Present Collaborative Study Research Articles

La Estela 87 de Tak’alik Ab’aj: ensayo de un estudio colaborativo

The discovery of Stela 87 in situ in a secondary context, as a reused element of sacralization in a possibly royal residence from the Early Classic, allows us to locate the time of the original function as a stela in the Late Preclassic. It is in the Late Preclassic that the image and the text with 4 glyphic signs allude to the ruler represented there. It is in the early part of the Late Preclassic that stelae at Tak’alik Ab’aj and other early cities represent their rulers, still without a long count date. This was implemented in the second part of the Late Preclassic, of which a good example is Stela 5 (126 ad). For this reason, the iconography and writing of Estela 87 adds another exponent and opportunity, particularly for the Pacific Coast region, to the study of the still small universe of early texts, and more precisely, of the first part of the Late Preclassic (100 BC-50 ad) (Schieber de Lavarreda, 2020a). It is this opportunity that motivated the present collaborative study.

Continuity of care as experienced by mental health service users - a qualitative study

BackgroundPeople who struggle with mental health problems can provide valuable insight into understanding and improving the coordination of mental health and welfare services. The aims of the study were to explore service users’ experiences and perceptions of continuity of care within and across services relevant to personal recovery, to elicit which dimensions of continuity of care are most essential to service users, and to generate ideas for improving service users’ experiences of continuity of care.MethodsIn the context of a hermeneutic-phenomenological approach, ten service users at a community mental health centre were interviewed about their experiences of continuity of care in and across services. Eight of these were re-interviewed two years later. A collaborative research approach was adopted. Data were analysed by means of a data-driven stepwise approach in line with thematic analysis.ResultsFollowing the analysis five themes representing experiences of continuity of care were developed. Each theme ranged from poor to good experiences of continuity of care: Relationship – from experiencing frequent setbacks and anxiety due to breaks in relationships, to feeling safe in an ongoing personal relationship; Timeliness – from experiencing frustrating waiting times with worsening of problems, to getting help when needed; Mutuality – from having a one-sided struggle, to a situation in which both professionals and service users take initiatives; Choice – from not having the opportunity to make practical arrangements within the context of one’s everyday life, to having an array of support options to choose from; Knowledge – from feeling confused and insecure because one does not know what is happening, to feeling safe because one is informed about what is going to happen. Participants provided a range of suggestions for improving experiences of continuity of care.ConclusionsA discrepancy between aspects of continuity that are essential for service users and their experiences of actual practice was revealed. The valid evidence generated in the present collaborative study therefore offers knowledge to policy makers, professionals and service users that may be of help in their future efforts in orienting primary care, mental health, addiction and welfare services towards recovery.

Collaborative study on the effect of grinding on the detection of bones from processed animal proteins in feed by light microscopy

ABSTRACTBone fragments are essential structures for the detection of processed animal proteins (PAPs) in feed by light microscopy for official controls according to Annex VI of European Union Regulation EC/152/2009. The preparation of samples submitted for analysis requires a grinding step to make them suitable for microscopic slide preparation and observation. However, there are no technical guidelines set down for this step despite the fact that it can lead to an increase in bone numbers due to fragmentation. This was demonstrated by an in-house study carried out by the Irish National Reference Laboratory (NRL) for animal protein detection. The present collaborative study investigated the possible effects of three different grinding conditions on the final result for a feed adulterated with 0.05 and 0.01% (w/w) of PAP. The microscopic analysis either combined or not with an Alizarin Red staining was carried out by 10 different laboratories. The results demonstrated that although a large variation in the numbers of bone fragments was noted, five of the six different grinding/staining combinations applied at two levels of PAP adulteration did not significantly (at p = 0.05) differ from one another. The only exception occurred when grinding the feed containing 0.05% of PAP with a rotor mill equipped with a 0.5-mm sieve and combined with a staining which resulted in a greater number of bone fragments by forced fragmentation. Overall, the impact of the grinding/staining combinations on the final results was shown to be negligible when considering the regulatory limit of detection (LOD) requirement for the method and the current rules of implementation of the light microscopic method. From a total of 180 analyses carried out on the feed matrix containing 0.05% of PAP no false-negative result was observed, and at a level of 0.01% PAP only 10 false-negative results occurred.

