Malignant Peripheral Nerve Sheath Tumour of Uterine Cervix-a Case Report and Review of Literature

Malignant peripheral nerve sheath tumour (MPNST) is a rare variety of sarcoma occurring in the uterine cervix. Only 16 cases have been reported in literature till date. There is no clear consensus on the treatment due to the rarity of the disease. This is primarily managed by surgery. Here, we present a case of MPNST of the cervix who was treated with preoperative radiotherapy followed by radical hysterectomy and bilateral salpingo-oophorectomy.

The psoriasis-protective TYK2 I684S variant impairs IL-12 stimulated pSTAT4 response in skin-homing CD4+ and CD8+ memory T-cells

Tyrosine kinase 2 (TYK2) belongs to the Janus kinase (JAK) family of tyrosine kinases, which transmit signals from activated cytokine receptors. GWAS have consistently implicated TYK2 in psoriasis susceptibility. We performed an in-depth association analysis of TYK2 using GWAS and resequencing data. Strong genetic association of three nonsynonymous variants in the exonic regions of the TYK2 gene (rs34536443, rs12720356, and rs2304256) were found. rs12720356 encoding I684S is predicted to be deleterious based on its location in the pseudokinase domain. We analyzed PBMCs from 29 individuals representing the haplotypes containing each of the significantly associated signals. STAT4 phosphorylation was evaluated by phospho-flow cytometry after CD3/CD28 activation of cells followed by IL-12 stimulation. Individuals carrying the protective I684S variant manifested significantly reduced p-STAT4 levels in CD4 + CD25 + CD45RO+ (mean Stimulation Index (S.I.) 48.08, n = 10) and CD8 + CD25 + CD45RO + cells (S.I. 55.71, n = 10), compared to controls homozygous for the ancestral haplotype (S.I. 68.19, n = 10 (p = 0.002) and 76.76 n = 10 (p = 0.0008) respectively). Reduced p-STAT4 levels were also observed in skin-homing, cutaneous lymphocyte associated antigen (CLA)-positive CD4 and CD8 cells from I684S carriers. No significant changes in p-STAT4 for the psoriasis-associated variant rs34536443 was found. These data establish the functional significance of the TYK2 I684S variant in psoriasis susceptibility.

Extra Mammary Paget's Disease of Vulva-a Case Report

Extra mammary Paget's disease (EMPD) is a rare condition involving the vulva, anogenital region, and axilla. Vulvar disease usually presents as a slow growing well-defined itchy plaque with crustations or ulcerations over the affected area in postmenopausal women. Well-established guidelines for diagnosis and management are not available for this rare condition. Our patient is a 64-year-old postmenopausal woman with a history of similar complaints of 2 years duration, not responding to multiple topical treatments. She was diagnosed with EMPD on incisional biopsy and treated with surgery at our centre.

Role of frozen section in intraoperative assessment of ovarian masses: a tertiary oncology center experience

Surgical management of ovarian lesions vary considerably depending on the nature of the lesion. As the preoperative imaging and serum tumor marker levels are of limited value in the proper categorization of ovarian lesions, intraoperative pathological assessment is commonly requested for a primary diagnosis. Aim of the study is to assess the accuracy of the frozen section in the diagnosis of ovarian masses in our center and to analyze the causes of diagnostic discrepancies. In this retrospective study, frozen section diagnosis of 233 cases of ovarian masses was compared with the permanent section diagnosis. The overall accuracy of frozen section was 91.85 %. The sensitivity of frozen section diagnosis for benign, borderline and malignant tumors was 99.2, 88.46 and 82.95 % respectively. The corresponding specificity was 96.5, 93.23 and 99.3 %. There were 19 discordant cases including 18 false negative cases and one false positive case. Frozen section is an important diagnostic tool to determine the nature of ovarian masses. Careful macroscopic examination, evaluation of multiple sections along with clinical and radiological findings helps to reduce false positive and false negative results. Frozen section examination has limitations especially in cases of borderline tumors. This modality is most effective when the pathologist and surgeon are aware of the advantages and limitations.

Genetic associations of psoriasis in a Pakistani population

BACKGROUND

Genetic predisposition to psoriasis, an inflammatory skin disease affecting 0·2-4% of the world population, is well established. Thus far, 41 psoriasis susceptibility loci reach genome-wide significance (P ≤ 5 × 10(-8) ). Identification of genetic susceptibility loci in diverse populations will help understand the underlying biology of psoriasis susceptibility.

OBJECTIVES

The primary objective of this study was to examine psoriasis susceptibility associations previously reported in Chinese and caucasian populations in a Pakistani cohort.

