Oxytocin-induced increases in cytokines and clinical effect on the core social features of autism: Analyses of RCT datasets

Although oxytocin may provide a novel therapeutics for the core features of autism spectrum disorder (ASD), previous results regarding the efficacy of repeated or higher dose oxytocin are controversial, and the underlying mechanisms remain unclear. The current study is aimed to clarify whether repeated oxytocin alter plasma cytokine levels in relation to clinical changes of autism social core feature. Here we analyzed cytokine concentrations using comprehensive proteomics of plasmas of 207 adult males with high-functioning ASD collected from two independent multi-center large-scale randomized controlled trials (RCTs): Testing effects of 4-week intranasal administrations of TTA-121 (A novel oxytocin spray with enhanced bioavailability: 3U, 6U, 10U, or 20U/day) and placebo in the crossover discovery RCT; 48U/day Syntocinon or placebo in the parallel-group verification RCT. Among the successfully quantified 17 cytokines, 4 weeks TTA-121 6U (the peak dose for clinical effects) significantly elevated IL-7 (9.74, 95 % confidence interval [CI] 3.59 to 15.90, False discovery rate corrected P (PFDR) < 0.001), IL-9 (56.64, 20.46 to 92.82, PFDR < 0.001) and MIP-1b (18.27, 4.96 to 31.57, PFDR < 0.001) compared with placebo. Inverted U-shape dose-response relationships peaking at TTA-121 6U were consistently observed for all these cytokines (IL-7: P < 0.001; IL-9: P < 0.001; MIP-1b: P = 0.002). Increased IL-7 and IL-9 in participants with ASD after 4 weeks TTA-121 6U administration compared with placebo was verified in the confirmatory analyses in the dataset before crossover (PFDR < 0.001). Furthermore, the changes in all these cytokines during 4 weeks of TTA-121 10U administration revealed associations with changes in reciprocity score, the original primary outcome, observed during the same period (IL-7: Coefficient = -0.05, -0.10 to 0.003, P = 0.067; IL-9: -0.01, -0.02 to -0.003, P = 0.005; MIP-1b: -0.02, -0.04 to -0.007, P = 0.005). These findings provide the first evidence for a role of interaction between oxytocin and neuroinflammation in the change of ASD core social features, and support the potential role of this interaction as a novel therapeutic seed. Trial registration: UMIN000015264, NCT03466671/UMIN000031412.

Effect of a novel nasal oxytocin spray with enhanced bioavailability on autism: a randomized trial

Although intranasal oxytocin is expected to be a novel therapy for the core symptoms of autism spectrum disorder, which has currently no approved medication, the efficacy of repeated administrations was inconsistent, suggesting that the optimal dose for a single administration of oxytocin is not optimal for repeated administration.

The current double-blind, placebo-controlled, multicentre, crossover trial (ClinicalTrials.gov Identifier: NCT03466671) was aimed to test the effect of TTA-121, a new formulation of intranasal oxytocin spray with an enhanced bioavailability (3.6 times higher than Syntocinon® spray, as assessed by area under the concentration–time curve in rabbit brains), which enabled us to test a wide range of multiple doses, on autism spectrum disorder core symptoms and to determine the dose–response relationship. Four-week administrations of TTA-121, at low dose once per day (3 U/day), low dose twice per day (6 U/day), high dose once per day (10 U/day), or high dose twice per day (20 U/day), and 4-week placebo were administered in a crossover manner. The primary outcome was the mean difference in the reciprocity score (range: 0–14, higher values represent worse outcomes) on the Autism Diagnostic Observation Schedule between the baseline and end point of each administration period. This trial with two administration periods and eight groups was conducted at seven university hospitals in Japan, enrolling adult males with high-functioning autism spectrum disorder. Enrolment began from June 2018 and ended December 2019. Follow-up ended March 2020.

Of 109 males with high-functioning autism spectrum disorder who were randomized, 103 completed the trial. The smallest P-value, judged as the dose–response relationship, was the contrast with the peak at TTA-121 6 U/day, with inverted U-shape for both the full analysis set (P = 0.182) and per protocol set (P = 0.073). The Autism Diagnostic Observation Schedule reciprocity score, the primary outcome, was reduced in the TTA-121 6 U/day administration period compared with the placebo (full analysis set: P = 0.118, mean difference = −0.5; 95% CI: −1.1 to 0.1; per protocol set: P = 0.012, mean difference = −0.8; 95% CI: −1.3 to −0.2). The per protocol set was the analysis target population, consisting of all full analysis set participants except those who deviated from the protocol. Most dropouts from the full analysis set to the per protocol set occurred because of poor adherence to the test drug (9 of 12 in the first period and 8 of 15 in the second period). None of the secondary clinical and behavioural outcomes were significantly improved with the TTA-121 compared with the placebo in the full analysis set.

A novel intranasal spray of oxytocin with enhanced bioavailability enabled us to test a wide range of multiple doses, revealing an inverted U-shape dose–response curve, with the peak at a dose that was lower than expected from previous studies. The efficacy of TTA-121 shown in the current exploratory study should be verified in a future large-scale, parallel-group trial.

P5577Preoperative transaortic pressure gradient predicts renal functional improvement after transcatheter aortic valve implantation in patients with chronic kidney disease

Introduction

Transcatheter aortic valve implantation (TAVI) theoretically increases renal blood flow through increasing cardiac output by relieving aortic valvular obstruction of blood flow from left ventricle, resulting in a renal functional recovery in patients with severe aortic valve stenosis (AS). However, procedural steps of TAVI including contrast use potentially damages renal medulla and may deteriorate renal function.

Purpose

The aim of this study was to investigate renal functional change and clarify preoperative predictors for renal functional improvement after TAVI in chronic kidney disease (CKD) patients with severe AS.

Methods

A total of 88 consecutive severe AS patients with CKD (grade >3) who underwent TAVI from 2015 to 2018 was enrolled in this observational study. They were divided into two groups depending on their renal functional improvement after TAVI that was defined as more than 10% increase in estimated glomerular filtration rate (eGFR) at discharge from their preoperative level.

