Investigation of the potential of buffalo and couch grasses to grow on AFIs and for removal of nutrients from paper mill wastewater.

The potential growth of buffalo grass (Stenotaphrum secundatum) and couch grass (Cynodon dactylon) on artificial floating islands (AFIs) and their ability to remove total nitrogen (TN) and total phosphorus (TP) from a simulated paper mill wastewater was studied. This was done to assess the potential of AFIs for removal of nutrients from aerated stabilization basins (ASBs) that had occasional growth of blue-green algae (BGA) to bloom levels. Small scale AFIs were prepared using polyethylene foam and planted with the grasses in 30 L of tested water. Trials were conducted in a plastic covered greenhouse over a three-month period where temperatures ranged from 15 to 44 °C. The results showed that both buffalo and couch grasses can adapt to planting in AFIs showing increases of 125% and 148% in wet weight, respectively. Nutrient uptake by buffalo grass and couch grass were found to be similar. Percentage uptakes of TP and TN from the synthetic water by the buffalo grass were 82% and 47%, whereas by couch grass, uptakes were 83% and 45%, respectively.

Three-dimensional ultrasound of carotid atherosclerosis: semiautomated segmentation using a level set-based method.

PURPOSE: Three-dimensional ultrasound (3D US) of the carotid artery provides measurements of arterial wall and plaque [vessel wall volume (VWV)] that are complementary to the one-dimensional measurement of the carotid artery intima-media thickness. 3D US VWV requires an observer to delineate the media-adventitia boundary (MAB) and lumen-intima boundary (LIB) of the carotid artery. The main purpose of this work was to develop and evaluate a semiautomated segmentation algorithm for delineating the MAB and LIB of the carotid artery from 3D US images. METHODS: To segment the MAB and LIB, the authors used a level set method and combined several low-level image cues with high-level domain knowledge and limited user interaction. First, the operator initialized the algorithm by choosing anchor points on the boundaries, identified in the images. The MAB was segmented using local region- and edge-based energies and an energy that encourages the boundary to pass through anchor points from the preprocessed images. For the LIB segmentation, the authors used local and global region-based energies, the anchor point-based energy, as well as a constraint promoting a boundary separation between the MAB and LIB. The data set consisted of 231 2D images (11 2D images per each of 21 subjects) extracted from 3D US images. The image slices were segmented five times each by a single observer using the algorithm and the manual method. Volume-based, region-based, and boundary distance-based metrics were used to evaluate accuracy. Moreover, repeated measures analysis was used to evaluate precision. RESULTS: The algorithm yielded an absolute VWV difference of 5.0% +/- 4.3% with a segmentation bias of -0.9% +/- 6.6%. For the MAB and LIB segmentations, the method gave absolute volume differences of 2.5% +/- 1.8% and 5.6% +/- 3.0%, Dice coefficients of 95.4% +/- 1.6% and 93.1% +/- 3.1%, mean absolute distances of 0.2 +/- 0.1 and 0.2 +/- 0.1 mm, and maximum absolute distances of 0.6 +/- 0.3 and 0.7 +/- 0.6 mm, respectively. The coefficients of variation of the algorithm (5.1%) and manual methods (3.9%) were not significantly different, but the average time saved using the algorithm (2.8 min versus 8.3 min) was substantial. CONCLUSIONS: The authors generated and tested a semiautomated carotid artery VWV measurement tool to provide measurements with reduced operator time and interaction, with high Dice coefficients, and with necessary required precision.

Regulation of eicosanoid production and mitogenesis in rat intestinal epithelial cells by transforming growth factor-alpha and phorbol ester.

Growth factors and tumor promoters have been shown to play a role in intestinal epithelial growth regulation and transformation. In this study, transforming growth factor-alpha (TGF alpha) and the tumor promoter, tetradecanoyl phorbol acetate (TPA), are shown to stimulate the production of eicosanoids by rat intestinal epithelial (RIE-1) cells in culture. A 4.5-kb mRNA, which hybridizes to the mouse cyclooxygenase-2 cDNA probe, is elevated 18-fold within 30 min after TGF alpha or TPA treatment. Stimulation of RIE-1 cells with TGF alpha leads to the increase of a protein (M(r) approximately 69,000), which binds a monospecific antibody to the mouse cyclooxygenase-2 protein. Dexamethasone markedly inhibits the increase of the 4.5-kb mRNA. Pretreatment of TGF alpha or TPA-stimulated RIE-1 cells with dexamethasone or cyclooxygenase inhibitors prevents the increase in eicosanoid production by these cells. Treatment of quiescent RIE-1 cells with TGF alpha stimulates mitogenesis. This mitogenic activity is blocked by pretreating the cells with dexamethasone or cyclooxygenase inhibitors. A mitogen-inducible cyclooxygenase gene is thus shown to be regulated by TGF alpha and TPA in rat intestinal epithelial cells. We suggest that products of an intestinal growth factor-inducible cyclooxygenase may play a role in the regulation of mitogenesis.

