Diagnosis and management against the complications of human cystic echinococcosis

Primary Retroperitoneal Hydatid Cyst: A Diagnostic and Treatment Conundrum

Hydatid cysts are caused by accidental egg ingestion of the Echinococcus granulosus parasite. A 24-year-old female was admitted to our hospital for chronic left lumbar pain. Computed tomography (CT) and abdominal ultrasonography identified an 8/12 cm retroperitoneal cyst. The CT results coupled with enzyme-linked immunosorbent assay tests (positive IgG for Echinococcus granulosus) confirmed that the tumor was a hydatid cyst. Treatment consisted of preoperative chemotherapy with albendazole, intraoperative parasite inactivation, laparoscopic partial cystectomy, and drainage. The drain was removed after three days. Chemotherapy was maintained for two years after surgery. No relapse was observed at the six-month reevaluation. In this article, the diagnostic and therapeutic options and resources are discussed and compared with the published literature.

Anaphylaxis during puncture of a hepatic hydatid cyst

Although hydatid cyst infects many organs, it most commonly involves liver, lungs, and central nervous system. The goal of hydatid cyst treatment is to completely eliminate the parasite and to prevent recurrences with minimal mortality and morbidity. The procedure of puncture, aspiration, injection of a scolicidal, and reaspiration (PAIR) of a cyst has been introduced as an alternative to surgical method since it is less invasive and less morbid and is associated with a shorter hospital stay and a lower cost. Herein, we report an 11-year-old girl who developed anaphylaxis during the puncture of a hepatic hydatid cyst. The patient who developed anaphylaxis during the PAIR procedure was administered intravenous adrenaline, methyl prednisolone, and antihistaminic medication. She was intubated and provided assisted ventilation using a mechanic ventilator. The child was extubated 4 h after her admission to the pediatric intensive care unit. During follow-up, the contents of her hepatic hydatid cysts were aspirated through a catheter, followed by their irrigation with 20% sodium chloride and re-aspiration. Then, 97% ethyl alcohol was injected into the cyst cavity to make it collapse. The goal of this report was to draw attention to the rare occurrence of anaphylaxis during the PAIR procedure and to stress that clini-cians should be vigilant for this complication.

LncRNA Regulation Mechanism in Hepatic Alveolar Echinococcosis with Nanosecond Pulse

BACKGROUND

The mortality of patients infected with hepatic alveolar echinococcosis (HAE) was higher. The aim of this study was to investigate the therapeutic effect of nanosecond pulsed electric fields (nsPEFs) on HAE in rats and explore the related molecular mechanisms.

METHODS

Establishment of HAE rat model and the lesions were treated with nsPEFs. The RNA of lesions in the high voltage nsPEFs treatment group and model group were extracted, and lncRNA and mRNA sequence analyses was performed. After obtaining the differentially expressed lncRNAs and mRNAs between the two groups, enrichment analysis was performed for mRNAs. The target genes of lncRNAs were predicted through co-location and co-expression. The expression of important lncRNAs and target genes in lesions was detected by qPCR.

RESULTS

The HAE rat model was successfully established. After nsPEFs treatment, the size of lesions was improved significantly. Then, we identified 270 differentially expressed lncRNAs and 1659 differentially expressed mRNAs between the high voltage nsPEFs treatment group and model group. Enrichment analysis showed that the differentially expressed mRNAs were mainly enriched in metabolism and inflammation. Five important lncRNAs regulatory networks were identified, then Cpa1, Cpb1, Cel, Cela2a, and Cela3b were identified as key target genes. Importantly, the expression of 5 lncRNAs and 5 target genes was verified in the lesions.

CONCLUSIONS

Preliminary results had shown that HAE treatment with nsPEFs can inhibit the growth of lesions. NsPEFs treatment altered gene expression in the lesions, and some genes were regulated by lncRNAs. The therapeutic mechanism may involve metabolism and inflammation.

