A distinctive epigenetic ageing profile in human granulosa cells

STUDY QUESTION

Does women’s age affect the DNA methylation (DNAm) profile differently in mural granulosa cells (MGCs) from other somatic cells?

SUMMARY ANSWER

Accumulation of epimutations by age and a higher number of age-related differentially methylated regions (DMR) in MGCs were found compared to leukocytes from the same woman, suggesting that the MGCs have a distinctive epigenetic profile.

WHAT IS KNOWN ALREADY

The mechanisms underlying the decline in women’s fertility from the mid-30s remain to be fully elucidated. The DNAm age of many healthy tissues changes predictably with and follows chronological age, but DNAm age in some reproductive tissues has been shown to depart from chronological age (older: endometrium; younger: cumulus cells, spermatozoa).

STUDY DESIGN, SIZE, DURATION

This study is a multicenter cohort study based on retrospective analysis of prospectively collected data and material derived from healthy women undergoing IVF or ICSI treatment following ovarian stimulation with antagonist protocol. One hundred and nineteen women were included from September 2016 to June 2018 from four clinics in Denmark and Sweden.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Blood samples were obtained from 118 healthy women with varying ovarian reserve status. MGCs were collected from 63 of the 119 women by isolation from pooled follicles immediately after oocyte retrieval. DNA from leukocytes and MGCs was extracted and analysed with a genome-wide methylation array. Data from the methylation array were processed using the ENmix package. Subsequently, DNAm age was calculated using established and tailored age predictors and DMRs were analysed with the DMRcate package.

MAIN RESULTS AND ROLE OF CHANCE

Using established age predictors, DNAm age in MGCs was found to be considerable younger and constant (average: 2.7 years) compared to chronological age (average: 33.9 years). A Granulosa Cell clock able to predict the age of both MGCs (average: 32.4 years) and leukocytes (average: 38.8 years) was successfully developed. MGCs differed from leukocytes in having a higher number of epimutations (P = 0.003) but predicted telomere lengths unaffected by age (Pearson’s correlation coefficient = −0.1, P = 0.47). DMRs associated with age (age-DMRs) were identified in MGCs (n = 335) and in leukocytes (n = 1) with a significant enrichment in MGCs for genes involved in RNA processing (45 genes, P = 3.96 × 10−08) and gene expression (152 genes, P = 2.3 × 10−06). The top age-DMRs included the metastable epiallele VTRNA2-1, the DNAm regulator ZFP57 and the anti-Müllerian hormone (AMH) gene. The apparent discordance between different epigenetic measures of age in MGCs suggests that they reflect difference stages in the MGC life cycle.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

No gene expression data were available to associate with the epigenetic findings. The MGCs are collected during ovarian stimulation, which may influence DNAm; however, no correlation between FSH dose and number of epimutations was found.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings underline that the somatic compartment of the follicle follows a different methylation trajectory with age than other somatic cells. The higher number of epimutations and age-DMRs in MGCs suggest that their function is affected by age.

STUDY FUNDING/COMPETING INTEREST(S)

This project is part of ReproUnion collaborative study, co-financed by the European Union, Interreg V ÖKS, the Danish National Research Foundation and the European Research Council. The authors declare no conflict of interest.

Tissue-specific localization of polyketide synthase and other associated genes in the lichen, Cladonia rangiferina, using laser microdissection

The biosynthesis of two polyketides, atranorin and fumarprotocetraric acid, produced from a lichen-forming fungus, Cladonia rangiferina (L.) F. H. Wigg. was correlated with the expression of eight fungal genes (CrPKS1, CrPKS3, CrPKS16, Catalase (CAT), Sugar Transporter (MFsug), Dioxygenase (YQE1), C₂H₂ Transcription factor (C₂H₂), Transcription Factor PacC (PacC), which are thought to be involved in polyketide biosynthesis, and one algal gene, NAD-dependent deacetylase sirtuin 2 (AsNAD)), using laser microdissection (LMD). The differential gene expression levels within the thallus tissue layers demonstrate that the most active region for potential polyketide biosynthesis within the lichen is the outer apical region proximal to the photobiont but some expression also occurs in reproductive tissue. This is the first study using laser microdissection to explore gene expression of these nine genes and their location of expression; it provides a proof-of-concept for future experiments exploring tissue-specific gene expression within lichens; and it highlights the utility of LMD for use in lichen systems.

Transcriptome analysis of the Brassica napus-Leptosphaeria maculans pathosystem identifies receptor, signaling and structural genes underlying plant resistance

The hemibiotrophic fungal pathogen Leptosphaeria maculans is the causal agent of blackleg disease in Brassica napus (canola, oilseed rape) and causes significant loss of yield worldwide. While genetic resistance has been used to mitigate the disease by means of traditional breeding strategies, there is little knowledge about the genes that contribute to blackleg resistance. RNA sequencing and a streamlined bioinformatics pipeline identified unique genes and plant defense pathways specific to plant resistance in the B. napus-L. maculans LepR1-AvrLepR1 interaction over time. We complemented our temporal analyses by monitoring gene activity directly at the infection site using laser microdissection coupled to quantitative PCR. Finally, we characterized genes involved in plant resistance to blackleg in the Arabidopsis-L. maculans model pathosystem. Data reveal an accelerated activation of the plant transcriptome in resistant host cotyledons associated with transcripts coding for extracellular receptors and phytohormone signaling molecules. Functional characterization provides direct support for transcriptome data and positively identifies resistance regulators in the Brassicaceae. Spatial gradients of gene activity were identified in response to L. maculans proximal to the site of infection. This dataset provides unprecedented spatial and temporal resolution of the genes required for blackleg resistance and serves as a valuable resource for those interested in host-pathogen interactions.

Transcriptome analysis of the Brassica napus-Leptosphaeria maculans pathosystem identifies receptor, signaling and structural genes underlying plant resistance

The hemibiotrophic fungal pathogen Leptosphaeria maculans is the causal agent of blackleg disease in Brassica napus (canola, oilseed rape) and causes significant loss of yield worldwide. While genetic resistance has been used to mitigate the disease by means of traditional breeding strategies, there is little knowledge about the genes that contribute to blackleg resistance. RNA sequencing and a streamlined bioinformatics pipeline identified unique genes and plant defense pathways specific to plant resistance in the B. napus-L. maculans LepR1-AvrLepR1 interaction over time. We complemented our temporal analyses by monitoring gene activity directly at the infection site using laser microdissection coupled to quantitative PCR. Finally, we characterized genes involved in plant resistance to blackleg in the Arabidopsis-L. maculans model pathosystem. Data reveal an accelerated activation of the plant transcriptome in resistant host cotyledons associated with transcripts coding for extracellular receptors and phytohormone signaling molecules. Functional characterization provides direct support for transcriptome data and positively identifies resistance regulators in the Brassicaceae. Spatial gradients of gene activity were identified in response to L. maculans proximal to the site of infection. This dataset provides unprecedented spatial and temporal resolution of the genes required for blackleg resistance and serves as a valuable resource for those interested in host-pathogen interactions.

