Real-world experience supporting the role of oncologic resection and adjuvant chemotherapy in biliary tract cancers

Background

Complete resection followed by adjuvant chemotherapy is the gold standard for patients with localized cholangiocarcinoma (CC) or gallbladder cancer (GBC). However, this is not always feasible, and recurrence rates remain high.

Objectives

To understand the real-world proportions and reason for treatment failure in resected biliary tract cancers.

Design and methods

We performed a retrospective population-based review of patients with GBC or CC [intrahepatic (IHCC) or extrahepatic (EHCC)] resected between 2005 and 2019 using the BC Cancer provincial database. A chart review was conducted to characterize demographics, treatments received and outcomes.

Results

In total, 594 patients were identified of whom 416 (70%) had disease recurrence. Most GBCs (96%) were diagnosed incidentally, and repeat oncologic resection was performed in 45%. Adjuvant chemotherapy was received in 51% of patients diagnosed after 2017 (mostly capecitabine). Patient co-morbidities, disease progression and patient preference were the commonest reasons for not proceeding with adjuvant chemotherapy. One-third of patients did not complete all planned cycles. Median overall survival was significantly higher in those with complete (R0) versus incomplete (R1) resection [31.6 versus 18 months, hazard ratio (HR): 0.43, 95% confidence interval (CI): 0.35-0.53] and in those with versus without re-resection for GBC [29.4 versus 19 months, HR: 0.55, 95% CI: 0.41-0.73]. There was a trend towards improved survival with versus without adjuvant therapy (HR: 0.79, 95% CI: 0.61-1.02). Only 25% in the more contemporary cohort (2017-2019) had an R0 resection and completed adjuvant chemotherapy.

Conclusion

Complete resection, including reresection for incidentally diagnosed GBCs, and adjuvant chemotherapy were associated with improved outcomes in this retrospective cohort, yet many patients were not able to complete these treatments. Neoadjuvant strategies may improve treatment delivery and ultimately, outcomes.

Clinical impact of unsuccessful subcutaneous administration of octreotide LAR instead of intramuscular administration in patients with metastatic gastroenteropancreatic neuroendocrine tumors

Octreotide LAR is a long-acting somatostatin analogue (SSA) used in the management of metastatic gastroenteropancreatic neuroendocrine tumors (GEP NETs). It requires intramuscular (IM) injection. Missed IM injections cause subcutaneous nodules (SCNs) on radiologic images. We reviewed the rates of SCNs in a real-world cohort of GEP NETs receiving octreotide LAR and explored treatment outcomes. Patients commencing octreotide LAR between August 5, 2010 and March 8, 2018 at a single cancer center in Canada were identified from pharmacy records. Patients were included if they had a computed tomography (CT) scan performed at the time of progression and a preceding CT with pelvis included to enable assessment for the presence of nodules. Fisher's exact test was used to examine predictors of SCNs, and Kaplan-Meier curves summarized differences in progression free (PFS) and overall survival (OS) that were compared with log-rank tests. Of 243 patients receiving octreotide LAR, 45 had all required CT images available for central review. SCNs were found in 20/45 (44%) of patients on the last scan showing stable disease before progression and were numerically but not statistically more likely in females (OR: 2.36, 95% CI: 0.66-8.29, p = .23). There was an increased risk of SCNs in patients with a skin-to-muscle distance >38 mm (the length of an octreotide LAR needle) on CT (OR: 5.09, 95% CI: 1.39-16.6, p = .018) and a trend toward increased risk in obese patients (OR: 5.71, 95% CI: 1.26-23.4, p = .061). PFS (HR: 1.01, 95% CI: 0.56-1.78, p = .98) and OS (HR: 0.86, 95% CI: 0.41-1.8, p = .70) was similar between those with/without SCNs. In conclusion, almost half of patients receiving octreotide LAR had SCNs; however, missed administration of SSA did not appear to result in worse survival in this small study. Factors such as sex, younger age skin-to-muscle distance, and obesity may affect SCN development and should be considered when choosing an SSA.

Primary site and treatment impact in unresectable metastatic colorectal cancer

INTRODUCTION

Colorectal cancer is a heterogenous disease, with various clinical and molecular subtypes related to the primary site (left versus right colon) of the original tumour. Primary colon tumour side is both a prognostic and predictive marker in metastatic colorectal cancer.

AREAS COVERED

There is an increasing body of evidence for how primary site may impact treatment decisions in metastatic colorectal cancer. We reviewed the evidence for its prognostic and predictive value.