Splenic-preserving surgery in hydatid spleen: a single institutional experience

Though hydatid disease affects many organs in the human body, splenic hydatid accounts for approximately 0.8-4% of all human echinococcosis cases. Up to recently, splenectomy was the preferred surgery for hydatid spleen. Since 1980, conservative options to treat such a disease have become more and more prevalent. Our study aimed to assess our experience in open splenic preservative surgery for splenic hydatid in a single institutional center. Our retrospective research included ten patients with splenic hydatid operated between August 2013 and January 2018 at our medical center. The spleen was affected alone in seven cases, the liver and spleen were affected in three cases, and one of the patients had intra-peritoneal cyst disease. The diagnosis was confirmed primarily by ultrasonography. In some instances, computed tomography and magnetic resonance imaging were required. A chest x-ray was performed to rule out pulmonary hydatid in all patients. Open surgery procedure, field isolation, cystic fluid aspiration, and injection of 1% cetrimide solution, respiration, endocystectomy, suture of cystic edges to the intracystic tube drain were performed. All surgeries had albendazole before and after the operation 15 mg/kg/day. There were no significant intra or postoperative complications, and no further surgery was required. Patients remained hospitalized for 3-5 days. No recurrence after 1-3 follow-up years. However, three patients failed to follow up within two years. Our experience with splenic hydatids prompts us to use splenic conservation surgery whenever possible instead of splenectomy.

Construction of ceRNA regulatory network in mice with Echinococcosis-induced allergic reactions

BACKGROUND

Cystic echinococcosis (CE) is a common chronic zoonotic parasitic disease infected with the Echinococcus granulosus. This study aimed to construct the competitive endogenous RNA (ceRNA) network and investigate the mechanism of mice in echinococcosis sensitization.

METHODS

The animal model of echinococcosis was established in mice, and the RNA sequencing was then performed using cysts. The differentially expressed RNAs (DERNAs: DEmRNAs, DEmiRNAs, and DElncRNAs) were screened between anaphylactic mice or non-anaphylactic mice and controls, respectively. The interactions of two DERNAs groups were identified and the ceRNA network was constructed. Moreover, the potential biological functions and pathways of the DEmRNAs were explored by enrichment analyses. Finally, the qRT-PCR and the western blot were performed to validate the expression levels of key RNAs and proteins.

RESULTS

A total of 285 common DEmRNAs, 157 common DElncRNAs and 4 common DEmiRNAs were observed. CeRNA network contained 3 DElncRNAs, 4 DEmiRNAs, and 27 DEmRNAs corporately. Enrichment results revealed that the functions of DEmRNAs focus on biological functions and pathways that specifically interact with the immune inflammatory response. In addition, the expression of 1700099I09Rik, let-7a-5p, Ccl28 and IL-13 was validated by RT-qPCR and western blot.

CONCLUSION

In this study, ceRNA network associated with CE sensitization in mice was constructed. The DEmRNAs in this network may be key clues for the immune mechanism of CE sensitization.

Novel Multimodal Treatment Regimen for the Management of Primary Sacrococcygeal Cystic Echinococcosis

INTRODUCTION

Osseous hydatidosis is a rare condition most commonly involving the spine. Among spinal segments, sacrococcygeal involvement is even rarer. Moreover, the lesion is more prone to recurrence owing to the infiltrative nature of microvesicular lesions involving the spine. In this case report, we describe an effective multimodal management approach toward the management of primary sacrococcygeal cystic echinococcosis.

CASE REPORT

A 56-year-old female presented with complaints of severe back pain and urinary incontinence for 3 months. She presented with a slow-onset cauda equina syndrome with radiating pain to both lower limbs. Radiographic evaluation showed an expansile lytic lesion affecting the right iliac wing with near-complete cortical bone destruction of the sacrum. Magnetic resonance imaging revealed neural involvement with sacral destruction by a multiloculated cystic mass, extending to the spinal canal. No coexisting lesions were noted anywhere. Echinococcosis was diagnosed with serum enzyme-linked immunosorbent assay. She underwent neoadjuvant therapy with albendazole and praziquantel, followed by ultrasound-guided percutaneous aspiration injection and reaspiration (PAIR) with hypertonic saline followed by sclerosant (95% ethyl alcohol) into the residual cyst cavity. Later, she open excision of the residual multiloculated cystic mass was performed. Adjuvant medical therapy was continued for 3 months post-surgery. The patient regained her neurological functions by 6 months without any residual sequelae or symptomatic recurrence until 4 years of follow-up.