Tissue-specific laser microdissection of the Brassica napus funiculus improves gene discovery and spatial identification of biological processes

The three primary tissue systems of the funiculus each undergo unique developmental programs to support the growth and development of the filial seed. To understand the underlying transcriptional mechanisms that orchestrate development of the funiculus at the globular embryonic stage of seed development, we used laser microdissection coupled with RNA-sequencing to produce a high-resolution dataset of the mRNAs present in the epidermis, cortex, and vasculature of the Brassica napus (canola) funiculus. We identified 7761 additional genes in these tissues compared with the whole funiculus organ alone using this technology. Differential expression and enrichment analyses were used to identify several biological processes associated with each tissue system. Our data show that cell wall modification and lipid metabolism are prominent in the epidermis, cell growth and modification occur in the cortex, and vascular tissue proliferation and differentiation occur in the central vascular strand. We provide further evidence that each of the three tissue systems of the globular stage funiculus are involved in specific biological processes that all co-ordinate to support seed development. The identification of genes and gene regulators responsible for tissue-specific developmental processes of the canola funiculus now serves as a valuable resource for seed improvement research.

Natural killer T cell defects in multiple myeloma and the impact of lenalidomide therapy

The causes of multiple myeloma (MM) remain obscure and there are few known risk factors; however, natural killer T (NKT) cell abnormalities have been reported in patients with MM, and therapeutic targeting of NKT cells is promoted as a potential treatment. We characterized NKT cell defects in treated and untreated patients with MM and determined the impact of lenalidomide therapy on the NKT cell pool. Lenalidomide is an immunomodulatory drug with co-stimulatory effects on NKT cells in vitro and is an approved treatment for MM, although its mode of action in that context is not well defined. We find that patients with relapsed/progressive MM had a marked deficiency in NKT cell numbers. In contrast, newly diagnosed patients had relatively normal NKT cell frequency and function prior to treatment, although a specific NKT cell deficiency emerged after high-dose melphalan and autologous stem cell transplantation (ASCT) regimen. This also impacted NK cells and conventional T cells, but the recovery of NKT cells was considerably delayed, resulting in a prolonged, treatment-induced NKT cell deficit. Longitudinal analysis of individual patients revealed that lenalidomide therapy had no in-vivo impact on NKT cell numbers or cytokine production, either as induction therapy, or as maintenance therapy following ASCT, indicating that its clinical benefits in this setting are independent of NKT cell modulation.

Chylous leakage post mastectomy and axillary clearance: clinical aspect, causes and review of literature

Chylous leakage after mastectomy & axillary clearance is a rare complication. The incidence is less than 0.5%. Anatomical variations in the termination of thoracic duct can occur, rendering it susceptible to injury during axillary dissection. Most chyle leaks in the axilla are managed through conservative measures. Surgical intervention is required in high output chylous leaks. We encountered a case of chylous leak post mastectomy with axillary clearance, which was successfully treated conservatively.

Ex-vivo analysis of human natural killer T cells demonstrates heterogeneity between tissues and within established CD4(+) and CD4(-) subsets

Our understanding of human type 1 natural killer T (NKT) cells has been heavily dependent on studies of cells from peripheral blood. These have identified two functionally distinct subsets defined by expression of CD4, although it is widely believed that this underestimates the true number of subsets. Two recent studies supporting this view have provided more detail about diversity of the human NKT cells, but relied on analysis of NKT cells from human blood that had been expanded in vitro prior to analysis. In this study we extend those findings by assessing the heterogeneity of CD4(+) and CD4(-) human NKT cell subsets from peripheral blood, cord blood, thymus and spleen without prior expansion ex vivo, and identifying for the first time cytokines expressed by human NKT cells from spleen and thymus. Our comparative analysis reveals highly heterogeneous expression of surface antigens by CD4(+) and CD4(-) NKT cell subsets and identifies several antigens whose differential expression correlates with the cytokine response. Collectively, our findings reveal that the common classification of NKT cells into CD4(+) and CD4(-) subsets fails to reflect the diversity of this lineage, and that more studies are needed to establish the functional significance of the antigen expression patterns and tissue residency of human NKT cells.

Ammonia excretion in the freshwater planarian Schmidtea mediterranea

In aquatic invertebrates metabolic nitrogenous waste is excreted predominately as ammonia. Very little is known, however, of the underlying mechanisms of ammonia excretion, particularly in freshwater species. Our results indicate that in the non-parasitic freshwater planarian Schmidtea mediterranea ammonia excretion depends on an acidification of the apical unstirred layer of the body surface and consequent ammonia trapping. Buffering of the environment to a pH of 7 or higher decreased excretion rate. Inhibitor experiments suggested further that the excretion mechanism involves the participation of the V-type H+-ATPase and carbonic anhydrase and possibly also the Na+/K+-ATPase and Na+/H+ exchangers (NHEs). Alkalinization (pH 8.5, 2 days) of the environment led to a 1.9-fold increase in body ammonia levels and to a down-regulation of V-ATPase (subunit A) and Rh-protein mRNA. Further, a two day exposure to non-lethal ammonia concentrations (1 mmol L-1) caused a doubling of body ammonia levels and led to an increase in Rh-protein and Na+/K+-ATPase (α-subunit) mRNA expression levels. In-situ hybridization studies indicated a strong mRNA expression of the Rh-protein in the epidermal epithelium. The ammonia excretion mechanism proposed for S. mediterranea reveals striking similarities to the current model suggested to function in gills of freshwater fish.

Examining the adverse effects of limb position on pattern recognition based myoelectric control

Pattern recognition of myoelectric signals for the control of prosthetic devices has been widely reported and debated. A large portion of the literature focuses on offline classification accuracy of pre-recorded signals. Historically, however, there has been a semantic gap between research findings and a clinically viable implementation. Recently, renewed focus on prosthetics research has pushed the field to provide more clinically relevant outcomes. One way to work towards this goal is to examine the differences between research and clinical results. The constrained nature in which offline training and test data is often collected compared to the dynamic nature of prosthetic use is just one example. In this work, we demonstrate that variations in limb position after training can have a substantial impact on the robustness of myoelectric pattern recognition.