EXPERT OPINION

Primary site is a prognostic marker in metastatic colorectal cancer, with right colon tumours being associated with more aggressive disease behaviour and poorer outcomes. Primary site also appears to predict for outcomes to various treatments, in particular anti-EGFR antibodies. As our understanding and testing of the molecular and biological differences within colorectal cancer increases beyond primary site, this should be integrated into the current treatment algorithm to ensure an individualised patient-centred approach to care.

First-line anti-EGFR or anti-VEGF therapy, tumour sidedness, and survival: Results from the South Australian (SA) Metastatic Colorectal Cancer (mCRC) Registry

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Background: The anti-EGFR monoclonal antibodies panitumumab (Pmab) and cetuximab (Cmab) and the anti-VEGF antibody bevacizumab (bev) have demonstrated clinical efficacy in mCRC in combination with first-line chemotherapy. Clinical and molecular characteristics, such as primary tumour sidedness, RAS, BRAF and MMR status are prognostic and predictive biomarkers for response to treatment. Our aim was to compare the survival and tumour characteristics of patients receiving first-line chemotherapy and antibody combinations using the SA mCRC Registry. Methods: This real-world registry has collected data from all patients diagnosed with mCRC in SA prospectively since 2006. We identified patients who had received first-line Pmab, Cmab or bev. Survival was analysed using the Kaplan-Meier method and log-rank test to compare outcomes based on primary tumour location. Results: Of the 5537 patients currently entered onto the registry, 1313 with RAS results available had received first-line anti-EGFR/VEGF antibodies and had colon tumour side recorded. The table summarises median overall survival (mOS) and patient characteristics. Survival was significantly shorter for those with right colon cancers (P < 0.001). There were more high-grade (P < 0.001), KRAS mutant (P = 0.004) and BRAF mutant (P = 0.036) tumours in those with right colon cancers, and a trend towards fewer curative liver resections (P = 0.059). There was no significant difference in mOS seen between Pmab, Cmab or bev for both left (P = 0.14) and right-sided (P = 0.88) primary tumours. Conclusions: There were more high-grade, BRAF and KRAS mutant patients with right colon tumours, and lower rates of liver resection, which may explain the significantly shorter mOS. The survival seen for Pmab and Cmab was almost identical for both right and left primary tumours. When comparing Pmab, Cmab and bev as first-line therapy, there was no significant difference in mOS for both left- and right-sided CRC. [Table: see text]

Targeting Mutated KRAS Genes to Treat Solid Tumours

Kirsten rat sarcoma (KRAS) is one of the most frequently mutated oncogenes in solid tumours. It encodes an important signalling pathway that drives cellular proliferation and growth. It is frequently mutated in aggressive advanced solid tumours, particularly colorectal, lung and pancreatic cancer. Since the first mutated KRAS was discovered in the 1980s, decades of research to develop targeted inhibitors of mutant KRAS have fallen short of the task, until recently. Multiple agents are now in clinical trials, including specific mutant KRAS inhibitors, pan-KRAS inhibitors, therapeutic vaccines and other targeted inhibitors. Mutant-specific KRAS G12C inhibitors are the most advanced, with two inhibitors, adagrasib and sotorasib, achieving approval in 2021 for the second-line treatment of patients with KRAS G12C mutant lung cancer. In this review, we summarise the importance of mutant KRAS in solid tumours, prior attempts at inhibiting mutant KRAS, and the current promising targeted agents being investigated in clinical trials, along with future challenges.

Recent advancements in melanoma management

The treatment options for patients with melanoma have expanded significantly over the past decade. In particular, the use of targeted therapy and immunotherapy has dramatically transformed the outlook for patients with advanced disease. These treatments are now being utilised as adjuvant therapy for patients with earlier stage melanoma after surgical resection. We review the latest updates for melanoma staging, surgical resection, radiotherapy and systemic therapies.

Curative therapy for rectal cancer

Introduction: A comprehensive trimodality approach has become the standard of care for patients with locally advanced rectal cancer. However, the sequencing and duration of chemotherapy and chemoradiotherapy around surgery varies between clinical studies and geographical regions. Growing evidence is also mounting for strategies such as total neoadjuvant therapy and non-operative management for carefully selected patients.Areas covered: We provide a perspective review of the current evidence and controversies in the treatment of locally advanced rectal cancer including the recent updates from the 2020 ASCO annual conference.Expert opinion: With ongoing advances in the management of locally advanced rectal cancer, a multidisciplinary team approach is necessary as treatments could involve multiple approaches. Chemoradiotherapy whether short or long course followed by at least 3 months of systemic chemotherapy may be the preferred option to balance local and distant disease control. Albeit the choice of doublet or triplet chemotherapy is still controversial. As total neoadjuvant treatment becomes part of the standard of care in rectal cancer, modification of the surveillance schedule is needed to detect early recurrences which may be limited by resources and availability of services.