CONCLUSION

Multimodal treatment regimen comprising of oral medical therapy by albendazole and praziquantel along with PAIR and surgical in toto excision of the cyst followed by post-operative oral medical therapy for 3 months has given excellent results in sacrococcygeal cystic echinococcosis.

A Conservative Management of Spontaneously Ruptured Liver Hydatid Cyst

Hydatid disease is a zoonotic disease caused mainly by the cestode (tapeworm) Echinococcus granulosus, also known as hydatidosis. It is endemic mainly in areas where dog/horse breeding and sheep farming are common, such as Australia, New Zealand and the Mediterranean region. A rare, yet serious, complication of hydatid cyst of the liver is rupture, which could be spontaneous due to increased intra-cystic pressure or following a traumatic injury of the abdomen. Rupture into the peritoneal cavity may result in an anaphylactic reaction, usually treated by means of emergency surgical intervention. Herein, we present a case of a 55-year-old male patient, known to have liver hydatid cystic disease 3 years ago, who presented to other hospital with acute abdominal pain, tachycardia and hypotension. A computed tomography (CT) scan of the abdomen revealed ruptured liver hydatid cyst into the peritoneal cavity, with free intra-abdominal fluid and dissemination into the mesentery. The patient was treated successfully by conservative means including nil per os (NPO), intravenous fluids, noradrenaline and anthelminthic treatment by albendazole. Two months later the patient underwent laparoscopic resection of the mesenteric as well as the hepatic cyst. The presentation, diagnosis, course of treatment and follow-up are discussed in this report. Reviewing the current English literature reveals that this is the first case to report a successful initial conservative management of spontaneous intraperitoneal rupture of liver hydatid cyst.

[Anaphylaxis due to a ruptured hydatid cyst]

HISTORY AND CLINICAL FINDINGS

We report the case of a 27-year-old Syrian patient who came to the emergency department with a syncopal episode. No medical history could be raised due to a language barrier and so the clinical presentation was leading.

INVESTIGATIONS AND DIAGNOSIS

The patient exhibited signs of shock, accompanied by an exanthema as well as perioral hematin. In an ultrasound sonography free intraabdominal fluid and an obscure change in the upper abdomen could be visualized. An esophagogastroduodenoscopy showed evidence of an ulcer, however did not explain all symptoms. In a CT abdomen, signs of a ruptured cyst could be demonstrated.

TREATMENT AND COURSE

The patient stabilized under the treatment protocol for anaphylaxis. Due to the clinical course and country of origin the patient received albendazole and a partial liver resection for a suspected echinococcus cyst.

CONCLUSION

Obscure clinical symptoms alongside signs of shock, should always considered to be an allergic reaction in absence of sepsis or hemorrhage. In anaphylaxis, echinococcosis should always be included in the differential diagnosis.

Misleading findings of liver-specific MR contrast agent for radiological diagnosis of cysto-biliary communication in hydatid cysts

OBJECTIVE

To investigate the effectiveness of gadoxetic acid-enhanced magnetic resonance cholangiopancreatography (CE-MRCP) and T2-weighted half-Fourier acquisition single-shot turbo spin-echo (T2W HASTE) sequences for diagnosis of cysto-biliary communication in hydatid cysts compared to surgical results.

METHODS

Preoperative abdominal magnetic resonance imaging examinations of patients who underwent surgery for hepatic hydatid cysts were reviewed by two radiologists retrospectively. A total of 45 patients with hydatid cysts were included. Of 45, 27 also had CE-MRCPs. T2W HASTE sequences and CE-MRCPs were investigated separately for cysto-biliary communication. The relationship between radiological and surgical results was analyzed. The interobserver agreement was evaluated.