Formation of novel non-cyclooxygenase-derived prostanoids (F2-isoprostanes) in carbon tetrachloride hepatotoxicity. An animal model of lipid peroxidation.

These studies examine the in vivo formation of a unique series of PGF2-like compounds (F2-isoprostanes) derived from free radical-catalyzed nonenzymatic peroxidation of arachidonic acid. We have previously shown that levels of these compounds increase up to 50-fold in rats administered CCl4. To understand further the formation of these compounds in vivo, we carried out a series of experiments assessing factors influencing their generation. After CCl4 (2 ml/kg) was administered to rats, plasma F2-isoprostanes increased 55-fold by 4 h. Levels declined thereafter, but at 24 h, they were still elevated 21-fold, indicating continued lipid peroxidation. Pretreatment of rats with isonicotinic acid hydrazide and phenobarbital to induce cytochrome P-450 enhanced the production of F2-isoprostanes after CCl4 administration eightfold and fivefold, respectively, whereas inhibition of the cytochrome P-450 system with SKF-525A and 4-methylpyrazole decreased formation of F2-isoprostanes after CCl4 by 55 and 82%, respectively. Further, the glutathione-depleting agents buthionine sulfoximine and phorone augmented the F2-isoprostane response to CCl4 by 22- and 11-fold, respectively. F2-isoprostanes are formed in situ esterified to lipids and, in addition to increases in levels of free F2-isoprostanes in the circulation, levels of F2-isoprostanes esterified to lipids in various organs and plasma also increase sharply during CCl4 poisoning. The measurement of F2-isoprostanes may facilitate investigation of the role of lipid peroxidation in human diseases.

HLA class II alpha chain gene polymorphisms in patients with insulin-dependent diabetes mellitus, dermatitis herpetiformis, and celiac disease.

We have investigated DNA polymorphism of the class II alpha chain genes in HLA typed patients with insulin dependent diabetes mellitus (IDDM; n = 79), celiac disease (CD; n = 46), dermatitis herpetiformis (DH; n = 53), and controls (n = 86). Preferential allelic associations of HLA genes and gene products have thus been constructed for susceptibility to these diseases. DR alpha and DQ alpha gene polymorphisms indicated heterogeneity of HLA DR3, DRw6, and DR7, and HLA DR2 and DRw6, respectively. In DR7 positive CD patients a 3.8-kilobase (kb) DR alpha fragment, which correlated with DQw3, was found in only 11% of patients compared with 45% of corresponding controls (P less than 0.05). An increased frequency of a DX alpha genotype UU in all three diseases was found (IDDM 59%, DH 45%, CD 48%, compared to 21% in controls, P less than 0.001), which is not explained solely by the increased frequencies of DR3-DX alpha U. We therefore conclude part of the genetic susceptibility for these three conditions is encoded by genes within the DQ-DX subregion.

Transforming growth factor alpha protection against drug-induced injury to the rat gastric mucosa in vivo.

This study was designed to determine whether transforming growth factor alpha (TGF alpha) protects rat gastric mucosa against ethanol- and aspirin-induced injury. Systemic administration of TGF alpha dose-dependently decreased 100% ethanol-induced gastric mucosal injury; a dose of 50 micrograms/kg delivered intraperitoneally 15 min before ethanol decreased macroscopic mucosal injury by > 90%. At the microscopic level, TGF alpha prevented deep gastric necrotic lesions and reduced disruption of surface epithelium. Pretreatment with orogastric TGF alpha (200 micrograms/kg) only partially (40%) decreased macroscopic ethanol damage. Intraperitoneal administration of TGF alpha at a dose of 10 micrograms/kg, which does not significantly inhibit gastric acid secretion, decreased aspirin-induced macroscopic damage by > 80%. TGF alpha protection does not seem to be mediated by prostaglandin, glutathione, or ornithine decarboxylase-related events, as evidenced by lack of influence of the inhibition of their production. Pretreatment with the sulfhydryl blocking agent N-ethylmaleimide partially abolished (40%) the protective effect of TGF alpha. In addition, systemic administration of TGF alpha resulted in a two-fold increase in tyrosine phosphorylation of phospholipase C-gamma 1 and in a time- and dose-dependent increase in levels of immunoreactive insoluble gastric mucin; these events occurred in a time frame consistent with their participation in the protective effect of TGF alpha.

