Study of cellular immune response against Hepatitis E virus (HEV)

Hepatitis E virus infection (HEV) is a major cause of acute viral hepatitis in the developing world. The immunopathology of HEV infections has not yet been elucidated. The virus is noncytopathic, and therefore, liver injury may be attributed to immune-mediated damage by cytotoxic T cells and natural killer cells. Therefore, we studied the nature of immune cells involved in HEV-induced liver damage using immunohistochemistry in liver biopsies taken from patients with HEV-induced acute liver failure and demonstrated a significant infiltration of activated CD8(+) T cells containing granzymes. These findings suggest the possible involvement of cytotoxic T cells in disease pathogenesis during HEV infection.

DNA triplex-mediated inhibition of MET leads to cell death and tumor regression in hepatoma

Mesenchymal epithelial transition factor (MET) is one of the critical cell signaling molecules whose aberrant expression is reported in several human cancers. The aim of the study is to investigate the antigene and antiproliferative effect of short triplex forming oligonucleotides, TFO-1 (part of the positive regulatory element) and TFO-2 (away from the transcription start site) on MET expression. HepG2 cells transfected only with TFO-1 (but not with TFO-2 and non-specific TFO) significantly decreased MET levels, which is accompanied by decrease in antiapoptotic proteins and increase in pro-apoptotic proteins. Phosphoproteome-array analysis of 46 intracellular kinases revealed hypophosphorylation of about 15 kinases including ERK, AKT, Src and MEK, suggesting the growth inhibitory effect of TFO-1. Further, the efficacy of TFO-1 was tested on diethylnitrosamine-induced liver tumors in wistar rats. T2-weighted magnetic resonance imaging showed decrease in liver tumor volume up to 90% after treatment with TFO-1. Decreased MET expression and elevated apoptotic activity further indicate that TFO-1 targeted to c-met leads to cell death and tumor regression in hepatoma. Formation of stable DNA triplex between TFO-1 and targeted gene sequence was confirmed by circular dichroic spectroscopy and gel retardation assay. Therefore, it can be concluded that DNA triplex-based therapeutic approaches hold promise in the treatment of malignancies associated with MET overexpression.

Sphingolipids in the root play an important role in regulating the leaf ionome in Arabidopsis thaliana

Sphingolipid synthesis is initiated by condensation of Ser with palmitoyl-CoA producing 3-ketodihydrosphinganine (3-KDS), which is reduced by a 3-KDS reductase to dihydrosphinganine. Ser palmitoyltransferase is essential for plant viability. Arabidopsis thaliana contains two genes (At3g06060/TSC10A and At5g19200/TSC10B) encoding proteins with significant similarity to the yeast 3-KDS reductase, Tsc10p. Heterologous expression in yeast of either Arabidopsis gene restored 3-KDS reductase activity to the yeast tsc10Δ mutant, confirming both as bona fide 3-KDS reductase genes. Consistent with sphingolipids having essential functions in plants, double mutant progeny lacking both genes were not recovered from crosses of single tsc10A and tsc10B mutants. Although the 3-KDS reductase genes are functionally redundant and ubiquitously expressed in Arabidopsis, 3-KDS reductase activity was reduced to 10% of wild-type levels in the loss-of-function tsc10a mutant, leading to an altered sphingolipid profile. This perturbation of sphingolipid biosynthesis in the Arabidopsis tsc10a mutant leads an altered leaf ionome, including increases in Na, K, and Rb and decreases in Mg, Ca, Fe, and Mo. Reciprocal grafting revealed that these changes in the leaf ionome are driven by the root and are associated with increases in root suberin and alterations in Fe homeostasis.

Loss of heterozygosity on chromosome 11p15.5 and relapse in hepatoblastomas

BACKGROUND

IGF2 is a tumor suppressor gene at locus 11p15. Many hepatoblastomas have loss of heterozygosity (LOH) at this locus. Earlier studies have not demonstrated any association between LOH and prognosis. Aim of the study was to evaluate the prognostic significance of LOH at 11p15.5 in hepatoblastomas.

METHODS

DNA was isolated from normal liver and tumor tissue in 20 patients with hepatoblastoma. PCR was performed and cases were classified as LOH present, absent or non-informative. Patients' follow-up data was analyzed using Fischer's exact test and Kaplan-Meier survival analysis for relapse-free survival (RFS) in relation to LOH. Ethical clearance was obtained from the institutional ethics board.