RESULTS

Of 45 hydatid cysts, there were surgically proven 21 cysts without biliary communications and 24 cysts with biliary communications. All cysts with biliary communications were shown on T2W HASTE sequences. There was no leakage of gadoxetic acid into these cysts (n = 24). Sensitivity, specificity, negative predictive value, positive predictive value (PPV), and accuracy of diagnosis of cyst with biliary communication on T2W HASTE sequences was 100%, 63.64%, 100%, 66.67%, and 78.95%, respectively. Specificity (77.78%), PPV (87.50%), and accuracy (91.30%) were increased in ≥ 10 cm cysts. There was almost perfect interobserver agreement (K = 0.81-1.00).

CONCLUSION

Leakage of gadoxetic acid inside the cyst indicates biliary communication. However, the lack of leakage does not rule out cysto-biliary communication. When biliary communication is clearly shown on T2W HASTE sequences, it should be reported as cysto-biliary communication even if there is no leakage of gadoxetic acid into the cyst on CE-MRCP.

The choose of different surgical therapies of hepatic alveolar echinococcosis: A single-center retrospective case-control study

The aim of this study was to evaluate different surgical therapies for hepatic alveolar echinococcosis in different clinical stages.We analyze the clinical data of 115 patients who received surgical treatment in West China Hospital from January 2004 to June 2016. Among these patients, 77 cases underwent radical hepatic resection (group A, n = 77); 17 cases underwent palliative resection (group B, n = 17), and 21 cases underwent liver transplantation (group C, n = 21) with 12 cases of orthotopic liver transplantation and 9 cases of liver autotransplantation.The postoperative complication rate of radical hepatic resection group was 13.0% (10/77), which is statistically significant (P < .05) than the rate of palliative resection group 29.4% (5/17) or liver transplantation group 23.8% (5/21). The follow-up period ranged from 1 to 72 months. The overall median survival rate of radical resection was 72/77, higher than the rate of palliative group (12/17) or transplantation group (17/21), which was also statistically significant (P < .01).In our study, we believe in that all stages of hepatic alveolar echinococcosis should take active surgical interventions, and radical hepatic resection should be considered as the first-choice treatment for early stage of alveolar echinococcosis, while palliative surgery is still helpful to relieve symptoms and improve the life quality for advanced patients. Liver transplantation might also be an alternative option for the late-stage hepatic alveolar echinococcosis.

Bioinformatic prediction of the epitopes of Echinococcus granulosus antigen 5

The aim of the present study was to predict and analyze the secondary structure, and B and T cell epitopes of Echinococcus granulosus antigen 5 (Ag5) using online software in order to investigate its immunogenicity and preliminarily evaluate its potential as an effective antigen peptide vaccine for cystic echinococcosis. The PortParam program was used to analyze molecular weight, the theoretical isoelectric point, instability index and other physicochemical properties. The secondary structure of the Ag5 protein was predicted using Self-Optimized Prediction method With Alignment and the tertiary structure of the Ag5 protein was predicted using 3DLigandSite together with Center for Biological Sequence Analysis Prediction Servers. Furthermore, the Immune Epitope Database software was used to predict B cell epitopes, and T cell epitopes were predicted with the BioInformatics and Molecular Analysis Section and SYFPEITHI programs. The results demonstrated that α-helixes, β-turns, random coils and extended strands account for 23.35, 10.95, 41.32, and 24.38% of the secondary structure of the Ag5 protein, respectively. Ten potential B cell epitopes of Ag5 were identified as the amino acids sequences 27-39, 70-80, 117-130, 146-168, 250-262, 284-293, 339-349, 359-371, 403-412 and 454-462, and seven potential T cell epitopes were identified as the amino acid sequences 52-60, 57-65, 182-190, 231-239, 273-281, 318-326 and 467-475. Thus, ten B cell epitopes and seven T cell epitopes were identified on Ag5, suggesting the strong immunogenicity of this protein, which could be applied to design antigen peptide vaccines for echinococcosis.