Testing the NKT cell hypothesis in lenalidomide-treated myelodysplastic syndrome patients

Myelodysplastic syndrome (MDS) comprises a group of clonal bone marrow disorders characterized by ineffective hematopoiesis and increased predisposition to acute myeloid leukemia. The causes of MDS remain poorly defined, but several studies have reported the NKT cell compartment of patients with MDS is deficient in number and functionally defective. In support of a central role for NKT cells, a pilot clinical study reported that lenalidomide (an approved treatment for MDS) increased NKT cell numbers in patients with MDS, and several in vitro studies showed lenalidomide specifically promoted NKT cell proliferation and cytokine production. We tested this in a much larger study and confirm a moderate in vitro augmentation of some NKT cell functions by lenalidomide, but find no impact on the NKT cell compartment of patients treated with lenalidomide, despite a consistently positive clinical response. We further show that the frequency and cytokine production of NKT cells is normal in patients with MDS before treatment and remains stable throughout 10 months of lenalidomide therapy. Collectively, our data challenge the concept that NKT cell defects contribute to the development of MDS, and show that a clinical response to lenalidomide is not dependent on modulation of NKT cell frequency or function.

Immune characterization of an individual with an exceptionally high natural killer T cell frequency and her immediate family

Natural killer T cells (NKT) are a regulatory subset of T lymphocytes whose frequency in peripheral blood is highly variable within the human population. Lower than normal NKT frequencies are associated with increased predisposition to a number of diseases, including type 1 diabetes and some forms of cancer, raising the possibility that an increased frequency may be protective. However, there is little or no understanding of how high NKT frequencies arise or, most importantly, whether the potential exists to boost and maintain NKT levels for therapeutic advantage. Here, we provide a detailed functional and phenotypic characterization of the NKT compartment of a human donor with NKT levels approximately 50 times greater than normal, including an analysis of NKT in her immediate family members. The study focuses upon the characteristics of this donor and her family, but demonstrates more broadly that the size and flexibility of the NKT niche is far greater than envisioned previously. This has important implications for understanding how the human NKT compartment is regulated, and supports the concept that the human NKT compartment might be expanded successfully for therapeutic benefit.

Emphysematous pyelonephritis in a diabetic patient with pelvic-ureteric stone

Emphysematous pyelonephritis is a rare but life threatening infection of kidney that is characterized by gas formation within or around the kidney. We describe a case of emphysematous pyelonephritis as a consequence of inadequately treated pelvic-ureteric stone in a diabetic man and complement this with a brief review of the literature pertaining in particular to the management of this condition.

Immune response in silico (IRIS): immune-specific genes identified from a compendium of microarray expression data

Immune cell-specific expression is one indication of the importance of a gene's role in the immune response. We have compiled a compendium of microarray expression data for virtually all human genes from six key immune cell types and their activated and differentiated states. Immune Response In Silico (IRIS) is a collection of genes that have been selected for specific expression in immune cells. The expression pattern of IRIS genes recapitulates the phylogeny of immune cells in terms of the lineages of their differentiation. Gene Ontology assignments for IRIS genes reveal significant involvement in inflammation and immunity. Genes encoding CD antigens, cytokines, integrins and many other gene families playing key roles in the immune response are highly represented. IRIS also includes proteins of unknown function and expressed sequence tags that may not represent genes. The predicted cellular localization of IRIS proteins is evenly distributed between cell surface and intracellular compartments, indicating that immune specificity is important at many points in the signaling pathways of the immune response. IRIS provides a resource for further investigation into the function of the immune system and immune diseases.

Subfascial endoscopic perforator vein surgery (SEPS) using the ultrasonic scalpel

Subfascial endoscopic perforator vein surgery (SEPS) was recently introduced as a minimally invasive method to ligate incompetent perforating veins in patients with severe chronic venous insufficiency of the lower extremities. Herein we describe a technique in which we used a 5-mm ultrasonic scalpel for the transection of perforating veins in 16 SEPS performed in 14 patients. The use of the ultrasonic scalpel allowed for the precise coagulation and transection of the perforator vein with hemostasis, while avoiding the use of metal clips. Our initial results showed that the technique was feasible with minimal morbidity. We recommend the use of the ultrasonic scalpel as an alternative tool to transect perforating veins in SEPS.

Inefficient ZAP-70 phosphorylation and decreased thymic selection in vivo result from inhibition of NF-kappaB/Rel

Signaling from the TCR regulates T lymphoid survival, deletion by apoptosis, and selective clonal expansion. One set of signaling pathways activated during thymic selection leads to degradation of a cytosolic retention protein, the inhibitor of kappaB (IkappaB)alpha, followed by nuclear translocation of the NF-kappaB/Rel family of transcription factors. It has been found previously that NF-kappaB proteins mediate a pathway signaling the survival of mature T cells and protection of thymocytes against TNF-induced apoptosis. In contrast, we show in this study that a transgenic inhibitor of NF-kappaB/Rel signaling interferes with the negative selection of immature thymocytes by endogenous MHC ligands in vivo. Positive selection of the H-Y TCR also was diminished. This attenuation of thymic selection efficiency was associated with decreased ZAP-70 phosphorylation and TCR signaling of CD69 induction. These findings demonstrate that the NF-kappaB transcriptional pathway plays an important role in normal processes of clonal deletion and they indicate that the NF-kappaB/IkappaB axis can regulate the efficiency of TCR signaling.

Unique signaling properties of B cell antigen receptor in mature and immature B cells: implications for tolerance and activation

Immature B cells display increased sensitivity to tolerance induction compared with their mature counterparts. The molecular mechanisms underlying these differences are poorly defined. In this study, we demonstrate unique maturation stage-dependent differences in B cell Ag receptor (BCR) signaling, including BCR-mediated calcium mobilization responses. Immature B cells display greater increases in intracellular calcium concentrations following Ag stimulation. This has consequences for the induction of biologically relevant responses: immature B cells require lower Ag concentrations for activation than mature B cells, as measured by induction of receptor editing and CD86 expression, respectively. BCR-induced tyrosine phosphorylation of CD79a, Lyn, B cell linker protein, and phospholipase Cgamma2 is enhanced in immature B cells and they exhibit greater capacitative calcium entry in response to Ag. Moreover, B cell linker protein, Bruton's tyrosine kinase, and phospholipase Cgamma2, which are crucial for the induction of calcium mobilization responses, are present at approximately 3-fold higher levels in immature B cells, potentially contributing to increased mobilization of calcium. Consistent with this possibility, we found that the previously reported lack of inositol-1,4,5-triphosphate production in immature B cells may be explained by enhanced inositol-1,4,5-triphosphate breakdown. These data demonstrate that multiple mechanisms guarantee increased Ag-induced mobilization of calcium in immature B cells and presumably ensure elimination of autoreactive B cells from the repertoire.