METHODS

Blood samples and phenotype data were collected from psoriasis cases and controls in Islamabad, Pakistan. DNA was isolated and genotypes of selected susceptibility markers were determined. The data were analysed using χ(2) tests or logistic regression for psoriasis association.

RESULTS

HLA-Cw6 showed the strongest association [odds ratio (OR) 2·43, P = 2·3 × 10(-12) ]. HLA-Cw1 showed marginally significant association (OR 1·66, P = 0·049), suggesting that the HLA-Cw1-B46 risk haplotype may be present in the Pakistani population. Three other loci (IL4/IL13, NOS2, TRAF3IP2) showed nominally significant association (P < 0·05).

CONCLUSIONS

HLA-Cw6 is strongly associated with psoriasis susceptibility in the Pakistani population, as has been found in every other population studied. In addition, HLA-Cw1 showed marginal association, reflecting the relative geographical proximity and thus likely genetic relatedness to other populations in which the HLA-Cw1-B46 haplotype is known to be associated. A larger cohort and a denser marker set will be required for further analysis of psoriasis associations in the South Asian population.

Comparison of MHC class I risk haplotypes in Thai and Caucasian psoriatics shows locus heterogeneity at PSORS1

Earlier studies have shown that psoriasis in Japan and Thailand is associated with two different major histocompatibility complex (MHC) haplotypes - those bearing HLA-Cw6 and those bearing HLA-Cw1 and HLA-B46. In an independent case-control sample from Thailand, we confirmed the association of psoriasis with both haplotypes. No association was seen in Thai HLA-Cw1 haplotypes lacking HLA-B46, nor was HLA-Cw1 associated with psoriasis in a large Caucasian sample. To assess whether these risk haplotypes share a common origin, we sequenced genomic DNA from a Thai HLA-Cw1-B46 homozygote across the ∼300 kb MHC risk interval, and compared it with sequence of a HLA-Cw6-B57 risk haplotype. Three small regions of homology were found, but these regions share equivalent sequence similarity with one or more clearly non-risk haplotypes, and they contain no polymorphism alleles unique to all risk haplotypes. Differences in psoriasis phenotype were also observed, including lower risk of disease, greater nail involvement, and later age at onset in HLA-Cw1-B46 carriers compared with HLA-Cw6 carriers. These findings suggest locus heterogeneity at PSORS1 (psoriasis susceptibility 1), the major psoriasis susceptibility locus in the MHC, with HLA-Cw6 imparting risk in both Caucasians and Asians, and an allele other than HLA-Cw1 on the HLA-Cw1-B46 haplotype acting as an additional risk variant in East Asians.

Scar recurrence of uterine sarcoma: a case report

BACKGROUND

Uterine leiomyosarcoma is an aggressive tumor that has a propensity for recurrence. Most of the recurrences occur at either pelvic or distant sites, such as lung or liver. Recurrences in the laparotomy scar are extremely rare.

CASE

A 52-year-old woman underwent hysterectomy for stage I, grade 2 uterine leiomyosarcoma. She did not receive any adjuvant treatment. She presented 2 years later with wound recurrence. She had no evidence of intraabdominal disease. She underwent radical resection with mesh repair. Pathology revealed high grade spindle cell sarcoma very similar to the previous cancer. After completion of 18 months of follow-up, she was disease free.

CONCLUSION

Radical resection of isolated metastases may be of benefit for these patients.

Analysis of RUNX1 binding site and RAPTOR polymorphisms in psoriasis: no evidence for association despite adequate power and evidence for linkage

BACKGROUND

A previous study identified two peaks of allelic association between psoriasis and single nucleotide polymorphisms (SNPs) mapping to distal chromosome 17q, including a disease associated SNP that leads to loss of a RUNX1 transcription factor binding site, and additional SNPs in the third intron of the RAPTOR gene. Another study found an association with SNPs in the RAPTOR gene, but not with the RUNX1 binding site polymorphism.

METHODS

In an effort to confirm these observations, we genotyped 579 pedigrees containing 1285 affected individuals for three SNPs immediately flanking and including the RUNX1 binding site, and for three SNPs in the RAPTOR gene.

RESULTS

Here we report further evidence for linkage to distal chromosome 17q, with a linkage peak mapping 1.7 cM distal to the RUNX1 binding site (logarithm of the odds 2.26 to 2.73, depending upon statistic used). However, we found no evidence for association to individual SNPs or haplotypes in either of the previously identified peaks of association. Power analysis demonstrated 80% power to detect significant association at genotype relative risks of 1.2 (additive and multiplicative models) to 1.5 (dominant and recessive models) for the RUNX1 binding site, and 1.3 to 1.4 for the RAPTOR locus under all models except dominant.