Prevalence of elevated serum anti-N-methyl-D-aspartate receptor antibody titers in patients presenting exclusively with psychiatric symptoms: a comparative follow-up study.

BackgroundIncreasing numbers of patients with elevated anti-N-methyl-D-aspartate (NMDA) receptor antibody titers presenting exclusively with psychiatric symptoms have been reported. The aim of the present study was to clarify the prevalence of elevated serum anti-NMDA receptor antibody titers in patients with new-onset or acute exacerbations of psychiatric symptoms. In addition, the present study aimed to investigate the association between elevated anti-NMDA receptor titers and psychiatric symptoms.MethodsThe present collaborative study included 59 inpatients (23 male, 36 female) presenting with new-onset or exacerbations of schizophrenia-like symptoms at involved institutions from June 2012 to March 2014. Patient information was collected using questionnaires. Anti-NMDA receptor antibody titers were measured using NMDAR NR1 and NR2B co-transfected human embryonic kidney (HEK) 293 cells as an antigen (cell-based assay). Statistical analyses were performed for each questionnaire item.ResultsThe mean age of participants was 42.0 ± 13.7 years. Six cases had elevated serum anti-NMDA antibody titers (10.2 %), four cases were first onset, and two cases with disease duration >10 years presented with third and fifth recurrences. No statistically significant difference in vital signs or major symptoms was observed between antibody-positive and antibody-negative groups. However, a trend toward an increased frequency of schizophrenia-like symptoms was observed in the antibody-positive group.ConclusionSerum anti-NMDA receptor antibody titers may be associated with psychiatric conditions. However, an association with specific psychiatric symptoms was not observed in the present study. Further studies are required to validate the utility of serum anti-NMDA receptor antibody titer measurements at the time of symptom onset.

Interleukin 28B rs12979860 single-nucleotide polymorphism predicts spontaneous clearance of hepatitis C virus in children.

Recent genome-wide association studies performed in adults correlated single-nucleotide polymorphisms (SNPs rs12979860 and rs8099917) located on chromosome 19, upstream of the interleukin 28B gene, with spontaneous clearance of hepatitis C virus and with response to treatment with paginated interferon and ribavirin. The aim of the present collaborative study was to evaluate the rs12979860 SNP in a large cohort of Italian children with perinatal acquisition of hepatitis C. Children were prospectively enrolled in 2 Italian centers. The interleukin 28B rs12979860 SNP was studied according to the diagnosis of chronic infection or spontaneous clearance. One hundred thirty children (86.7%) with chronic infection and 23 (13.3%) with spontaneous clearance of the virus were enrolled. Overall, the interleukin 28B C/C and C/T-T/T genotypes were found in 57 (37.3%) and 96 (62.7%) children, respectively. The proportion of C/C genotype was higher among children who cleared infection (14/23; 60.9%) compared with children with chronic infection (43/130; 33.1%; P = 0.01; odds ratio 3.15; 90% confidence intervals 1.34-7.53). The present study showed that, as already demonstrated in adults, children with the rs12979860 C/C SNP of the interleukin 28B gene have a higher probability of spontaneous clearance of hepatitis C virus.

Nutritional Differences Between a Gluten-free Diet and a Diet Containing Equivalent Products with Gluten

The gluten-free (GF) products market represents one of the most prosperous markets in the field of food and beverages in the immediate future. Historically, counselling for celiac disease has focused on the absence of gluten in foods, however the nutritional quality of GF foodstuffs is an important aspect to consider. The aim of the present work was to compare the nutritional composition of the 206 GF rendered products most consumed in Spain, against the composition of 289 equivalent foods with gluten, and to make a comparison between the diet including GF products and the same diet with equivalent products with gluten in a 58 adult celiac population. The results of the present collaborative study pointed out differences in calorie, macronutrient, fiber, sodium, salt and cholesterol content between GF rendered and gluten-containing foodstuffs. Thus, calorie and nutrient intake in a GF diet is different when compared to its equivalent diet with gluten. Following a diet based on GF products could suppose a nutritional imbalance for celiac patients as well as for non-celiacs who follow a diet that includes many GF rendered foodstuffs.