RESULTS

All cases were informative for at least one microsatellite marker used. 4 of the 20 cases (20%) had LOH at 11p15.5. One patient died in the immediate postoperative period. 5 of 19 patients relapsed (26%). Of 4 patients who had LOH, 3 (75%) relapsed, the time to relapse being 7, 7 and 9 months, respectively. Of the 15 cases without LOH, 2 (13.3%) relapsed. 4 patients had mixed epithelial and mesenchymal histology; 3 of them had LOH. The 2 groups with and without LOH were well matched. The RFS for patients with LOH (n=4) was 13% (mean survival time [MST]: 8.7 months; 95CI 6.7-10.7), while the RFS for cases without LOH (n=15) was 75% (MST: 100.7 months; 95CI 74.5-126.8).

CONCLUSION

Mixed epithelial and mesenchymal histology is more frequently associated with LOH on chromosome 11p15.5 than pure epithelial histology. LOH on chromosome 11p15.5 is associated with a significantly increased incidence of relapse and a significantly shorter relapse-free survival in patients with hepatoblastoma. The risk of relapse is higher and the RFS lower both in standard-risk and high-risk patients with hepatoblastoma if they demonstrate the presence of LOH at 11p15.5.

A disease-causing mutation in the active site of serine palmitoyltransferase causes catalytic promiscuity

The autosomal dominant peripheral sensory neuropathy HSAN1 results from mutations in the LCB1 subunit of serine palmitoyltransferase (SPT). Serum from patients and transgenic mice expressing a disease-causing mutation (C133W) contain elevated levels of 1-deoxysphinganine (1-deoxySa), which presumably arise from inappropriate condensation of alanine with palmitoyl-CoA. Mutant heterodimeric SPT is catalytically inactive. However, mutant heterotrimeric SPT has approximately 10-20% of wild-type activity and supports growth of yeast cells lacking endogenous SPT. In addition, long chain base profiling revealed the synthesis of significantly more 1-deoxySa in yeast and mammalian cells expressing the heterotrimeric mutant enzyme than in cells expressing wild-type enzyme. Wild-type and mutant enzymes had similar affinities for serine. Surprisingly, the enzymes also had similar affinities for alanine, indicating that the major affect of the C133W mutation is to enhance activation of alanine for condensation with the acyl-CoA substrate. In vivo synthesis of 1-deoxySa by the mutant enzyme was proportional to the ratio of alanine to serine in the growth media, suggesting that this ratio can be used to modulate the relative synthesis of sphinganine and 1-deoxySa. By expressing SPT as a single-chain fusion protein to ensure stoichiometric expression of all three subunits, we showed that GADD153, a marker for endoplasmic reticulum stress, was significantly elevated in cells expressing mutant heterotrimers. GADD153 was also elevated in cells treated with 1-deoxySa. Taken together, these data indicate that the HSAN1 mutations perturb the active site of SPT resulting in a gain of function that is responsible for the HSAN1 phenotype.

Prognostic significance of location of the primary tumor in operable breast cancers

BACKGROUND

The prognostic significance of the primary tumor site in breast cancers is not established with only a few studies having evaluated the issue.

MATERIALS AND METHODS

The relevance of a primary tumor site with respect to systemic disease relapse was evaluated in 187 patients with breast cancer treated with primary surgery and adjuvant chemotherapy, in whom the location of primary tumor was classifiable in any one of the three sites, namely: outer, periareolar, and inner, quadrants. Data was obtained from prospectively maintained records of breast cancer patients treated at a single surgical unit in a tertiary care center.

RESULTS

The three groups were comparable with regard to demographic, pathological tumor, and treatment characteristics. In the multivariate analysis, patients with inner and periareolar quadrant tumors had a higher hazard for systemic disease relapse, (2.53, 95% CI: 1.18-5.42; P = 0.02, and 2.73, 95% CI: 1.04-7.14; P = 0.04, respectively) as compared to outer quadrant tumors. The projected five-year survival estimates in Kaplan Meier were 87%, 61%, and 69%, respectively, for outer, periareolar, and inner quadrant. On further substratification the difference was particularly noted in high risk inner quadrant tumors: age 45, premenopausal patients, tumor size> 2 cms, positive nodes and intermediate or high grade histology, as also in patients treated with breast conservation and CMF, Cyclophosphamide, Methorexate, 5 Fluorouracil chemotherapy.

CONCLUSION

The location of the primary tumor influences survival in breast cancer with inferior outcome for tumors in inner and periareolar quadrants, especially in high risk groups and those treated with conservative approaches. The role of aggressive therapies merits investigation in these patients.