CONCLUSIONS

Our data provide no support for the previously identified RUNX1 binding site or for the RAPTOR locus as genetic determinants of psoriasis, despite evidence for linkage of psoriasis to distal chromosome 17q.

The genetics of psoriasis 2001: the odyssey continues

Accumulating evidence indicates that psoriasis is a multifactorial disorder caused by the concerted action of multiple disease genes in a single individual, triggered by environmental factors. Some of these genes control the severity of multiple diseases by regulating inflammation and immunity (severity genes), whereas others are unique to psoriasis. Various combinations of these genes can occur even within a single family, accounting in large measure for the many clinical manifestations of psoriasis. The disease-causing variants (alleles) of these genes probably arose early in the history of modern humans. As a result, psoriasis disease alleles are common in the general population, have a worldwide distribution, and often share the same ancestral chromosome with neutral alleles at adjacent loci. This phenomenon, called linkage disequilibrium, explains why psoriasis is strongly associated with HLA-Cw6 worldwide, although HLA-Cw6 is unlikely to be the disease allele. Many unaffected individuals carry 1 or more disease alleles, but lack other genetic and/or environmental factors necessary to produce disease. This explains why psoriasis develops in only about 10% of HLA-Cw6-positive individuals, and why genome-wide linkage scans for psoriasis and other multifactorial genetic disorders have not been uniformly successful. The Human Genome Project is rapidly generating a catalog of human DNA sequence variations. This resource has already allowed precise linkage disequilibrium mapping of the major histocompatibility complex psoriasis gene to just beyond HLA-C, toward HLA-A. This gene is likely to be identified soon. Further development and use of linkage disequilibrium resources will provide a powerful tool for the identification of the remaining psoriasis genes.

S100A2 coding sequence polymorphism: characterization and lack of association with psoriasis

Psoriasis is a chronic inflammatory skin disease with a strong genetic component. Linkage studies have identified several susceptibility loci for psoriasis including a region on chromosome 1q21 termed the 'epidermal differentiation complex'. At least 20 genes involved in epidermal differentiation and proliferation have been mapped to this region including S100A2, a gene known to be over-expressed in psoriasis lesions. In the course of cloning and sequencing several S100A2 cDNAs, we identified an A/G (Asn62Ser) polymorphism at nucleotide 185 of the S100A2 coding region. To determine whether this polymorphism is associated with psoriasis, we tested DNA from 38 unrelated normal and 40 unrelated psoriatic individuals. The 185G allele was present in 148 of the 156 chromosomes analysed, giving an allele frequency of 94.9%. All of the remaining chromosomes carried 185A. There was no significant difference in the allele distribution between normal and psoriatic individuals (normals 72G, 4A; psoriatics 76G, 4A; P = 1.00 by Fisher's exact test). Our data explain conflicting results in the literature regarding the sequence of S100A2 but provide no support for a direct causal role for S100A2 in psoriasis.

Localization of psoriasis-susceptibility locus PSORS1 to a 60-kb interval telomeric to HLA-C

Recent genome scans have established the presence of a major psoriasis-susceptibility locus in the human leukocyte antigen (HLA) complex on chromosome 6p21.3. To narrow the interval for candidate gene testing, we performed a linkage-disequilibrium analysis of 339 families, with the use of 62 physically mapped microsatellite markers spanning the major histocompatibility complex (MHC). As detected by use of the transmission/disequilibrium test (TDT), individual markers yielded significant linkage disequilibrium across most of the MHC. However, the strongest evidence for marker-trait disequilibrium was found in an approximately 300-kb region extending from the MICA gene to the corneodesmosin gene. Maximum-likelihood haplotypes were constructed across the entire MHC in the original sample and across a 1.2-Mb region of the central MHC in an expanded sample containing 139 additional families. Short (two- to five-marker) haplotypes were subjected to the TDT using a "moving-window" strategy that reduced the variability of TDT P values relative to the single-locus results. Furthermore, the expanded sample yielded a sharp peak of evidence for linkage disequilibrium that spanned approximately 170 kb and that was centered 100 kb telomeric to HLA-C. The 1.2-Mb interval was further dissected by means of recombinant ancestral haplotype analysis. This analysis identified risk haplotype 1 (RH1), which is a 60-kb fragment of ancestral haplotype 57.1, on all identifiable HLA risk haplotypes. One of these haplotypes exhibits significant linkage disequilibrium with psoriasis but does not carry Cw6, which is the HLA allele most strongly associated with the disease. These results demonstrate that RH1 is highly likely to carry the disease allele at PSORS1, and they exclude HLA-C and corneodesmosin with a high degree of confidence.