Results

Among the whole candidates, 49 patients (55.7%) were improved their renal function. Patients with the lowest preoperative eGFR achieved the highest increase in eGFR after TAVI (CKD grade >4: +22.7±23.7%, Figure). Patients in the Improved group had lower hemoglobin level, higher mean transaortic pressure gradient (TAPG), and higher aortic valve gradient before TAVI, compared to those in the Non-improved group. However, contrast volume during the procedure was not significantly different between the groups. Multivariate logistic regression analysis revealed that high mean TAPG and low left ventricular ejection fraction (LVEF) before TAVI were independent predictors for the improvement of renal function (odds ratio (OR): 1.04, 95% confidence interval (CI): 1.00–1.08; OR: 0.94, 95% CI: 0.89–0.99, respectively), even after the adjustment of baseline eGFR level and hemoglobin level that were statistically significant on univariate logistic regression analysis. Receiver Operating Characteristic (ROC) curve showed the cut-off level of preoperative mean TAPG in renal functional improvement after TAVI as 47.0 mmHg (Sensitivity: 47.9%, Specificity: 79.5%, area under the curve: 0.62).

Correlation between CKDgrade and ΔeGFR

Conclusions

Preoperative high mean TAPG may predict renal functional improvement after TAVI in patients with deteriorated renal function. This non-invasive predictor may help clinicians to consider to perform TAVI in a challenging case with severe CKD.

Estimated cognitive decline in patients with schizophrenia: A multicenter study

AIM

Studies have reported that cognitive decline occurs after the onset of schizophrenia despite heterogeneity in cognitive function among patients. The aim of this study was to investigate the degree of estimated cognitive decline in patients with schizophrenia by comparing estimated premorbid intellectual functioning and current intellectual functioning.

METHODS

A total of 446 patients with schizophrenia (228 male, 218 female), consisting of three sample sets obtained from 11 psychiatric facilities, and 686 healthy controls participated in this study. The Wechsler Adult Intelligence Scale-III (WAIS-III) was used to measure the participants' current full-scale IQ (FSIQ). The premorbid IQ was estimated using the Japanese Adult Reading Test-25. Estimated cognitive decline (difference score) was defined as the difference between the estimated premorbid IQ and the current FSIQ.

RESULTS

Patients with schizophrenia showed greater estimated cognitive decline, a lower FSIQ, and a lower premorbid IQ compared with the healthy controls. The mean difference score, FSIQ, and estimated premorbid IQ were -16.3, 84.2, and 100.5, respectively, in patients with schizophrenia. Furthermore, 39.7% of the patients had a difference score of 20 points or greater decline. A discriminant analysis showed that the difference score accurately predicted 81.6% of the patients and healthy controls.

CONCLUSION

These results show the distribution of difference score in patients with schizophrenia. These findings may contribute to assessing the severity of estimated cognitive decline and identifying patients with schizophrenia who suffer from cognitive decline.

Abnormal asymmetries in subcortical brain volume in schizophrenia

Subcortical structures, which include the basal ganglia and parts of the limbic system, have key roles in learning, motor control and emotion, but also contribute to higher-order executive functions. Prior studies have reported volumetric alterations in subcortical regions in schizophrenia. Reported results have sometimes been heterogeneous, and few large-scale investigations have been conducted. Moreover, few large-scale studies have assessed asymmetries of subcortical volumes in schizophrenia. Here, as a work completely independent of a study performed by the ENIGMA consortium, we conducted a large-scale multisite study of subcortical volumetric differences between patients with schizophrenia and controls. We also explored the laterality of subcortical regions to identify characteristic similarities and differences between them. T1-weighted images from 1680 healthy individuals and 884 patients with schizophrenia, obtained with 15 imaging protocols at 11 sites, were processed with FreeSurfer. Group differences were calculated for each protocol and meta-analyzed. Compared with controls, patients with schizophrenia demonstrated smaller bilateral hippocampus, amygdala, thalamus and accumbens volumes as well as intracranial volume, but larger bilateral caudate, putamen, pallidum and lateral ventricle volumes. We replicated the rank order of effect sizes for subcortical volumetric changes in schizophrenia reported by the ENIGMA consortium. Further, we revealed leftward asymmetry for thalamus, lateral ventricle, caudate and putamen volumes, and rightward asymmetry for amygdala and hippocampal volumes in both controls and patients with schizophrenia. Also, we demonstrated a schizophrenia-specific leftward asymmetry for pallidum volume. These findings suggest the possibility of aberrant laterality in neural pathways and connectivity patterns related to the pallidum in schizophrenia.

Differentiation between major depressive disorder and bipolar disorder by auditory steady-state responses

BACKGROUND

The auditory steady-state response (ASSR) elicited by gamma band neural oscillations has received considerable interest as a biomarker of psychiatric disorders. Although recent ASSR studies have reported that patients with bipolar disorder (BD) show altered ASSRs, little is known about ASSRs in patients with major depressive disorder (MDD). The aim of this study was to evaluate whether ASSRs in MDD subjects differed from those in BD subjects or normal controls (NC).

METHOD

We analyzed ASSRs in 14 MDD patients, 19 BD patients, and 29 normal control subjects. We used whole-head 306-channel magnetoencephalography to evaluate ASSR power and phase-locking factors (PLF) elicited by 20-, 30-, 40-, and 80-Hz click trains. We determined optimal sensitivity and specificity of ASSR power and PLF for the diagnosis of MDD or BD via receiver operating characteristic (ROC) curve analysis using a nonparametric approach.

RESULTS

MDD patients exhibited no significant differences in ASSR power or PLF compared with NC subjects, while BD patients showed deficits on the ASSR measures. MDD patients showed significantly larger ASSR power and PLF for 30-, 40-, and 80-Hz stimuli compared with BD patients. The area under the curve (AUC) for the ROC analysis (MDD vs. BD) was 0.81 [95% CI=0.66-0.96, p=0.003] concerning 40-Hz ASSR power.