Cardiac angiosarcoma: A diagnostic and therapeutic challenge

Cardiac angiosarcomas are a rare group of soft tissue sarcomas, characterized by aggressive local growth and early spread. Because this is an uncommon disease, there is currently no standard treatment approach. When localized, surgery appears to lead to the best outcomes, but this can be technically challenging and not always feasible. Upfront chemoradiotherapy provides an alternative that may shrink the tumor to enable definitive surgical resection. We report a case of primary cardiac angiosarcoma with a complete metabolic and pathological response after upfront chemoradiotherapy with paclitaxel, who then underwent surgery, as a potential treatment option for patients with this rare condition. <Learning objective: Cardiac angiosarcoma can present with non-specific symptoms and signs making early diagnosis difficult. When localized, surgery provides the best survival outcomes for patients, but may not be possible due to the extent of invasion into surrounding critical structures. In this case of locally advanced disease in a young patient, there was the opportunity to treat this tumor aggressively with upfront combined chemoradiotherapy followed by surgery, with a dramatic response observed.>.

A retrospective analysis of eosinophilia as a predictive marker of response and toxicity to cancer immunotherapy

Aim:

To investigate eosinophilia as a potential on-treatment biomarker for patients receiving cancer immunotherapy.

Materials & methods:

We evaluated the association between eosinophilia and treatment response and toxicity in a retrospective cohort of patients receiving cancer immunotherapy.

Results:

The study involved 146 patients. Eosinophilia developed in 22%. Patients who developed eosinophilia were more likely to achieve disease control (p = 0.009), with every 0.1 × 10⁹/l rise in eosinophil count, while receiving treatment was associated with a 28% relative increased chance achieving disease control. Although there was a trend toward improved survival, there was no significant association between eosinophilia and improved overall survival (p = 0.136). Patients with eosinophilia were more likely to develop toxicity (p = 0.042).

Conclusion:

Eosinophilia is a potentially useful biomarker warranting further prospective clinical investigation.

Immunotherapy has revolutionized the way we treat many cancers. However, we do not have good predictors for which patients are going to respond to treatment or experience side effects. ‘Eosinophilia’ is when a particular type of white blood cell is present at high levels in the blood. This can occur in patients on immunotherapy. This paper reports a possible link between eosinophilia and the likelihood of responding well to immunotherapy but also the possibility of developing side effects.

Membrane disruption and anti-quorum sensing effects of synergistic interaction between Lavandula angustifolia (lavender oil) in combination with antibiotic against plasmid-conferred multi-drug-resistant Escherichia coli

AIM

The aim of this study was to investigate the mode of action of the lavender essential oil (LV) on antimicrobial activity against multi-drug-resistant Escherichia coli J53 R1 when used singly and in combination with piperacillin.

METHOD AND RESULTS

In the time-kill analysis, a complete killing of bacteria was observed based on colony counts within 4 h when LV was combined with piperacillin during exposure at determined FIC concentrations. Analysis of the membrane permeabilizing effects of LV on treated cultures through their stability against sodium dodecyl sulphate revealed that the LV played a role in disrupting the bacterial cell membrane. The finding is further supported by scanning electron microscopy analysis and zeta potential measurement. In addition, reduction in light production expression of E. coli [pSB1075] by the LV showed the presence of potential quorum sensing (QS) inhibitors.

CONCLUSIONS

These results indicated that the LV has the potential to reverse bacterial resistance to piperacillin in E. coli J53 R1. It may operate via two mechanisms: alteration of outer membrane permeability and inhibition of bacterial QS.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings offer a novel approach to develop a new option of phytopharmaceuticals against multi-drug-resistant E. coli.

The role of leukemia inhibitory factor in tubal ectopic pregnancy

INTRODUCTION

Ectopic pregnancy is unique to humans and a leading cause of maternal morbidity and mortality. The etiology remains unknown however factors regulating embryo implantation likely contribute. Leukemia inhibitory factor (LIF) has roles in extravillous trophoblast adhesion and invasion and is present in ectopic implantation sites. We hypothesised that LIF facilitates blastocyst adhesion/invasion in the Fallopian tube, contributing to ectopic pregnancy.

METHODS

We immunolocalised LIF receptor (R) in tubal ectopic pregnancy (N = 5). We used an oviduct cell line (OE-E6/E7) to model Fallopian tube epithelial cells and a trophoblast spheroid co-culture model (HTR-8/SVneo cell line formed spheroids) to model blastocyst attachment to the Fallopian tube. We examined LIF signaling pathways in OE-E6/E7 cells by Western blot. The effect of LIF and LIF inhibition (using a novel LIF inhibitor, PEGLA) on first-trimester placental outgrowth was determined.

