Expression of Xhdsi-1VOC, a novel member of the vicinal oxygen chelate (VOC) metalloenzyme superfamily, is up-regulated in leaves and roots during desiccation in the resurrection plant Xerophyta humilis (Bak) Dur and Schinz.

The annotation of novel plant genes is frequently based on sequence and structural similarity to known protein motifs. Understanding the biological function of these genes is dependent on identifying conditions under which they are activated, however. The resurrection plant, Xerophyta humilis is a good model system for identifying and characterizing genes which are important for desiccation tolerance. Desiccation induced-1 (dsi-1(VOC)), a previously uncharacterized plant gene, is up-regulated during desiccation in leaves, roots, and seeds in X. humilis. The X. humilis desiccation induced-1 gene, Xhdsi-1(VOC), shares structural homology with the vicinal oxygen chelate (VOC) metalloenzyme superfamily. Proteins in this superfamily share little sequence similarity, but are characterized by a common betaalphabetabetabeta structural fold. A number of plant orthologues of XhDsi-1(VOC) have been identified, including Arabidopsis thaliana At1g07645, which is currently annotated as a glyoxalase I-like gene, and many ESTs derived from seed cDNA libraries. Xhdsi-1(VOC) and its orthologues do not, however, contain the glutathione and zinc binding sites conserved in glyoxalase I genes. Furthermore, expression of Xhdsi-1(VOC) in yeast failed to rescue a yeast glyoxalase I mutant. Messenger RNA transcripts for At1g07645 accumulate during seed maturation, but are not induced by water loss, salt or mannitol stress in vegetative tissue in Arabidopsis. It is concluded that dsi-1(VOC) is a seed-specific gene in desiccation-sensitive plants that is activated by water loss in vegetative tissues in the resurrection plant X. humilis and plays an important role in allowing plant tissues to survive loss of 95% of their relative water content.

MR imaging of erosions in interphalangeal joint osteoarthritis: is all osteoarthritis erosive?

OBJECTIVE: Erosive osteoarthritis is usually considered as an inflammatory subset of osteoarthritis (OA). However, an inflammatory component is now recognised in all subsets of OA, so this subgroup of erosive or inflammatory OA is more difficult to conceptualise. The aim of this study was to compare routine CR and MRI to investigate erosion numbers and morphology to determine whether hand OA in general is a more erosive disease than previously recognised. DESIGN AND METHODS: Fifteen patients with clinical (OA) of the small joints of the hand underwent MRI of one of the affected proximal interphalangeal (PIP) or distal interphalangeal (DIP) joints. Conventional radiographs (CR) of the hand were also obtained. The MR images were reviewed by two observers for the presence of central and marginal erosions. The site and morphology of any erosions was recorded. CR images of the same hand joint were scored independently for central and marginal erosions by the same observers. RESULTS: There was 100% agreement between the observers for scoring erosions on CR. Agreement for the MRI scores was also excellent (kappa = 0.84). MRI detected 37 erosions, of which only 9 were seen on CR. The increase in sensitivity using MRI was much greater for marginal erosions (1 detected on CR, 19 on MRI) than for central erosions (8 on CR, 18 on MRI). Using MRI 80% of joints examined showed 1 or more erosions compared with 40% using CR. If only marginal erosions were considered 80% of joints were still considered erosive by MRI criteria, but only 1 showed evidence of erosion on CR. Morphologically central erosions appeared to represent areas of subchondral collapse and pressure atrophy. In contrast, marginal erosions resembled those seen in inflammatory arthritides. CONCLUSION: Erosions, and particularly marginal erosions typical of those seen in inflammatory arthritis, are a more common feature of small joint OA than conventional radiographs have previously indicated.

Advanced imaging in rheumatoid arthritis. Part 1: synovitis.

