A sub-hepatic nodule in a young female: Chase the case.

Sertoli-Leydig cell tumours (SLCTs) are rare, mixed sex-cord stromal tumours composed of varying proportions of both Sertoli and Leydig cells, which account for <0.5% of all ovarian tumours. The cytomorphologic features of SLCTs are not well described in literature. Herein, we describe the cytomorphologic features of an SLCT at an uncommon metastatic site in a young female. Sertoli-Leydig cell tumours (SLCTs) are rare, mixed sex-cord stromal tumours composed of varying proportions of both Sertoli and Leydig cells, which account for <0.5% of all ovarian tumours. The cytomorphologic features of SLCTs are not well described in literature. Herein, we describe the cytomorphologic features of an SLCT at an uncommon metastatic site in a young female.

Diminution of Primary Cilia in the Stromal Cells at the Tumor-stromal Interface Correlates With an Aggressive Tumor Biology in the Urothelial Carcinoma of the Urinary Bladder.

BACKGROUND AND AIMS: Primary cilia (PC) are cellular organelles that regulate the cellular homeostasis. They are the seats of many oncogenic pathways and indirectly regulate the epithelial-mesenchymal transition (EMT) and extracellular matrix, both critical for the tumor microenvironment (TME). Though there are a few studies highlighting the alteration of PC in the tumor cells of various malignancies, none depict the PC in the stromal cells in the urothelial carcinoma of the urinary bladder (UC), the stromal cells being an essential component of TME. Therefore, we intend to evaluate the PC in the stromal cells at the tumor-stromal interface in UC. METHODS: Immunohistochemistry for acetylated-α-tubulin (for PC), Ki67, E-cadherin, and SNAI1 was performed in 141 cases of UC and 5 normal controls, and primary cilium: nucleus (C:N) ratio was counted in the stromal cells at the tumor-stromal interface. The C:N ratio was correlated with various clinical and histopathological parameters. RESULTS: The C:N ratio showed significant diminution from normal control (mean=0.75) to low-grade UC (mean=0.24) ( P =0.001) to high-grade UC (mean value=0.17) ( P =0.001). There was a significant diminution of the C:N ratio from the noninvasive to invasive UC ( P =0.025). The C:N ratio did not show any correlation with EMT although negatively correlated with the Ki67 index ( r =-0.32; P =0.001), and a higher ratio showed a trend with a higher recurrence-free survival ( P =0.07). CONCLUSIONS: The diminution of the PC in the stromal cells at the tumor-stromal interface is an early event and correlates with an aggressive tumor biology of UC.

All groin swellings are not lipoma.

An interesting case of an abdominal wall swelling near an old operative scar showing epithelial and stromal cells. In this present paper, fine needle aspiration cytology of an inguinal swelling is discussed which may often create diagnostic confusion.

Assessment of Matrix Metalloprotease - 7 (MMP7) Immunohistochemistry in Biliary Atresia and Other Pediatric Cholestatic Liver Diseases.

Background and aims: Biliary atresia (BA) is a progressive fibro-obliterative cholangiopathy. The histopathological diagnosis is often challenging and an immunohistochemical marker is often sought as an adjunct. We evaluated MMP7 immunohistochemistry in BA and other non-BA pediatric cholestatic liver diseases. Materials and methods: MMP7 immunohistochemistry was applied in 5 age-matched normal control, 23 cases of BA and 43 cases of non-BA pediatric cholestasis including 16 cases of choledochal cyst (CC), and a multiplication score was obtained by multiplying the intensity and percentage positivity in the cholangiocytes. Results: BA showed a high mean MMP7 multiplication score which was significantly different from the normal control and other non-BA pediatric cholestatic diseases including CC (p value < 0.001). The sensitivity, specificity, positive, and negative predictive values of MMP7 immunohistochemistry were 91.3%, 93.02%, 87.5%, and 95.2% respectively. Conclusion: MMP7 immunohistochemistry may be an adjunct to histomorphology in BA.

Metastatic juvenile granulosa cell tumor in abdominal wall.

Juvenile granulosa cell tumor (JGCT) is an uncommon ovarian tumor. There are only a few cases in the literature that depict the cytomorphology of JGCT at the primary/metastatic site. We described the fine-needle aspiration cytology of a recurrent metastatic JGCT of the anterior abdominal wall, 5 years post-surgery (total abdominal hysterectomy with bilateral salpingo-oophorectomy).

Malignant gastrointestinal neuroectodermal tumor: A case-based review of literature.

