The association between human papillomavirus infection, vaginal microecology, and cervical intraepithelial neoplasia in women from Xinjiang, China

PURPOSE

This study analyzes the relationship between human papillomavirus (HPV) infection, vaginal microecology, and cervical lesions to provide a basis for the prevention and treatment of cervical cancer (CC) in the Xinjiang region.

METHODS

Real-time quantitative PCR was used for HPV genotyping and viral load. The Gram staining and dry biochemical enzyme kit were utilized to diagnose vaginal secretions. The χ2 test and Logistic regression analysis were used for statistical analysis.

RESULTS

The HPV infection rate among women in the Xinjiang region was 30.29%, of which the single HPV infection accounts for 77%. HPV16 and HPV52 were the main infection types. There was significant differences in the HPV infection rate and infection types among the Han, Uighur, Hui, and Kazakh ethnic groups. The viral load of HPV16 and HPV52 increases with the upgrade of cervical lesions. There were significant differences in vaginal microecology evaluation indicators H2O2, SNA, LE, GUS, trichomonas, clue cells, and lactobacilli among different ethnic groups. HPV negative patients with varying grades of cervical lesions exhibit a notable variance in H2O2 and LE, which is statistically significant. Single HPV infection and high viral load HPV significantly increase the risk of CC.

CONCLUSIONS

This study indicates that HPV infection and vaginal microecology differ among ethnic groups, which have a strong correlation with the progression of CC, offering guidance on CC screening and interventions in the Xinjiang area.

[Effects of radical radiotherapy combined with different regimens of chemotherapy on radiation intestinal injury in patients with non-metastatic anal squamous cell carcinoma]

Objective: To investigate the effects of radical radiotherapy combined with different chemotherapy regimens (fluorouracil-based versus docetaxel plus cisplatin) on the incidence of radiation intestinal injury and the prognosis in patients with non-metastatic anal squamous cell carcinoma. Methods: A retrospective cohort study was conducted to recruit non-metastatic anal squamous cell carcinoma patients who underwent chemoradiotherapy in the Sixth Affiliated Hospital of Sun Yat-sen University and Nanfang Hospital from July 2013 to January 2021. Inclusion criteria: (1) newly diagnosed anal and perianal squamous cell carcinoma; (2) completed radical radiotherapy combined with concurrent chemotherapy; (3) tumor could be evaluated before radiotherapy. Exclusion criteria: (1) no imaging evaluation before treatment, or the tumor stage could not be determined; (2) patients undergoing local or radical resection before radiotherapy; (3) distant metastasis occurred before or during treatment; (4) recurrent anal squamous cell carcinoma. A total of 55 patients (48 from the Sixth Affiliated Hospital of Sun Yat-sen University and 7 from Nanfang Hospital) were given fluorouracil (the 5-FU group, n=34) or docetaxel combined with the cisplatin (the TP group, n=21). The evaluation of radiation intestinal injury, hematological toxicity and 3-year disease-free survival (DFS) rate were compared between the two groups. The effects of chemotherapy regimen and other clinicopathological factors on the incidence and severity of acute and chronic radiation intestinal injury were analyzed. The assessment of radiation intestinal injury was based on the American Cancer Radiotherapy Cooperation Group (RTOG) criteria. Results: During radiotherapy and within 3 months after radiotherapy, a total of 45 patients developed acute radiation intestinal injury, including 18 cases of grade 1 (32.7%), 22 cases of grade 2 (40.0%) and 5 cases of grade 3 (9.1%). No patient developed chronic radiation intestinal injury. Among the 34 patients in the 5-FU group, 21 had grade 2-3 radiation intestinal injury (21/34, 61.8%), which was significantly higher than that in the TP group (6/21, 28.6%) (χ(2)=5.723, P=0.017). Multivariate analysis showed that 5-FU chemotherapy regimen was an independent risk factor for radiation intestinal injury (HR=4.038, 95% CI: 1.250-13.045, P=0.020). With a median follow-up period of 26 (5-94) months, the 3-year DFS rate of patients in TP group and 5-FU group was 66.8% and 77.9%, respectively, whose difference was not significant (P=0.478). Univariate analysis showed that the DFS rate was associated with sex, age, tumor location, T stage, N stage, and induction chemotherapy (all P<0.05), while the DFS rate was not associated with chemotherapy regimen or radiation intestinal injury (both P>0.05). Multivariate analysis revealed that age ≥ 50 years old was an independent risk factor affecting the prognosis of patients (HR=8.301, 95% CI: 1.130-60.996, P=0.038). Conclusions: For patients with non-metastatic anal squamous cell carcinoma, radical radiotherapy combined with TP chemotherapy regimen can significantly reduce the incidence of radiation intestinal injury as compared to 5-FU regimen. However, due to the short follow-up time, the effect of different chemotherapy regimens on the prognosis is not yet clear.