The association of interferon with the development of pulmonary tuberculosis.

We report a new case of a patient suffering from chronic hepatitis C (CHC) and treated with interferon-alpha2a (IFN-alpha) who presented with the diagnosis of active pulmonary tuberculosis. Interferon was stopped and appropriate treatment with antituberculous drugs initiated. Several weeks later the patient was free of clinical symptoms. Our case demonstrates a rare association between interferon and tuberculosis since only one case in the literature has described a similar association.

Analysis of the risk factors for the development of post-operative spinal epidural haematoma.

In order to identify the risk factors and the incidence of post-operative spinal epidural haematoma, we analysed the records of 14 932 patients undergoing spinal surgery between 1984 and 2002. Of these, 32 (0.2%) required re-operation within one week of the initial procedure and had an International Classification of Diseases (ICD)-9 code for haematoma complicating a procedure (998.12). As controls, we selected those who had undergone a procedure of equal complexity by the same surgeon but who had not developed this complication. Risks identified before operation were older than 60 years of age, the use of pre-operative non-steroidal anti-inflammatories and Rh-positive blood type. Those during the procedure were involvement of more than five operative levels, a haemoglobin < 10 g/dL, and blood loss > 1 L, and after operation an international normalised ratio > 2.0 within the first 48 hours. All these were identified as significant (p < 0.03). Well-controlled anticoagulation and the use of drains were not associated with an increased risk of post-operative spinal epidural haematoma.

Identification of skin as a major site of prostaglandin D2 release following oral administration of niacin in humans.

Oral administration of niacin (nicotinic acid) at pharmacologic doses that reduce serum cholesterol levels induces intense flushing in humans. We have recently shown that the vasodilation following ingestion of niacin is due to the release of prostaglandin (PG) D2. However, the site from which PGD2 is released is not known. It has previously been shown that topical application of methylnicotinate causes local cutaneous erythema. Thus, we investigated whether topical methylnicotinate causes a release of PGD2 locally from skin and the possibility that skin may be a major contributor to the release of PGD2 when niacin is administered by mouth. Topical administration of methylnicotinate (10(-1) M) to the forearms of human volunteers resulted in 58- to 122-times increases in levels of PGD2 and 25- to 33-times increases in levels of the metabolite of PGD2, 9 alpha,11 beta-PGF2, in blood drawn from the antecubital vein draining the treated sites. Increased levels of PGD2 and 9 alpha,11 beta-PGF2 were not found in blood drawn simultaneously from veins in the contralateral arm, indicating that the PGD2 was released from the site of methylnicotinate application. The release of PGD2 in response to topically applied methylnicotinate occurred in a dose-dependent manner over the concentration range of 10(-3) to 10(-1) M. The release of PGD2 was not accompanied by a release of histamine, suggesting that the release of PGD2 was not from the mast cell. Following oral ingestion of niacin, levels of PGD2 in superficial venous blood draining the skin were 14 to 1200 times higher than the level in arterial blood supplying the skin of the same arm. This finding indicates that the skin is a major site from which PGD2 is released following oral ingestion of niacin. These studies thus indicate that the cutaneous vasodilation that occurs following oral administration of niacin is primarily due to a release of PGD2 from a niacin responsive cell that resides in the skin.

Increased urinary F2-isoprostane excretion in alcoholic liver disease.