LIMITATIONS

We could not exclude the effect of medication and the sample size of the current study is relatively small.

CONCLUSIONS

We could differentiate between MDD and BD subjects in terms of gamma band ASSR. Our data suggest that the 40-Hz ASSR may be a potential biomarker for differentiation between MDD and BD patients.

An immunotherapeutic program for the treatment of nicotine addiction: hapten design and synthesis

People continue to smoke and use tobacco products despite well-established hazardous consequences. The most contributing factor is the addictive nature of nicotine. There is no highly effective treatment for the problem of nicotine dependence. Immunotherapy offers an alternative to conventional approaches. The chemistry necessary for a comprehensive immunopharmacological program is presented. Haptens for the generation of antibodies specific for naturally occurring (S)-nicotine, (S)- and (R)-nornicotine, and the metabolite (S)-cotinine were prepared with high optical purity. Preliminary data for antinicotine antibodies are reported.

Sequence diversity of serine repeat antigen gene exon II of Plasmodium falciparum in worldwide collected wild isolates

Field isolates of Plasmodium falciparum collected from endemic areas of Southeast Asia, Solomon Islands, tropical African countries and Brazil were analyzed for the genetic diversity of the exon II of serine repeat antigen gene (SERA) by sequencing of genomic DNA. Of sixty-nine isolates, as compared to the reported FCR3, K1 and Honduras-1 types of exon II sequences, 5, 9 and 20 new allelic forms were found in 23 isolates of the FCR3 type, 36 of the K1 type and 10 of the Honduras-1 type. A group of novel non-synonymous substitutions, 4 new insertions and 3 new deletions of octamer units were found in the octamer repeat region (OR) of the exon II, and most of them clustered within a 40-residues domain. An octamer "SNPVSSEP" revealed in the OR was confirmed as a new repeat unit. Based on the sequences of the serine repeat region (SR) of the exon II, the allelic forms of the Honduras-1 type were conjectured to be the recombinant forms between the K1 type and FCR3 type. The allelic forms of K1 type with less or more repeat serine residues in the serine stretch of the SR than the reported 21 serine residues had most of the variations in the OR. Moreover, a biased geographical distribution of allelic forms was observed. Isolates from African and Southeast Asian countries accounted for most of the new allelic forms (29/33). All of the three types were detected in Southeast Asia but none of the FCR3 type in Africa. One of two groups of FCR3 new allelic forms was found solely in Brazil while another was mainly in Solomon Islands.

Rotavirus infection among infants with diarrhea in Vietnam

Rotavirus was examined from diarrheal stool samples of 158 infants in rural area near Ho Chi Minh City, Vietnam, from 1994 to 1996. Group A rotavirus was detected in 50%. G1 and G4 were the predominant serotypes. G3 was not detected. The most predominant type changed from year to year. Rotavirus was found in all seasons, especially in winter and autumn. Infants younger than 2 years of age were those mostly infected and the virus was suspected to invade high concentration in this area.

Rotavirus infection among infants with diarrhea in Pakistan

Rotavirus was examined in 818 diarrheal stool samples collected in Karachi, Pakistan, from 1990 to 1997. Rotavirus was detected in 112 samples (13.7%). The predominant serotypes were G1 and G4 and G3 was not detected. The predominant type changed between years. Rotavirus was found in all seasons and most infections were found in children aged less than 2 years.

Intratypic differentiation & partial nucleotide sequencing of poliovirus isolates of northern India

The potential resolving power of molecular epidemiological studies has enhanced the precision and reliability of poliovirus (PV) surveillance. PV has an error prone RNA polymerase responsible for rapid evolution of genome (approximately 10(-2) nt substitution/site/year), during inter and intra-human passages. The present study included a serotyped panel of 60 PV (42 PV type-1, 13 PV type-2 and 5 PV type-3) isolated during 1997. They were differentiated into vaccine (Sabin) and wild strains by two methods viz., genotype specific RNA probe hybridization (Rpro-Hy) based on genotypic variability; and ELISA that uses cross-absorbed antiserum (Pab-E) based on phenotypic variability. For obtaining information on molecular epidemiology, partial nucleotide sequencing (VP1/2A region) of five clinical PV isolates was also done. Three of the 60 isolates (two PV type-1 and one PV type-3) intratyped, could not be differentiated correctly by either method. Genotypic characterization of PV isolates was done for confirmation of intratyping results. All five wild PV1 sequenced belonged to the same genotype (> 85% homology) and sequence divergence among the strains was < or = 4.5 per cent. This indicated circulation of a single genetic lineage in the area.

An infectious DNA clone of HIV type 1 subtype C

Among the 10 subtypes of the M group of human immunodeficiency virus type 1, subtype C is the most prevalent in India and may dominate worldwide in the near future; however, there has been no report on the infectious DNA clone of this subtype. We have isolated an infectious DNA clone of the 93IN101 strain of HIV-1 subtype C, which was isolated in India in 1993. MAGIC5 cells, which are derived from HeLa-CD4-LTR-beta-gal (MAGI) cells and express CCR5, were inoculated with the 93IN101 strain of HIV-1 subtype C. The genomic DNA of the infected cells was used as a template for amplification of the HIV-1 genome. The genome DNA obtained was subcloned into pBR322, and the resulting plasmid was designated as pIndie-C1. The insert of pIndie-C1 was 9680 bp in length and had an intact genomic organization with open reading frames of all structural, regulatory, and accessory proteins. Phylogenetic analysis confirmed that the nucleotide sequence of pIndie-C1 is closely related to those of HIV-1 subtype C isolated in India. Transfection of pIndie-C1 into 293T cells yielded as much virus as did pNL432, one of the most widely used HIV DNA clones. The recovered Indie-C1 virus infected MAGIC5 but not the parent MAGI cells, indicating that Indie-C1 is CCR5 tropic. Expressed Env protein was reacted efficiently with the sera of HIV-1-infected patients of India, but not of Japan. Expression of Nef and Vpr was also confirmed by immunoblotting.