RESULTS

LIFR localised to villous and extravillous trophoblast and Fallopian tube epithelium in ectopic pregnancy. LIF activated STAT3 but not the ERK pathway in OE-E6/E7 cells. LIF stimulated HTR-8/SVneo spheroid adhesion to OE-E6/E7 cells which was significantly reduced after PEGLA treatment. LIF promoted placental explants outgrowth, while co-treatment with PEGLA blocked outgrowth.

DISCUSSION

Our data suggests LIF facilitates the development of ectopic pregnancy by stimulating blastocyst adhesion and trophoblast outgrowth from placental explants. Ectopic pregnancy is usually diagnosed after 6 weeks of pregnancy, therefore PEGLA may be useful in targeting trophoblast growth/invasion.

CONCLUSION

LIF may contribute to the development of ectopic pregnancies and that pharmacologically targeting LIF-mediated trophoblast outgrowth may be useful as a treatment for ectopic pregnancy.

Emergence of Noroviruses homologous to strains reported from Djibouti (horn of Africa), Brazil, Italy, Japan and USA among children in Kolkata, India

AIM

A total of 625 faecal specimens of diarrheic cases (n-313) and non diarrheic controls (n-312), were screened by RT-PCR to detect Noroviruses in children aged below 5 years in Kolkata, India.

MATERIALS AND METHODS

Out of the 313 fecal specimens (cases) screened using CDC primer set, 10 (3.19%) showed amplification in reverse transcription-polymerase chain reaction (RT-PCR) for Norovirus. These included 5 of 260 (1.92%) from hospitalized and 5 of 53 (9.43%) from out patients departament (OPD) cases.

RESULTS

Nine (90%) of Norovirus positive cases belonged to genogroup GII and one specimen (10%) was positive for genogroup GI. Among the 312 non diarrheic controls 2 (0.63%) were positive for Norovirus GII. Partial RNA dependent RNA polymerase gene (RdRp) sequences corresponding to the six Norovirus GII positive samples showed homology to the sequences of Djibouti (horn of Africa), Brazil, Italy, Japan and US norovirus strains.

CONCLUSION

This study shows the detection of newly emerging Norovirus strains among diarrheic and non diarrheic children in Kolkata.

A study on the possibility of zoonotic infection in rotaviral diarrhoea among calves and buffalo calves in and around Kolkata, India

Group A and group B rotaviruses are important diarrhea causing agents among calves and buffalo calves. Epidemiological studies in Indian calves revealed the predominance of group A rotavirus strains with G6, G8, and G10 specificity and group B rotaviruses. A total of 95 fecal samples were collected from calves and buffalo calves affected with diarrhea from an unorganized cattle farm and two cattle markets in and around Kolkata, in the state of West Bengal of Eastern India. Rotaviruses were detected in 23.15% (22/95) samples by polyacrylamide gel electrophoresis. Of 22 rotavirus positive cases, 10.52% (10/95) samples showed characteristic group A rotavirus-like long type electropherotype (e-type) pattern and 4.21% (4/95) samples showed the characteristic group B rotavirus long type of electropherotype pattern and in 8.42% (8/95) the electropherotype pattern could not be recorded. Out of 22 positive samples, 7 samples of group A rotaviruses were subjected to reverse transcription-polymerase chain reaction, using VP7 generic and genotype [G type] specific primers and 2 of 7 isolates were identified as G10.

Identical rearrangement of NSP3 genes found in three independently isolated virus clones derived from mixed infection and multiple passages of Rotaviruses

Three rotavirus variants with a rearranged RNA segment derived from the NSP3 gene were isolated in three independent experiments of coinfection and multiple passages of simian rotavirus strain SA11 and single-VP7-gene- or NSP1-gene-substitution reassortants having genetic background of SA11. Sequence analysis indicated that the three rearranged NSP3 genes had almost identical sequences and genomic structures organized by partial duplication of the open reading frame in a head-to-tail orientation following the termination codon. The junction site of the original NSP3 gene (first copy) and the duplicated portion (second copy) was identical among the three rearranged genes, while a direct repeat, i.e., a homologous sequence between the first copy and second template for duplication, typically located at the junction site, was not detected. However, short similar sequences were present at the end of the first copy and beginning of the second copy. These findings suggest that rearrangement of the NSP3 gene may occur at a certain preferential site which is related to sequence similarity between 3'-untranslated region and a region near the 5'-end of ORF.

Changing pattern of human group A rotaviruses: Emergence of G12 as an important pathogen among children in eastern India

BACKGROUND

Rotavirus genotypes, G1-G4 and G9 are associated with childhood diarrhoea throughout the world. In our previous study, we detected G1, G2, G4 and three G12 strains from Kolkata, India.