[Comparison of epidermal growth factor receptor gene mutation in lung adenocarcinoma using biopsied tissue, pleural effusion and blood samples]

Objective: To compare different specimen types of lung adenocarcinoma in the detection of epidermal growth factor receptor (EGFR) gene and to correlate EGFR mutations with patient clinical features. Methods: One hundred lung adenocarcinoma cases were collected from June to December in 2015, at the First Affiliated Hospital of Xinjiang Medical University.Of the 100 lung adenocarcinoma samples, 43 were male and 57 were female. The age was from 40 to 88 years old, and the average age was 66 years. One hundred lung adenocarcinoma cases were divided equally into two groups. Mutation analysis of EGFR gene by real-time PCR was performed using biopsied tissue and paired blood samples in one group (n=50) and using pleural effusion and paired blood samples in the other group (n=50). Results: The mutation rate of EGFR gene in biopsy samples was 54% (27/50) , higher than that of blood samples (46%, 23/50), but without statistical differences (χ(2)=0.640, P=0.424). In contrast, mutation rate of EGFR gene in pleural effusion samples (42%, 21/50) was higher than that of blood samples (34%, 17/50), but without statistical differences(χ(2)=0.679, P=0.409). Two patients had EGFR mutation detected in paired blood samples but not in the corresponding biopsy samples, and four patients had EGFR mutation detected in pleural effusion samples but not in their paired blood samples. The mean progression-free survival of patients with detectable EGFR mutation were 9.5 months (tissue samples), 8.6 months (pleural effusion) and 8.5 months (blood). However, there was no statistical difference. Conclusions: Blood samples may be used to assess EGFR mutations for patients with lung adenocarcinoma. However, further studies are needed to improve the sensitivity and accuracy in the detection of EGFR mutations using blood samples.

Relationship between enteric pathogens and acute gastroenteritis disease severity: a prospective cohort study

OBJECTIVES

To evaluate the relationship between individual bacterial and viral pathogens and disease severity.

METHODS

Children <18 years with three or more episodes of vomiting and/or diarrhoea were enrolled in two Canadian paediatric emergency departments between December 2014 and August 2016. Specimens were analysed employing molecular panels, and outcome data were collected 14 days after enrolment. The primary outcome was severe disease over the entire illness (symptom onset until 14-day follow-up), quantified employing the Modified Vesikari Scale (MVS) score. The score was additionally analysed in two other time periods: index (symptom onset until enrolment) and follow-up (enrolment until 14-day follow-up).

RESULTS

Median participant age was 20.7 (IQR: 11.3, 44.2) months; 47.4% (518/1093) and 73.4% (802/1093) of participants had index and total MVS scores ≥11, respectively. The most commonly identified pathogens were rotavirus (289/1093; 26.4%) and norovirus (258/1093; 23.6%). In multivariable analysis, severe disease over the entire illness was associated with rotavirus (OR = 9.60; 95%CI: 5.69, 16.19), Salmonella (OR = 6.61; 95%CI: 1.50, 29.17), adenovirus (OR = 2.53; 95%CI: 1.62, 3.97), and norovirus (OR = 1.43; 95%CI: 1.01, 2.01). Pathogens associated with severe disease at the index visit were: rotavirus only (OR = 6.13; 95%CI: 4.29, 8.75), Salmonella (OR = 4.59; 95%CI: 1.71, 12.29), adenovirus only (OR = 2.06; 95%CI: 1.41, 3.00), rotavirus plus adenovirus (OR = 3.15; 95%CI: 1.35, 7.37), and norovirus (OR = 0.68; 95%CI: 0.49, 0.94). During the follow-up period, rotavirus (OR = 2.21; 95%CI: 1.50, 3.25) and adenovirus (OR = 2.10; 95%CI: 1.39, 3.18) were associated with severe disease.