Early clinical outcomes after subfascial endoscopic perforator surgery (SEPS) and saphenous vein surgery in chronic venous insufficiency

BACKGROUND

Subfascial endoscopic perforator surgery (SEPS) has recently become popular as a minimally invasive way to treat chronic venous insufficiency (CVI) of the lower extremities. We report the early clinical outcomes of SEPS and saphenous vein surgery in a prospective series of Chinese patients who presented with severe CVI.

METHODS

All patients referred to our hospital for the management of severe CVI (class IV disease or above) after January 1998 underwent SEPS using an ultrasonic scalpel in conjunction with saphenous vein surgery. All patients were followed up prospectively to assess ulcer healing, ulcer recurrence, and symptoms after SEPS. Clinical outcome was evaluated by the scoring system suggested by the Consensus Committee of the American Venous Forum on Chronic Venous Disease.

RESULTS

Over a 24-month period, we performed 36 SEPS on 31 patients. Nineteen lower extremities (53%) had active or healing ulcers. Sapheno-femoral ligation was also performed in 33 limbs (92%). Four limbs (11%) developed superficial wound infection, and two (6%) had saphenous nerve dysesthesia. The mean clinical score and disability score decreased from 8.42 to 3.42 and 1.45 to 0.31 respectively, after a median follow-up of 14 months (range, 6-22) (p < 0.005). Eleven ulcers (58%) healed within 6 weeks after surgery. At 1-year follow-up, ulcer recurrence was found in two legs (11%).

CONCLUSION

SEPS is safe and feasible. Early clinical results have shown a promising outcome in patients with severe chronic venous insufficiency.

Development of follicular dendritic cell sarcoma in hyaline-vascular Castleman's disease of the nasopharynx: tracing its evolution by sequential biopsies

AIMS

Hyaline-vascular Castleman's disease (HVCD) and follicular dendritic cell (FDC) sarcoma occurring in the nasopharynx are both extremely rare. We report the first case of transformation of the former into the latter as documented by sequential biopsies. The steps involved in the transformation were described in detail and the possible role of p53 studied.

METHODS AND RESULTS

The patient presented at the age of 23 years with nasopharyngeal HVCD. Hyaline- vascular Castleman's disease with FDC overgrowth was diagnosed in a recurrence 8 years later, and a frank FDC sarcoma developed at the same site 11 years after initial presentation. The patient remained disease-free 3 years after excision and adjuvant chemotherapy. The FDC sarcoma comprised swirling fascicles of spindly cells with indistinct cell borders. The tumour cells expressed the FDC markers CD21, CD35 and CNA.42 and in-situ hybridization for Epstein-Barr virus-encoded RNAs was negative. Over-expression of p53 protein was observed in the FDC sarcoma and an increased number of weakly p53-positive spindly cells could also be demonstrated in the HVCD specimen. This finding suggested a possible role of p53 in the evolution from HVCD to FDC sarcoma. Critical analysis of the literature shows that, among the 13 reported cases of FDC sarcoma associated with Castleman's disease, possible progression from the latter to the former is documented in only two cases.

CONCLUSIONS

The sequential changes observed in the current case provide further evidence to strengthen the role of HVCD as a possible precursor of FDC sarcoma. There is a possible role of p53 in the transformation process but confirmation by future studies is needed.

Inflammatory pseudotumor-like follicular dendritic cell tumor: a distinctive low-grade malignant intra-abdominal neoplasm with consistent Epstein-Barr virus association

Follicular dendritic cell (FDC) tumors are uncommon neoplasms that can involve lymph nodes or extranodal sites. They can exhibit a broad spectrum of histologic appearances and behavior, but the intra-abdominal ones usually pursue an aggressive course. The purpose of this study was to characterize a distinctive variant of FDC tumor morphologically mimicking inflammatory pseudotumor through analysis of the clinicopathologic features of 11 cases. The patients included 10 women and one man (age range, 19-61 years; median age, 40 years) who presented with abdominal discomfort or pain. Six patients had systemic symptoms such as marked weight loss, fever, or malaise. All tumors occurred in intra-abdominal sites: liver (n = 7), spleen (n = 3), and peripancreatic region (n = 1). Of the nine patients with follow-up data, six were alive and well, one developed recurrence at 9 years, and two had repeated recurrences over many years. Grossly, the tumors were usually solitary and fleshy, punctuated by areas of hemorrhage and necrosis. Histologically, in a background of abundant lymphocytes and plasma cells were dispersed spindle or ovoid cells with vesicular nuclei and distinct nucleoli. The degree of nuclear atypia was variable, and some nuclei could be grotesque or resemble Reed-Sternberg cells. Focally, spindle cell fascicles could be formed. The atypical cells were immunoreactive for FDC markers such as CD21/CD35, CD23, and CNA.42. In situ hybridization for Epstein-Barr virus (EBV)-encoded RNA was positive in all cases, remarkably highlighting the spindle cells and their atypia. EBV-latent membrane protein-1 was expressed commonly, albeit often focally and weakly. Therefore, inflammatory pseudotumor-like FDC tumor represents a distinctive variant of FDC tumor that differs from conventional FDC tumor in the following aspects: marked female predominance; selective localization in intra-abdominal sites, especially the liver and spleen; frequent presence of systemic symptoms; indolent behavior despite an intra-abdominal location; dispersed distribution of tumor cells and prominent lymphoplasmacytic infiltration; and consistent association with EBV.

Immune system dysfunction and autoimmune disease in mice lacking Emk (Par-1) protein kinase

Emk is a serine/threonine protein kinase implicated in regulating polarity, cell cycle progression, and microtubule dynamics. To delineate the role of Emk in development and adult tissues, mice lacking Emk were generated by targeted gene disruption. Emk(-/-) mice displayed growth retardation and immune cell dysfunction. Although B- and T-cell development were normal, CD4(+)T cells lacking Emk exhibited a marked upregulation of the memory marker CD44/pgp-1 and produced more gamma interferon and interleukin-4 on stimulation through the T-cell receptor in vitro. In addition, B-cell responses to T-cell-dependent and -independent antigen challenge were altered in vivo. As Emk(-/-) animals aged, they developed splenomegaly, lymphadenopathy, membranoproliferative glomerulonephritis, and lymphocytic infiltrates in the lungs, parotid glands and kidneys. Taken together, these results demonstrate that the Emk protein kinase is essential for maintaining immune system homeostasis and that loss of Emk may contribute to autoimmune disease in mammals.