OBJECTIVES

To study the prevalence of G- and P-genotypes of rotaviruses associated with dehydrating diarrhoea in children admitted to two leading hospitals in eastern India.

STUDY DESIGN

An active surveillance was conducted for elucidation of rotavirus infection in two leading hospitals in Kolkata, West Bengal and Berhampur (GM), Orissa, India, separated by 603km from January 2003 to April 2005. The rotaviruses were detected by RNA electrophoresis in polyacrylamide gels. G- and P-typing of the positive samples were accomplished by amplifying VP7 and VP4 genes by RT-PCR and genotyped by seminested multiplex PCR methods. Sequencing, sequence analysis and phylogenetic analysis of VP7 genes of G12 strains were carried out to understand the variations between the strains isolated from different parts of the world.

RESULTS

The genotypic distribution varied remarkably from our earlier study period (1998-2001) with G1 (53.8%) being the most predominant strain followed by G2 (22.5%), G12 (17.1%), G9 (2.1%) and not a single G3 or G4 isolate was detected separately. 35.2% samples exhibited mixed P-types followed by P[4] (31.7%), P[8] (21.8%) and P[6] (9.8%). The phylogenetic analysis of G12 strains revealed that the G12 strains detected from different parts of the world clustered into three different lineages. Though VP7 sequences of G12 strains isolated from Kolkata and Berhampur are conserved, their P-types were different.

CONCLUSION

During this study period we reported emergence of G12 strains as an important pathogen among children in eastern India, thus necessitating its inclusion in future polyvalent vaccine to control rotavirus diarrhoea.

RT-PCR based diagnosis revealed importance of human group B rotavirus infection in childhood diarrhoea

BACKGROUND

Human group B rotavirus was first identified as causative agent of a large outbreak of severe gastroenteritis affecting more than 1 million people, predominantly adults in China in 1982-1983. In spite of serological evidences for the presence of group B rotavirus in many countries of the world, the virus has been detected only from China, India and Bangladesh, where most of the cases were from adults.

OBJECTIVES

To ascertain the role of group B rotavirus as an aetiological agent of diarrhoea among children in Kolkata, India.

STUDY DESIGN

An active surveillance was conducted for rotavirus infection in children in a leading referral paediatric hospital and a few samples were also collected from adults of another hospital in Kolkata, India over a period of 3 years (2002-2004). After primary screening of rotaviruses by RNA electrophoresis in polyacrylamide gel, 200 of 412 samples negative by PAGE were screened by reverse transcription polymerase chain reaction for group B rotaviruses. The group B rotavirus positives samples were also confirmed by dot-blot hybridization.

RESULT

During the study period, we detected 37 (18.5%) sporadic cases of human group B rotavirus infection in children below 3 years of age of which 15 (7.5%) showed mixed infection with group A rotaviruses by RT-PCR. In dot-blot hybridization studies the RNA of all rotavirus positive samples hybridized with the nonisotopic psoralen-biotin labeled total RNA probe generated from a human group B rotavirus CAL-1 strain confirming the samples as group B rotaviruses.

CONCLUSION

The shift in age preference of group B rotavirus infection from adult to children and mixed infection of group B and group A rotaviruses reveals the importance of group B rotavirus as an etiological agent of childhood diarrhoea. Therefore, future vaccination strategy should include both group A and B rotaviruses to control rotavirus diarrhoea.

Sequencing and sequence analysis of VP7 and NSP5 genes reveal emergence of a new genotype of bovine group B rotaviruses in India

Three bovine group B rotavirus strains were detected from diarrheic calves during a surveillance study of rotaviral diarrhea in West Bengal, India. The sequence analysis of VP7 and NSP5 genes of these strains demonstrates a high degree of sequence variation from other group B rotavirus strains, indicating the emergence of a new genotype.

Molecular characterization of a human rotavirus reveals porcine characteristics in most of the genes including VP6 and NSP4

Long electropherotype with Subgroup I specificity is a common feature of animal rotaviruses. In an epidemic of infantile gastroenteritis in Manipur, India, long but SG I strains predominated in the outbreak in the year 1987-88. One such strain isolated from that region, following the outbreak had G9P [19] specificity. As this is a rare combination, the gene sequences encoding VP4, VP6, VP7, NSP1, NSP2, NSP3, NSP4 and NSP5 of this strain were analyzed. All these genes except VP7 were closely related to porcine rotaviruses (95-99% identity at amino acid level) and clustered with the porcine strains in phylogenetic analysis. In addition, it had subgroup I nature and belonged to NSP4 genotype B which is characteristic of animal rotaviruses. This is the first report of a rotavirus with VP6 and NSP4, two crucial proteins thought to be involved in host range restriction and pathogenicity, were of porcine origin and caused diarrhoea in a human host. Among the genes of this strain sequenced so far, only VP7 had highest identity to human strains at amino acid level. This study suggests reassortment may be occurring between human and other animal strains and some of the reassortant viruses may be virulent to humans.