Rheumatoid arthritis (RA) is a chronic and progressive inflammatory disorder primarily affecting the synovium. We now recognise that conventional radiographic images show changes of rheumatoid arthritis long after irreversible joint damage has occured. With the advent of powerful disease-modifying drugs, there is a need for early demonstration of rheumatoid arthritis and a need to monitor progress of the disease and response to therapy. Advanced imaging techniques such as ultrasound and MRI have focussed on the demonstration and quantification of synovitis and erosions and allow early diagnosis of RA. The technology to quantify synovitis and erosions is developing rapidly and now allows change in disease activity to be assessed. However, problems undoubtedly exist in quantification techniques, and this review serves to highlight them. Much of the literature on advanced imaging in RA appears in rheumatological journals and may not be familiar to radiologists. This review article aims to increase the awareness of radiologists about this field and to encourage them to participate and contribute to the ongoing development of these modalities. Without this collaboration, it is unlikely that these modalities will reach their full potential in the field of rheumatological imaging. This review is in two parts. The first part addresses synovitis imaging. The second part will look at advanced imaging of erosions in RA.

Advanced imaging in rheumatoid arthritis: part 2: erosions.

Rheumatoid arthritis (RA) is a chronic and progressive inflammatory disorder primarily affecting the synovium. We now recognise that conventional radiographic images show changes of rheumatoid arthritis late after irreversible joint damage has occured. With the advent of powerful disease-modifying drugs there is a need for early demonstration of rheumatoid arthritis and to monitor progress of the disease and response to therapy. Advanced imaging techniques such as ultrasound and MRI have focussed on the demonstration and quantification of synovitis and erosions and allow early diagnosis of RA. The technology to quantify synovitis and erosions is developing rapidly and now allows change in disease activity to be assessed. However, problems undoubtedly exist in quantification techniques and this review serves to highlight them. Much of the literature on advanced imaging in RA appears in rheumatological journals and may not be familiar to radiologists. This review article aims to increase the awareness of radiologists to this field and to encourage them to participate and contribute to the ongoing development of these modalities. Without this collaboration it is unlikely that these modalities will reach their full potential in the field of rheumatological imaging. This review is in two parts. This first part addresses synovitis imaging. The second part will look at advanced imaging of erosions in RA.

An aldose reductase homolog from the resurrection plant Xerophyta viscosa Baker.

An aldose reductase homologue (ALDRXV4) was cloned from the resurrection plant Xerophyta viscosa Baker using complementation by functional sufficiency in Escherichia coli. A cDNA library constructed from X. viscosa leaves dehydrated to 85%, 37% and 5% relative water contents (RWC) was converted into an infective phagemid library. Escherichia coli (sr1::Tn10) cells transformed with ds-pBluescript phagemids were selected on minimal medium plates supplemented with 1 mM isopropyl beta-D-thiogalactopyranoside and 1.25 M sorbitol. Nine cDNA clones that conferred tolerance to the osmotically stressed E. coli cells were selected. The phagemid from one clone contained the ALDRXV4 insert. The E. coli cells expressing ALDRXV4 were capable of tolerating the osmotic stress, whereas control cultures were not. The ALDRXV4 insert contained an open reading frame that can code for 319 amino acids, and the predicted protein had a calculated Mr of 35,667. Amino acid sequence comparisons revealed significant similarity to several aldose reductases, with the highest similarity to aldose reductase proteins from Hordeum vulgare, Bromus inermis and Avena fatua, in the order of 66%, 65% and 65% respectively. Northern blot analysis revealed that ALDRXV4 was expressed only under dehydration conditions in X. viscosa leaves. Western blot analysis detected a protein of 36 kDa under dehydration conditions only. Aldose reductase activity levels in X. viscosa leaves increased as the leaf RWC decreased, whereas there was no significant change in aldose reductase activity in Sporobolus stafianus as the leaf RWC decreased.

Inclusion of polyvinylpyrrolidone in the polymerase chain reaction reverses the inhibitory effects of polyphenolic contamination of RNA.

Polysaccharides, secondary metabolites and poly-phenolics are known to co-isolate with nucleic acids from plant tissues resulting in inhibition of molecular manipulations. RNA isolated from the polyphenolic-rich resurrection plant, Myrothamnus flabellifolius, was demonstrated to inhibit a standard polymerase chain reaction used as an assay despite the inclusion of the polyphenolic-binding compound poly(1-vinylpyrrolidone-2) (PVP) into the RNA isolation medium. This inhibition was, however, reversed by the addition of PVP into the PCR mixture itself. Confirmation of the inhibitory effect of polyphenolics on PCR was obtained by addition of green tea polyphenolics to the standard PCR assay. This inhibition was also reversed by the simultaneous inclusion of PVP.