CONCLUSIONS

In children presenting for emergency department care with acute gastroenteritis, pathogens identified were predominantly viruses, and several of which were associated with severe disease. Salmonella was the sole bacterium independently associated with severe disease.

[Impact of PRDM1 gene inactivation on C-MYC regulation in diffuse large B-cell lymphoma]

Objective: To investigate the role of PRDM1 gene inactivaion in the regulation of C-MYC in diffuse large B-cell lymphoma (DLBCL), and to explore the correlation of its immunophenotype and prognosis. Methods: 100 cases paraffin-embedded DLBCL tissues were collected from January 2009 to December 2015 at the First Affiliated Hospital of Xinjiang Medical University along with 20 cases of reactive proliferative lymph nodes as control. Immunohistochemical methods were used to detect the expression of CD20, CD10, MUM1, Ki-67, bcl-6, PRDM1/Blimp1, C-MYC and PAX5 protein. The tumors were classified into two subtypes according to Hans classification.The expression of PRDM1 and C-MYC gene in tumor group and control group was detected by reverse transcription PCR (RT-PCR) and the relationship between PRDM1 and C-MYC gene was analyzed.OCI-LY1 (GCB subtype) and OCI-LY3 (non-GCB subtype) cell lines were transfected with small interfering RNA by cationic liposome reagent transfection, and the expression of C-MYC in the transfected cell lines was detected by RT-PCR and Western blot. The Kaplan-Meier method was used to analyze the prognostic significance of PRDM1/Blimp1 and C-MYC at protein and mRNA levels. Results: There were 27 cases of GCB subtype and 73 cases of non-GCB subtype according to Hans classification. The positive expression of Blimp1 in DLBCL group and proliferative lymph nodes in control group was seen in 26(26.0%) and 20 cases(100%), respectively. There were 58 cases with high expression of PRDM1 at mRNA level, including 22 cases of GCB subtype and 36 cases non-GCB subtype, and the difference was statistically significant (P=0.004). There were differences in PRDM1 gene expression between the two immunological subtypes, serum lactate dehydrogenase (serum LDH) level, presence of B symptoms, tumor primary sites and other clinical pathological parameters, while C-MYC expression was different in gender, IPI score, and serum LDH levels. Upon PRDM1/Blimp1 gene silencing in the two cell lines, C-MYC protein and gene expression were up-regulated in the transfection group, compared with the blank control group and negative control group by reverse transcription PCR and Western blot analyses. Moreover, PRDM1 expression was significantly associated with C-MYC(χ(2)=7.648, P=0.006) at mRNA level. Conclusion: The up-regulation of C-MYC gene expression induced by PRDM1 inactivation in DLBCL may play an important role for the development of DLBCL.PRDM1 protein and mRNA are associated with immunophenotyping and PRDM1 mRNA is a marker of poor prognosis.

Hcmv-miR-UL22A-5p: A Biomarker in Transplantation With Broad Impact on Host Gene Expression and Potential Immunological Implications

Cytomegalovirus (CMV) encodes multiple microRNAs. While these have been partially characterized in vitro, their relevance to clinical CMV infection has not been evaluated. We analyzed samples from a cohort of solid organ transplant patients with CMV disease (n = 245) for viral microRNA expression. Several CMV microRNAs were readily detectable in patients with CMV disease in variable relative abundance. Expression level generally correlated with DNA viral load and the absence of viral microRNA was associated with faster viral clearance. Detection of hcmv-miR-UL22A-5p at baseline independently predicted the recurrence of CMV viremia upon discontinuation of antiviral therapy (OR 3.024, 95% CI: 1.35-6.8; p = 0.007). A combination of direct mRNA targeting by the microRNA and indirect modulation of gene expression involving isoforms of the transcriptional regulator C-MYC may be responsible for the broad effects seen in the association of gene transcripts with the RNA-induced silencing complex and in global protein expression upon hcmv-miR-UL22A-5p transfection. This novel study of in vivo viral microRNA expression profiles provides unique insight into the complexity of clinical CMV infection following transplantation. We provide evidence that viral microRNAs may have complex effects on gene expression and be associated with specific virologic and clinical outcomes, and thus could be further evaluated as biomarkers.