Factors Associated with Echinococcosis-Induced Perioperative Anaphylactic Shock

This retrospective case-control study explored the factors associated with anaphylactic shock during surgery for cystic echinococcosis (CE) at the First Affiliated Hospital of Xinjiang Medical University between October 2008 and September 2013. Patients who suffered from anaphylactic shock (n=16) were age-matched 3:1 to patients who did not (n=43). Multivariate analysis suggested that IL-4 levels (odds ratio=1.096; 95% confidence interval=1.015–1.185; P=0.02) and cyst size (odds ratio=3.028, 95% confidence interval=1.259–7.283, P=0.013) were independently associated with CE-induced perioperative anaphylactic shock. Using the receiver operating characteristic (ROC) curves and a cut-off value of 415.7 ng/ml, IL-4 showed an area under the ROC (AUC) of 0.926, sensitivity of 75.0%, and specificity of 97.7%. Using a cut-off value of 7.8 cm, cyst size showed an AUC of 0.828, sensitivity of 81.3%, and specificity of 76.7%. In conclusion, results suggest that levels of IL-4 and cyst size were independently associated with echinococcosis-induced perioperative anaphylactic shock. These results could help identifying patients with echinococcosis at risk of anaphylactic shock in whom appropriate prophylaxis could be undertaken.

Investigation of the use of serology and ultrasonography to detect hepatic cystic echinococcosis in Heilongjiang, China, using a Bayesian framework

BACKGROUND

Cystic echinococcosis (CE) is a public health problem in China. However, the prevalence and incidence of CE in Heilongjiang province is still poorly understood. Because there is no perfect gold standard, evaluation of ultrasound (US) and serological methods have been limited. This study evaluated the use of these two diagnostic methods for the diagnosis of CE in suspected cases.

METHODS

A total of 522 suspected hepatic CE patients, as well as their demographic and clinical features were collected and detected by immunoglobulin (IgG)-ELISA and US. The marginal posterior densities of sensitivity and specificity for both tests, and the prevalence of hepatic CE amongst participants, were estimated from the product of the likelihood function of observed and latent data by a Bayesian framework.

RESULTS

Most of the patients were from rural areas. The most common symptom was upper abdominal pain. The antibody-positive proportion determined by IgG-ELISA was 24.33% (127/522), significantly higher than with US examination (17.24%, 90/522). Bayesian analysis indicated that the estimated prevalence of CE amongst suspected cases was 17.70% (95% credible interval: 14.23-21.54%). The sensitivity and specificity of the ELISA test were 92.63% and 90.37%, and that of US were 93.05% and 98.44%, respectively. Among US-confirmed hepatic CE cases, the male to female ratio was 0.46 and the peak age group was 40-49 years.

CONCLUSIONS

The results of the current study demonstrate that CE is present in Heilongjiang province. They also suggest that, whilst ultrasonography appears to be the detection modality of choice, serology may have a use for detection of infection in individuals suspected to be infected. This may have applications for surveillance within the province.

The Comparison of 2 New Promising Weapons for the Treatment of Hydatid Cyst Disease: PAIR and Laparoscopic Therapy

BACKGROUND

To compare the effectiveness and safety for hydatid disease treatment, the 2 new minimally invasive therapies: laparoscopic and PAIR (puncture, aspiration, injection, and reaspiration) were compared by systematic meta-analysis.

METHODS

A comprehensive analysis of published cases from 1990 to 2014 was performed using PubMed database. A total of 231 publications on laparoscopic treatment of hydatid cysts and 298 publications on the PAIR treatment were identified. Thirty-eight studies involved 1230 laparoscope-treated subjects and 41 involved 2686 PAIR-treated subjects in this review. The effectiveness and safety of emphasis is placed on the recurrence, insufficient response, death, cure, and postoperative complications. Operation time and hospital stay are also discussed as new evaluation index. The stages of cyst are summarized to determine which stage is suitable for PAIR.