Evaluation of an enzyme-linked immunosorbent assay based on binding inhibition for type-specific quantification of poliovirus neutralization-relevant antibodies

To detect neutralization-relevant antibodies against 3 types of poliovirus (PV) without using tissue cultures and live viruses, an enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibody-binding inhibition was evaluated using sera from 80 vaccinated Japanese children and 60 Pakistani poliomyelitis patients. Compared with the neutralization test, the sensitivity of the inhibition ELISA was 100% (111/111) for detection of anti-PV1 antibody, 98.3% (118/120) for anti-PV2, and 96.5% (82/85) for anti-PV3, and the specificity was 93.1% (27/29), 100% (20/20), and 92.7% (51/55), respectively. Thus, the inhibition ELISA showed excellent potential as a seroepidemiologic tool in both vaccinated and naturally-infected populations.

Phospholipase A2-like catalytic antibody

The phospholipase A2-like catalytic antibody 13C2-1F6 was elicited against the hapten 1 as the transition state analog for the hydrolysis of the C2 ester in the phospholipid. The Michaelis-Menten kinetics for the hydrolysis of the phospholipid 2 by 13C2-1F6 afforded a kcat of 1.0 x 10(-2) min(-1) and aKm of 71 microM. This antibody hydrolyzes the C2 ester in (R)-2, regio- and enantioselectively.

Quantitative analysis of the kinetics of phospholipase A2 using fast atom bombardment mass spectrometry

Fast atom bombardment mass spectrometry that can directly analyze lysophospholipids was used to quantitatively determine the kinetics of phospholipase A2. This method is 1250 times more sensitive than the colorimetric assay.

Sequence variation in the small-subunit rRNA gene of Plasmodium malariae and prevalence of isolates with the variant sequence in Sichuan, China

By two PCR-based diagnostic methods, Plasmodium malariae infections have been rediscovered at two foci in the Sichuan province of China, a region where no cases of P. malariae have been officially reported for the last 2 decades. In addition, a variant form of P. malariae which has a deletion of 19 bp and seven substitutions of base pairs in the target sequence of the small-subunit (SSU) rRNA gene was detected with high frequency. Alignment analysis of Plasmodium sp. SSU rRNA gene sequences revealed that the 5' region of the variant sequence is identical to that of P. vivax or P. knowlesi and its 3' region is identical to that of P. malariae. The same sequence variations were also found in P. malariae isolates collected along the Thai-Myanmar border, suggesting a wide distribution of this variant form from southern China to Southeast Asia.

Correlation analysis between fatty acid compositions of zooplankter individuals, fed on different phytoplankton species by means of pyrolysis-gas chromatography combined with on-line methylation

Pyrolysis-gas chromatography (Py-GC) combined with on-line methylation was applied to a correlation analysis between the distributions of fatty acid components in the lipids of zooplankter individuals and those of ingested algae using principal component analysis (PCA). Py-GC in the presence of organic alkali, tetramethylammonium hydroxide (TMAH), was used to estimate the apparent distributions of fatty acid components contained in a single individual zooplankter weighing several tens of micrograms and a small sample size of ingested algae samples in the order of 10 microg. The observed fatty acid compositions were used as a database for the PCA in order to discriminate the zooplankton and ingested algae samples. The result obtained indicated that the fatty acid compositions of zooplankton individuals used in this work were significantly reflected in those of their ingested food in spite of some contribution from isomerization and/or elongation of fatty acid components during digestion of the ingested algae phytoplankton in living zooplankters.

Allelic diversity at the merozoite surface protein-1 locus of Plasmodium falciparum in clinical isolates from the southwestern Brazilian Amazon

Nucleotide sequences of each variable block in the Plasmodium falciparum merozoite surface protein-1 gene (PfMSP-1) may be grouped into one of two or three possible allelic types, named after the reference isolates MAD20, K1, and RO33. Allelic diversity at this locus basically results from different combinations of allelic types in variable blocks. We used a polymerase chain reaction (PCR)-based strategy to type the variable blocks 2, 4a, 4b, and 10 of the PfMSP-1 gene of P. falciparum isolates from 54 symptomatic malaria patients living in Rondonia, a hypoendemic area in the southwestern Brazilian Amazon. Ten different PfMSP-1 gene types, defined as unique combinations of allelic types in variable blocks, were identified among the 54 isolates. Twenty-one isolates (39%) harbored more than one gene type and two had at least three genetically distinct clones. Hybrid sequences, with a MAD20-type sequence in the 5' segment (4a) and a K1-type sequence in the 3' segment (4b), were quite common in block 4. Direct sequencing of block 4 PCR products revealed a new putative recombination site in four isolates. In contrast with previous studies, the observed distribution of gene types does not deviate significantly from that expected under the null hypothesis of random association between allelic types detected in each variable block. These contradictory data are discussed with reference to the immunoepidemiologic features prevailing in distinct malaria-endemic areas.

High prevalence of Plasmodium malariae and Plasmodium ovale in malaria patients along the Thai-Myanmar border, as revealed by acridine orange staining and PCR-based diagnoses

The prevalence of the four human malaria parasites was investigated among malaria patients at northern, central and southern towns in Thailand along the border with Myanmar between September 1995 and May 1996. Thin smears obtained from 548 Thai and Burmese patients were reviewed by an acridine orange staining method, and many mixed infections with two to four species, including P. malariae and P. ovale, were detected. These diagnostic results were compared with those by two PCR-based diagnoses, microtitre plate hybridization (MPH) and a nested PCR method, both of which targets the same, species-specific regions in the 18S rRNA genes. In both PCR diagnoses, many P. malariae and P. ovale infections were also detected. Detection sensitivity of P. malariae infection was higher in nested PCR than MPH, and a total prevalence of P. malariae infection estimated by nested PCR reached 24.3% (133/548). In 16 of them, the size of PCR products amplified by the P. malariae-specific primer was about 20-bp shorter than the expected size of 115-bp. Four of 16 possessed two different bands with normal and shorter sizes, suggesting that P. malariae isolates may be separated into two types, and that those with shorter products may be new variant form (s) with a nucleotide deletion in the target region. On the other hand, 21 P. ovale infections (3.8%) were detected by nested PCR, but four of them were MPH-negative because of the sequence variation at the probe region. These results indicated that the prevalence of P. malariae and P. ovale along the Thai-Myanmar border may be substantially higher than previously reported.