Management of paraffinoma of the breast: 10 years' experience

Paraffin injection was regarded as a simple and effective method of improving body contour. It was widely used in breast augmentation until the long-term complication of paraffinoma was recognised. Paraffinoma of the breast can present as a spectrum of disease ranging from a painless mass to a destructive ulcer simulating breast cancer. This makes it difficult to make the correct diagnosis and provide suitable treatment. Eight patients with paraffinoma of the breast have been managed at a teaching hospital over a 10 year period. All were females, with a mean age of 65.6 years (range: 57-73 years). The average time between paraffin injection and the onset of symptoms was 24 years (range: 11-30 years). These patients have been followed up for between 3 and 10 years (mean: 6.1 years). One patient died of congestive heart failure 4 years after bilateral mastectomy for painful paraffinomas of the breasts. Another patient had a coexisting infiltrative ductal carcinoma of the breast. The clinical presentations, radiological appearances, histopathological features and the treatment are discussed.

[Detection of Immunoglobulin light chain restriction of mucosa-associated lymphoid tissue type gastric lymphoma using mRNA in situ hybridization]

OBJECTIVE

To evaluate the usefulness of in situ hybridization for Immunoglobulin kappa and lambda light chain mRNA to detect light chain restriction in the diagnosis of primary gastric lymphoma (PGL) of mucosa-associated lymphoid tissue (MALT) type.

METHODS

Twenty-seven cases of PGL of MALT type and 5 cases of gastritis were analyzed using in situ hybridization with fluorescent isothiocyanate (FITC)-labeled oligonucleotide probes for kappa and lambda light chain mRNA. The kappa:lambda ratios of tumor cells, lymphocytes and plasma cells were analyzed to detect light chain restriction and clonal plasma cells.

RESULTS

Light chain restriction was found in 10 of 27 (37%) cases of PGL cases (in 5/9 low grade and 5/18 in high grade). Clonal plasma cells were detected in low grade but not in high-grade cases. No light chain restriction was found in gastritis specimens, the adjacent tissue of tumors or the distant stomach mucosa in lymphoma cases.

CONCLUSIONS

The detection of clonality using mRNA in situ hybridization could be a helpful diagnostic tool for gastric lymphoma. The presence of clonal plasma cells can be a marker of the early lesion of low-grade PGL.

Disruption of T cell signaling networks and development by Grb2 haploid insufficiency

The developmental processes of positive and negative selection in the thymus shape the T cell antigen receptor (TCR) repertoire and require the integration of multiple signaling networks. These networks involve the efficient assembly of macromolecular complexes and are mediated by multimodular adaptor proteins that permit the functional integration of distinct signaling molecules. We show here that decreased expression of the adaptor protein Grb2 in Grb2+/- mice weakens TCR-induced c-Jun N-terminal kinase (JNK) and p38, but not extracellular signal-regulated kinase (ERK), activation. In turn, this selective effect decreases the ability of thymocytes to undergo negative, but not positive, selection. We also show that there are differences in the signaling thresholds of the three mitogen-activated protein kinase (MAPK) families. These differences may provide a mechanism by which quantitative differences in signal strength can alter the balance of downstream signaling pathways to induce the qualitatively distinct biological outcomes of proliferation, differentiation or apoptosis.

Morphological analysis of adrenal glands: a prospective analysis

There is a lack of studies to document the weight range of normal adrenal glands. The aims of the current study are to find out the weight range of normal adrenal glands in Chinese patients and to analyze any potential factors affecting it. Adrenal glands not affected by disease were prospectively collected from autopsies on 333 Chinese patients (208 men, 125 women). The weight and longest dimension of each adrenal gland were noted. The impact of various clinicopathological factors on the adrenal weight was studied. In addition, the morphometric features of these adrenal glands were compared with that of 28 surgically resected adrenal glands with cortical adenomas. The mean combined weight of adrenal glands was 11.8 g (range = 5.8 g to 19.9 g). The left adrenal gland was often heavier than the right (mean weight = 6.1 g and 5.7 g respectively) and with a greater longitudinal length than the right (mean length = 5.2 cm and 4.8 cm respectively). Adrenal glands were often heavier in male, younger age group (less than 60-yr-old) and patients with history of hypertension or lung cancers. In comparison, the mean weight of right adrenal gland with cortical adenoma was 11.7 g (range = 6 g to 26 g) and that of left adrenal gland with cortical adenoma was 9.4 g (range = 4.6 g to 25 g). This is the first study in the English literature that provides data on the weight of normal adrenal glands in a solely Chinese population. Adrenal weight may be affected by patients' gender, age, laterality of adrenal gland and presence of systemic disease.

An unusual case of double tuberculous broncho-oesophageal fistulas in an adult

Broncho-oesophageal fistula associated with tuberculosis is rarely reported in the literature and has not been reported in Hong Kong. We describe a 30-year-old Chinese human immunodeficiency virus (HIV)-negative man with double tuberculous broncho-oesophageal fistulas proven by histology. Constitutional symptoms of active tuberculosis were absent and chest radiograph did not show an obvious lung lesion. Our case shows that broncho-oesophageal fistula can be the sole manifestation of active tuberculosis and that the diagnosis should be suspected in patients who are seen with chronic respiratory symptoms in areas where the prevalence of tuberculosis is high.

Is it safe to reuse disposable laparoscopic trocars? An in vitro testing

BACKGROUND

The reuse of disposable laparoscopic instruments carries a risk of transmitting infectious diseases such as hepatitis and HIV. We evaluated the safety of reusing disposable trocars by studying the chances of their harboring infectious viruses after resterilization in an in vitro setting.

METHODS

Disposable laparoscopic trocars were exposed to horse blood contaminated with high or low viral concentrations of herpes simplex virus type 1 (HSV1) and attenuated polio virus type 1 at room temperature for 2 h. HSV1 was chosen as the surrogate for lipid viruses that include hepatitis B and HIV virus; polio virus represented the nonlipid viruses that cause infections in immunocompromised patients and are more resistant to sterilization. The trocars were subsequently cleaned and resterilized by low-temperature steam and formaldehyde at 80 degrees C for 3 h. Viral cultures were then repeated after sterilization.

RESULTS

A cytopathic effect (CPE) was demonstrated at both concentrations for HSV1 in all trocars before but not after sterilization. For the polio virus, CPE was evident in 50% of the trocars (two of four) exposed to high viral concentration after sterilization.

CONCLUSION

Disposable trocars are difficult to resterilize and may harbor infectious viruses after their initial use. Therefore, the reuse of disposable trocars in laparoscopic surgery cannot be recommended.