Corneodesmosin gene polymorphism demonstrates strong linkage disequilibrium with HLA and association with psoriasis vulgaris

Corneodesmosin (CD) is thought to play a key role in corneocyte cohesion, and its proteolysis appears to be a major event in the process of desquamation. Recently it was shown that CD is encoded by the S-gene, which is located approximately 160 kb telomeric of HLA-C. In the present study, the role of CD in the genetics of psoriasis vulgaris was studied in greater detail. The second exon of the CD gene was sequenced in 86 HLA-typed individuals from 13 psoriasis multiplex families. A total of 11 silent dimorphisms and 7 variants resulting in amino acid substitutions were found. Pedigree analysis showed that these variants could be grouped into 7 alleles, encoding 6 different amino acid sequences. These alleles are in strong linkage disequilibrium with HLA-B and -C, indicating that the polymorphism of the CD gene is ancient and well conserved rather than sporadic. One allele at the CD locus, designated CD2, displayed strong linkage disequilibrium with HLA-Cw6, the HLA allele most prominently associated with psoriasis. CD2 demonstrated a greater relative risk than Cw6 (3.4 vs. 2.5, not significant) and higher significant transmission disequilibrium with psoriasis than any of the investigated HLA-alleles. Due to its biologic function, cellular location and disease association, the CD gene appears to be an excellent candidate gene for PSORS1, the HLA-linked determinant of psoriasis vulgaris.

Linkage disequilibrium analysis of familial psoriasis: identification of multiple disease-associated MHC haplotypes

Although psoriasis vulgaris (PsV) is strongly associated with certain human leukocyte antigens, the pathogenetic nature of these associations remains elusive. The objectives of this study were: (i) to determine whether HLA loci directly determine susceptibility or merely serve as markers for the susceptibility allele; and (ii) to identify additional disease-associated haplotypes. By applying maximum likelihood linkage disequilibrium analysis (LDA) in cases vs. controls, we found the susceptibility gene to be more strongly associated with specific HLA haplotypes than with their component alleles. Stronger linkage disequilibrium between PsV and HLA alleles was detected at HLA-C and HLA-B than at DRB1 and DQB1. Parametric linkage analysis accounting for marker-trait disequilibrium in psoriasis vulgaris pedigrees yielded most significant results for a locus close to HLA-B and -C. Furthermore, we found that susceptibility is linked to at least three different ancestral HLA haplotypes; among them, HLA-Cw7-B8-DRB1*0301-DQB1*02 is linked to PsV for the first time. These results identify a major PsV susceptibility locus in the immediate vicinity of, but distinct from HLA-B or HLA-C, and suggest that multiple disease alleles have arisen during human evolution.

Linkage analysis of human leukocyte antigen (HLA) markers in familial psoriasis: strong disequilibrium effects provide evidence for a major determinant in the HLA-B/-C region

Although psoriasis is strongly associated with certain human leukocyte antigens (HLAs), evidence for linkage to HLA markers has been limited. The objectives of this study were (1) to provide more definitive evidence for linkage of psoriasis to HLA markers in multiplex families; (2) to compare the major HLA risk alleles in these families with those determined by previous case-control studies; and (3) to localize the gene more precisely. By applying the transmission/disequilibrium test (TDT) and parametric linkage analysis, we found evidence for linkage of psoriasis to HLA-C, -B, -DR, and -DQ, with HLA-B and -C yielding the most-significant results. Linkage was detectable by parametric methods only when marker-trait disequilibrium was considered. Case-control association tests and the TDT identified alleles belonging to the EH57.1 ancestral haplotype as the major risk alleles in our sample. Among individuals carrying recombinant ancestral haplotypes involving EH57. 1, the class I markers were retained selectively among affecteds four times more often than among unaffecteds; among the few affected individuals carrying only the class II alleles from the ancestral haplotype, all but one also carried Cw6. These data show that familial and "sporadic" psoriasis share the same risk alleles. They also illustrate that substantial parametric linkage information can be extracted by accounting for linkage disequilibrium. Finally, they strongly suggest that a major susceptibility gene resides near HLA-C.