Pigbel-like syndrome in a vegetarian in Oxford.

Enterocolitis necroticans or pigbel is a rare condition characteristically affecting chronically malnourished people who abruptly increase their intake of protein. The classic presentation of the disease as seen in the highlands of Papua New Guinea is that of a necrotising enterocolitis after the ritual ingestion of contaminated pork. In this context, the presentation of the same disease in a well nourished white vegetarian in Oxford was all the more intriguing.

Predicting outcome in severe ulcerative colitis.

BACKGROUND: Simple criteria are needed to predict which patients with severe ulcerative colitis will respond poorly to intensive medical treatment and require colectomy. AIMS: To find out if the early pattern of change in inflammatory markers or other variables could predict the need for surgery and to evaluate the outcome of medical treatment during one year follow up. PATIENTS: 51 consecutive episodes of severe colitis (Truelove and Witts criteria) affecting 49 patients admitted to John Radcliffe Hospital, Oxford. METHODS: Prospective study monitoring 36 clinical, laboratory, and radiographic variables. All episodes treated with intravenous and rectal hydrocortisone and 14 of 51 with cyclosporine. RESULTS: Complete response in 21 episodes (< or = 3 stools on day 7, without visible blood), incomplete response in 15 (> 3 stools or visible blood on day 7, but no colectomy), and colectomy on that admission in 15. During the first five days, stool frequency and C reactive protein (CRP) distinguished between outcomes (p < 0.00625, corrected for multiple comparisons) irrespective of whether patients or the number of episodes were analysed. It could be predicted on day 3, that 85% of patients with more than eight stools on that day, or a stool frequency between three and eight together with a CRP > 45 mg/l, would require colectomy. For patients given cyclosporine, four of 14 avoided colectomy but two continued to have symptoms. After admission, complete responders remained in remission for a median nine months and had a 5% chance of colectomy. Incomplete responders had a 60% chance of continuous symptoms and 40% chance of colectomy. CONCLUSIONS: After three days intensive treatment, patients with frequent stools (> 8/day), or raised CRP (> 45 mg/l) need to be identified, as most will require colectomy on that admission. The role of cyclosporine for treating severe colitis has yet to be defined. After seven days' treatment, patients with > 3 stools/day of visible blood have a 60% chance of continuous symptoms and 40% chance of colectomy in the following months.

Contribution of genes of the major histocompatibility complex to susceptibility and disease phenotype in inflammatory bowel disease.

BACKGROUND: Despite strong evidence implicating immune dysfunction and genetic predisposition in the pathogenesis of the chronic inflammatory bowel diseases Crohn's disease and ulcerative colitis, the importance of the genes of the major histocompatibility complex remains uncertain. We have investigated the contribution of HLA DRB1 and DQB genes by the strategies of non-parametric linkage analysis (affected sibling pair method) as well as association study. The relation between genotype and phenotype was examined in detail. METHODS: For linkage analysis 74 families in whom two or more siblings had inflammatory bowel disease were studied. A total of 83 affected sibling pairs were involved: in 42 pairs both siblings had Crohn's disease; in 29 both had ulcerative colitis; in 12 one sibling had Crohn's disease, the other ulcerative colitis. For the association study there were 175 patients with ulcerative colitis, 173 with Crohn's disease, and 472 controls. Details of sex, age of onset, disease extent, and family history were analysed. 24 patients with ulcerative colitis and 92 with Crohn's disease required surgery for refractory disease. HLA DRB1 and DQB1 gene-typing was performed by polymerase chain reaction with sequence-specific primers. FINDINGS: In ulcerative colitis, the sharing of alleles among affected sibling pairs provided evidence for linkage with DRB1 locus (p = 0.017, chi2 = 5.32). Of 29 affected sibling pairs studied, only one pair shared no DRB1 DQB haplotypes. 15 shared two DRB DQB haplotypes. In contrast, no linkage was noted for Crohn's disease (42 sibling pairs; p = 0.30, chi2 = 0.16) or for inflammatory bowel disease overall (83 sibling pairs, p = 0.16, chi2 = 2.28). In the association study the rare DRB1*103 (8.3% vs 3.2% in controls) and DRB1*12 (8.6% vs 2.1% in controls) alleles were associated with ulcerative colitis (p = 0.0074, chi2 = 7.22, odds ratio OR = 2.9 [95% CI 1.3-6.4] and p = 0.0056, chi2 = 12.63, OR = 4.33 [1.8-11.0] respectively). No association with alleles representing DR2 (p = 0.55, chi2 = 0.34) was noted. No overall association was seen in Crohn's disease. In ulcerative colitis, the frequency of DRB1*0301 DQB*0201 (DR3 DQ2) was reduced in females (9.8% vs 26.3% in controls, p = 0.037, chi2 = 8.39 OR = 0.34 [0.15-0.71]), particularly in those with distal disease (2.3%, p = 0.001 vs controls, chi2 = 11.35, OR = 0.07 [0.00-0.39]). In both males and females, the DR3 DQ2 haplotype was predictive of extensive ulcerative colitis (32.9% vs 10.7% in distal disease, p < 0.01, chi2 = 10.94, OR 4.09 [1.70-10.6]) but not of need for surgery (p = 0.93, chi2 = 0.01). INTERPRETATION: These data provide strong evidence for genetic heterogeneity in inflammatory bowel disease. Genes of the major histocompatibility complex are implicated as important inherited determinants of susceptibility to ulcerative colitis and may also influence the pattern of disease. In Crohn's disease, important susceptibility genes are likely to exist outside the HLA region.