Case report. Schwannoma of both intrahepatic and extrahepatic bile ducts: a rare case

Schwannoma of the biliary tree is extremely uncommon, with only a few cases having been reported so far. They commonly present with obstructive jaundice. Although involvement of the extrahepatic duct is common, occurrence in the intrahepatic ducts has not been reported. We report a case of combined intrahepatic and extrahepatic schwannoma in a 46-year-old man presenting with obstructive jaundice.

Outcome of endoscopic fulguration of posterior urethral valves in children

Posterior urethral valves are the most common cause of congenital obstructive uropathy leading to renal failure in childhood. This study was undertaken to assess the outcome of endoscopic fulguration of posterior urethral valves based upon the clinical, radiological and laboratory findings. This prospective study was carried out on 50 male children with posterior urethral valves who were treated by endoscopic fulguration and came for routine follow-up. Diagnosis of posterior urethral valves (PUV) was confirmed by voiding cystourethrogram (VCUG). After valve ablation, urine R/M/E, urine for culture and sensitivity test, serum creatinine level, USG of KUB including PVR were done in all cases at 1,3,6,12 months and then at six months interval maximum up to 3 years. Mean age of the patients was 2 years ranging from 1 to 12 years old. Mean follow-up period was 30.48 months after valve ablation. At diagnosis mean serum creatinine +/-SD was 90.4+/-44.8 mumol/lit and it decreased to 56.3+/-11.1micromol/lit at the end of 3-years follow-up. Hydronephrotic changes decreased from 84% to 4%. Proteinuria decreased from 38% to 6% and urinary tract infections decreased from 58% to 4% at the end of final follow up. Although the techniques for posterior urethral valves ablation have been refined and the short-term management of patients with posterior urethral valves has improved remarkably, there is growing concern about the long-term outcome. At present endoscopic fulguration with observation is the treatment of choice for posterior urethral valves. In this study patients improved dramatically following fulguration of posterior urethral valves. Early diagnosis and appropriate therapy may arrest progressive damage and facilitate recovery. Further follow-up studies of longer duration are needed.

Solitary fibrous tumour of the liver: a rare imaging diagnosis using MRI and diffusion-weighted imaging

Solitary fibrous tumour of the liver is an extremely rare neoplasm, the reported imaging features of which are largely non-specific. We present a case in which dynamic contrast-enhanced CT, MRI and diffusion-weighted MRI findings suggested a diagnosis of solitary fibrous tumour of the liver that was subsequently confirmed by immunohistochemical evaluation.

Prognostic significance of GSTP1 and MGMT hypermethylation in invasive ductal breast carcinoma patients

Abstract #4053

Purpose: Methylation-mediated suppression of detoxification, DNA repair and tumor suppressor genes has been implicated in cancer development, by shifting cells from the normal cellular cycle to a state of high proliferation that favors tumor development and progression. The current study was designed to analyze the methylation status of these genes in sera of breast cancer patients and determine the correlation of promoter hypermethylation of these genes with disease prognosis and patient survival.
 Experimental design: To test the hypothesis that promoter methylation of GSTP1 and MGMT is associated with disease prognosis, the methylation status of these genes was analyzed in invasive ductal carcinoma tissues and corresponding sera of breast cancer patients and correlated with disease free survival of these patients.
 Results: Promoter methylation of GSTP1 and MGMT was observed in 25% and 38% of breast tumor tissues, respectively and in 23% and 35% of the corresponding sera of breast cancer patients. There was significant association between methylation of GSTP1 and advanced tumor stage. Patients harboring methylated GSTP1 were more likely to have disease progression and reduced overall survival compared with patients who did not have the methylated gene.
 Conclusion: GSTP1 methylation in tumor and sera may serve as a poor prognostic marker in patients with invasive ductal carcinoma.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4053.

Tsc10p and FVT1: topologically distinct short-chain reductases required for long-chain base synthesis in yeast and mammals

In yeast, Tsc10p catalyzes reduction of 3-ketosphinganine to dihydrosphingosine. In mammals, it has been proposed that this reaction is catalyzed by FVT1, which despite limited homology and a different predicted topology, can replace Tsc10p in yeast. Silencing of FVT1 revealed a direct correlation between FVT1 levels and reductase activity, showing that FVT1 is the principal 3-ketosphinganine reductase in mammalian cells. Localization and topology studies identified an N-terminal membrane-spanning domain in FVT1 (absent in Tsc10p) oriented to place it in the endoplasmic reticulum (ER) lumen. In contrast, protease digestion studies showed that the N terminus of Tsc10p is cytoplasmic. Fusion of the N-terminal domain of FVT1 to green fluorescent protein directed the fusion protein to the ER, demonstrating that it is sufficient for targeting. Although both proteins have two predicted transmembrane domains C-terminal to a cytoplasmic catalytic domain, neither had an identifiable lumenal loop. Nevertheless, both Tsc10p and the residual fragment of FVT1 produced by removal of the N-terminal domain with factor Xa protease behave as integral membrane proteins. In addition to their topological differences, mutation of conserved catalytic residues had different effects on the activities of the two enzymes. Thus, while FVT1 can replace Tsc10p in yeast, there are substantial differences between the two enzymes that may be important for regulation of sphingolipid biosynthesis in higher eukaryotes.