Congenital cytomegalovirus infection in high-risk Canadian infants: Report of a pilot screening study

OBJECTIVES

Congenital cytomegalovirus (cCMV) is the most common congenital infection; however, the epidemiology in Canada has not been recently examined. The present prospective study pilots tools for a population-based study of cCMV infection in Canada by determining the maternal seroprevalence and risk factors, the clinical characteristics and the incidence of cCMV using a variety of diagnostic tests in a cohort of high-risk infants in northern Alberta.

METHODS

All infants born at the Royal Alexandra Hospital in Edmonton, Alberta, from June 1, 2003, to May 31, 2004, were screened for the study. Eligible infants were those with very low birth weights (VLBWs) or small for gestational age (SGA). Maternal CMV serostatus was determined, and chart review and parental interviews were completed. Neonatal urine and throat cultures, and polymerase chain reaction (PCR) were performed. Dried blood spots (DBS) were tested for CMV by PCR.

RESULTS

In total, 213 infants were eligible for the study. Of these, 137 entered the study (79 VLBW and 58 SGA). Some families were not contacted for participation in the study due to neonatal deaths or early discharge. The mean age of the mothers was 27.6 years; 68% of the mothers were Caucasian and 16% were Aboriginal. The maternal CMV seroprevalence was 55%. Seropositivity was significantly associated with ethnicity (First Nations [100%]; Caucasian [34%]) and country of birth (outside Canada [94%]; Canadian born [45%]). The rate of cCMV was two in 137 (1.5%), with a rate of one in 79 (1.3%) for the VLBW infants and one in 58 (1.7%) for the SGA infants. Both had positive throat or urine specimens, but only the symptomatic infant was positive on DBS.

CONCLUSIONS

A cCMV screening program should be universal and routine to successfully screen all newborns. Maternal CMV seropositivity varies widely within the Canadian population. In the present pilot study, DBS PCR was not a sensitive screening tool and throat swab was the best screening specimen.

Interlaboratory comparison of epstein-barr virus viral load assays

To assess interlaboratory variability in qualitative and quantitative Epstein-Barr virus (EBV) viral load (VL) testing, we distributed a panel of samples to 28 laboratories in the USA, Canada and Europe who performed testing using commercially available reagents (n = 12) or laboratory-developed assays (n = 18). The panel included two negatives, seven constructed samples using Namalwa and Molt-3 cell lines diluted in plasma (1.30-5.30 log(10) copies/mL) and three clinical plasma samples. Significant interlaboratory variation was observed for both actual (range 1.30-4.30 log(10) copies/mL) and self-reported (range, 1.70-3.30 log(10) copies/mL) lower limits of detection. The variation observed in reported results on individual samples ranged from 2.28 log(10) (minimum) to 4.14 log(10) (maximum). Variation was independent of dynamic range and use of commercial versus laboratory-developed assays. Overall, only 47.0% of all results fell within acceptable standards of variation: defined as the expected result +/- 0.50 log(10). Interlaboratory variability on replicate samples was significantly greater than intralaboratory variability (p < 0.0001). Kinetics of change in VL appears more relevant than absolute values and clinicians should understand the uncertainty associated with absolute VL values at their institutions. The creation of an international reference standard for EBV VL assay calibration would be an initial important step in quality improvement of this laboratory tool.

Interlaboratory comparison of cytomegalovirus viral load assays

To assess interlaboratory variability in qualitative and quantitative cytomegalovirus (CMV) viral load (VL) testing, we distributed a panel of samples to 33 laboratories in the USA, Canada and Europe who performed testing using commercial reagents (n = 17) or laboratory-developed assays (n = 18). The panel included two negatives, seven samples constructed from purified CMV nucleocapsids in plasma (2.0-6.0 log(10) copies/mL) and three clinical plasma samples. Interlaboratory variation was observed in both actual (range, 2.0-4.0 log(10) copies/mL) and self-reported lower limits of detection (range, 1.0-4.0 log(10) copies/mL). Variation observed in reported results for individual samples ranged from 2.0 log(10) (minimum) to 4.3 log(10) (maximum)(.) Variation was greatest at low VLs. Assuming +/- 0.5 log(10) relative to the expected result represents an acceptable result, 57.6% of results fell within this range. Use of commercially available reagents and procedures was associated with less variability compared with laboratory-developed assays. Interlaboratory variability on replicate samples was significantly greater than intralaboratory variability (p < 0.0001). The significant interlaboratory variability in CMV VL observed may be impacting patient care and limiting interinstitutional comparisons. The creation of an international reference standard for CMV VL assay calibration would be an important step in quality improvement of this laboratory tool.