Emergence of novel human group A rotavirus G12 strains in India

Three rare human G12 strains were detected from diarrheic clinical samples of children (<8 months of age) in Calcutta during a routine surveillance study of rotaviral diarrhea in India. The VP7 genes of G12 strains and their products showed maximum homology (97 to 99% at the nucleotide level and 98% at the amino acid level, respectively) with those of two recently reported G12 strains (from the United States and Thailand) but lesser homology with those of prototype G12 strain L26.

Genomic diversity of group A rotavirus strains infecting humans in eastern India

Between 1998 and 2000, a total of 266 samples were found positive for group A rotaviruses by RNA electrophoresis. Samples were collected from patients admitted to two leading hospitals in Calcutta. Serotyping could be done only with 22% of the positive samples, leaving 78% untypeable. The G (VP7 genotypes) and P (VP4 genotypes) types were determined for 159 samples by reverse transcription and multiplex PCR. The predominant genotype was G1P[8] (20%), followed by G2P[4] (15%) and G4P[8] (6%). A number of uncommon genotypes, G1P[4] (4%), G2P[8] (2.5%), G2P[6] (0.6%), G4P[4] (2.5%), and G4P[6] (1.25%), were also detected during this study period. Twenty two percent of specimens showed mixed infections, 38 (24%) of the total samples remained untypeable for either VP7 or VP4, while only 4 (2.5%) of the samples were untypeable for both genes. Eleven specimens collected from Manipur were also genotyped and revealed a very high degree of genomic reassortment.

Sequence analysis of genes encoding structural and nonstructural proteins of a human group B rotavirus detected in Calcutta, India

Nucleotide sequences of RNA segments encoding structural proteins(VP4, VP6, and VP7) and nonstructural proteins(NSP1 and NSP3) of a human group B rotavirus CAL-1, which was detected in Calcutta, India, were determined and their relatedness with cognate genes of other group B rotaviruses was analyzed. The CAL-1 genes showed generally high sequence identities (more than 90%) to those of human group B rotavirus, adult diarrheal rotavirus (ADRV) in China, while identities with bovine, murine, and ovine viruses were considerably lower (58-73%). Among RNA segments analyzed, sequence identity of the VP6 gene was relatively high compared with other gene segments. In the CAL-1 VP7 sequence, many characteristics were shared by ADRV, but not by other animal group B rotaviruses. In contrast, VP4 and NSP3 of CAL-1 were single amino acid and 23 amino acids longer than those of ADRV strain, respectively, due to differences of a few nucleotides. These findings suggested that human group B rotaviruses CAL-1 and ADRV might have originated from a common ancestral virus distinct from animal group B rotaviruses reported so far, while some notable sequence differences indicated the distinct nature of these viruses.

The evolution of human group B rotaviruses

The largest reported rotavirus epidemic affected well over a million people in China during 1982-83 and was caused by the adult diarrhoea rotavirus (ADRV), a serogroup B rotavirus. However, ADRV has not been reported outside China since the last recorded small outbreak there in 1987. Here we present evidence that offers an explanation for the sudden appearance and disappearance of the epidemic ADRV strain.

Amplification of various genes of human group B rotavirus from stool specimens by RT-PCR

BACKGROUND

The detection of the human group B rotavirus (HuGBR) CAL strain from India has given us an opportunity to design suitable primers for the detection of HuGBR since CAL is the second HuGBR detected until now, the Chinese Adult Diarrhoea Rotavirus (ADRV) being the first reported human pathogen belonging to this group of viruses. The primers described here may thus be used for the detection of human group B rotaviruses by reverse transcription-PCR (RT-PCR) in a diagnostic laboratory.

OBJECTIVE

To establish a set of primers suitable for the detection of various genes of human group B rotaviruses using a rapid RT-PCR assay.

STUDY DESIGN

Until recently, the Chinese ADRV strain was the only HuGBR strain that had been partially sequenced by cloning various viral genes using vector-specific primers. Consequently, there are very few reports in the literature describing primers that may be used for the detection of HuGBR viruses using RT-PCR in a clinical laboratory. The sequences of various genes from the ADRV strain that had been submitted to the nucleotide sequence database GenBank were analyzed in order to design several putative detection primer pairs for an RT-PCR assay. The rationale was to amplify the cognate genes from five isolates of the HuGBR CAL strain (CAL-1 to CAL-5) that have been detected to date from India. Primers that resulted in a specific product of the expected size from the CAL isolates were used to standardize a protocol for amplifying various genes of the CAL isolates under identical reaction conditions.