RESULTS

Clinical and parasitological cure occurred in 98.7% of patients undergoing laparoscopic intervention and in 97.5% of patients receiving PAIR plus chemotherapy (P<0.014). Recurrence occurred in 1.0% and 1.6%, respectively (P<0.087). Insufficient response occurred in 0.16% and 0.9%, respectively (P<0.009); 2 patients died in each group (P<0.594). Allergic reaction/urticarial/anaphylactic shock occurs in 0.14% and 4.24% of patients receiving laparoscopic intervention and PAIR plus chemotherapy, respectively (P<0.001). Infection/abscess (5.37% and 2.57%; P<0.001) and surgical-related complications (7.32% and 3.43%; P<0.001) were seen more frequently in laparoscopic intervention subjects than PAIR plus chemotherapy subjects.

CONCLUSIONS

Laparoscopic therapy and PAIR intervention are shown to be safe and effective alternative for open surgery with suitable indication such as cyst type and location. They have different postoperative complication features. The biliary fistula/bile leakage was more frequent in laparoscopic intervention (P<0.001) and fever occurred more in PAIR plus chemotherapy patients.

Immunological Characteristics of Recurrent Echinococcosis-Induced Anaphylactic Shock

Anaphylactic shock represents a serious complication of echinococcosis as up to 4.6% of patients die as a result of its severity and improper handling. Once a definite diagnosis is made, effective treatments need to be immediately initiated. Here, we report the immunological characteristics and management of two patients with recurrent anaphylactic shock concurrent with the surgical removal of hydatid cysts. Both patients had systemic echinococcosis classified as cystic echinococcosis type 2 (CE2) with multiple, immature cysts (absence of calcification and necrosis). In addition, both patients had increased eosinophils and basophils before surgery, as well as elevated crude hydatid cyst fluid antigen (anti-EgCF) and hydatid cyst fluid native antigen B (anti-EgB) antibodies and high IgG levels. Although we cannot definitively predict which patients are at risk for cyst fluid leakage or anaphylactic shock at present, clinicians may consider taking precautions before surgery on encountering patients with a similar profile to prevent the occurrence of anaphylactic shock and the likelihood of a second incident. However, these observations need to be confirmed in further studies with a larger number of patients.

Laparoscopic approach for total cystectomy in treating hepatic cystic echinococcosis

Background: The laparoscopic approach has been proposed for treating hepatic cystic echinococcosis (HCE) and has already been used in clinical practice, mostly for non-radical operations. In this study, we aimed to evaluate the feasibility of total cystectomy of HCE under laparoscopy (LS).

Results: A retrospective review of the medical records obtained from 22 patients diagnosed with HCE between June 2009 and June 2013 and treated with an LS approach was conducted in the First Affiliated Hospital of Xinjiang Medical University. A total of 15 patients underwent total cystectomy of HCE using LS. The average time of surgery was 174 min (160–210 min). Intraoperative bleeding was 103 mL (80–200 mL). The mean duration of hospitalization was 7 days (6–15 days). Seven patients were transferred to open surgery (OS). For these patients, the average duration of surgery was 177 min (150–230 min). Intraoperative bleeding was 237 mL (160–350 mL), and the mean duration of hospitalization was 10 days (8–15 days). The most frequent postoperative complications were hydrops in the surgical area (two cases in LS and three cases in OS), and temporary bile leakage (one patient in the LS group). Recurrence was not seen in any cases in either group with a follow-up of 6–12 months.

Conclusions: Total cystectomy of HCE appears to be safe and effective in selected patients with unique, small-sized, superficially located cysts. To establish precise recommendations about the technique and its indications, prospective studies are necessary.

Spleen-preserving surgery is effective for the treatment of spleen cystic echinococcosis

OBJECTIVE

This study evaluated two surgical procedures, total splenectomy and spleen-preserving surgery, for the treatment of spleen cystic echinococcosis (CE).

METHODS

A total of 21 patients who underwent surgery for removal of spleen CE were evaluated retrospectively. Patients were divided into two groups, those who received a total splenectomy (n=7) and those who underwent spleen-preserving surgery (n=14).