Natural human immunoglobulin G subclass responses to Plasmodium falciparum serine repeat antigen in Uganda

Serum samples from Ugandan residents of a malaria-hyperendemic region were tested by enzyme-linked immunosorbent assay for reactivity against recombinant constructs of the 47 (SE47')- and 50 (SE50A)-kDa fragments of Plasmodium falciparum serine repeat antigen (SERA). Immunoglobulin (Ig) G3 and IgG1 were the predominant subclass responses to SE47' and SE50A, respectively. The geometric mean optical density (OD) for IgG3 anti-SE47' was significantly lower in children < 15 years compared with adults > or = 15 years (P < 0.0001). By contrast, the geometric mean IgG1 anti-SE50A was slightly higher in children compared with adults (P < 0.01). The proportion of high responders (ODs > 0.5) to SE47' was significantly lower in children compared with adults (P < 0.001), whereas the proportion of high responders to SE50A was comparable in children and adults (P = 0.07). This first detailed study of SERA in a malaria-hyperendemic region suggests that natural human IgG3 anti-SE47' might be associated with immunity to malaria.

Effect of rotavirus vaccine on Sapporo virus gastroenteritis in Finnish infants

BACKGROUND

Sapporo-like viruses (SLVs) occur worldwide, but there is limited information about the SLV-associated gastroenteritis outside Japan.

METHODS

Stool specimens from 1,432 episodes of gastroenteritis that occurred in children between 2 months and 2 years of age during a rotavirus vaccine trial (776 episodes in placebo-vaccinated and 656 in rotavirus-vaccinated infants) were examined for SLVs using a reverse transcription-PCR assay. The reverse transcription-PCR took advantage of new primers specific for Sapporo virus genetic clusters I, II and III; SV/SV82 (SV/Sapporo virus 82); SV/Lond92 (SV/ London 92); and SV/PV (Parkville virus).

RESULTS

SLVs were detected in association with 132 (9.2%) of all episodes; in 80 (5.6%) episodes SLV was the only gastroenteritis virus detected. The epidemic season of SLVs peaked from March to May concurrently with rotaviruses and astroviruses and overlapping withNorwalk-like viruses. Clinically SLV gastroenteritis was characterized by a mild diarrheal disease, being sharply different from the Norwalk-like virus-associated "winter vomiting disease." Rotavirus vaccination did not have any effect on the number of SLV episodes, but the intensity and duration of SLV-associated diarrhea were reduced in rotavirus-vaccinated children compared with placebo-vaccinated children (P = 0.0008).

CONCLUSIONS

SLVs are common causative agents of acute gastroenteritis in young Finnish children. SLV disease is characterized by diarrhea, which is usually mild but can be severe. By an unknown mechanism rotavirus vaccine seems to reduce the severity of SLV-associated diarrhea.

Human caliciviruses in acute gastroenteritis of young children in the community

Episodes of acute gastroenteritis in prospectively followed children between 2 months and 2 years of age were examined for rotaviruses, enteric adenoviruses, astroviruses, and human caliciviruses, including both Norwalk-like viruses (NLVs) and Sapporo-like viruses (SLVs), using PCR and reverse transcription (RT)-PCR assays. A virus was identified in 60% (502/832) of all episodes and in 85% of the moderately severe or severe episodes. Human caliciviruses were as common as rotaviruses, both being detected in 29% of the cases. NLVs accounted for a 20% etiologic share of all cases; the clinical picture was a moderately severe disease with vomiting as a predominant symptom. SLVs were detected in 9% of the cases, the clinical picture being a mild diarrheal disease. Astroviruses were found in 10% and enteric adenoviruses in 6% of the cases. Diagnosis with PCR and RT-PCR methods increases the detection of all gastroenteritis viruses, particularly human caliciviruses. As a group, human caliciviruses are common causative agents of gastroenteritis in children <2 years of age in Finland, and, of these, NLVs cause more severe disease than SLVs.