RESULTS

Out of several synthetic oligonucleotides designed, 12 were found to be satisfactory for the amplification of gene segments 4, 5, 6, 7, and 9 from the five CAL isolates and are presented here. A set of previously described primers that have been shown to be specific for human group B rotavirus gene segment 8 were also found to amplify the cognate gene from the CAL isolates. All the reactions were carried out using the same thermal cycling conditions.

CONCLUSIONS

The extreme virulence potential of HuGBR has been documented in several epidemics in China. Until recently, the Chinese ADRV strain was the only known HuGBr strain. As there have not been any reports of HuGBR infections outside China, there are no consensus nucleotide sequences available for HuGBR that may be used to validate primers for the detection of HuGBR. Here we report a set of 12 primer sequences that were designed from ADRV sequences and also found to amplify various genes from the different CAL isolates and hence may represent consensus primers suitable for the detection of HuGBR.

Electronmicroscopic evidence of torovirus like particles in children with diarrhoea

Pleomorphic virus-like particles approximately 90 nm in diameter with short fringe (7-9 nm long) were observed in faecal specimens of two diarrhoeic children in the course of routine screening of samples for viruses by electronmicroscopy. No other viral, bacterial or parasitic pathogens were detected in the same samples. Immune electronmicroscopic examination showed that these virus like particles were agglutinated by immunesera raised against Breda I and Breda II viruses of calves. This observation suggests that torovirus may be a new viral pathogen of humans.

Production of the beta-subunit of human chorionic gonadotropin in Escherichia coli and its export mediated by the heat-labile enterotoxin chain-B signal sequence

The PCR-amplified beta-subunit of the human chorionic gonadotropin structural gene (betahCG) was cloned under the control of the tac promoter and the heat-labile enterotoxin chain B (LTB) signal sequence (LTBss). BetahCG was successfully produced, processed and exported to the periplasmic space in Escherichia coli. Expression of betahCG was confirmed by immunoblot analysis using an anti-betahCG polyclonal antibody. The processing of the protein was very efficient, as only the processed band could be detected at all time points during the course of induction. Expression was evident soon after the addition of the lactose analogue, IPTG. These results demonstrate that E. coli cells can synthesize, process and export betahCG using the LTBss.

Rotavirus vaccine: current status & future prospects

A number of rotavirus vaccines, live attenuated, killed, and subunit, genetically engineered vaccines have been developed to control infantile diarrhoea. Field trials in several parts of the world have met with moderate or no success as the vaccinees failed to develop heterotypic protection. The failure of vaccine to control rotavirus diarrhoea may be due to the lack of understanding of the neonatal mucosal immune response, evolution of reassortant strains in nature and seasonal re-emergence of different types of strains in the field situation.

Molecular epidemiology of human rotaviruses in Manipur: genome analysis of rotaviruses of long electropherotype and subgroup I

In 1987/88 a winter outbreak of infantile gastroenteritis occurred in Manipur, India which was mainly due to rotaviruses of long electropherotype and subgroup (SG) I. The VP7 gene of one of these viruses (M48) has been cloned and sequenced. It was found to be very closely related to the VP7 genes of the G2 serotype human rotaviruses RV-5 and S2. Follow-up epidemiology of this event in Manipur during 1989-1992 yielded mainly rotaviruses of more conventional characteristics (94 isolates of SG II and long electropherotype, and 90 isolates of SG I and short electropherotype), but also 6 isolates of SG I with long electropherotype, indicating that these viruses continue to circulate in the Manipur community. One isolate of short electropherotype was of subgroup II, and one long electropherotype isolate reacted with the group A but not with either the subgroup I or subgroup II monoclonal antibodies.

Geographical and ethnic variability of finger ridge-counts: biplots of male and female Indian samples

The graphical technique of biplot due to Gabriel and others is explained, and is applied to ten finger ridge-count means of 239 populations, mostly Indian. The biplots, together with concentration ellipses based on them, are used to study geographical, gender and ethnic/social group variability, to compare Indian populations with other populations and to study relations between individual counts and populations. The correlation structure of ridge-counts exhibits a tripartite division of digits demonstrated by many other studies, but with a somewhat different combination of digits. Comparisons are also made with the results of Leguebe and Vrydagh, who used principal components, discriminant functions, Andrews functions, etc., to study geographical and gender variations. There is a great deal of homogeneity in Indian populations when compared to populations from the rest of the world. Although broad geographical contiguity is reflected in the biplots, local (states within India) level contiguity is not maintained. Monogoloids and Caucasoids have distinct ridge-count structures. The higher level of homogeneity in females and on the left side observed by Leguebe and Vrydagh is also observed in the biplots. A comparison with principal component plots indicates that biplots yield a graphical representation similar to component plots, and convey more information than component plots.