Malignant gastrointestinal (GI) neuroectodermal tumor is an extremely rare entity that was first described by Zambrano et al. in 2003 as "clear cell sarcoma (CCS)-like tumor of the GI tract." It shares some of the histopathological features of CCS but lacks the immunohistochemical (IHC) reactivity for melanocytic markers. Most mesenchymal neoplasms of the GI tract belong to the category of GI stromal tumors and are characterized by the IHC expression of c-KIT. In cases, without detectable KIT receptor expression, several differential diagnoses have to be taken into consideration. In this article, we describe such a case and present a review of all the reported cases till date. We also present the current available knowledge on its pathology and molecular genetics along with the limitations in its diagnosis. Here, we report a case of a 32-year-old man with a tumor of the small bowel composed of polygonal tumor cells arranged in solid nests, alveolar pattern, and pseudopapillary and admixed with numerous osteoclast-like multinucleated giant cells. Immunohistochemically, the tumor cells strongly expressed S-100 protein only. HMB-45, melan-A, CD117, cytokeratin, desmin, smooth muscle actin, and CD-34 were absent. Ki-67 index was 15%. The diagnosis was further confirmed by fluorescence in situ hybridization (FISH) demonstrating the presence of EWSR1 (22q12) translocation. A final diagnosis of malignant gastroneuroectodermal tumor was rendered. The patient is disease-free for 20 months of postsurgery. The diagnosis of this entity should be considered in the presence of S-100-positivity and multinucleated osteoclastic giant cells and the absence of melanocytic differentiation in a tumor arising from GI tract. Further confirmation can be done by performing FISH analysis.

T-Regulatory Cells in Erythema Nodosum Leprosum: An Immunohistochemical and Image Morphometric Study.

ABSTRACT: Erythema nodosum leprosum (ENL) occurs as an immune-inflammatory complication of multibacillary leprosy (MBL), precipitated by an interaction between the host, bacilli, and the environment. This complication often causes significant morbidity due to systemic involvement and needs to be treated aggressively. T-regulatory cells (T-regs) are the immunomodulatory subset of T cells that are hypothesized to play a role in ENL. We have performed immunohistochemistry for FoxP3 (T-reg), CD3 (pan-T), CD4 (helper T), and CD8 (cytotoxic T) on 50 biopsy-proven cases of ENL along with 84 biopsy-proven cases of paucibacillary leprosy (PBL) (n = 49) and MBL (n = 35). Image morphometry was applied to objectively assess the relative preponderance of these subsets of T cells. The area fraction of T-regs showed a trend of reduction from PBL to MBL to ENL (P = 0.068), whereas the FoxP3:CD3 (T-reg: pan-T) ratio showed a significant reduction across these groups (P = 0.023). However, there was no significant difference of T-regs or FoxP3:CD3 ratio between MBL and ENL. The T-regs showed a significant positive correlation (P = 0.007) with the cytotoxic T cells in the skin biopsy. The presence of dermal eosinophils in ENL showed a trend association with the FoxP3:CD3 ratio (P = 0.05). Various histopathological parameters including epidermal spongiosis, dermal stromal edema, dermal ill-formed granuloma, and the presence of bacilli within the endothelium and vascular smooth muscle correlated with various T-cell subsets. Our study, one of the largest on this topic, objectively assessed the role of T-regs in the spectrum of leprosy. Nevertheless, the precipitation of ENL from MBL is probably not associated with the T-reg subset alone.

Image Morphometric Analysis of B Cells and Plasma Cells in Erythema Nodosum Leprosum With Clinicopathological Correlation.

ABSTRACT: Erythema nodosum leprosum (ENL) occurs as an immunological complication of multibacillary leprosy (MBL). The pathogenesis of ENL is long considered to be a T-cell-mediated process. The role of B cells and plasma cells in ENL is not well described in the literature. Therefore, we investigated the B-cell and plasma cell infiltrates in the skin biopsies of biopsy-proven cases of ENL by immunohistochemistry and image morphometry and compared the result with paucibacillary leprosy and MBL. Moreover, we sought a correlation of the B-cell and plasma cell infiltrates with different clinical, hematological, histopathological, and bacteriological parameters as well as the T-cell subsets in the skin biopsies. Our study highlighted a significant reduction in the number of B cells from paucibacillary leprosy to MBL to ENL, although there was no significant variation in the plasma cell infiltrate. The plasma cell infiltrate correlated with absolute neutrophilia in the blood and the presence of eosinophils in the ENL lesions. Both B cells and plasma cells positively correlated with CD4-positive T-helper cells and the CD8-positive cytotoxic T cells. Besides, the B cells also correlated positively with the CD3-positive pan T cells in the biopsy and negatively correlated with the T-regulatory:T-cell ratio. Our results suggested the role of B cells and plasma cells even at the tissue level in the pathobiogenesis of ENL.