Prevalence of hepatitis B, hepatitis C, and GB virus C/hepatitis G virus infections in liver disease patients and inhabitants in Ho Chi Minh, Vietnam

The prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and GB virus C or hepatitis G virus (GBV-C/HGV) infections was determined in 289 patients with liver disease in Ho Chi Minh City and 890 healthy inhabitants of its rural area, Dalat City, Vietnam, respectively. Serum HCV RNA and GBV-C/HGV RNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). HBsAg, HCV antibodies, and GBV-C/HGV RNA were detected in 139 (47%), 69 (23%), and ten (3%) subjects, respectively, often accompanied by elevated serum levels of alanine aminotransferase. HBsAg and HCV antibodies or HCV antibodies and GBV-C/HGV RNA were detectable simultaneously in 8% and 2% of the patients, respectively. In the inhabitants, HBsAg, HCV antibodies, and GBV-C/HGV RNA were found in 51 (5.7%), nine (1.0%), and 11 (1.2%) subjects, respectively. Thus, the prevalence of HBsAg, HCV antibodies, and GBV-C/HGV RNA was significantly higher in liver disease patients than those in the general population. In the samples from 69 patients and nine inhabitants who were seropositive for HCV antibodies, HCV RNA was detectable in 42 (61%) and 4 (44%), respectively. In patients with liver disease, ten belonged to HCV genotype 1a, ten to HCV 1b, three to HCV 2a, four to HCV 2b, and two to HCV 3a by PCR with genotype-specific primers. Nine patients had mixed genotypes, and the remaining four were not classified. Of the GBV-C/HGV RNA-positive individuals, two patients and two inhabitants were positive for HBsAg, while none of the residents had HCV antibodies, although six HCV antibodies (60%) and four HCV RNA (40%) were found in patients. When a phylogenetic tree of GBV-C/HGV was constructed based on the nucleotide sequences, the 21 isolates were classified into at least two genotypes; four isolates belonged to G2, and 17 to G3. The results indicate that in Ho Chi Minh HCV infection prevails with broad distribution of genotypes together with HBV infection among patients with liver disease. This study suggests that GBV-C/HGV infection occurs independently in the two different districts in association with HCV infection.

An epidemiologic study of herpes simplex virus type 1 and 2 infection in Japan based on type-specific serological assays

A seroepidemiologic study of herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) was performed on Japanese adults. Serum samples collected between 1985-9 from a total of 536 healthy adults, female prostitutes, males with sexually transmitted diseases (STD), homosexual men, and pregnant women were studied by immunodot assays using HSV type-specific antigens, glycoproteins G (gG1 and gG2). HSV-1 infections correlated mostly with age and was widely prevalent among subjects < 40 years. HSV-2 prevalence varied greatly among subgroups defined by sexual activity and was associated with risk behaviours for prostitution, infection with STD, and homosexual activity. HSV-2 seroprevalence was highest among prostitutes (80%), lowest among pregnant women (7%), and intermediate in STD patients (23%) and homosexuals (24%). Because HSV-1 infection during childhood has been decreasing, primary genital HSV-2 infection, with its higher frequency of clinical manifestations, will become a greater burden to the public health in Japan.

Stable patterns of allelic diversity at the Merozoite surface protein-1 locus of Plasmodium falciparum in clinical isolates from southern Vietnam

The extent of allelic diversity at the Merozoite Surface Protein-1 locus of Plasmodium falciparum (PfMSP-1) was examined in isolates collected from symptomatic patients living in a mesoendemic area in southern Vietnam. The variable blocks 2, 4 and 10 were typed by polymerase chain reaction and 24 PfMSP-1 gene types were defined as unique combinations of allelic types detected in each variable block. Nineteen PfMSP-1 gene types were identified and 182 parasite populations were fully typed among 102 isolates. Forty-eight (47%) patients harbored more than one typed parasite population, and one patient had at least eight genetically distinct subpopulations. As previously shown in the same endemic area, recombination between blocks 4 and 10 was significantly less frequent than expected from random assortment of allelic types. The distribution of PfMSP-1 gene types, however, did not differ significantly from that observed in isolates collected in the same area 17-24 mo before the present study. Furthermore, the prevalence of the most common gene types and the average number of different gene types harbored by the same host did not decrease with age. This argues against the prominence of frequency-dependent immune selection of PfMSP-1 polymorphisms in this parasite population.

Epidemiology of poliomyelitis in Karachi, Pakistan: prospective studies during 1990-93

Between October 1989 and September 1993, 245 cases of poliomyelitis visited the Department of Pediatrics, Civil Hospital Karachi, Pakistan. The majority of them were between 6 months and 2 years of age and the epidemic occurred during the hot season. The dominant serotype was polio type 1. All of the polioviruses isolated from the patients were wild type. Virological studies also disclosed that enteroviruses other than polioviruses were prevalent among healthy children as well as diarrheal and polio patients. Serodiagnosis by poliovirus-specific immunoglobulin M antibody tests using the capture enzyme-linked immunosorbent assay method were in good agreement with the results of virus isolation. The present study demonstrated that Pakistan is a region endemic for wild poliovirus and more aggressive preventive measures are needed to eradicate poliomyelitis from the region.

Sequence variation in the 18S rRNA gene, a target for PCR-based malaria diagnosis, in Plasmodium ovale from southern Vietnam

Field surveys of malaria were performed in southern Vietnam by using an acridine orange staining method for rapid diagnosis and a PCR-based, microtiter plate hybridization method for accurate diagnosis. A total of three patients of Plasmodium ovale infection were detected, but PCR-amplified DNA of the P. ovale isolates from two of the patients did not hybridize with the P. ovale-specific probe. Analysis of the target sequence in the 18S rRNA gene indicated that in the DNA of isolates from both patients three nucleotides in the probe region from the typical P. ovale sequence were different, with deletions of two nucleotides and the substitution of one nucleotide. These results may suggest that in addition to molecular biological methods, careful microscopic examination of stained thin blood films is still required in studies of the prevalence of different malaria species.