P01-199 - Selective DNA methylation of BDNF promoter and nociceptin gene in bipolar disorder

IntroductionThe etiology of bipolar disorder (BD) is still poorly understood and it has been proposed that altered expression of multiple mRNAs, affecting neurotransmission, in psychotic subjects may be due to epigenetic mechanisms (e.g., DNA methylation or histone modification).AimsThe present collaborative study was aimed to investigate, in subjects with BD, dysregulation of DNA methylation, in the brain-derived neurotrophic factor (BDNF), previously associated with psychosis and linked to epigenetic changes at promoter regions, and in the nociceptin gene (N/OFQ), a new proposed target in psychiatric disorders.MethodsDNA was isolated from blood of patients diagnosed with BD (either type I [n = 19] or II [n = 20]) according to DSM-IV criteria, and from healthy controls (n = 20) and, thereafter, bisulfite conversion was performed. Real-Time Methylation Specific PCR (MSP) was used for the quantification of the methylated promoters in all samples.ResultsA hypermethylation of BDNF promoter region was observed in BD II patients (but not in BD I) compared to controls (CONT: 19.0 ± 3.2%; BD I: 27.2 ± 4.0%; BD II: 36.3 ± 6.2% * P = 0.0167; ANOVA F = 3.464; P = 0.0384; Bonferroni’s post hoc test). No significant differences were found for DNA methylation of N/OFQ promoter.ConclusionsPresent preliminary findings suggest selective changes in DNA methylation of BDNF promoter in type II bipolar patients and highlight the importance of epigenetic factors in mediating the onset and/or susceptibility to BD, providing new insight into the mechanisms of gene expression.

M1886 Proton Pump Inhibitor Related Acute Interstitial Nephritis

INTRODUCTION: An increasing number of case reports have identified acute kidney injury (AKI) secondary to acute interstitial nephritis (AIN) provoked by Proton Pump Inhibitor (PPI) therapy. The present collaborative study identifies experience from a major UK renal unit. AIMS & METHODS: All cases of biopsy-proven AIN between Jan 1st 2007 and October 1st 2008 presenting to the regional renal centre (serving a population of 1.1 million), were identified. The notes of all patients (pts) with a diagnosis of AIN and a history of PPI were analysed. Pre-PPI treatment, diagnosis and most recent plasma creatinine and estimated glomerular filtration rate (eGFR) were obtained. Pts were deemed likely to have PPI-associated AKI if a deterioration in kidney function was identified after starting PPI therapy in the absence of a history of any other medications associated with AIN and other renal or systemic causes. RESULTS: 210 kidney biopsy reports were analysed of which 27 reported AIN due to a multitude of causes. Of these, 6 cases of AIN were found to be strongly associated with PPI therapy. PPI's were the most common drug class associated with AIN. Male : Female 1 : 5. The median age at diagnosis was 66 yrs (range 60-86). All pts presented with nonspecific malaise and tiredness. 5 cases were due to omeprazole & 1 pt esomeprazole. Mean ± SD duration of PPI therapy was 7.7 ± 5.6 months, (range 5-18). Mean ± SD pre-PPI creatinine was 73 ± 30 μmol/L (range 45-103); eGFR 69 ± 23 ml/min/1.73m2 (range 4590). At diagnosis, mean ± SD creatinine was 269 ± 217 μmol/L (range 141-697) and eGFR 24 ± 16 ml/min/1.73m2 (range 5-52), representing a mean decline in eGFR of 65%. The PPI was immediately stopped in all pts. 1 pt required temporary renal replacement therapy. 5 pts were treated with steroids. The mean ± SD most recent creatinine post diagnosis was 129.5 ± 36.5 μmol/L (range 94-196) and eGFR 41 ± 11 ml/min/1.73m2 (range=23-52). Although kidney function improved following cessation of PPI and/or treatment with steroids, there was a net decline in kidney function from pre-PPI exposure levels. CONCLUSION: PPI related AIN is an important iatrogenic cause of potentially reversible AKI and is likely to be significantly underestimated. Kidney function should be assessed in patients receiving PPI therapy presenting with non specific malaise or tiredness. AIN should be considered in patients with deteriorating kidney function when receiving PPI therapy. Prompt identification of PPI induced AIN is important as our study suggests (in line with the established literature) that cessation of therapy can at least partially reverse decline in renal function inmost patients.