Prenatal exclusion of lamellar ichthyosis based on identification of two new mutations in the transglutaminase 1 gene

Lamellar ichthyosis is a severe, generalized, autosomal recessive genodermatosis characterized clinically by large, parchment-like scales and histologically by acanthosis and marked hyperkeratosis. Genetic heterogeneity in lamellar ichthyosis has been recognized with reports of two linked loci (on chromosomes 14q11 and 2q33-35). In a cohort of four small families with lamellar ichthyosis we found confirmatory evidence for linkage (p < or = 0.01) to D14S275, a microsatellite marker close to transglutaminase 1 on chromosome 14q11. We also identified two novel transglutaminase 1 mutations in an affected sibling pair from one of these families. The paternal mutation in exon 3, 1387insCAGC, causes a frameshift predicted to result in premature termination of translation within the same exon. The maternal mutation in exon 8, 4561delAC, also causes a frameshift and a premature stop codon in this exon. The mother of these siblings recently became pregnant with twins. Genotyping and direct sequencing of DNA isolated from fetal amniotic fluid cultures revealed the presence of the paternal but the absence of the maternal mutation, thus predicting a normal skin phenotype. Both twins were born with normal-appearing skin. Our findings demonstrate that mutations of both alleles of the transglutaminase 1 gene are the cause of lamellar ichthyosis in this family, and illustrate an emerging clinical application of molecular genetics in dermatology.

Evidence for two psoriasis susceptibility loci (HLA and 17q) and two novel candidate regions (16q and 20p) by genome-wide scan

In a 12.5 cM genome-wide scan for psoriasis susceptibility loci, recombination-based tests revealed linkage to the HLA region (Zmax = 3.52), as well as suggestive linkage to two novel regions: chromosome 16q (60-83.1 cM from pter, Zmax = 2.50), and chromosome 20p (7.5-25 cM from pter, Zmax = 2.62). All three regions yielded P values < or = 0.01 by non-parametric analysis. Recombination-based and allele sharing methods also confirmed a previous report of a dominant susceptibility locus on distal chromosome 17q (108.2 cM from pter, Zmax = 2.09, GENEHUNTER P = 0.0056). We could not confirm a previously reported locus on distal chromosome 4q; however, a broad region of unclear significance was identified proximal to this proposed locus (153.6-178.4 cM from pter, Zmax = 1.01). Taken together with our recent results demonstrating linkage to HLA-B and -C, this genome-wide scan identifies a psoriasis susceptibility locus at HLA, confirms linkage to 17q, and recommends two novel genomic regions for further scrutiny. One of these regions (16q) overlaps with a recently-identified susceptibility locus for Crohn's disease. Psoriasis is much more common in patients with Crohn's disease than in controls, suggesting that an immunomodulatory locus capable of influencing both diseases may reside in this region.

Scanning chromosome 17 for psoriasis susceptibility: lack of evidence for a distal 17q locus

Evidence for a genetically heterogeneous psoriasis susceptibility locus on distal human chromosome 17q has recently been reported [Science 1994;264:1141]. Making use of an independently ascertained collection of 24 multiplex psoriasis kindreds, we have performed a genotyping scan of chromosome 17 using 12 microsatellite markers and analyzed the data using parametric (lod score) as well as novel nonparametric methods. Pairwise lod scores revealed no evidence for linkage to the previously implicated marker D17S784 under any of eight models varying in mode of inheritance, penetrance, and sporadic cases. Homogeneous linkage to D17S784 could be excluded under all four autosomal dominant models tested (Z < - 5.8 at theta = 0.05), and there was no evidence for genetic heterogeneity. All other chromosome 17 markers tested also failed to detect evidence for linkage in any of the kindreds under either a dominant or a recessive model. Although further analysis using affected sib pair methods provided no statistically significant evidence for linkage to any chromosome 17 marker, a cluster of three distal 17q loci displayed a trend towards greater than expected allele-sharing values (observed/expected = 1.10-1.14). These results do not formally confirm the existence of a psoriasis susceptibility locus on the distal long arm of human chromosome 17, but are suggestive of its possible involvement under a polygenic model, warranting its further investigation in familial psoriasis.

Of genes and antigens: the inheritance of psoriasis

Psoriasis is one of a number of autoimmune diseases that display significant HLA associations. In particular, individuals with onset of disease prior to 40 years of age display striking associations with HLA-Cw6 and are much more likely to have a positive family for psoriasis. However, only about 10% of Cw6-positive individuals develop disease, suggesting that other genetic and/or environmental factors must be involved. Several compelling lines of epidemiologic evidence indicate that psoriasis susceptibility is inherited, albeit not in a simple monogenic fashion, and that genetic, rather than environmental, factors are primarily responsible for the variability in inheritance of psoriasis. Taken together, these observations suggest that one or more loci in addition to HLA are necessary for the development of psoriasis. The number of additional loci is likely to be small, because i) the disease is very common ii) substantial excess risk of psoriasis is observed in first degree relatives, and iii) nevoid variants of psoriasis have been reported, suggestive of somatic mutation of a single gene during development. The substantial homogeneity of the psoriatic phenotype and the clear evidence for increased HLA association and heritability in juvenile onset disease indicate that despite its complexity, psoriasis is a common disease whose etiology is amendable to elucidation through the techniques of modern molecular genetics.