Serum tumor markers for the diagnosis of cholangiocarcinoma in primary sclerosing cholangitis.

BACKGROUND/AIMS: The diagnosis of cholangiocarcinoma in primary sclerosing cholangitis (PSC), even with the use of current imaging techniques and brush cytology, is difficult and particularly important in patients being assessed for liver transplantation. This study investigated the accuracy of serum levels of a combination of the tumor markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in the diagnosis of cholangiocarcinoma in patients with PSC. METHODS: Seventy-four patients with PSC were studied. Fifteen patients had tumors (11 occult on imaging), 22 had severe PSC that necessitated transplantation (with explanted liver known to be free of tumor), and 37 patients had stable PSC. RESULTS: An index of the two serum tumor markers [using the formula CA19-9 + (CEA x 40)] gave an accuracy of 86% in diagnosis of cholangiocarcinoma, with 10 of the 15 cases of cholangiocarcinoma having an increased value compared with none in a group of 22 comparable cases with no tumor. In addition, 6 of the 11 patients with occult tumors had abnormal values. Ultrasonography, computerized tomographic scanning, and endoscopic retrograde cholangiopancreatography were poor predictors of the presence of tumor. CONCLUSIONS: A combination of serum tumor markers will identify most occult tumors and will improve selection of appropriate cases for orthotopic liver transplantation.

Allelic sequence variation in the HLA class II genes and proteins in patients with autoimmune hepatitis.

Susceptibility to autoimmune hepatitis in white patients is associated with the human leukocyte antigen class II antigens DR3 and DR4. To analyze the molecular basis of these associations, we used oligonucleotide probes to determine the DRB, DQA and DQB hypervariable nucleotide sequences in 119 patients with autoimmune hepatitis and 177 matched controls. DRB3*0101, which encodes DR52a, predisposed patients most strongly to the disease. It was present in 58% of patients and 25% of controls (corrected P < 0.000005), whereas DQA1*0101 and 0102 conferred protection in males only. The DR4 subtype, DRB1*0401, was raised in the DRB3*0101-negative patients; 81% possessed either DRB3*0101 or DRB1*0401, compared with 42% of controls (corrected P < 0.0000001). These alleles encode the amino acid sequence Leu-Leu-Glu-Gln-Lys-Arg at positions 67 to 72 of the DR beta polypeptide, which was present in 94% of patients and 64% of controls (corrected P < 0.000001) and in all patients who tested positive for autoantibodies to the hepatic asialoglycoprotein receptor. The patients with DRB1*0401 had less severe disease, relapsed less frequently and were first seen significantly later in life than those patients with DRB3*0101; and whereas a single copy of DRB1*0401 predisposed to autoimmune hepatitis, DRB3*0101-associated susceptibility had a dose-related effect. These data provide evidence that specific residues in the DR beta polypeptides predispose to autoimmune hepatitis in white patients and genes linked to DRB3*0101 and DRB1*0401 may determine two clinically distinct disease patterns.