Free radical-induced lipid peroxidation (LP) is thought to be important in alcoholic liver disease (ALD), however, direct demonstration of increased LP in patients with ALD has been difficult. Quantification of F2-isoprostanes (F2-isoP), prostanoids produced by peroxidation of arachidonic acid, in plasma and urine are sensitive and specific indices of LP in vivo. To determine if LP is increased in ALD, 24-h urinary excretion of F2-isoPs were measured in 10 patients hospitalized because of ALD. The mean urinary excretion of the F2-isoP in the ALD patients' urine was 9.6+/-3.5 ng/mg creatinine, which was significantly elevated compared to controls' urinary excretion, which was 1.7+/-0.2 ng/mg creatinine (p<.01). The urinary excretion of F2-isoP decreased to 3.6+/-1.1 ng/mg creatinine as the patients improved clinically with abstinence over the 1-month period. These data suggest that lipid peroxidation, as assessed by this noninvasive method, is increased in patients with acute ALD and decreases with time as the patients improve clinically with abstinence.

HLA-Dw specificity assignments are independent of HLA-DQ, HLA-DR, and other class II specificities and define a biologically important segregant series which strongly activates a functionally distinct T cell subset.

Several lines of evidence indicate that HLA-Dw, as defined by HTC typing, is not the result of the combined stimulatory effect of HLA-DR and DQ. Therefore, responder cells do not have to share HLA-DQ antigens with the stimulator HTCs to give a typing response. The common HLA-DR-DQ associations observed in HTCs correspond to different patterns of linkage disequilibrium in different populations. HLA-DQ and HLA-Dw are functionally heterogeneous. Although HLA-DQ molecules may play a role in primary stimulation, this role is distinct from that of Dw determinants which have strong lymphocyte activating properties. The role of the HLA-DQ determinants on the other hand, is one of modulating the total T cell response by controlling the proliferation of suppressor and cytotoxic cells. The primary MLC response is the result of the proliferative effect of HLA-Dw, DR, DP, and other associated determinants, in conjunction with a modulatory effect of DQ molecules. However, HLA-Dw (as detected by HTC typing) are DR associated determinants which are immunodominant in primary MLR. The genes of the HLA-DR subregion have been named DR by the WHO nomenclature committee. This subregion encodes the HLA-DR specificities and the DRw52 and DRw53 determinants. Unfortunately this nomenclature does not take into account the need to define the genetic basis of the HLA-Dw determinants--whether they are encoded by separate genes within the HLA-DR subregion or whether they are encoded by as yet unspecified genes in the HLA class II region in linkage disequilibrium with HLA-DR DRw52/53. There are at least three and possibly four beta chain genes in the HLA-DR subregion, all in strong linkage disequilibrium with each other. Some of these are expressed in most haplotypes while others are not; some behave as pseudogenes in some haplotypes and in others, all the genes are expressed. All the genes of the class II region have not been fully characterized. HLA-Dw determinants may be specified by one or more of these genes. When more information becomes available, the genetic and molecular basis of the HLA-Dw series as well as the functional heterogeneity and antigenic strength of the various class II determinants will be better understood.

HLA-DR alpha, -DX alpha, and DR beta III gene association studies in DR3 individuals.

In this study we have examined the results of probing with synthetic oligomers at the DR beta III locus, together with restriction fragment length polymorphisms defined by BglII digestion and a cDNA DR alpha probe, and Taq 1 digestion and a genomic DQ alpha probe. We have demonstrated heterogeneity of the human leukocyte antigen DR3 and close association of the DR alpha, DR beta III, and DX alpha genes. Two DR3-related preferential allelic associations have been identified, which may prove useful in family analysis as well as for investigations of DR3-related diseases.

HLA class III haplotypes in multicase rheumatoid arthritis families.

The class III complement proteins (C2, BF, C4A, and C4B) were studied in 57 multicase rheumatoid arthritis (RA) families. When the gene frequencies for RA probands were compared to a normal control panel (162 haplotypes), a significantly higher frequency of the rare variant C4B*3 was observed (p less than 0.05). No significant differences were seen for the other C2, BF, C4A, or C4B alleles. The most common haplotype found in the probands was HLA-Cw5,B44,C2*C,BF*S,C4A*3,C4B*3,DR4, occurring with a frequency of 0.088. Haplotypes containing HLA-DR4 and Bw62 were found to carry either C4A*3,C4B*3; C4A*3,C4B*1; or C4A*4,C4B*2. When only haplotypes containing DR4 were compared between probands and controls, the frequency of the C4B*3-bearing haplotype remained higher in the probands. It is concluded that Bw62,C4A*3,C4B*3DR4 is a haplotype which is especially associated with RA. The low frequency in the RA population of this haplotype indicates that C4B*3 has a minor role in overall RA susceptibility.