Epidemiology and the genetics of psoriasis

Several lines of compelling epidemiologic evidence indicate that susceptibility to psorasis is inherited, albeit not in a simple monogenic fashion. Psoriasis is one of a number of diseases with a presumed autoimmune pathogenesis that display significant human leukocyte antigen (HLA) associations. However, only a small fraction of those who carry the implicated HLA susceptibility alleles develop disease. Taken together with the epidemiologic data indicative of high heritability, this observations suggests that one or more loci in addition to HLA are necessary for the development of psoriasis. As the identity of these other genes is unknown, genetic linkage analysis offers an attractive strategy for their identification. To this end, we have initiated a large linkage study of multiplex psoriasis kindreds, and PCR-based genotyping of CA repeat polymorphisms has been performed for several markers in the HLA region (6p21.3). As expected given the hypothesis of oligogenic inheritance, these analyses have thus far failed to reveal tight linkage of psoriasis to the 6p21 region. Nevertheless, the substantial homogeneity of the psoriatric phenotype and the clear evidence for increased HLA association and heritability in juvenile onset disease (40 years) indicate that, like insulin-dependent diabetes mellitus, psoriasis is an HLA-associated, genetically complex disease whose etiology is potentially amenable to elucidation through linkage analysis.

The genetics of psoriasis

BACKGROUND AND DESIGN

Psoriasis is a member of a class of common, HLA-associated conditions in which disease susceptibility appears to be heritable. However, the mode of inheritance of these diseases has been difficult to define in simple mendelian terms. Psoriasis displays one of the strongest HLA associations of this class of diseases. However, only a small fraction of those who carry the implicated HLA susceptibility alleles develop disease, and it has proven difficult to demonstrate that the HLA associations observed are due to formal genetic linkage between the disease and the HLA locus. Although the role of environmental factors in psoriasis and these other diseases cannot be denied, the participation of additional genes, not necessarily linked to HLA, has long been suspected.

OBSERVATIONS

Epidemiologic and immunogenetic data are reviewed and analyzed, which demonstrate that a predisposition to psoriasis is heritable, and which implicate genes of the HLA locus as necessary but not sufficient determinants of psoriasis. Recent developments in human genome research are described, which make possible a systematic search for additional genetic determinants of psoriasis, including those unlinked to HLA.

CONCLUSIONS

As one of the most common, most heritable, and most highly HLA-associated examples of this class of HLA-associated diseases, psoriasis represents an ideal target for the application of this emerging genomic technology.

Cyclosporin A rapidly inhibits epidermal cytokine expression in psoriasis lesions, but not in cytokine-stimulated cultured keratinocytes

To better understand the cellular target(s) of cyclosporin action in psoriasis, we have studied the effects of systemic short-term (7 d), low-dose (3-7.5 mg/kg) cyclosporin A administration on the expression of the cytokines interleukin (IL)-8 and IL-1 beta in psoriatic lesions. RNA blot hybridization analysis of pretreatment keratome biopsies revealed that expression of both cytokine mRNAs was highly variable from patient to patient. Significant covariation of both cytokine mRNA levels was noted (r = 0.86, p < 0.0001). However, there was no significant correlation between expression of either cytokine and clinical severity, as measured by the pretreatment Psoriasis Area and Severity Index (PASI). IL-1 beta protein levels measured by enzyme-linked immunosorbent assay (ELISA) were highly correlated with IL-1 beta mRNA levels, indicating that the differences in transcript levels accurately reflect differences in epidermal cytokine protein. Significant reductions in both cytokine transcripts and in IL-1 beta immunoreactive protein were noted in the high expression subgroup after 1 week of cyclosporin A therapy, prior to detectable clinical improvement. In contrast to its pronounced effects on epidermal cytokine expression in vivo and the allogeneic mixed lymphocyte reaction in vitro, cyclosporine A did not inhibit the induction of intercellular adhesion molecule (ICAM)-1 or IL-8 mRNAs by cultured keratinocytes in response to IL-1 beta or the combination of tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma. These data suggest that epidermal keratinocytes respond to signals produced by activated T cells by coordinate expression of multiple cytokines, and that cyclosporin A acts primarily through blockade of T cells, rather than through keratinocyte activation.

