefit during active treatment, but its discontinuation may contribute to a higher rate of recurrence of symptoms post treatment. Of course, this study cannot be extrapolated to the efficacy of fluoxetine when used as the only form of treatment in patients for whom intensive nutritional counselling or other structured psychological programs are not available.

Cross-talk between cell adhesion molecules regulates the migration velocity of neutrophils

BACKGROUND

Although the adhesive mechanisms underlying the capture and immobilization of circulating neutrophils in inflamed blood vessels have been well described, factors controlling the subsequent migration of neutrophils over and through the blood vessel endothelium are poorly understood. Directional rearrangement of the actin cytoskeleton within the neutrophil, along with modulation of integrin-mediated adhesion, are necessary for neutrophil migration. Signals from chemotactic agents and from the adhesive substrate may regulate these processes, but little is known about their relative importance or their mode of integration.

RESULTS

We examined the kinetics of neutrophil migration after formyl tripeptide or platelet-activating factor was perfused over neutrophils that were already rolling on the adhesion molecule P-selectin, which was presented either on the surface of immobilized platelets or in purified form coated on glass capillaries. Upon activation, neutrophils stopped rolling, spread and began to migrate; each of these processes was dependent on beta2 integrin (CD11b/CD18). The rate of migration increased over a period of about 8 minutes and was modulated directly by both the P-selectin and the CD31 surface receptors. Antibody blockade of either CD31 or P-selectin on platelets resulted in a reduction in the velocity of migration, and simultaneous blockade of both receptors reduced velocity further. Purified CD31 and P-selectin (but not a control adhesion molecule, ICAM-1) increased migration velocity in a concentration-dependent and additive manner that reconstituted the migratory behaviour observed on platelets.

CONCLUSIONS

These studies show that binding of ligands to CD31 and/or P-selectin modifies the rate of integrin-supported neutrophil migration. This novel example of 'cross-talk' between surface receptors suggests that cell adhesion molecules might generally transduce accessory signals between adjacent cells to modify their migratory responses to chemotactic signals.

Botulism

Equine botulism is being recognized with increasing frequency by veterinarians throughout North America. Muscular weakness and dysphagia that progress during a period of 1 to 4 days, in the absence of laboratory derangements that indicate the presence of systemic disease, are suggestive of botulism. A tentative diagnosis usually is based on the presence of the following findings on physical examination: delayed pupillary light response, mydriasis, ptosis, generalized weakness, decreased tail tone, and slow prehension of feed. Definitive diagnosis requires detection of botulinum toxin in plasma, serum, gastrointestinal contents, or body tissues. Early treatment with antitoxin generally results in a favorable outcome. Botulism in foals and adult horses can be prevented by vaccination.

Use of intravascular ultrasound in the endovascular management of atherosclerotic aortoiliac occlusive disease

BACKGROUND

Intravascular ultrasound (IVUS) has been described as interesting technology in search of a clinical application by some and by others as a valuable diagnostic tool for many endovascular interventions. Its clinical usefulness has yet to be fully defined. When used during endovascular interventions, it can provide structural and diagnostic information, assess effectiveness of the therapy, and identify treatment-related complications.

METHODS

Thirty-two consecutive patients with atherosclerotic aortoiliac occlusive disease who presented with 40 separate arterial lesions were evaluated with IVUS before and after balloon angioplasty and intraluminal stent placement. Information obtained from IVUS was compared with similar data obtained from simultaneous angiographic images. Both techniques were evaluated with respect to assessment of vessel size, lesion location, adequacy of therapy, and identification of complications.

RESULTS

Real time IVUS imaging compared with angiographic imaging showed that in 62% of the patients, vessel diameter was underassessed using angiographic criteria alone. More importantly, 40% (16 of the 40 lesions) had underdeployed stents by IVUS evaluation that appeared adequately expanded by angiographic criteria. Further stent expansion with a larger balloon was necessary to achieve accurate stent to vessel wall apposition. This was found to be significant by an exact binomial 95% confidence interval. Incomplete stent deployment has been identified as a possible cause for restenosis and vessel occlusion. Information obtained from IVUS imaging substantially altered the endovascular therapy in approximately 40% of our patients and provided valuable vessel sizing and lesion composition information in 62% of the patients.

CONCLUSION

Intravascular ultrasound can provide important diagnostic information that can alter the conduct of selected endovascular procedures. It is especially useful when the procedure requires deployment of arterial stents.