Rotaviruses detected by reverse transcription polymerase chain reaction in acute gastroenteritis during a trial of rhesus-human reassortant rotavirus tetravalent vaccine: implications for vaccine efficacy analysis

BACKGROUND

Rotaviruses are routinely diagnosed by detection of rotavirus antigen in stools using an enzyme immunoassay (EIA). A sensitive method, like reverse transcription polymerase chain reaction (RT-PCR), may reveal more rotaviruses, but the clinical significance of such findings is not well established.

OBJECTIVES

To study whether RT-PCR can detect more episodes of rotavirus-associated gastroenteritis than EIA and to determine how rotavirus RT-PCR findings might change efficacy analysis of a rotavirus vaccine trial, in which the outcome measure was rotavirus gastroenteritis diagnosis with EIA.

STUDY DESIGN

We applied RT-PCR for detection of rotaviruses in gastroenteritis episodes encountered in an efficacy trial of rhesus-human reassortant rotavirus tetravalent (RRV-TV) vaccine, in a total of 2398 infants. During a follow-up, covering two rotavirus epidemic seasons, 256 cases of rotavirus associated gastroenteritis were detected by EIA; 226 were in the primary efficacy analysis period that included children who had received three doses of vaccine or placebo.

RESULTS

With RT-PCR, 84 (33%) more cases of rotavirus gastroenteritis were diagnosed than with EIA, 65 of these were in the primary efficacy analysis period. Clinically, cases of rotavirus gastroenteritis diagnosed by RT-PCR were much milder (median severity score 6 on a 20-point scale) than those diagnosed by EIA (median score 11), P < 0.0001. RT-PCR revealed proportionally more G2 and G4 rotaviruses than EIA. G1 rotaviruses detected by RT-PCR were almost equally divided between RRV-TV (25) vaccine and placebo (28) groups, whereas an apparent vaccine protective effect was seen in the distribution of G2 (one in the RRV-TV and eight in the placebo group) and G4 rotaviruses (six in the RRV-TV and 14 in the placebo group).

CONCLUSION

RT-PCR is a useful tool in the diagnosis of rotavirus gastroenteritis, particularly for cases associated with other than the epidemiologically dominant G-type. Application of RT-PCR contributes to the overall appraisal of performance of rotavirus vaccine.

Human astrovirus-associated gastroenteritis in children under 2 years of age followed prospectively during a rotavirus vaccine trial

This study evaluated the clinical significance of human astrovirus-associated gastroenteritis in young children in the community. Placebo- (n = 1207) and rhesus rotavirus tetravalent (RRV-TV) vaccine- (n = 1191) recipient children were followed from 2 mo to 2 y of age. Stool specimens from 1528 episodes of acute gastroenteritis (805 in the placebo group and 723 in the RRV-TV vaccine group) were tested for astrovirus with a sensitive reverse transcription-polymerase chain reaction (RT-PCR) assay and positive results were confirmed by Southern hybridization using probes specific for astrovirus serotypes 1 and 2. Astroviruses were detected in 144 (9%) episodes of gastroenteritis; 92% of the findings were serotype 1 and 6% were serotype 2. The astrovirus peak season was in winter. Of the 102 children who had gastroenteritis with astrovirus as the only diarrhoea virus in the stools, 72% had watery diarrhoea, 59% had vomiting, 26% had fever, 5% needed oral rehydration and 3% were hospitalized. Overall, the clinical severity of astrovirus gastroenteritis was much lower than that of rotavirus gastroenteritis. RRV-TV rotavirus vaccine did not protect against astrovirus gastroenteritis. It is concluded that astroviruses are common causative agents in acute gastroenteritis in young children, but the symptoms of astrovirus gastroenteritis are usually mild and the illness is therefore only of minor clinical significance.

Human calicivirus-associated sporadic gastroenteritis in Finnish children less than two years of age followed prospectively during a rotavirus vaccine trial

BACKGROUND

Human caliciviruses (HuCV) cause outbreaks of gastroenteritis, but their role in sporadic diarrhea in young children is not well-established.