Isolation of a novel human alpha (1,3)fucosyltransferase gene and molecular comparison to the human Lewis blood group alpha (1,3/1,4)fucosyltransferase gene. Syntenic, homologous, nonallelic genes encoding enzymes with distinct acceptor substrate specificities

Biochemical and genetic evidence indicates that the human genome may encode four or more distinct GDP-fucose:beta-D-N-acetylglucosaminide 3-alpha-L-fucosyltransferase (alpha(1,3)fucosyltransferase) activities. Genes encoding two of these activities have been previously isolated. These correspond to an alpha(1,3/1,4)fucosyltransferase thought to represent the human Lewis blood group locus and an alpha(1,3)fucosyltransferase expressed in the myeloid lineage. We report here the molecular cloning and expression of a third human alpha(1,3)fucosyltransferase gene, homologous to but distinct from the two previously reported human fucosyltransferase genes. When expressed in transfected mammalian cells, this gene determines expression of a fucosyltransferase capable of using N-acetyllactosamine to form the Lewis x epitope, and alpha(2,3)sialyl-N-acetyllactosamine to construct the sialyl Lewis x moiety. This enzyme shares 91% amino acid sequence identity with the human Lewis blood group alpha(1,3/1,4)fucosyltransferase, yet exhibits only trace amounts of alpha(1,4)fucosyltransferase activity. Polymerase chain reaction analyses were used to demonstrate that the gene is syntenic to the Lewis locus on chromosome 19. These analyses also excluded the possibility that this DNA segment represents an allele of the Lewis locus that encodes alpha(1,3)fucosyltransferase but not alpha(1,4)fucosyltransferase activity. These results are consistent with the hypothesis that this gene encodes the human "plasma type" alpha(1,3)fucosyltransferase, and suggest a molecular basis for a family of human alpha(1,3)fucosyltransferase genes.

Molecular cloning of a human fucosyltransferase gene that determines expression of the Lewis x and VIM-2 epitopes but not ELAM-1-dependent cell adhesion

We have used the human Lewis blood group fucosyltransferase cDNA and cross-hybridization procedures to isolate a human gene that encodes a distinct fucosyltransferase. Its DNA sequence predicts a type II transmembrane protein whose sequence is identical to 133 of 231 amino acids at corresponding positions within the catalytic domain of the Lewis fucosyltransferase. When expressed by transfection in cultured cell lines, this gene determines expression of a fucosyltransferase capable of efficiently utilizing N-acetyllactosamine to form the Lewis x determinant (Gal beta 1----4[Fuc alpha 1----3]GlcNAc). By contrast, biochemical and flow cytometry analyses suggest that the enzyme cannot efficiently utilize the type II acceptor NeuNAc alpha 2----3Gal beta 1----4GlcNAc, to form the sialyl Lewis x determinant. In Chinese hamster ovary cells, however, the enzyme can determine expression of the alpha 2----3-sialylated, alpha 1----3-fucosylated structure known as VIM-2, a putative oligosaccharide ligand for ELAM-1. Cell adhesion assays using VIM-2-positive, sialyl Lewis x-negative transfected Chinese hamster ovary cells indicate that surface expression of the VIM-2 determinant is not sufficient to confer ELAM-1-dependent adhesive properties upon the cells. These results demonstrate that substantial structural similarities can exist between mammalian glycosyltransferases with closely related enzymatic properties, thus facilitating isolation of their cognate genes by cross-hybridization methods. The results further suggest that cell surface expression of the VIM-2 determinant is not necessarily sufficient to mediate ELAM-1-dependent cell adhesion.

ELAM-1--dependent cell adhesion to vascular endothelium determined by a transfected human fucosyltransferase cDNA

Adhesion of circulating leukocytes to the vascular endothelium during inflammation is mediated in part by their interaction with the endothelial-leukocyte adhesion molecule ELAM-1. ELAM-1, a member of the LEC-CAM family of cell adhesion molecules, expresses an N-terminal carbohydrate recognition domain (CRD) homologous to various calcium-dependent mammalian lectins. However, the contribution of the CRD to cell adhesion and its carbohydrate binding specificity have not been elucidated. This study demonstrates that transfection of a human fucosyltransferase cDNA into nonmyeloid cell lines confers ELAM-1--dependent endothelial adhesion. Binding activity correlates with de novo cell surface expression of the sialylated Lewis x tetrasaccharide, whose biosynthesis is determined by the transfected fucosyltransferase cDNA. We propose that specific alpha(1,3)fucosyltransferases regulate cell adhesion to ELAM-1 by modulating cell surface expression of one or more alpha(2,3)sialylated, alpha(1,3)fucosylated lactosaminoglycans represented by the sialyl Lewis x carbohydrate determinant.