Oxidized low-density lipoproteins inhibit endothelium-dependent relaxations in isolated large and small rabbit coronary arteries

1. Previous studies suggest that oxidatively modified low-density lipoproteins (oxLDL) contribute to the impairment of endothelium-dependent vasodilation in the large arteries of hypercholesterolaemic animals, whereas this may not be the case with regard to the impairment of coronary resistance vessels. For this reason, the effect of lipoproteins on coronary resistance arteries has been examined in this study. 2. The influence of lipoproteins on endothelium-dependent relaxation induced by acetylcholine (ACh) or sodium nitroprusside in PGF2 alpha-preconstricted rings from the large (1st order branch) and small coronary arteries (3rd order branch) and the aorta of New Zealand White rabbits, was investigated. 3. The sensitivity to ACh was greater in the large compared with the small diameter coronary arteries. 4. Endothelium-dependent relaxations were unaffected by native LDL. Oxidized LDL (0.5 and 1 mg protein mL-1) caused a reversible inhibition of relaxations in both preconstricted small and large coronary arteries which was overcome at high ACh concentrations. Similar inhibitions were found in the aorta. 5. Endothelium-independent relaxations elicited by sodium nitroprusside in the large and small coronary arteries were unaffected by the oxidized lipoproteins, indicating that soluble guanylate cyclase activity was unaltered. 6. It is concluded that inhibition of endothelium-dependent relaxation in the small diameter coronary arteries in hypercholesterolaemia may arise from products of oxidative modification of LDL present in the artery itself or released upstream from proximal lesions.

Immunohistological analysis of 'negative' patch test sites in atopic dermatitis

BACKGROUND

Variable results have been obtained when patients with atopic dermatitis (AD),) have been patch tested with allergens known to produce a positive prick test. The significance of patch test results in our understanding of the pathogenesis of AD therefore remains questionable.

OBJECTIVE

This study was designed to determine the relevance of either positive or negative patch test results in relation to the expression of cell mediated immunity to allergens in patients with AD.

METHODS

Thirty-five patients with AD exhibiting patch test positivity to one or more aeroallergens on 'tape stripped' areas of the back were retested without prior tape stripping. Nine patients again showed positivity to one or more allergens while 26 failed to show positive reactions. In six of the positive patients both positive and negative patch tests were observed. Skin biopsies were taken from these matched positive and negative patch test sites as well as from an area of uninvolved skin. Samples were frozen and cryostat sections were analysed with immunohistological techniques using monoclonal antibodies to investigate the distribution of immunocompetent cells.

RESULTS

All positive patch tests exhibited characteristics of a cell mediated immune response. The negative patch test sites were also found to contain evidence of mononuclear cell infiltration. Both negative and positive patch test sites showed significantly greater proportions of T cells compared to uninvolved skin. No increase in numbers of RFD1 positive and RFD7 positive macrophages were observed in either positive or negative patch test sites. Expression of CD23 by CD1 positive Langerhans cells was raised in both negative and positive patch tests compared to uninvolved areas. A significant increase in the population (RFD7+, CD23+) was seen in positive patch test sites compared to uninvolved skin. An increase in the proportion of RFD1 positive cells expressing CD23 was also seen in both negative and positive patch tests compared to uninvolved skin.

CONCLUSIONS

This paper demonstrates that immunological reactions are promoted at 'non-tape stripped' patch test sites where no clinical evidence of reactivity is seen. Together the data demonstrate that the presence of systemic cell mediated immunity to specific allergens identified in patients by positive patch test, may also be present when no clinical signs are seen at the patch test site.

Differentiation and CD23 expression of peripheral blood monocytes in patients with atopic dermatitis

In this study we investigate the expression of the low affinity immunoglobulin E (IgE) receptor (Fc epsilon RII) on plastic-adherent leucocytes from patients with atopic dermatitis (AD). Peripheral blood mononuclear cells were obtained from patients with AD, normal controls (and in one study from a group of atopic asthmatic patients). Monocytes were separated by 2-h adherence to plastic. These cells were then cultured for up to 7 days. Cells were harvested at time 0 (after adherence), and after 5 and 7 days culture, and cytospins were prepared. The proportion of cells expressing the phenotype of antigen presenting cells (monoclonal antibodies (mAb) RFD1+), and mature phagocytes (mAb RFD7+) together with CD23, were evaluated using combination staining with immunoperoxidase and alkaline phosphatase anti-alkaline phosphatase methods. It was found that a significantly larger proportion of circulating adherent cells in AD patients expressed the RFD1 antigen, and that increases in the proportion of these adherent cells expressing RFD1 or RFD7 occurred faster as cells matured in culture, when compared with cells obtained from normal controls. By day 7, however, equivalent proportions of RFD1+ and RFD7+ cells were present in AD and control cultures. None the less, expression of the CD23 molecule was consistently present on a larger proportion of both RFD1+ and RFD7+ cells from AD patients compared with controls. The raised proportion of circulating RFD1+ cells found in AD was not present in samples from atopic asthmatics, while the raised expression of CD23 on these cells occurred in samples from both these groups. These data support the suggestion that abnormalities in peripheral blood adherent cell phenotype, maturation, and CD23 expression, occur in AD patients. Some of these observations may be related to atopy in general rather than being specific for this skin disease.