M1887 The Gain in Quality-Adjusted Life Years By Switching to Esomeprazole in Those with Persistent GERD Symptoms in Primary Care: EncomPASS - a Cluster-Randomized Trial

INTRODUCTION: An increasing number of case reports have identified acute kidney injury (AKI) secondary to acute interstitial nephritis (AIN) provoked by Proton Pump Inhibitor (PPI) therapy. The present collaborative study identifies experience from a major UK renal unit. AIMS & METHODS: All cases of biopsy-proven AIN between Jan 1st 2007 and October 1st 2008 presenting to the regional renal centre (serving a population of 1.1 million), were identified. The notes of all patients (pts) with a diagnosis of AIN and a history of PPI were analysed. Pre-PPI treatment, diagnosis and most recent plasma creatinine and estimated glomerular filtration rate (eGFR) were obtained. Pts were deemed likely to have PPI-associated AKI if a deterioration in kidney function was identified after starting PPI therapy in the absence of a history of any other medications associated with AIN and other renal or systemic causes. RESULTS: 210 kidney biopsy reports were analysed of which 27 reported AIN due to a multitude of causes. Of these, 6 cases of AIN were found to be strongly associated with PPI therapy. PPI's were the most common drug class associated with AIN. Male : Female 1 : 5. The median age at diagnosis was 66 yrs (range 60-86). All pts presented with nonspecific malaise and tiredness. 5 cases were due to omeprazole & 1 pt esomeprazole. Mean ± SD duration of PPI therapy was 7.7 ± 5.6 months, (range 5-18). Mean ± SD pre-PPI creatinine was 73 ± 30 μmol/L (range 45-103); eGFR 69 ± 23 ml/min/1.73m2 (range 4590). At diagnosis, mean ± SD creatinine was 269 ± 217 μmol/L (range 141-697) and eGFR 24 ± 16 ml/min/1.73m2 (range 5-52), representing a mean decline in eGFR of 65%. The PPI was immediately stopped in all pts. 1 pt required temporary renal replacement therapy. 5 pts were treated with steroids. The mean ± SD most recent creatinine post diagnosis was 129.5 ± 36.5 μmol/L (range 94-196) and eGFR 41 ± 11 ml/min/1.73m2 (range=23-52). Although kidney function improved following cessation of PPI and/or treatment with steroids, there was a net decline in kidney function from pre-PPI exposure levels. CONCLUSION: PPI related AIN is an important iatrogenic cause of potentially reversible AKI and is likely to be significantly underestimated. Kidney function should be assessed in patients receiving PPI therapy presenting with non specific malaise or tiredness. AIN should be considered in patients with deteriorating kidney function when receiving PPI therapy. Prompt identification of PPI induced AIN is important as our study suggests (in line with the established literature) that cessation of therapy can at least partially reverse decline in renal function inmost patients.