METHODS

Children (n = 2398) participating in a trial of oral rhesus-human reassortant rotavirus tetravalent (RRV-TV) vaccine were evaluated from 2 months to 2 years of age. Stool specimens from 1477 episodes of acute gastroenteritis (788 in a placebo and 689 in a RRV-TV vaccine recipient group) were tested for human calicivirus (HuCV) by reverse transcriptase-PCR with the use of broadly reactive primers, and positive results were confirmed by Southern hybridization with probes specific for main genetic clusters of Genogroups I and II of HuCV.

RESULTS

HuCV were detected in 158 (20%) and 155 (22%) cases of gastroenteritis in the placebo and RRV-TV vaccine groups, respectively. According to hybridization results, 8% of HuCV were of Genogroup I and 92% were of Genogroup II. The peak season of HuCV gastroenteritis was from November to February. Of the 148 patients with pure HuCV infection in the placebo group, 89% had vomiting, 79% had watery diarrhea, 21% had fever, 28% needed oral rehydration and 1.4% were hospitalized. The diarrhea in HuCV gastroenteritis was much less severe than that in rotavirus gastroenteritis, but vomiting was equally severe. There was no effect of RRV-TV vaccine on the frequency or clinical severity of HuCV gastroenteritis.

CONCLUSION

HuCVs are second in frequency to rotaviruses as causative agents in acute gastroenteritis in young children in the community.

Antibodies reactive with the N-terminal domain of Plasmodium falciparum serine repeat antigen inhibit cell proliferation by agglutinating merozoites and schizonts

The serine repeat antigen (SERA) is a vaccine candidate antigen of Plasmodium falciparum. Immunization of mice with Escherichia coli-produced recombinant protein of the SERA N-terminal domain (SE47') induced an antiserum that was inhibitory to parasite growth in vitro. Affinity-purified mouse antibodies specific to the recombinant protein inhibited parasite growth between the schizont and ring stages but not between the ring and schizont stages. When Percoll-purified schizonts were cultured with the affinity-purified SE47'-specific antibodies, schizonts and merozoites were agglutinated. Indirect-immunofluorescence assays with unfixed parasite cells showed that SE47'-specific immunoglobulin G (IgG) bound to SERA molecules on rupturing schizonts and merozoites but the IgG did not react with the schizont-infected erythrocytes (RBC). Furthermore, double-fluorescence staining against SE47'-specific IgG and anti-human RBC membrane IgG showed that the RBC membrane disappeared from SE47'-specific-IgG-bound schizonts after cultivation. These observations suggest that the SE47'-specific antibodies inhibit parasite growth by cross-linking SERA molecules that are associated with merozoites in rupturing schizonts with partly broken RBC and parasitophorous vacuole membranes, blocking merozoite release.

Complement-mediated killing of Plasmodium falciparum erythrocytic schizont with antibodies to the recombinant serine repeat antigen (SERA)

Mouse antiserum against the recombinant N-terminal domain (SE47') of serine repeat antigen (SERA) of Plasmodium falciparum inhibited the in vitro proliferation of the parasite. We purified the immunoglobulin G from mice immunized with SE47' and with Freund's or aluminum hydroxide gel, or without adjuvants. Antiserum prepared with aluminum hydroxide gel contained predominantly IgG1 subclass and was the least inhibitory to parasite proliferation. Antiserum prepared with Freund's adjuvant or without adjuvants contained SE47'-specific IgG2a, IgG2b and IgG3. These mixed IgG subclasses was more potent in growth inhibition that the IgG1. Furthermore, guinea pig complement enhanced the parasite growth inhibitory effect of the mixed SE47'-specific IgG2a, IgG2b and IgG3, but not that of the IgG1 or non-specific IgG. Heat inactivated complement could not support the enhanced growth inhibitory effect. When purified schizonts were incubated with SE47'-specific IgG2a, IgG2b and IgG3 and complement, abnormal schizonts with degenerated nuclei were observed. These data suggest that complement-mediated lysis of the schizonts by the classical pathway enhances the inhibition of the parasite cell proliferation by SE47' specific IgGs.

Randomised placebo-controlled trial of rhesus-human reassortant rotavirus vaccine for prevention of severe rotavirus gastroenteritis

BACKGROUND

Rotavirus is the most common cause of acute childhood gastroenteritis. Vaccination with live oral heterologous rotavirus vaccines may prevent rotavirus gastroenteritis. We assessed the efficacy of rhesus-human reassortant rotavirus tetravalent vaccine (RRV-TV) against severe rotavirus gastroenteritis in Finnish children in a randomised placebo-controlled double-blind trial.