Mapping the homotypic binding sites in CD31 and the role of CD31 adhesion in the formation of interendothelial cell contacts

CD31 is a member of the immunoglobulin superfamily consisting of six Ig-related domains. It is constitutively expressed by platelets, monocytes, and some lymphocytes, but at tenfold higher levels on vascular endothelial cells. CD31 has both homotypic and heterotypic adhesive properties. We have mapped the homotypic binding sites using a deletion series of CD31-Fc chimeras and a panel of anti-CD31 monoclonal antibodies. An extensive surface of CD31 is involved in homotypic binding with domains 2 and 3 and domains 5 and 6 playing key roles. A model consistent with the experimental data is that CD31 on one cell binds to CD31 on an apposing cell in an antiparallel interdigitating mode requiring full alignment of the six domains of each molecule. In addition to establishing intercellular homotypic contacts. CD31 binding leads to augmented adhesion via beta 1 integrins. The positive cooperation between CD31 and beta 1 integrins can occur in heterologous primate cells (COS cells). The interaction is specific to both CD31 and beta 1 integrins. Neither intercellular adhesion molecule-1 (ICAM-1)/leukocyte function-associated antigen-1 (LCAM-1) nor neural cell adhesion molecule (NCAM)/NCAM adhesion leads to recruitment of beta 1 integrin adhesion pathways. Establishment of CD31 contacts have effects on the growth and morphology of endothelial cells. CD31(D1-D6)Fc inhibits the growth of endothelial cells in culture. In addition, papain fragments of anti-CD31 antibodies (Fab fragments) disrupt interendothelial contact formation and monolayer integrity when intercellular contacts are being formed. The same reagents are without effect once these contacts have been established, suggesting that CD31-CD31 interactions are critically important only in the initial phases of intercellular adhesion.

Automatic Analysis, Theme Generation, and Summarization of Machine-Readable Texts

Vast amounts of text material are now available in machine-readable form for automatic processing. Here, approaches are outlined for manipulating and accessing texts in arbitrary subject areas in accordance with user needs. In particular, methods are given for determining text themes, traversing texts selectively, and extracting summary statements that reflect text content.

Stelazine-induced pigmentation

A case of a West Indian patient is reported who developed abnormal blue-grey pigmentation on exposed areas of skin following treatment with low dose stelazine. Oculocutaneous melanosis is a well-recognized side-effect of prolonged phenothiazine treatment. In this condition the areas of skin exposed to sunlight develop a violaceous, blue-grey or slate-grey colour in more severe cases. These characteristic changes are rarely seen now. We describe the case of a patient who developed pigmentation while taking a low dose of stelazine for 5 years.

CD23/Fc epsilon R11 expression in contact sensitivity reactions: a comparison between aeroallergen patch test reactions in atopic dermatitis and the nickel patch test reaction in non-atopic individuals

The immunopathology of patch test reactions to aeroallergens in patients with atopic dermatitis (AD) has been compared to that of contact sensitivity reactions to nickel in non-atopic individuals. Both reactions were found to exhibit equivalent erythema and induration on gross examination at 48 h. Four millimetre punch biopsies were obtained at 48 h frozen, and cryostat sections stained with a panel of MoAbs. The distribution of macrophages, dermal dendritic cells, Langerhans cells, T lymphocytes and the expression of CD23 antigen was recorded. Increased numbers of dermal dendritic cells, macrophages, T lymphocytes and Langerhans cells were found in the dermal infiltrates of both the nickel patch test reactions and the aeroallergen patch test reactions compared with their respective controls. There were no significant differences between atopic patch test reaction and nickel patch test reaction samples in the tissue distribution of these cell types. There was a significant increase in CD23 expression on Langerhans cells and dermal dendritic cells in the atopic patch test reactions, whereas an increase was only observed on dendritic cells in nickel patch test reactions. No significant difference in CD23 expression was observed in the control skin samples taken from patients with AD, nickel-sensitive patients and normal controls. This study supports the hypothesis that the aeroallergen patch test reaction in atopic dermatitis is a delayed hypersensitivity reaction, yet is distinct from the contact sensitivity reaction to nickel in terms of raised expression of CD23.