Pulmonary sclerosing hemangioma consistently expresses thyroid transcription factor-1 (TTF-1): a new clue to its histogenesis

The histogenesis of pulmonary sclerosing hemangioma has remained controversial despite extensive studies by many investigators. The availability of an antibody to thyroid transcription factor-1 (TTF-1), which is expressed in type II pneumocytes and Clara cells, has prompted us to readdress this issue. Sixteen cases were immunostained with a panel of antibodies including TTF-1. The patients were predominantly women with an age range of 30 to 73 years (mean, 52 yrs). All tumors were solitary. The single male patient showed regional lymph node metastases, an unusual occurrence reported only once in the literature. All cases exhibited the classic histologic features, with variegated patterns. TTF-1 expression was observed in both the surface lining cells and the pale polygonal cells. The surface lining cells were epithelial membrane antigen (EMA)+ cytokeratin+ surfactant apoprotein A+, whereas the polygonal cells were EMA+ cytokeratin- surfactant apoprotein A-. The neuroendocrine markers synaptophysin and chromogranin were both negative. The metastatic deposits in the lymph nodes comprised only polygonal cells and exhibited an EMA+ cytokeratin- surfactant apoprotein A- TTF- 1+ immunophenotype. These results suggest that pulmonary sclerosing hemangioma is an epithelial neoplasm derived from primitive respiratory epithelium or incompletely differentiated type II pneumocyte or Clara cell.

Functional complementation of BLNK by SLP-76 and LAT linker proteins

Recent studies have demonstrated a requirement for the SLP-76 (SH2 domain-containing leukocyte protein of 76 kDa) and LAT (linker for activation of T cells) adaptor/linker proteins in T cell antigen receptor activation and T cell development as well as the BLNK (B cell linker) linker protein in B cell antigen receptor (BCR) signal transduction and B cell development. Whereas the SLP-76 and LAT adaptor proteins are expressed in T, natural killer, and myeloid cells and platelets, BLNK is preferentially expressed in B cells and monocytes. Although BLNK is structurally homologous to SLP-76, BLNK interacts with a variety of downstream signaling proteins that interact directly with both SLP-76 and LAT. Here, we demonstrate that neither SLP-76 nor LAT alone is sufficient to restore the signaling deficits observed in BLNK-deficient B cells. Conversely, the coexpression of SLP-76 and LAT together restored BCR-inducible calcium responses as well as activation of all three families of mitogen-activated protein kinases. Together, these data suggest functional complementation of SLP-76 and LAT in T cell antigen receptor function with BLNK in BCR function.

Transhepatic balloon sphincteroplasty for bile duct stones after total gastrectomy

Previous upper gastrointestinal surgery with the construction of a Roux-en-Y jejunal loop may prevent endoscopic access to the second part of the duodenum. We report a technique of percutaneous transhepatic balloon sphincteroplasty to facilitate the removal of common bile duct (CBD) stones. A 67-year-old woman presented with a 1-week history of right upper quadrant abdominal pain and fever, deranged liver function tests, and dilated intrahepatic ducts. The patient had previously had a total gastrectomy with Roux-en-Y reconstruction for a high-grade B-cell lymphoma of the stomach. Peroral endoscopic access to the biliary tree was unsuccessful. Percutaneous transhepatic cholangiography confirmed the presence of CBD stones. Over a period of 8 weeks, sequential dilatation of the percutaneous tract was undertaken. After a further 2 weeks, percutaneous choledochoscopy was performed. Several large stones were visualized and then fragmented. The choledochoscope would not pass through to the duodenum due to postinflammatory stenosis of the papilla, so the papilla was dilated with an endoscopic balloon. The remaining fragments were pushed through, and the duct was thoroughly irrigated with saline. Repeat cholangiography confirmed a clear CBD. Balloon catheter sphincteroplasty and biliary stone extrusion into the duodenum is a novel technique that enabled clearance of the CBD in an elderly patient who may otherwise have required open surgical exploration.

Involvement of LAT, Gads, and Grb2 in compartmentation of SLP-76 to the plasma membrane

B cell linker protein (BLNK) and Src homology 2 domain-containing leukocyte protein of 76 kD (SLP-76) are adaptor proteins required for B cell receptor (BCR) and T cell receptor function, respectively. Here, we show that expression of SLP-76 cannot reconstitute BCR function in Zap-70(+)BLNK(-) B cells. This could be attributable to inability of SLP-76 to be recruited into glycolipid-enriched microdomains (GEMs) after antigen receptor cross-linking. Supporting this idea, the BCR function was restored when a membrane-associated SLP-76 chimera was enforcedly localized to GEMs. Moreover, we demonstrate that addition of both linker for activation of T cells (LAT) and Grb2-related adaptor downstream of Shc (Gads) to SLP-76 allow SLP-76 to be recruited into GEMs, whereby the BCR function is reconstituted. The Gads function was able to be replaced by overexpression of Grb2. In contrast to SLP-76, BLNK did not require Grb2 families for its recruitment to GEMs. Hence, these data suggest a functional overlap between BLNK and SLP-76, while emphasizing the difference in requirement for additional adaptor molecules in their targeting to GEMs.

Neck ultrasound in staging squamous oesophageal carcinoma - a high yield technique

AIM

This study evaluates the use of neck ultrasound in staging squamous oesophageal carcinoma.

MATERIALS AND METHODS

A prospective analysis of the clinical, neck ultrasound (US) and thoraco-abdominal computed tomography (CT) findings in 121 patients with squamous oesophageal carcinoma at presentation was performed. The relationship between malignant neck nodes, mediastinal and abdominal adenopathy, location and size of the primary tumour was analysed.

RESULTS

Ten of 121 patients (8%) had clinically palpable neck nodes which were deemed malignant in six (5%) following US and fine-needle aspiration for cytology. Of those 111 patients with no palpable neck nodes, 31 (28%) had malignant nodes shown on US. The more cephalad the location of the primary tumour, the higher the frequency of malignant neck nodes which were found in 80%, 52%, 29% and 9% of cervical, upper thoracic, mid-thoracic and lower thoracic oesophageal tumours, respectively. Eleven (29%) of the 38 patients with malignant neck nodes shown on US had no CT evidence of additional adenopathy in the mediastinum or upper abdomen. Neck US altered TNM staging in 22/121 (18%) patients at presentation.

CONCLUSION

Neck US frequently detects clinically impalpable metastatic nodes leading to altered TNM staging in patients with squamous oesophageal carcinoma. We advocate its routine use when staging squamous oesophageal carcinoma.

Effect of intravenous omeprazole on recurrent bleeding after endoscopic treatment of bleeding peptic ulcers

BACKGROUND

After endoscopic treatment of bleeding peptic ulcers, bleeding recurs in 15 to 20 percent of patients.