Amino acid substitutions at position 38 of the DR beta polypeptide confer susceptibility to and protection from primary sclerosing cholangitis.

Previous studies based on serological HLA phenotyping have implicated genes in the HLA class II region in susceptibility to and protection from primary sclerosing cholangitis. In a recent report, the HLA DRw52a antigen was present in all 29 patients who had been referred for liver transplantation. In this study, HLA DRB, DQA and DQB genotypes were studied using gene amplification and sequence-specific oligonucleotide probing in 71 patients with primary sclerosing cholangitis and 68 healthy controls to determine the frequency among the patients of the DRB3*0101 allele that encodes DRw52a and whether other class II alleles are involved in susceptibility or protection. DRB3*0101 was the most strongly associated allele, being present in 55% of the patients and 22% of the controls. Survival among the DRB3*0101-positive patients was reduced compared with the DRB3*0101-negative patients. Both DRB3*0101 and DRB5*0101, a possible second DRB susceptibility allele, encode a leucine residue at position 38 of the DR beta molecule. The DRB4*0101 allele, which encodes DRw53 and may be protective, encodes an alanine residue at this position. Susceptibility to and protection from primary sclerosing cholangitis may result from amino acid substitutions at position 38 of the DR beta molecule because maximum relative risk was conferred by two leucine-38-containing DR beta molecules, whereas minimum relative risk was conferred by two alanine-38-containing molecules.

Etiologic and clinical characteristics of peripheral and hilar cholangiocarcinoma.

A 20-year experience with 112 patients with cholangiocarcinoma was reviewed with reference to the demographic, etiologic, and clinical features and prognosis in the following two types: peripheral (originating from the intrahepatic small duct radicles) and hilar (originating from the major hepatic ducts at or near the junction of the right and left hepatic ducts). Seventy of the 112 patients were in the hilar group, and 42 were in the peripheral group. Prolonged high alcohol consumption was a prominent feature in both categories (45% and 37%, respectively). Among the women, 35% of those with the peripheral tumor had used oral contraceptive preparations. The major identifiable etiologic factor among the hilar tumors was ulcerative colitis, with or without sclerosing cholangitis, which was documented in 20 of 70 cases (28.6%), with an additional 4 patients having Crohn's disease. The hilar group mainly had obstructive jaundice initially, whereas abdominal pain and weight loss were the predominant symptoms in the peripheral type. Tumor recurrence was frequent in those undergoing resection or transplantation, and none of those undergoing chemotherapy or radiation therapy showed any objective evidence of response. Overall median survival time was poor in both groups at 12 months.

Natural history and prognostic variables in primary sclerosing cholangitis.

The clinical features at the time of presentation and the outcome in 126 patients with primary sclerosing cholangitis were studied to clarify the natural history and prognosis in symptomatic and asymptomatic individuals. The median age of the patients at the time of presentation was 36 years, 62% were male, and 16% were asymptomatic. The median follow-up from time of presentation was 5.8 years. There were more patients who had liver transplants (21%) than patients who died of liver-related disease (16%); the estimated median survival to these end points was 12 years. Cholangiocarcinoma was found in 8 patients and in 23% of those undergoing liver transplantation. Asymptomatic patients had milder disease than symptomatic patients, but in a univariate analysis the presence of symptoms was not prognostically significant. On multivariate analysis, the following independent prognostic factors were found: hepatomegaly, splenomegaly, serum alkaline phosphatase, histological stage, and age. These features were combined to produce a prognostic model that should be valuable in the stratification of patients in clinical trials and in the timing of liver transplantation, particularly in those patients seen soon after presentation.

Dual association of HLA DR2 and DR3 with primary sclerosing cholangitis.