Hemorrhagic pseudocyst of the adrenal gland causing acute abdominal pain

Acute abdominal pain is a common clinical entity with varied etiology. Hemorrhagic pseudocysts of the adrenal gland are rare lesions that might be considered in the differential diagnosis of acute abdominal pain. Herein, we report a case of young married female presenting with acute pain abdomen and fever, who was diagnosed to have hemorrhagic pseudocyst of the adrenal gland.

Congenital extrahepatic portosystemic venous shunt: imaging features

Congenital extrahepatic portosystemic venous shunt (CEPS) is a rare anomaly. It causes metabolic derangements and is often associated with liver tumours and other anomalies. Imaging plays an important role in the diagnosis of CEPS. However, it may be misleading in determining the type of shunt. We present a six-year-old girl with CEPS to illustrate the importance of histology in determining the presence of portal veins in the portal triad, which were too small to be seen on imaging.

Non-specific immune parameters of brood Indian major carp Labeo rohita and their seasonal variations

Different non-specific immune parameters and their seasonal changes in brood Indian major carp Labeo rohita reared in two major freshwater aquaculture regions of India viz. West Bengal and Orissa were investigated. It was undertaken for 2 consecutive years and included three main seasons of a year such as summer (March-May), rainy (July-September) and winter (November-January). Total serum protein, albumin and globulin levels were not significantly different throughout the year (p>0.01). Serum lysozyme and myeloperoxidase activities were lower (7.26+/-0.87mg/ml and, 0.54+/-0.11 OD, respectively) in winter as compared to any other season of the year. The bacterial agglutination titer was higher (p<0.01) in the rainy season (8.70+/-1.70) compared to summer and winter seasons (3.40+/-0.60 and 4.00+/-0.89, respectively). Haemagglutination and haemolytic activities did not vary (p>0.01) throughout the year. In blood smears, lymphocyte percentage was higher (75-80%) as compared to those of neutrophil (10-15%) and monocytes (5-10%) but eosinophilic granulocytes were present only in few cases. The differential leucocyte count did not vary significantly (p>0.05) in any season. This study indicated that certain non-specific immune parameters of this species can be modulated at certain times of the year.

Second echelon node predicts metastatic involvement of additional axillary nodes following sentinel node biopsy in early breast cancer

BACKGROUND

In many patients with early breast cancer, the sentinel lymph node (SLN) is the sole site of regional nodal metastasis. This subgroup of patients may not benefit from completion axillary lymph node dissection (CALND).

AIMS

This pilot study evaluates the status of 2nd echelon (station) lymph nodes in the axilla as a predictor of additional positive nodes in the axilla in the presence of sentinel node metastasis.

SETTINGS AND DESIGN

Cross-sectional study of 40 breast cancer patients.

MATERIALS AND METHODS

Forty patients with invasive breast cancer underwent SLN biopsy followed by 2nd echelon lymph node biopsy in the same sitting. SLN mapping was performed using a combined technique of isosulfan blue and 99 mTc-sulfur colloid. SLNs (Station I) were defined as blue and/or hot nodes. These nodes were then injected with 0.1 ml of blue dye using a fine needle and their efferent lymphatic was traced to identify the Station II nodes. Then a complete ALND was performed. All the specimens were sent separately for histopathological evaluation.

RESULTS

SLNs (Station I nodes) were successfully identified in 98% (39/40) patients. Of the 17 patients with a positive SLN, 8 (47%) patients had no further positive nodes in the axilla, 9 (53%) patients had additional metastasis in nonsentinel lymph nodes upon CALND. Station II nodes were identified in 76% (13/17) patients with a positive SLN. Station II nodes accurately predicted the status of the remaining axilla in 92% patients (12/13).

STATISTICAL ANALYSIS

We calculated the Sensitivity, Negative predictive value, Positive predictive value, False negative rate and Identification rate.

CONCLUSION

Station II nodes may predict metastatic involvement of additional nodes in the axilla.

Passive transfer of maternal antibodies and their existence in eggs, larvae and fry of Indian major carp, Labeo rohita (Ham.)