[Epidemiology of pertussis and studies on culture positive pertussis cases in Japan]

The number of pertussis patients has decreased steadily in the late 1960s and was extremely small in early 1970s. During 1973-74 the first national survey on pertussis cases confirmed by culture was conducted, when whole cell pertussis vaccine was used. The study revealed that 33.3% of culture positive cases had 2-4 doses of DT combined with whole cell pertussis vaccine. Acellular pertussis vaccine was introduced in 1981 and for the last several years the number of pertussis patients became low for the second time. During 1988-92 exactly the same study was conducted as the previous one. Among 2501 pertussis cases diagnosed clinically 403 were culture positive. Most of the patients were below 1 year of age. Most of the patients were below 1 year of age. Clinical symptoms of those infants were more serious than those of older children. Only 7 out of 403 (1.8%) had a history of 2-4 doses of DT combined with acellular pertussis vaccine. This proved that the acellular pertussis vaccine is by far more effective than the whole cell pertussis vaccine. Serotypes of 377 Bordetella pertussis were identified and 370/377 (98.1%) were serotype 1-3 group.

Immunogenicity and reactogenicity of the component acellular pertussis vaccine produced by a combination of column purified pertussis toxin and filamentous haemagglutinin

This is the report on a prospective, single blind, comparative study of a component acellular pertussis vaccine produced by a combination of detoxified, column purified pertussis toxin (PT) and filamentous hemagglutinin (FHA) combined with diphtheria and tetanus toxoids (DTcaP) and the traditional acellular pertussis vaccine produced with essentially the same method as described by Sato with DT (DTaP) of the same manufacturer. A total of 616 infants and children received DTcaP and a total of 289 received DTaP. In all age groups for both vaccines values of serum antibodies to PT and FHA after two doses of the vaccines were comparable to those of convalescent sera. Incidences of systemic and local reactions were, in general, not greatly different between DTcaP and DTaP recipients. In Japan the use of traditional acellular vaccines replaced whole cell vaccines in 1981. Protective antigens of Bordetella pertussis have now been specified and thus component vaccines have become theoretically possible. This is the first component vaccine which has been developed in Japan. Several other component vaccines are now under investigation in the world.

Isolation of cytopathic small round virus (Aichi virus) from Pakistani children and Japanese travelers from Southeast Asia

Aichi virus was isolated in Vero cells from 5 (2.3%) of 222 Pakistani children with gastroenteritis but none was found in 91 healthy children. Aichi virus was also isolated from 5 (0.7%) of 722 Japanese travelers returned from tours to Southeast Asian countries and complained of gastrointestinal symptoms at the quarantine station of Nagoya International Airport in Japan. Of 5 Japanese travelers, 3 were returning from Indonesia, and 2 from Thailand or Malaysia. These results indicate that Aichi virus or a similar agent is endemic in Southeast Asian countries and is a cause of gastrointestinal symptoms in children in these areas or in Japanese travelers who visit there.

Enteric viral infections in pre-school children in Karachi, Pakistan

A prospective study was conducted in Karachi, Pakistan on the virology of enteropathogens excreted by children with acute gastroenteritis and the results were compared with a control group of healthy children. Rotavirus and Adenovirus detection was done using ELISA techniques, while enterovirus isolation was done by virus culture. In 1990, 12.3% children with acute watery diarrhoea excreted rotavirus, as compared to 24.4% children in 1991. None of the healthy children excreted adenovirus 40 and 41. Preliminary results of 1992 revealed that rotavirus was seen in 13% of children with acute watery diarrhoea and adenovirus in 10% of children. Enteroviruses were isolated in the same frequency in all three groups i.e. children with acute watery diarrhoea, children with poliomyelitis and healthy children. Non-polio enteroviruses were excreted in 50-52% in all the 3 groups. The rate of enterovirus excretion is much higher than seen in other developed countries and is the same in children with diarrhoea and healthy children.

Bactericidal effect of rat cystatin S on an oral bacterium Porphyromonas gingivalis

We tested antibacterial and antiviral activities of rat cystatin S, a cysteine proteinase inhibitor, belonging to the family 2 cystatins against 18 different bacterial species and poliovirus type 1 (Sabin). Rat cystatin S specifically inhibited the growth of a human oral anaerobic bacterium Porphyromonas gingivalis due to a bactericidal effect.

Hepatitis A, B and C seroprevalence in Pakistan

A cross sectional study was conducted to determine the seroprevalence of Hepatitis A, B, and C virus in healthy Pakistani children. HAV IgG antibody was assayed in 258 subjects and it was found that 94% children by 5 years of age had HAV IgG-antibody. The overall seroprevalence of HAV IgG antibody was 55.8% and IgM 5.3%. HBVsAb levels assayed in 236 healthy children showed a seroprevalence of 2.97%. Similarly, HCV antibody seroprevalence was found to be a low 0.44% in healthy children. HAV is a major cause of Hepatitis, as compared to HBV and HCV which are of low endemicity.

Differentiation between wild and vaccine-derived strains of poliovirus by stringent microplate hybridization of PCR products

Procedures for differentiation between wild and vaccine-derived strains of poliovirus are required, particularly in countries where wild and vaccine-related strains coexist. For this differentiation, we tested the method of Inouye and Hondo (S. Inouye and R. Hondo, Arch. Virol. 129:311-316, 1993) for discrimination of closely related viruses by using stringent microplate hybridization of PCR products. We used a pair of primers with enterovirus common sequences (between these primers there is a variable region for capsid proteins) for PCR using templates from wild and vaccine-derived poliovirus strains which were isolated in tissue culture and serotyped by neutralization assay. We also used the same primers for preparation of probes, which were labelled by incorporation of biotin-dUTP in the PCR, with the three original Sabin vaccine virus strains used as templates. The amplified DNAs from the isolates were immobilized on microplate wells and were then hybridized with the labelled probes. We found that, under the usual hybridization conditions, the Sabin vaccine virus strain probes hybridized with both wild and vaccine-derived viruses, but under stringent conditions, they reacted only with vaccine-derived viruses of the same serotype, clearly differentiating these from wild-type viruses.