Principal components of finger ridge-counts: their universality

A principal component analysis was carried out on radial and ulnar finger ridge-count data on a sample of fishermen of the sea coast of Puri in the state of Orissa in India. The component structure is very similar to that obtained earlier by Roberts and Coope for some English populations, by Arrieta and Lostao for a Basque population, by Siervogel et al. for a White American population, by Jantz and Hawkinson, and Jantz et al. for American and African populations, and by other authors for other populations. The initial components are bilaterally symmetric and the structure of these components is the same whether the two sides are taken separately or together. Only the latter components represent a certain amount of bilateral asymmetry. The first component is a 'size' component, indicating total finger ridge-count; the second component is a radial-ulnar contrast. From a comparison with previous studies on other populations, it appears that the component structure corresponding to the larger eigenvalues is fairly universal; there is a certain lack of universality in the structure of the components corresponding to smaller eigenvalues as well as in the order of these components, especially the rotated ones, when the corresponding eigenvalues are very close. As observed by previous authors, components corresponding to larger eigenvalues do not necessarily exhibit larger inter-population differences. However, there is lack of universality in the order of the components and in the structure of the components that exhibit large inter-population differences.

Purification and Characterization of α-Amylase from Bacillus licheniformis CUMC305

α-Amylase produced by Bacillus licheniformis CUMC305 was purified 212-fold with a 42% yield through a series of four steps. The purified enzyme was homogeneous as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and discontinuous gel electrophoresis. The purified enzyme showed maximal activity at 90�C and pH 9.0, and 91% of this activity remained at 100�C. The enzyme retained 91, 79, and 71% maximal activity after 3 h of treatment at 60�C, 3 h at 70�C, and 90 min at 80�C, respectively, in the absence of substrate. On the contrary, in the presence of substrate (soluble starch), the α-amylase enzyme was fully stable after a 4-h incubation at 100�C. The enzyme showed 100% stability in the pH range 7 to 9; 95% stability at pH 10; and 84, 74, 68, and 50% stability at pH values of 6, 5, 4, and 3, respectively, after 18 h of treatment. The activation energy for this enzyme was calculated as 5.1 � 10 5 J/mol. The molecular weight was estimated to be 28,000 by sodium dodecyl sulfate-gel electrophoresis. The relative rates of hydrolysis of soluble starch, amylose, amylopectin, and glycogen were 1.27, 1.8, 1.94, and 2.28 mg/ml, respectively. V max values for hydrolysis of these substrates were calculated as 0.738, 1.08, 0.8, and 0.5 mg of maltose/ml per min, respectively. Of the cations, Na + , Ca 2+ , and Mg 2+ , showed stimulatory effect, whereas Hg 2+ , Cu 2+ , Ni 2+ , Zn 2+ , Ag + , Fe 2+ , Co 2+ , Cd 2+ , Al 3+ , and Mn 2+ were inhibitory. Of the anions, azide, F − , SO 3 2− , SO 4 3− , S 2 O 3 2− , MoO 4 2− , and Wo 4 2− showed an excitant effect. p -Chloromercuribenzoic acid and sodium iodoacetate were inhibitory, whereas cysteine, reduced glutathione, thiourea, β-mercaptoethanol, and sodium glycerophosphate afforded protection to enzyme activity. α-Amylase was fairly resistant to EDTA treatment at 30�C, but heating at 90�C in presence of EDTA resulted in the complete loss of enzyme activity, which could be recovered partially by the addition of Cu 2+ and Fe 2+ but not by the addition of Ca 2+ or any other divalent ions.

Effect of oilseed cakes on alpha-amylase production by Bacillus licheniformis CUMC305

The effects of oilseed cakes on extracellular thermostable alpha-amylase production by Bacillus licheniformis CUMC305 was investigated. Each oilseed cake was made of groundnut, mustard, sesame, linseed, coconut copra, madhuca, or cotton. alpha-Amylase production was considerably improved in all instances and varied with the oilseed cake concentration in basal medium containing peptone and beef extract. Maximum increases were effected by a low concentration (0.5 to 1.0%) of groundnut or coconut, a high concentration (3%) of linseed or mustard, and an Rintermediate concentration (2%) of cotton, madhuca, or sesame. The oilseed cakes made of groundnut or mustard could completely replace the conventional peptone-beef extract medium as the fermentation base for the production of alpha-amylase by B. licheniformis. The addition of corn steep liquor to cotton, linseed, sesame, or madhuca cake in the medium improved alpha-amylase production.