Phenytoin-induced pseudolymphoma. A report of a case and review of the literature

We report a patient with phenytoin-induced pseudolymphoma mimicking cutaneous T-cell lymphoma (CTCL). Despite withdrawal of phenytoin, there was persistence of the cutaneous eruption and lymphadenopathy. Southern blot analysis of immunoglobulin and T-cell receptor genes was therefore used to assess whether there was a clonal lymphoid expansion. However, no rearrangement of the beta T-cell receptor gene or immunoglobulin heavy-chain gene was detected in tissue DNA from skin and lymph nodes. One year later the patient became asymptomatic, although he is still at risk of developing a true malignant lymphoma in the future, a condition known as pseudo-pseudolymphoma. It is suggested that genotypic studies may help in the initial diagnosis and the subsequent management of such patients.

Efficacy of traditional Chinese herbal therapy in adult atopic dermatitis

There has been considerable interest in traditional Chinese herbal therapy (TCHT) as a new treatment for atopic dermatitis. To establish the efficacy and safety of this treatment, a daily decoction of a formula containing ten herbs that has been found to be beneficial in open studies was tested in a double-blind placebo-controlled study. 40 adult patients with longstanding, refractory, widespread, atopic dermatitis were randomised into two groups to receive 2 months' treatment of either the active formulation of herbs (TCHT) or placebo herbs, followed by a crossover to the other treatment after a 4-week washout period. The main outcome measures were extent and severity of erythema and surface damage as judged by standardised body scores. The patients' own assessments of the overall response to treatment were also sought. The geometric mean score for erythema at the end of active treatment was 12.6 (95% confidence interval [CI] 5.9 to 22.0) and at the end of the placebo phase was 113 (65 to 180). The geometric mean score for surface damage was 11.3 (5.8 to 21.8) and 111.0 (68 to 182), respectively. The 95% CI for the mean geometric ratio for the two values with active treatment was 0.04 to 0.22 for erythema (p less than 0.0005) and 0.04 to 0.27 for surface damage (p less than 0.0005). Of the 31 patients who completed the study and expressed a preference, 20 preferred that phase of the trial in which they received TCHT whereas 4 patients preferred placebo (p less than 0.02). There was a subjective improvement in itching (p less than 0.001) and sleep (p less than 0.078) during the TCHT treatment phase. No side-effects were reported by the patients although many commented on the unpalatability of the decoction. TCHT seems to benefit patients with atopic dermatitis. Palatability of the treatment needs to be improved and its safety assured.

Atypical systemic sclerosis following exposure to vinyl chloride monomer. A case report and review of the cutaneous aspects of vinyl chloride disease

An unusual case of systemic sclerosis occurring in a patient exposed to the vinyl chloride monomer (VCM) is presented. The dermatological aspects of vinyl chloride disease (VCD) are outlined and the mechanisms of pathogenesis discussed.

Proliferating cell nuclear antigen counts in formalin-fixed paraffin-embedded tissue correlate with Ki-67 in fresh tissue

Cell proliferation can be studied by a variety of techniques. However, most require fresh tissue. To evaluate cell proliferation in formalin-fixed paraffin-embedded sections, the authors immunohistochemically studied 35 tumors and 11 samples of normal/hyperplastic tissue with PC10, a monoclonal antibody directed against proliferating cell nuclear antigen. Results were compared with those obtained with Ki-67 on fresh tissues. There was no significant difference between proliferating cell nuclear antigen and Ki-67 counts, which were strongly correlated (r = 0.8). Proliferating cell nuclear antigen positivity was easier to evaluate because morphology was better preserved in formalin-fixed tissue. The authors conclude that PC10 is an alternative to Ki-67 in evaluating cell proliferation and has the advantage of reacting with formalin-fixed paraffin-embedded tissue.

Eosinophilic pustular folliculitis in an HIV-positive man: response to cetirizine

Eosinophilic pustular folliculitis is a rare condition which is being increasingly reported in HIV-positive patients. Many therapies have been used to treat this condition. We report the first successful use of the H1 antihistamine cetirizine to treat the condition and postulate that the specific antieosinophilic action of this drug may explain the beneficial clinical effect seen in our patient.