Prevalence of newly isolated, cytopathic small round virus (Aichi strain) in Japan

Cytopathic small round virus (Aichi strain), isolated from a patient with oyster-associated gastroenteritis, showed no reaction in the polymerase chain reaction method for enteroviruses or in the enzyme-linked immunosorbent assay (ELISA) for the five serotypes of astroviruses. Our ELISA was sensitive in detecting the Aichi strain antigen in stool samples, but there was no reaction in this ELISA with any non-Aichi strains of enteric viruses, with such origins as enterovirus, rotavirus, Norwalk virus, calicivirus, or astrovirus. In the ELISA, 13 of 47 stool samples from adult patients in five of nine oyster-associated gastroenteritis outbreaks were positive, but only 1 of 397 pediatric stool samples in Aichi Prefecture was positive. The prevalence rate for Aichi strain antibody was found to be 7.2% for persons aged 7 months to 4 years. The prevalence rate for antibody to Aichi strain increased with age, to about 80% in persons 35 years old. On the basis of the results of the present study, it was hypothesized that Aichi strain could be a new type of small round virus that mainly produces diarrhea in patients in the 15- to 34-year-old age group, 50 to 76% of whom possess neutralizing antibody.

Virological and serological studies on poliomyelitis in Karachi, Pakistan. I. Outbreaks in 1990-91

Between October 1989 and September 1991, 124 cases of poliomyelitis visited the Department of Paediatrics, Civil Hospital Karachi, Pakistan. The majority of them were between 6 months and 2 years of age and the epidemics occurred during the hot seasons. The dominant serotype was poliovirus type 1 during the epidemic season in 1990 and type 2 in 1991. All the polioviruses isolated from the patients were wild-type. Virological studies also disclosed that enteroviruses other than polioviruses were prevalent among healthy children as well as among diarrheal and polio patients. A serological survey to elucidate the serological efficacy of oral polio vaccine (OPV) showed that: (i) in 112 unimmunized children, after disappearance of transplacental maternal antibody during early infancy, antibody prevalence increased gradually and > 80% of the children were seropositive against all three types of polioviruses at 5 years of age; (ii) in 201 children immunized with full doses of OPV in their infancy, the decrease in antibody titer during infancy was less and seroprevalence rose sharply afterwards: at 2 years of age, > 80% of them were seropositive against all three types of the virus. The rapid increase of seroprevalence might be the effect of OPV administration. However, the prevalence was lower than that in developed countries.

Pulsed-field gel electrophoretic analysis of Campylobacter jejuni DNA for use in epidemiological studies

The cleavage patterns of the genomic DNA of 42 clinical isolates of Campylobacter jejuni determined by pulsed-field gel electrophoresis (PFGE) were compared with their Lior and TCK serotypes. The fragment patterns of DNA obtained with SalI and SmaI restriction enzymes did not always accord with the corresponding serotypes but strains of the same serotype could be further divided into subtypes by their cleavage patterns. This PFGE method may prove useful for subclassifying C. jejuni.

Measles and measles vaccine in Japan

Before the introduction of measles vaccine in 1971, measles was a common and well-recognized disease in Japanese children. Seroepidemiological studies conducted before the general use of the vaccine disclosed that measles epidemics differed from community to community; in rural areas, epidemics appeared at intervals of several years with the accumulation of susceptibles, and in urban areas, measles was endemic affecting younger children. The measles vaccines developed in Japan showed excellent safety and efficacy in the clinical trials for general use. Since 1978 measles vaccines have been routinely given to children aged 12 months or older, and incidence of measles decreased dramatically. However, the vaccine acceptance rate has been only as high as 85% to 90% and small-scale outbreaks of measles have been observed periodically among unimmunized children: Measles is far from being eradicated in Japan. This is primarily due to the insufficient vaccine acceptance rate, and more efforts towards mobilization of parents to have their children vaccinated are now in progress.

[Rapid diagnosis of influenza infection by PCR method--detection of influenza virus HA gene in throat swab]

We studied the detection of the HA gene of human influenza viruses in throat swabs obtained from the outbreaks of influenza in school children utilizing the polymerase chain reaction (PCR) method. Sensitivity and specificity of the PCR method was compared to conventional virus isolation using MDCK cells. Three pairs of primers for PCR in detecting the HA genes of AH1, AH3, and B influenza viruses showed both subtype and type specificity. The dilution experiments showed that influenza viruses, as few as 1.1-3.5 plaque-forming units per 50 microliters, were sufficient for the detection of HA genes by PCR method and the detection rate by PCR method was 2-3 fold higher than that by conventional method. Our results showed that the PCR method was a fast, sensitive and reliable method for the diagnosis of influenza infections.

Epidemiological studies on measles in Karachi, Pakistan--mothers' knowledge, attitude and beliefs about measles and measles vaccine

In order to gather information on the factors affecting the spread of measles vaccine in Pakistan, 287 mothers living in Karachi were interviewed concerning their knowledge, attitude and beliefs about measles and measles vaccine. Measles had been highly prevalent, mainly among infants between 9 and 18 months of age. The severity of the illness and the frequency of complications were well known and the importance of immunizations was well recognized. In traditional combined families grandparents had made the decision to take children for immunization, but many mothers had begun to feel that they were responsible for participation in the programme. The vaccine acceptance rate had increased sharply in recent years, primarily due to local health educators' activities and mass media such as TV programmes. The present findings confirm the importance of continuous effort toward promotion of primary health care by collaboration of motivated mothers and community health workers.