Molecular cloning, sequence, and expression of a human GDP-L-fucose:beta-D-galactoside 2-alpha-L-fucosyltransferase cDNA that can form the H blood group antigen

We have previously used a gene-transfer scheme to isolate a human genomic DNA fragment that determines expression of a GDP-L-fucose:beta-D-galactoside 2-alpha-L-fucosyltransferase [alpha(1,2)FT; EC 2.4.1.69]. Although this fragment determined expression of an alpha(1,2)FT whose kinetic properties mirror those of the human H blood group alpha(1,2)FT, their precise nature remained undefined. We describe here the molecular cloning, sequence, and expression of a human cDNA corresponding to these human genomic sequences. When expressed in COS-1 cells, this cDNA directs expression of cell surface H structures and a cognate alpha(1,2)FT activity with properties analogous to the human H blood group alpha(1,2)FT. The cDNA sequence predicts a 365-amino acid polypeptide characteristic of a type II transmembrane glycoprotein with a domain structure analogous to that of other glycosyltransferases but without significant primary sequence similarity to these or other known proteins. To directly demonstrate that the cDNA encodes an alpha(1,2)FT, the COOH-terminal domain predicted to be Golgi-resident was expressed in COS-1 cells as a catalytically active, secreted, and soluble protein A fusion peptide. Southern blot analysis showed that this cDNA identifies DNA sequences syntenic to the human H locus on chromosome 19. These results strongly suggest that this cloned alpha(1,2)FT cDNA represents the product of the human H blood group locus.

A typical patient simulation and dosimetry data sheet

A typical, comprehensive "Patient Simulation & Dosimetry Data" sheet has been developed. It contains all essential patient simulation, treatment and radiation dosimetry parameters and also relevant anatomical diagrams. The form can be used for any radiation therapy modality.

Dosimetric considerations of d(15) + Be and p(26) + Be neutron beams from an isocentric cyclotron facility

To select the optimum therapeutic neutron beam available from a CS30 medical cyclotron (manufactured by the Cyclotron Corporation, Berkeley, California), central axis depth dose data and output dose rates were compared for the bombardment of beryllium with either the proton or deuteron beams available from the machine. The effect on these parameters of filtering the beams with either pure polyethylene, polyethylene loaded with 5% boron, or polyethylene loaded with 10% lithium was studied. A 4-cm, 10% lithiated filter used with a 26-MeV proton beam was selected for therapeutic use. Buildup curves, beam profiles at several transverse planes for different field sizes, and comparison of beam profiles with 60Co are given.

Radiation dosimetry of 12 MV photons from a CGR Therac 20 MeV Saturne linear accelerator

Typically useful clinical radiation dosimetry characteristics of 12 MV photon beams from a CGR Therac 20 MeV Saturne linear accelerator are briefly outlined. Central axis percent depth dose data are compared with other published data. Beam profiles for small, medium and large fields are delineated to show the uniformity of beams at various depths.

Evaluation of fetal dose from megavoltage irradiation of the knee and neonate followup

A 24-yr-old female patient who was to undergo radiation therapy management for a recurrent low-grade fibrosarcoma on her right knee was found to be 9 weeks pregnant. The patient and her relatives insisted on carrying the pregnancy to maturity, despite undergoing irradiation of her right knee for local control of her disease and to take the teratological risk, if any, that it entails. This paper discusses the measurement of scattered dose in water, fetal dose estimation in an Alderson-Rando human phantom and possible ways of minimizing it.

Shaped field electron dosimetry for a Philips SL75/10 linear accelerator

Both small and irregular fields are frequently the treatment of choice in many clinical applications of electron therapy. The fields are often shaped by lead or low melting point alloy placed at the end of the cone or on the patient's surface. The dosimetry for electrons of energies of 4, 6, 8, and 10 MeV is examined with particular emphasis on very small fields for treatment such as the lip, nose, and eye and irregular fields of various area/perimeter ratios. The paper discusses the dosimetry correction due to field shaping as a function of the location of the shield.

Dosimetry disparities resulting from two accepted methods of calibration of cobalt-60 teletherapy machines

The primary concern of all involved in the management of radiotherapeutic patients is that the tumor dose delivered to each and every patient in one institution is identical to that delivered anywhere else. Despite the advocacy 1,2,3,4 for the calibration of high energy photon beams at 5 cm depth or beyond in a water phantom to reduce the effect of electron "contamination" from collimators, filters, applicators, etc., the "in-air" method of calibration is still in vogue in many institutions in the United States and elsewhere. The introduction of S.I. units in radiology is likely to create ambiguity in proper conversion factors from exposure to absorbed dose which can be avoided if field instruments are calibrated in terms of absorbed dose in water under specified conditions. The present study shows that the estimated error can be as much as 7% low when the "in-air" method of calibration is used instead of measurements in a large water phantom at 5 cm depth for cobalt-60 photon beams and hence recommends that the procedure for "in-air" calibration for high energy photon beam should be discontinued.