METHODS

We assessed whether the use of a high dose of a proton-pump inhibitor would reduce the frequency of recurrent bleeding after endoscopic treatment of bleeding peptic ulcers. Patients with actively bleeding ulcers or ulcers with nonbleeding visible vessels were treated with an epinephrine injection followed by thermocoagulation. After hemostasis had been achieved, they were randomly assigned in a double-blind fashion to receive omeprazole (given as a bolus intravenous injection of 80 mg followed by an infusion of 8 mg per hour for 72 hours) or placebo. After the infusion, all patients were given 20 mg of omeprazole orally per day for eight weeks. The primary end point was recurrent bleeding within 30 days after endoscopy.

RESULTS

We enrolled 240 patients, 120 in each group. Bleeding recurred within 30 days in 8 patients (6.7 percent) in the omeprazole group, as compared with 27 (22.5 percent) in the placebo group (hazard ratio, 3.9; 95 percent confidence interval, 1.7 to 9.0). Most episodes of recurrent bleeding occurred during the first three days, which made up the infusion period (5 in the omeprazole group and 24 in the placebo group, P<0.001). Three patients in the omeprazole group and nine in the placebo group underwent surgery (P=0.14). Five patients (4.2 percent) in the omeprazole group and 12 (10 percent) in the placebo group died within 30 days after endoscopy (P=0.13).

CONCLUSIONS

After endoscopic treatment of bleeding peptic ulcers, a high-dose infusion of omeprazole substantially reduces the risk of recurrent bleeding.

Odontogenic keratocysts: a clinicopathological study in Hong Kong Chinese

OBJECTIVE

To analyze the clinicopathological features of odontogenic keratocysts in Chinese patients.

STUDY DESIGN

Retrospective analysis.

METHODS

The clinical records and pathological features of odontogenic keratocysts from 69 ethnic Hong Kong Chinese patients (40 male and 29 female patients) were reviewed.

RESULTS

The male-to-female ratio was 1.4:1; patient age ranged from 6 to 69 years with a modal peak in the third decade (mean age, 28 y; median age, 23 y). The preoperative diagnosis was correct in 78% of the cases and the most common misdiagnosis was dentigerous cyst. Sixty-two percent of the cysts were found in the mandible, and 38% in the maxilla. Multiple cysts occurred in 9% (including three cases of basal cell nevus syndrome). Histologically, 82.6%, 5.8%, and 11.6% of the cysts were parakeratinized, orthokeratinized, and mixed types, respectively. Patients with multiple cysts all showed parakeratinization. The majority (80%) of the cysts were lined by epithelia with a thickness of five to eight cells. Surface corrugation, subepithelial split, suprabasal split, satellite microcysts, epithelial islands, significant inflammation, hyaline bodies, and dystrophic calcification were present in 10%, 81%, 25%, 38%, 42%, 46%, 7%, and 10% of cysts, respectively. The overall recurrence rate was 240%, with a median time for first recurrence of 19 months (range, 1 mo-22 y). Cysts showing orthokeratinization or mixed types of keratinization recurred less often than parakeratinized cysts. Recurrence had the same type of keratinization as the initial cyst.

CONCLUSIONS

Pathological examination of keratocysts is important, because keratocysts have different clinicopathological features and carry a risk for clinical misdiagnosis.

Regulation of B cell function by linker proteins

Studies over the past few years have demonstrated the importance of linker or adaptor proteins in the signaling pathways activated by the B cell antigen-receptor. These proteins direct the appropriate subcellular localization of enzymatic complexes, amplify signaling pathways and integrate the functions of distinct signaling complexes. Many of the recently identified linker proteins function through these distinct mechanisms to upregulate the BCR signaling pathway. In addition, linker proteins facilitate the influences of co-receptors that augment or dampen the BCR signaling pathway.

Diagnostic and therapeutic fistuloscopy: an adjuvant management in postoperative fistulas and abscesses after upper gastrointestinal surgery

BACKGROUND AND STUDY AIMS

Postoperative fistulas and abscesses pose difficult management problems. We report our experience in the use of fistuloscopy in postoperative fistulas and abscesses after upper gastrointestinal surgery.

PATIENTS AND METHODS

From June 1993 to January 1997, nine patients (seven men, two women; mean age 65) with postoperative fistulas and abscesses were treated with therapeutic fistuloscopy. Diagnostic fistuloscopy was carried out using a 5-mm choledochoscope under fluoroscopic guidance. Therapeutic procedures included mechanical debridement, irrigation, and sealing of fistula with fibrin sealant and gelatin sponge.

RESULTS

The patients were suffering from duodenal stump fistula (three cases), gastrojejunostomy dehiscence after gastrectomy (three cases), gastropleurocutaneous fistula (two cases), and subphrenic abscesses (two cases). Fistuloscopy was performed 4-19 days (mean 12 days) after the diagnosis of the fistula. The median number of sessions required was 2 (range 1-4). The average daily fistula output prior to fistuloscopy was 154 ml (range 30-560 ml), and all fistulas healed in an average of 18.7 days (range 2-46 days) after index fistuloscopy. No procedure-related complications occurred. The mean hospital stay was 61 days. During a mean follow-up period of 12 months, no recurrent abscesses or fistulas developed.

CONCLUSIONS

Fistuloscopy provides a new means of managing patients with postoperative fistula and abscess formation.

Incidence and pathology of primary brain lymphoma in Hong Kong Chinese patients

Primary brain lymphoma (PBL) is an uncommon extranodal lymphoma. Its incidence is rapidly increasing in both immunocompromised and immunocompetent patients in Western countries. Eighteen cases of PBL were identified during a 16-year period among HIV negative patients in Queen Mary Hospital, Hong Kong. One case of post-transplantation lymphoproliferative disease (PTLD) was positive for Epstein Barr virus (EBV) encoded RNA (EBER) by in situ hybridization. All the remaining 17 immunocompetent cases were classified as diffuse large B-cell lymphoma, except for one case of Burkitt's lymphoma. EBER expression was negative in all 13 cases tested. Immunostaining for bcl-2 and bcl-6 was positive in 8/11 and 6/11 cases tested, with heterogeneous combination of expression and intensity. The incidence rate of PBL in immunocompetent patients was stable at 1.03 per million per year. The incidence of PBL in post transplantation (0.16%) and HIV related setting (0.29%) is also low in Chinese. PBL in Chinese patients is almost uniformly represented by EBV negative, diffuse large B-cell lymphoma, confined to the brain. However, the molecular pathogenesis may be heterogeneous.