[Family-acquired hepatitis A--prevalence of hepatitis A among the family in Aichi Prefecture, 1990]

We studied the transmission of hepatitis A virus (HAV) in 45 families, which members were diagnosed as hepatitis A in 8 hospitals in 1990. Feces and sera from 50 patients and their 126 family members were tested for HAV-specific antigen and IgM antibody by ELISA or polymerase chain reaction (PCR) technology. From the interval of the onset of hepatitis or detection of HAV antigen in feces, HAV transmission was recognized in 11 (24.4%) of 45 families. The transmission was found to be concerned with contacts of the children and that from children to parents was found in 4 families and the reverse in 2. HAV antigen was detected from feces of 4 family members before onset of icterus by ELISA and furthermore, 3 by PCR. It was indicated that these methods would be used to prevent the transmission in a family, day-care centers, or institutions for the mentally retarded.

Genetic relatedness of hepatitis A virus strains recovered from different geographical regions

A pairwise comparison of the nucleic acid sequence of 168 bases from 152 wild-type or unique cell culture-adapted strains of hepatitis A virus (HAV) revealed that HAV strains can be differentiated genetically into seven unique genotypes (I to VII). In general, the nucleotide sequence of viruses in different genotypes differs at 15 to 25% of positions within this segment of the genome. Viruses from four of the genotypes (I, II, III and VII) were recovered from cases of hepatitis A in humans, whereas viruses from the other three genotypes (IV, V and VI) were isolated only from simian species developing a hepatitis A-like illness during captivity. Among non-epidemiologically related human HAV strains, 81 were characterized as genotype I, and 19 as genotype III. Within each of these major genotypes, there were two distinct groups (subgenotypes), which differed in sequence at approximately 7.5% of base positions. Each genotype and subgenotype has a characteristic amino acid sequence in this region of the polyprotein, with the most divergent genotypes differing at 10 of 56 residues. Strains recovered from some geographical regions belonged to a common (endemic) genotype, whereas strains from other regions belonged to several, probably imported, genotypes. Thus, HAV strains recovered in North America were for the most part closely related at the nucleotide sequence level, whereas in other regions, such as Japan and Western Europe, HAV strains were derived from multiple genotypes or sub-genotypes. These data indicate that patterns of endemic transmission can be differentiated from situations in which infections are imported due to travel.

Adenovirus infection and specific secretory IgA responses in the intestine of infants

We investigated adenovirus (Ad) infection of the intestine and Ad group-specific fecal IgA antibody responses in seven infants who were followed up from birth to 16 months to seven years of age. We isolated in tissue culture from fecal samples not only enteric Ad type 41 but also other Ads (types 2, 3, 5, 6, and 12). We also detected Ad antigens in the feces by ELISA at the times of infection with even non-enteric Ads, suggesting that a large amount of antigens were produced in the intestine. We found that repeated Ad infections with different serotypes were occurring and there were good fecal IgA antibody responses at each time. The infection seemed usually mild or asymptomatic: only one out of 23 occasions of the detected infections required hospitalization.

The low rate of HIV infection in Japanese homosexual and bisexual men: an analysis of HIV seroprevalence and behavioural risk factors

OBJECTIVE

To assess the seroprevalence of HIV-1 infection in homosexual and bisexual men in Nagoya City, Japan.

DESIGN

A prospective study ongoing since April 1986.

METHODS

Nine hundred and thirty-eight serum samples were collected from 531 participants in August 1990 in an anonymous, confidential testing programme. A self-administered questionnaire was completed and all participants anonymized by a code number. Interviews were conducted and HIV-antibody test results given by telephone, except for the positive test results, which were given in person and counselling offered.

RESULTS

Two out of the 531 participants (0.38%) were found to be seropositive for HIV-1, although the seroprevalences of sexually transmitted diseases, including hepatitis B, syphilis, chlamydia infection and amoebiasis, were remarkably high. A small number of participants had had sexual contact with individuals from countries where HIV infection rates are high. No patient had had a recent episode of intravenous drug use. Numbers of male sexual partners were decreasing and unsafe sexual practices, such as anal intercourse without condom use, were also decreasing.

CONCLUSIONS

The apparent low-risk behaviour of the men studied here (low levels of sexual contact with foreigners, absence of intravenous drug use, decreasing numbers of sexual partners and unsafe sexual practices) may explain the low prevalence of HIV infection.

[Rapid detection of motile Salmonella in chicken meat by the 1-2 Test]

The 1-2 Test (BioControl) is an enrichment culture/immuno-diffusion assay for detecting Salmonella in foods by use of poly-H-antibodies. The performance of the 1-2 Test was compared with that of the traditional culture method on 85 chicken meat samples. The results were as follows: The detection frequency of Salmonella by the 1-2 Test 24-hour assay (28/85, 32.9%) was greater than that by the 8-hour assay (16/85, 18.8%) and almost equal to that by the traditional method (26/85, 30.6%). The 8-hour assay gave a 46.2% sensitivity and 93.2% specificity. The 24-hour assay gave an 84.6% sensitivity and 89.8% specificity. Detection appeared to show some influence from the number of Salmonella, number of viable cells (SPC) and coliform groups. Differences in serotypes of Salmonella detected by the 1-2 Test and the traditional methods were also observed. Although there were some differing results between the 1-2 Test and the traditional method, this system appears to be useful for detecting Salmonella in foods, since results can be obtained at least 24 hours earlier than by the conventional procedures.

A 2-year survey of the prevalence of enteric viral infections in children compared with contamination in locally-harvested oysters

We studied, for two years, the prevalence of indigenous human enteric viruses in wild oysters gathered each month from the bottom of Mikawa Bay, Aichi Prefecture, Japan. Viruses were detected periodically in 9 out of 54 oyster pools prepared by the acid or polyethylene glycol precipitation method although all these 9 pools met current national bacteriological safety standards. Since most of the serotypes of the enteric viruses detected in the oysters were identical with those of viruses isolated from sick children living in the area, it is suggested that contamination of enteric viruses in the oysters would depend on the prevalence of enteric viral infections in the local inhabitants.