Was it Ewing's? A Diagnostic and Therapeutic Dilemma.

We present an atypical case of histopathology suggesting hemangioendothelioma and immunohistochemistry-proven Ewing's sarcoma in a 39-year-old lady who presented with multiple stony hard swellings involving the occipital region of the scalp, right cervical lymph node, right scapular region, left infraclavicular region of the chest, right anterior abdominal wall swelling, and inner aspect of right thigh. She underwent left-sided below-knee amputation for parosteal osteosarcoma in the left distal tibia 3 years back. Palliative radiotherapy with dose of 30 Gy in 10 fractions over 2 weeks was administered to the right neck and right upper back following which she attained moderate pain relief but no reduction in swellings as was expected had it been a case of hemangioendothelioma or Ewing's sarcoma..

Inflammatory myofibroblastic tumor of maxillary sinus successfully treated with radiotherapy and corticosteroid: report of a rare case.

BACKGROUND: Inflammatory myofibroblastic tumor (IMT) is a mesenchymal tumor mainly found in lung or retroperitoneum and rarely affects head and neck region. Extensive English literature search reveals that less than fifty cases of head and neck IMT have been reported so far, maxillary sinus being fewer. CASE PRESENTATION: We present a case of IMT involving maxillary sinus in a 48-year-old gentleman who attained complete clinico-radiologic response after treatment with radiotherapy (RT) and concurrent oral prednisolone. CONCLUSIONS: This is the first report where such magnificent response was attained in primary setting treated with RT and steroids as opposed to surgery which used to be considered as standard of care till now.

A Subcentimetric Nodule on the Penile Shaft.

Juvenile xanthogranuloma (JXG) is a benign histiocytic disorder usually affecting the head and trunk region of a child. The isolated occurrence of JXG in the penile shaft of a young adult is hitherto unreported. This lesion is amenable to surgical resection although systemic and/or internal visceral involvement can occur. The clinical differential of this solid cystic lesion may include other solid cystic lesions of the penile shaft, namely, epidermal inclusion cyst. A typical yellowish color can aid in the diagnosis though it is not a constant feature. In this article, we discuss a case of isolated penile JXG in a young adult with salient clinical and histopathological differentials.

Development of an Efficient Transformation System for Halotolerant Yeast Debaryomyces hansenii CBS767.

Debaryomyces hansenii is one of the most osmotolerant and halotolerant yeasts. Further, its association with traditional cheese and meat products imparting special flavors to these products project this yeast with enormous biotechnological potential in the agrofood sector. However, lack of an efficient transformation system in D. hansenii still direct the complementation based assay in S. cerevisiae mutants for functional analysis of D. hansenii genes. Here, we have described the development of an efficient transformation system for D. hansenii that is based on a histidine auxotrophic recipient strain, DBH9 (generated by UV induced random mutagenesis), and the DhHIS4 gene as the selectable marker. Moreover, the same method has also been employed for gene disruption in D. hansenii by homologous recombination.

Hierarchy and extremes in selections from pools of randomized proteins.

Variation and selection are the core principles of Darwinian evolution, but quantitatively relating the diversity of a population to its capacity to respond to selection is challenging. Here, we examine this problem at a molecular level in the context of populations of partially randomized proteins selected for binding to well-defined targets. We built several minimal protein libraries, screened them in vitro by phage display, and analyzed their response to selection by high-throughput sequencing. A statistical analysis of the results reveals two main findings. First, libraries with the same sequence diversity but built around different "frameworks" typically have vastly different responses; second, the distribution of responses of the best binders in a library follows a simple scaling law. We show how an elementary probabilistic model based on extreme value theory rationalizes the latter finding. Our results have implications for designing synthetic protein libraries, estimating the density of functional biomolecules in sequence space, characterizing diversity in natural populations, and experimentally investigating evolvability (i.e., the potential for future evolution).

Studies on xylitol production by metabolic pathway engineered Debaryomyces hansenii.

Debaryomyces hansenii is one of the most promising natural xylitol producers. As the conversion of xylitol to xylulose mediated by NAD(+) cofactor dependent xylitol dehydrogenase (XDH) reduces its xylitol yield, xylitol dehydrogenase gene (DhXDH)-disrupted mutant of D. hansenii having potential for xylose assimilating pathway stopping at xylitol, was used to study the effects of co-substrates, xylose and oxygen availability on xylitol production. Compared to low cell growth and xylitol production in cultivation medium containing xylose as the only substrate, XDH disrupted mutants grown on glycerol as co-substrate accumulated 2.5-fold increased xylitol concentration over those cells grown on glucose as co-substrate. The oxygen availability, in terms of volumetric oxygen transfer coefficient, kLa (23.86-87.96 h(-1)), affected both xylitol productivity and yield, though the effect is more pronounced on the former. The addition of extra xylose at different phases of xylitol fermentation did not enhance xylitol productivity under experimental conditions.