Lack of immune competence in the early stages of life leads to severe mortality in larval stages of different fish species including Indian major carp (IMC). Investigation through indirect enzyme linked immunosorbent assay (ELISA) and agglutination test revealed a significant increase in specific serum antibody response in the brood fish of Indian major carp, Labeo rohita (Ham.) following immunisation with a virulent Aeromonas hydrophila bacterin 1 month prior to breeding, which was transferred to larvae through the egg. No significant differences (P > 0.05) in mean antibody levels in larvae at the 1st and 2nd weeks post-hatch was recorded while a slight rise in antibody level was observed in 3-week-old fry, perhaps due to exposure to A. hydrophila present in the aquatic environment. Immunised brood fish serum, egg and larval extracts in non-reducing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and subsequent western blot analysis revealed an antibody molecule of approximate molecular weight 210 kDa. On challenge with virulent A. hydrophila, a significant reduction in mortality was recorded in immunised larvae and fry (58.0, 43.75 and 37.14% in the 1st, 2nd and 3rd week, respectively) relative to control fish (87.0, 79.0 and 76.4% in 1st, 2nd and 3rd week, respectively). The present study indicated the role of maternally derived antibody in protection of hatchlings of Indian major carp against specific pathogens.

The topology of the Lcb1p subunit of yeast serine palmitoyltransferase

The structural organization and topology of the Lcb1p subunit of yeast and mammalian serine palmitoyltransferases (SPT) were investigated. In the yeast protein, three membrane-spanning domains were identified by insertion of glycosylation and factor Xa cleavage sites at various positions. The first domain of the yeast protein, located between residues 50 and 84, was not required for the stability, membrane association, interaction with Lcb2p, or enzymatic activity. Deletion of the comparable domain of the mammalian protein SPTLC1 also had little effect on its function, demonstrating that this region is not required for membrane localization or heterodimerization with SPTLC2. The second and third membrane-spanning domains of yeast Lcb1p, located between residues 342 and 371 and residues 425 and 457, respectively, create a luminal loop of approximately 60 residues. In contrast to the first membrane-spanning domain, the second and third membrane-spanning domains were both required for Lcb1p stability. In addition, mutations in the luminal loop destabilized the SPT heterodimer indicating that this region of the protein is important for SPT structure and function. Mutations in the extreme carboxyl-terminal region of Lcb1p also disrupted heterodimer formation. Taken together, these data suggest that in contrast to other members of the alpha-oxoamine synthases that are soluble homodimers, the Lcb1p and Lcb2p subunits of the SPT heterodimer may interact in the cytosol, as well as within the membrane and/or the lumen of the endoplasmic reticulum.

Neoadjuvant chemotherapy in squamous cell carcinoma of the esophagus using low dose continuous infusion 5-fluorouracil and cisplatin: results of a prospective study

BACKGROUND

Surgery is the treatment of choice for localized esophageal squamous cell carcinoma (ESCC). Despite curative surgical resection, the majority of patients develop local and systemic recurrence with poor 5-year survival.

AIMS

To study the role of low dose continuous infusion (CI) 5-fluorouracil (5-FU) and cisplatin as neoadjuvant chemotherapy in ESCC.

SETTINGS AND DESIGN

A non-randomized prospective study conducted over a period of two years (1996-1998) in the Department of Surgery, All India Institute of Medical Sciences, India.

MATERIAL AND METHODS

Twenty-two patients with ESCC were included in the study. Chemotherapy consisted of a continuous 30-day infusion of 5-FU (350 mg/m2/day) and cisplatin (7.5 mg/m2/day), 5 days/week for 4 weeks. All patients had surgery following chemotherapy.

RESULTS

A full course of chemotherapy was completed in 18 patients (82%). Chemotherapy was not completed due to non-compliance (n=2), thrombophlebitis (n=1), and vomiting (n=1). Grade-1 haematological and hepato-toxicity was observed in four patients. Thirteen patients developed thrombophlebitis. After chemotherapy, improvement in dysphagia was observed in 13 of 22 (59%) patients. Radiological partial response was observed in 8 patients (36.4%). 19 patients underwent surgical resection (86.4%) with zero mortality. Post-operative morbidity was observed in six patients (27%). Complete and partial pathological response was observed in two (11%) and one patient (5.5%) respectively. The overall median survival was 18 months and 4-year survival was 42%.

CONCLUSIONS

Low dose CI 5-FU and cisplatin is well tolerated with minimal toxicity. Histopathological response rates and survival figures are comparable with the more toxic neoadjuvant chemotherapeutic regimens.