RESULTS

Total splenectomy surgery took 127.1±11.1min and spleen-preserving surgery took 104.3±25.3min (p<0.05). The length of hospital stay was the same for both patient groups (10.6 days on average). No patient suffered from recurrence during follow-up and all of the patients made a good recovery. No patient developed post-splenectomy sepsis or serious infectious complications. No patient suffered recurrence.

CONCLUSIONS

The spleen-saving approach is likely an effective method for the removal of CE spleen cysts given that it is a quick procedure and preserves the function of the spleen. Total splenectomy procedures may be performed particularly for larger, centrally located cysts.

Complications of Hydatid Cysts of the Liver: Spiral Computed Tomography Findings

Background

The purpose of this retrospective study is to evaluate the role of Spiral Computed Tomography (CT) in the detection of the complications of hepatic hydatid cysts.

Methods

During a period of 8 years and after establishing the diagnosis of numerous hydatid cysts, 7 patients with complications of hydatid cysts were found. These 7 patients (5 females, 2 males, mean age 74.2 years, range 63 - 92 years) were studied. Four of them had a known medical history of hydatid disease, while all of them presented to our department as emergency cases.

Results

They underwent Spiral CT which revealed the following complications of hydatid cysts: intrabiliary rupture in 2 patients, rupture into the peritoneal cavity resulting to peritonitis in 1 patient, contained rupture and secondary transdiaphragmatic thoracic rupture in 1 patient, rupture into both biliary tract and hepatic subcapsular space in 1 patient, rupture into the subcapsular hepatic space in 1 patient and secondary bacterial infection of the cyst resulting to abscess formation in 1 patient. All of these CT findings were surgically confirmed.

Conclusions

CT provided a rapid and accurate diagnosis in all of these cases and proved to be a very useful preoperative imaging method.

Antigen-specific T cells and cytokines detection as useful tool for understanding immunity against zoonotic infections

Zoonoses include a broad range of diseases, that are becoming of great interest, due to the climate changing, that cause the adaptation of vectors to new niches and environments. Host immune responses play a crucial role in determining the outcome of infections, as documented by expansion of antigen-specific T cells during several zoonotic infections. Thus, understanding of the contribution of antigen-specific T-cell subsets in the host immune response is a powerful tool to evaluate the different immunological mechanisms involved in zoonotic infections and for the development of effective vaccines. In this paper we discuss the role of T cells in some eukaryotic and prokaryotic infectious models.

Gene cloning, expression, and localization of antigen 5 in the life cycle of Echinococcus granulosus

Antigen 5 (Ag5) has been identified as a dominant component of cyst fluid of Echinococcus granulosus and is considered as a member of serine proteases family, which in other helminth, plays an important role in the egg hatch and larva invasion. However, whether Ag5 is expressed and secreted in all life stages is unknown. In this study, according to the sequence in GenBank, we cloned and sequenced the open reading frame (ORF) of Ag5 gene from the protoscolices of E. granulosus isolated from the sheep in Qinhai Province of China, and found several substitutions and a base insert and deletion in a short region near the stop code, leading to a frameshift mutation which is conserved with the homologue of other cestode. The ORF is 1,455 bp in length, encoding 484 amino acids with a secretory signal peptide. Bioinformatics analysis predicted several phosphorylation and myristoylation sites and a N-glycosylation site and a species-specific linear B epitope in the protein. The ORF was cloned into the plasmid pET28a(+) vector and expressed in Escherichia coli . The recombinant protein was purified by affinity chromatography. Anti-rEgAg5 antiserum was prepared in rats and used to analyze the localization of Ag5 in protoscolex and adult worm by immunofluorescence technique. Results demonstrated that the Ag5 is strongly expressed in the tegument of protoscolex and the embryonic membrane of egg and surface of oncosphere; meanwhile, it is also weakly expressed in tegument of the adult. This study showed that Ag5 is expressed in all stages of life cycle, secreted from the surface of the worm and may be anchored in membrane by its myristoylation sites; these characteristics make it a candidate antigen for diagnosis and vaccine for both intermediate and definitive hosts.