Human leukocyte antigen typing was performed in 81 patients with primary sclerosing cholangitis to investigate reported associations between human leukocyte antigen type and this disease. The results showed a significant increase in the frequency of the antigens B8 and DR3 compared with controls (53% vs. 23%, p less than 0.0005, and 56% vs. 21%, p less than 0.0005). This was caused by a significant rise in the frequency of the human leukocyte antigen A1 B8 DR3 haplotype (32 of 81 patients, 40% vs. 12 of 100 patients, 12%, p less than 0.0005). By contrast, a significant reduction was seen in the frequency of the antigens B44 and DR4 (12% vs. 31%, p less than 0.005, and 12% vs. 34%, p less than 0.001, pc less than 0.011) because of the complete absence of the B44 DR4 haplotype in the patient group (p = 0.027, Fisher's exact test). When all the DR3-positive individuals (including the DR2/DR3 heterozygotes) were eliminated, a significant secondary association with DR2 was noted, 25 (69%) of 36 remaining patients being DR2-positive compared with 27 (34%) of 79 DR3 negative controls (p less than 0.0005, pc less than 0.006). Only 9% of the patients were DR2-positive and DR3-positive. Kaplan-Meier analysis demonstrated that survival was not influenced by the presence of either haplotype nor by the individual antigens. Patients who were DR3-positive were first seen at a significantly younger age than those who were DR2-positive (mean ages = 33 yr and 44 yr, respectively, p less than 0.002, Student's t test).(ABSTRACT TRUNCATED AT 250 WORDS)

Activation of the complement system in primary sclerosing cholangitis.

Recent evidence, including the presence of circulating immune complexes, suggests that abnormalities of humoral immunity may be important in the pathogenesis of primary sclerosing cholangitis. The aim of the present study was to determine whether activation of the complement system is present in patients with this disease, as this would be supportive evidence of a role for circulating immune complexes in primary sclerosing cholangitis. Plasma complement fragments C3d and C4d, and serum C3 and C4, their respective parent molecules, have been assayed. Both C3d and C4d were elevated in patients with primary sclerosing cholangitis compared with patients with extrahepatic obstructive cholestasis and normal controls (p less than 0.01 in all instances). C3 was elevated in both patient groups, in whom it was similar, compared with normal controls (p less than 0.001 in both cases), whereas C4 was similar in all groups. Elevated levels of circulating immune complexes were identified in 21 of 24 (88%) patients with primary sclerosing cholangitis, but in none of the normal controls. These findings support the hypothesis that in primary sclerosing cholangitis circulating immune complexes are associated with activation of complement via the classical pathway.

Thrombotic cutaneous nodules and hepatic vein thrombosis in the anticardiolipin syndrome.

A patient with the anticardiolipin syndrome presented with hepatic vein thrombosis (Budd-Chiari syndrome) and non-ulcerating, thrombotic, cutaneous nodules. This cutaneous manifestation of the anticardiolipin syndrome has not been described before, though its histological appearances resemble those of previously reported cutaneous complications, such as chronic ulceration, livedo reticularis and distal cutaneous ischaemia. Recognition of the skin lesion could allow the prevention of major systemic complications.

Germination-associated events and the desiccation sensitivity of recalcitrant seeds - a study on three unrelated species.

The storage behaviour of recalcitrant seeds was assessed using three diverse species: a gymnosperm, Araucaria angustifolia (Bert.) O. Kuntze; a herbaceous monocotyledon, Scadoxus membranaceus (Bak.) Friis Nordal; and a woody dicotyledon, Landolphia kirkii Dyer. Seeds were stored under conditions of high relative humidities that maintained seed moisture content and under low relative humidities that caused drying. At regular intervals moisture content was determined, germinability assessed and the ultrastructure of radicle meristem cells examined. Under storage at high relative humidity, seed moisture content was maintained at the original level and subcellular germination events were initiated in the short-term. Such seeds showed enhanced rates of germination when removed from storage and planted. Long-term storage under these conditions resulted in the initiation of subcellular damage which intensified with time and ultimately resulted in the loss of viability. The rate at which germination events proceeded varied among the three species, and could be directly correlated with the period of viability retention under humid storage conditions. Storage under desiccating conditions resulted in subcellular damage and rapid loss of viability. The rate at which the seeds dried varied among the three species. The proportion of water loss tolerated by the different species before loss of viability, correlated with the rate of drying. The storage behaviour of the seeds of these three species is discussed in terms of a previously described model.