Effect of oxygen tension on the generation of F2-isoprostanes and malondialdehyde in peroxidizing rat liver microsomes.

Although numerous methods have been developed for the detection of lipid peroxidation, it is generally recognized that most of these lack specificity and/or sensitivity, particularly when applied to in vivo situations. We have reported recently that a series of prostaglandin F2-like compounds, termed F2-isoprostanes, are formed in vivo from the free radical catalyzed peroxidation of arachidonic acid and appear to be a useful marker of oxidant stress. Because of formation of other products of lipid peroxidation, such as alkanes and malondialdehyde (MDA), are affected by oxygen tension, which may influence their usefulness as markers of oxidant stress, we carried out a systematic study of the generation of F2-isoprostanes at various oxygen concentrations and compared these changes with the generation of MDA. The disappearance of the F2-isoprostane precursor, arachidonic acid, was used as a reference measure. Rat liver microsomes were peroxidized using an iron-ascorbate system. The incubations were carried out in sealed flasks at 37 degrees under N2 and various concentrations of O2 up to 100%. F2-isoprostanes were quantified by mass spectrometry and MDA by the thiobarbituric acid reaction. Microsomal fatty acids were measured by gas chromatography. Both MDA and F2-isoprostane formation increased in a time-dependent manner up to 15 min. Their formation correlated with a loss of polyunsaturated fatty acid and with an increase in O2 tension up to 21% O2. At oxygen tensions above 21%, MDA generation continued to increase, while F2-isoprostane generation and arachidonic acid loss did not. Levels of MDA and F2-isoprostanes increased a maximum of 65 and 9.4 times baseline values, respectively. These studies, therefore, define factors that influence the formation of F2-isoprostanes in an in vitro model of lipid peroxidation. Further, they demonstrate that higher O2 tensions do not block formation of F2-isoprostanes and validate their usefulness for assessing lipid peroxidation under high, as well as low, oxygen tension.

HLA and rheumatoid arthritis: susceptibility or severity?

An analysis of data collected on 440 British Caucasoid rheumatoid arthritis patients has confirmed positive association with HLA-DR4, Dw4, DRw53, and A2 and negative associations with HLA-DR2, 3, and 7. HLA-DR4 is more associated with RA 'severity' than with RA 'susceptibility', when measured by the parameters of ARA classification, seropositivity, severity of erosions and extra-articular manifestations. The association between HLA-A2, Cw3, Bw62, DR4, DRw53, and Dw4 and extra-articular disease has been confirmed in this study. The analysis of HLA and RA severity with respect to sex showed high frequencies of DR4, Dw4, and DRw53 in females, which increased in those with severe erosions, seropositivity or extra-articular disease. In males with RA, the disease appears to be associated not only with DR4, Dw4 and DRw53, but also with A2, Cw3 and Bw62. However, no significant differences in these antigen frequencies were found between male patients with severe RA and those without. Despite a significant decrease in the frequencies of DR3, B8 and A1 in most RA patient subsets, RA patients with Sjogren's syndrome showed a marked increase of A1 and B8 and patients with auto-antibodies had a significant increase in HLA-DR3 frequency when compared with patients without these features.

DQ beta restriction fragment length polymorphism and its relationship to insulin dependent diabetes mellitus.

HLA Class II serological and DQ beta restriction fragment length polymorphisms (RFLPs) were compared in 69 patients with insulin-dependent diabetes mellitus (IDDM) and 81 healthy British Caucasoid controls. The backbone of the analysis was formed by two Taq 1 RFLPs of the DQ beta region designated T2 omega and T6. The two are not allelic and can be inherited individually, together on one, or separately on both, parental haplotypes, the latter almost invariably in association with DR4. In our study the frequency in IDDM patients of both T2 omega and T6 together (relative risk for IDDM = 6.4) is similar to that of DR3/DR4 (relative risk for IDDM = 5.4) with an even higher relative risk for IDDM when they are combined, (relative risk = 18 with 95 per cent confidence limits between 14 and 22). We have thus defined DQ beta RFLPs which tightly associate with IDDM individuals with DR4.

New HLA DNA polymorphisms associated with rheumatoid arthritis.