Molecular cloning, characterization, and engineering of xylitol dehydrogenase from Debaryomyces hansenii.

Because of its natural ability to utilize both xylose and arabinose, the halotolerant and osmotolerant yeast Debaryomyces hansenii is considered as a potential microbial platform for exploiting lignocellulosic biomass. To gain better understanding of the xylose metabolism in D. hansenii, we have cloned and characterized a xylitol dehydrogenase gene (DhXDH). The cloned gene appeared to be essential for xylose metabolism in D. hansenii as the deletion of this gene abolished the growth of the cells on xylose. The expression of DhXDH was strongly upregulated in the presence of xylose. Recombinant DhXdhp was expressed and purified from Escherichia coli. DhXdhp was highly active against xylitol and sorbitol as substrate. Our results showed that DhXdhp was thermo-sensitive, and except this, its biochemical properties were quite comparable with XDH from other yeast species. Furthermore, to make this enzyme suitable for metabolic engineering of D. hansenii, we have improved its thermotolerance and modified cofactor requirement through modelling and mutagenesis approach.

Co-factor binding confers substrate specificity to xylose reductase from Debaryomyces hansenii.

Binding of substrates into the active site, often through complementarity of shapes and charges, is central to the specificity of an enzyme. In many cases, substrate binding induces conformational changes in the active site, promoting specific interactions between them. In contrast, non-substrates either fail to bind or do not induce the requisite conformational changes upon binding and thus no catalysis occurs. In principle, both lock and key and induced-fit binding can provide specific interactions between the substrate and the enzyme. In this study, we present an interesting case where cofactor binding pre-tunes the active site geometry to recognize only the cognate substrates. We illustrate this principle by studying the substrate binding and kinetic properties of Xylose Reductase from Debaryomyces hansenii (DhXR), an AKR family enzyme which catalyzes the reduction of carbonyl substrates using NADPH as co-factor. DhXR reduces D-xylose with increased specificity and shows no activity towards "non-substrate" sugars like L-rhamnose. Interestingly, apo-DhXR binds to D-xylose and L-rhamnose with similar affinity (K(d)∼5.0-10.0 mM). Crystal structure of apo-DhXR-rhamnose complex shows that L-rhamnose is bound to the active site cavity. L-rhamnose does not bind to holo-DhXR complex and thus, it cannot competitively inhibit D-xylose binding and catalysis even at 4-5 fold molar excess. Comparison of K(d) values with K(m) values reveals that increased specificity for D-xylose is achieved at the cost of moderately reduced affinity. The present work reveals a latent regulatory role for cofactor binding which was previously unknown and suggests that cofactor induced conformational changes may increase the complimentarity between D-xylose and active site similar to specificity achieved through induced-fit mechanism.

Cloning and characterization of thermotolerant xylitol dehydrogenases from yeast Pichia angusta.

Pichia angusta (syn. Hansenula polymorpha) represents one of the rare yeast that can grow and ferment both xylose and glucose at higher temperature (50°C). However, little is known about the enzymes involved in xylose utilization from this species. Previous studies indicated the presence of one xylose reductase and two xylitol dehydrogenase genes in P. angusta. In this study, we have expressed both xylitol dehydrogenases (PaXdh1p and PaXdh2p) in Escherichia coli and purified them as 6X-Histidine-tagged proteins. Biochemical characterization of the recombinant proteins reveals that both PaXdh1p and PaXdh2p are thermotolerant enzymes. PaXdh2p contains a catalytic and a structural Zn atom. However, the structural Zn atom is not present in PaXdh1p. Both enzymes also differ in their affinity for the substrate as well as in the catalytic efficiency. Through mutagenesis and modeling approaches, we have also identified residues important for catalysis and substrate binding.

Development of host and vector for high-efficiency transformation and gene disruption in Debaryomyces hansenii.

Debaryomyces hansenii is one of the most osmotolerant and halotolerant yeasts. The molecular mechanisms underlying its extreme osmotolerance and halotolerance have drawn considerable attention in the recent past. However, progress in this regard has been limited due to lack of availability of a transformation system and molecular tools to study the functions of the genes in D. hansenii. Here, we have described the development of an efficient transformation system for D. hansenii that is based on a histidine auxotrophic recipient strain and the DhHIS4 gene as the selectable marker. By screening the D. hansenii genomic library, we have isolated several autonomous replication sequences that can be used for constructing a replicating vector. Moreover, our study is the first to demonstrate gene disruption in D. hansenii by homologous recombination.