METHODS

Placebo or RRV-TV (titre 4x10(5) plaque-forming units) was given to infants at ages 2, 3, and 5 months. The children were followed up for one or two rotavirus epidemic seasons. The main outcome measure was protection against severe rotavirus gastroenteritis (score > or =11 on a 20-point severity scale). 2398 children were enrolled and received at least one dose of RRV-TV (n=1191) or placebo (n=1207). The primary efficacy analysis was based on children who received three doses of RRV-TV (n=1128) or placebo (n=1145).

FINDINGS

256 episodes of rotavirus gastroenteritis occurred at any time during the study; 65 were among 1191 RRV-TV recipients, and 191 among 1207 placebo recipients (vaccine efficacy 66% [95% CI 55-74]; intention-to-treat analysis). 226 episodes were included in the primary efficacy analysis of fully vaccinated children (54 among 1128 RRV-TV recipients, 172 among 1145 placebo recipients; vaccine efficacy 68% [57-76]). 100 episodes were severe, eight in RRV-TV recipients and 92 in placebo recipients (vaccine efficacy 91% [82-96]).

INTERPRETATION

RRV-TV vaccine was highly effective against severe rotavirus gastroenteritis in young children. Incorporation of this vaccine into routine immunisation schedules of infants could reduce severe rotavirus gastroenteritis by 90% and severe gastroenteritis of all causes in young children by 60%.

Antibody responses against Em18 and Em16 serodiagnostic markers in alveolar and cystic echinococcosis patients from northwest China

Western blot analysis was carried out in order to evaluate new serodiagnostic markers, Em18 and Em16, for differentiation of alveolar echinococcosis (AE) from cystic echinococcosis (CE) using 36 serum samples from hydatid patients from Xinjiang, China, where AE and CE are both endemic and one double infection case has been reported. All AE cases except one (5/6) who exhibited a calcified lesion and a single case of double infection showed antibody responses against Em18 and Em16. Some of CE patient sera (6/22) showed antibody response against Em16 except one who showed that against Em18. Analyses of IgG subclass responses against Em18 and Em16 were carried out using all serum samples showing antibody responses against Em18 and/or Em16 (seven CE, five AE, and one AE + CE) and additional samples of three CE and 22 AE from Sichuan, China. IgG4 was the most predominant antibody subclass. Em18 and Em16 were recognized by both IgG4 and IgG1 (in most cases) or by either IgG4 or IgG1 (in minor cases) or by IgG3 (in very rare cases). Neither Em18 nor Em16 was recognized by IgG2 antibodies. The usefulness of Em18 and Em16 as potential new markers for serological differentiation of human AE and CE, respectively, is discussed.

Immunodiagnosis of alveolar echinococcosis by enzyme-linked immunosorbent assay using a partially purified Em18/16 enriched fraction

An improved enzyme-linked immunosorbent assay (ELISA) system using partially purified Eml8/16 enriched fraction (PP-Em18/16) prepared by isoelectric focusing was evaluated for serodiagnosis of alveolar echinococcosis (AE). The PP-Em18/16-ELISA was compared with Em2plus-ELISA by using sera from AE and cystic echinococcosis (CE) patients in China, where both AE and CE are endemic; sera from CE patients in Australia, where only CE exists; and sera from patients with cysticercosis, paragonimiasis, or sparganosis in Korea, where no indigenous AE or CE exists. We used Em2plus-ELISA as a standard ELISA and found 24.6% (17 of 69 specimens) cross-reactivity with sera from CE. Furthermore, some of the sera from paragonimiasis, sparganosis, and cysticercosis patients were also cross-reactive in the Em2plus-ELISA. When we tested for similar cross-reactivity in the same sera from CE patients by PP-Em18/16-ELISA (23.2%, 16 of 69), it became evident that the specificity of the PP-Em18/16-ELISA was better than that of the Em2plus-ELISA, since no sera from patients with the examined parasitic diseases except CE showed cross-reactivity. Some CE patients from China showed exceptionally high levels of antibody in comparison with those of CE patients from Australia, where no AE occurs. It is speculated that these patients with strongly positive cases of CE from China may have been exposed to both species of Echinococcus.