Studies of restriction enzyme fragment length polymorphisms (RFLP) have further clarified two DNA polymorphisms detected in DR4 positive individuals with a DQ beta probe. These patterns have been designated DQ beta omega, characterized in the Dw4 homozygous typing cell (HTC) BM14 and DQ beta phi, characterized in the Dw4 HTC MCF, and so do not correspond with different Dw types. These patterns clearly segregate in families with HLA haplotypes. We suggest that omega and phi may be polymorphisms of the DX beta gene. The previously reported DX alpha polymorphisms U and L were found with all DR types and in association with DQ beta omega (U) and DQ beta phi(L). In addition DQ beta phi was found to be strongly associated with TA10 positively (a subdivision of DQw3) although this association was not absolute. Associations between RFLP and other HLA Class II and I antigens seen in DR4 patients and DR4 controls suggest the existence of at least two preferential allelic associations (PAA), one containing omega/U and the other phi/L. PAA1: DX alpha U-DQ beta omega-TA10 negative-DQw3-Dw4-DR4----Bw62-Bw6-Cw3-A2 PAA2: DX alpha L-DQ beta phi-TA10 positive-DQw3-Dw4-DR4----B44-Bw4-Cw3-A2 The frequency of the omega pattern was higher, although not significantly in the RA patients compared with controls. However, a significantly higher frequency of omega was found in RA patients with extra-articular manifestations (EA) compared (a) with controls (p less than 0.04) and (h) with those patients without EA (p less than 0.05). In addition the frequency of phi was significantly higher in RA patients with nodules and/or erosions (N/ER) compared with patients without these features (p less than 0.008). When cumulative scores were assigned to patients after assessing the number of components fulfilled for each PAA, PAA1 appeared to be pronounced in patients with EA and PAA2 in patients with N/ER. The frequency of a previously reported DQ beta T6 band found with the enzyme Taq 1 and DQ-beta probe was found at a higher frequency in RA patients compared with controls. In addition a significantly higher frequency of this band was found in female RA patients compared to males.

Association of DR4 related RFLP bands and RA in Greeks.

Using the Taq1 restriction enzyme and DR beta, DQ alpha probes, the DNAs of Greek RA patients and controls were characterised for RFLP's associated with DR4. Three DR beta bands, 14.8kb, 6.1kb and 5.4kb were observed at significantly higher frequency in the patients compared with controls. By using a DQ alpha probe, the 2.6kb band (associated with DR1, DRw10, DRBR and DRw14 (Dw9)) was at a significantly raised frequency in the patients. The DQ alpha 5.3kb band associated with DR4, DR7 and DR9 was also raised in the RA patients although this increase did not reach statistical significance. In view of the previously documented lack of association between DR4 (and other DR antigens) and RA in Greeks, the results suggest that some degree of HLA class II association exists with RA in this population at the DNA level which may not be overtly reflected serologically.

HLA associations with multiple sclerosis in Sicily and Malta.

The islands of Sicily and Malta have very different prevalence rates for multiple sclerosis (MS): at least 44 per 100,000 in Sicily and only 4 per 100,000 in Malta. In Northern Europe, MS is associated with HLA-DR2/Dw2. The other components of the commonest DR2-containing haplotype of this region, HLA-A3-B7-DR2-Dw2, also tend to be present at higher frequency in MS patients. HLA Class I and II antigen frequencies and associations in controls and MS patients from Sicily and Malta were studied to discover whether they might account for the difference in MS prevalence. In Sicilian MS patients, DR2 is increased in frequency compared with controls and four out of five DR2-positive patients also type as Dw2. In the Maltese population, DR2 is present at high frequency but approximately half of the DR2 positive individuals do not type as Dw2 so that DR2 is probably most commonly present as part of Class II haplotypes other than those commonly associated with MS. Additional differences in HLA profile of the Sicilian and Maltese populations were found when HLA-A, -B, and B-DR antigen associations were examined. Therefore, some of the difference in MS prevalence might be explained by genetic factors.

HLA and celiac disease in Argentina: involvement of the DQ subregion.

A population of 62 unrelated homogeneous Argentinian celiac pediatric patients were typed for HLA-A,B,C,DR, and DQ antigens. The association between celiac disease and the DR3 and DR7 antigens was confirmed. The specificity DQw2 was present in 95.2 per cent of the patients. Nevertheless, it was of interest that the most significant phenotypes observed were DR3/DR7, DR7/DR5, and DR3/DR5. The significance of these findings is discussed.