Membrane cofactor protein (MCP; CD46): isoform-specific tyrosine phosphorylation

Membrane cofactor protein (MCP; CD46) is a widely expressed type 1 transmembrane glycoprotein that inhibits complement activation on host cells. It also is a receptor for several pathogens including measles virus, Streptococcus pyogenes, Neisseria gonorrhea, and Neisseria meningitidis. That MCP may have signaling capability was suggested by its microbial interactions. That is, binding of MCP on human monocytes by measles virus hemagglutinin or cross-linking by an anti-MCP Ab resulted in IL-12 down-regulation, while binding to MCP by Neisseria on epithelial cells produced a calcium flux. Through alternative splicing, MCP is expressed on most cells with two distinct cytoplasmic tails of 16 (CYT-1) or 23 (CYT-2) amino acids. These play pivotal roles in intracellular precursor processing and basolateral localization. We investigated the putative signal transduction pathway mediated by MCP and demonstrate that CYT-2, but not CYT-1, is phosphorylated on tyrosine. We examined MCP tail peptides and performed Ab cross-linking experiments on several human cell lines and MCP isoform transfectants. We found an MCP peptide of CYT-2 was phosphorylated by a src kinase system. Western blots of the cells lines demonstrated that cells bearing CYT-2 were also phosphorylated on tyrosine. Additionally, we provide genetic and biochemical evidence that the src family of kinases is responsible for the latter phosphorylation events. In particular, the src kinase, Lck, is required for phosphorylation of MCP in the Jurkat T cell line. Taken together, these studies suggest a src family-dependent pathway for signaling through MCP.

Adapter proteins SLP-76 and BLNK both are expressed by murine macrophages and are linked to signaling via Fcgamma receptors I and II/III

The SLP-76 (Src homology 2 domain-containing leukocyte protein of 76 kDa) adapter protein is expressed in T cells and myeloid cells, whereas its homologue BLNK (B cell linker protein) is expressed in B cells. SLP-76 and BLNK link immunoreceptor tyrosine-based activation motif-containing receptors to signaling molecules that include phospholipase C-gamma, mitogen-activated protein kinases, and the GTPases Ras and Rho. SLP-76 plays a critical role in T cell receptor, FcvarepsilonRI and gpVI collagen receptor signaling, and participates in signaling via FcgammaR and killer cell inhibitory receptors. BLNK plays a critical role in B cell receptor signaling. We show that murine bone marrow-derived macrophages express both SLP-76 and BLNK. Selective ligation of FcgammaRI and FcgammaRII/III resulted in tyrosine phosphorylation of both SLP-76 and BLNK. SLP-76(-/-) bone marrow-derived macrophages display FcgammaR-mediated tyrosine phosphorylation of Syk, phospholipase C-gamma2, and extracellular signal regulated kinases 1 and 2, and normal FcgammaR-dependent phagocytosis. These data suggest that both SLP-76 and BLNK are coupled to FcgammaR signaling in murine macrophages.

Eradication of Helicobacter pylori prevents recurrence of ulcer after simple closure of duodenal ulcer perforation: randomized controlled trial

OBJECTIVE

In this randomized trial, the authors sought to determine whether eradication of Helicobacter pylori could reduce the risk of ulcer recurrence after simple closure of perforated duodenal ulcer.

BACKGROUND DATA

Immediate acid-reduction surgery has been strongly advocated for perforated duodenal ulcers because of the high incidence of ulcer relapse after simple patch repair. Although H. pylori eradication is now the standard treatment of uncomplicated and bleeding peptic ulcers, its role in perforation remains controversial. Recently a high prevalence of H. pylori infection has been reported in patients with perforations of duodenal ulcer. It is unclear whether eradication of the bacterium confers prolonged ulcer remission after simple repair and hence obviates the need for an immediate definitive operation.

METHODS

Of 129 patients with perforated duodenal ulcers, 104 (81%) were shown to be infected by H. pylori. Ninety-nine H. pylori-positive patients were randomized to receive either a course of quadruple anti-helicobacter therapy or a 4-week course of omeprazole alone. Follow-up endoscopy was performed 8 weeks, 16 weeks (if the ulcer did not heal at 8 weeks), and 1 year after hospital discharge for surveillance of ulcer healing and determination of H. pylori status. The endpoints were initial ulcer healing and ulcer relapse rate after 1 year.

RESULTS

Fifty-one patients were assigned to the anti-Helicobacter therapy and 48 to omeprazole alone. Nine patients did not undergo the first follow-up endoscopy. Of the 90 patients who did undergo follow-up endoscopy, 43 of the 44 patients in the anti-Helicobacter group and 8 of the 46 in the omeprazole alone group had H. pylori eradicated; initial ulcer healing rates were similar in the two groups (82% vs. 87%). After 1 year, ulcer relapse was significantly less common in patients treated with anti-Helicobacter therapy than in those who received omeprazole alone (4.8% vs. 38.1%).

CONCLUSIONS

Eradication of H. pylori prevents ulcer recurrence in patients with H. pylori-associated perforated duodenal ulcers. Immediate acid-reduction surgery in the presence of generalized peritonitis is unnecessary.

Cytokeratin-Positive Malignant Tumors With Reticulum Cell Morphology

Cytokeratin-positive interstitial reticulum cells (CIRCs) have been described as a subset of fibroblastic reticulum cells (FBRCs) normally found in lymph nodes, the spleen, and tonsils. Although tumors derived form other reticulum (dendritic) cells, specifically follicular dendritic cells, interdigitating dendritic cells, and cytokeratin-negative FBRCs, have been well documented and are now accepted, this is not the case for tumors of CIRCs. A possible reason for this failure is the difficulty in distinguishing them from other tumors, particularly carcinoma. We report three cases of cytokeratin-positive malignant tumors with a reticulum cell morphology: two located in the mediastinum and one in the soft tissue in the proximal forearm. All cases coexpressed vimentin, and one case coexpressed smooth muscle actin and desmin, resulting in a phenotype similar to that of some normal CIRCs. Although metastatic carcinoma from an occult or regressed primary tumor cannot be excluded completely, we raise the possibility of a CIRC origin for these cases.

Clinical Utility of FDG-PET in Detecting Head and Neck Tumors. A Comparison of Diagnostic Methods and Modalities

Positron emission tomography (PET) using F-18-fluoro-2-deoxy-d-glucose(F-18-FDG) is gaining acceptance as a useful imaging method for head and neck tumors. Results of 59 PET scans done on 45 patients with head and neck tumors were evaluated retrospectively. Thirty-six patients had prior treatment consisting of surgery, radiation therapy, chemotherapy, or a combination of these modalities. PET results were compared to computed tomography and magnetic resonance imaging results and validated by histologic findings or survival. PET identified 36 out of 37 tumors (sensitivity 97%) and 18 of 22 benign processes (specificity 82%). Tumor was ruled out in 18 out of 19 patients. For CT, the sensitivity was 80% (20/25) and specificity was 31% (4/13). FDG-PET facilitates differentiation of recurrent head and neck tumors from treatment related changes sometimes difficult to characterize by CT or MRI and may have a significant impact on the management of patients reducing morbidity and costs.