Some Causes of Poor Performance and Chick Mortality in Farmed Ostriches in Alabama (USA) and Kenya

Commercial ostrich farming is rapidly becoming a desirable alternative source of profitable meat production among smallholder farmers. However, ostrich ranching, particularly, ostrich production is severely constrained by a very high chick mortality rate (up to 40 %). To help rural farmers including those in the developed countries such a s United States of America gain a successful foothold in this potentially lucrative farming enterprise, the causes of chick mortality must be identified and controlled. The present collaborative study was designed to characterize and compare disease causes of mortality in chicks in smallholder ratite farms in Macon and adjoining Counties of Alabama and some selected localities in Kenya. The study established that, in both Alabama (USA) and Kenya, ostrich farmers incur losses of considerable magnitude from a wide range of causes, some of which could not be established. Losses are experienced right from the embryonic stages whereby embryos may develop poorly causing death before hatching. In USA, hatchability was 72 % while in Kenya; hatchability was only 56 % on average. In Kenya, a high mortality rate in the early weeks of life (< 3 weeks) [27-40%] was noted. Pathogens isolated at postmortem from inflamed tissues and septic yolk sacs were mainly common bacteria [abstract truncated]. The Kenya Veterinarian Vol. 28 2005: pp. 6-10

Odontogenic tumours, a collaborative retrospective study of 75 cases covering more than 25 years from Estonia

Introduction: The aim of the present collaborative study was to analyse retrospectively the character of odontogenic tumours in Estonia, involving the entire Estonian population (1.4 million), and to compare their prevalence with the figures presented in similar reports from other countries. Material and methods: All material for the retrospective study was retrieved from the files of the Departments of Maxillofacial Surgery in Tartu and Tallinn, Estonia, where all in/out-patients are treated from the whole country. The final diagnosis in each case of odontogenic tumour was based on the 1992 WHO histological criteria. Results: A total of 75 odontogenic tumours was found, 74 (98.6%) of which were benign, and 1 (1.3%) was malignant. The frequency of odontogenic tumours in this study was the lowest ever reported. The most common tumours were odontoma (34.3%), followed by ameloblastoma with different subtypes (25.3%), ameloblastic fibroma (16%), odontogenic myxoma (12%) and benign cementoblastoma (8%). Conclusion: Odontogenic tumours are relatively rare in Estonia compared with the data from other countries.

Antipsychotic drug prescription for schizophrenia in East Asia: rationale for change.

The purpose of this international collaborative study was to investigate the prescription patterns of antipsychotic drugs for schizophrenia in East Asia and to analyze factors that affect these patterns. Prescription patterns for patients admitted for treatment of schizophrenia were surveyed using a standardized protocol from six East-Asian region/countries: China, Hong Kong, Japan, Korea, Singapore and Taiwan. Patients' social and clinical characteristics, psychiatric symptoms, course of illness, and adverse effects of medications were systematically assessed and recorded. Prescriptions of the first- and second-generation antipsychotic drugs were compared. A total of 2399 patients were recruited. The second-generation drugs comprised 28.1% of all prescribed antipsychotics, and 46% of the antipsychotic prescriptions were in the context of polypharmacy. The mean dosage of antipsychotics for the whole sample was 675.3 + 645.1 mg chlorpromazine equivalents. Japan had a high frequency of prescribing high doses and polypharmacy; Singapore had a high utilization of depot injections while China had a higher prescription of clozapine. Using multiple logistic regression analysis, distinctions in the prescription patterns of antipsychotic drugs were found: first-generation drugs were mainly for controlling aggressive behavior, while second-generation drugs were targeted at the alleviation of positive, negative psychotic symptoms as well as disruptive behavior in schizophrenia. The present collaborative study highlighted differences in the prescription patterns, especially the under-utilization of second-generation antipsychotic drugs in East Asia. The pattern of antipsychotic medication use varied from country to country and is likely to be influenced by the prevailing health-care system, the availability and cost of the drugs.

Stability of exploratory eye movements as a marker of schizophrenia — a WHO multi-center study

The exploratory eye movements of patients with schizophrenia reportedly differ from those of patients without schizophrenia and healthy controls. In an attempt to determine whether exploratory eye movements provide valid markers for schizophrenia, the present collaborative study was conducted in six countries to analyze the stability of and variation in the following parameters of exploratory eye movements: the number of eye fixations (NEFs) and mean eye scanning length (MESL) in a retention task; the cognitive search score (CSS) that indicates how frequently the eye focused on each important area of a figure in order to recognize it in a comparison task; and the responsive search score (RSS), which reflects the frequency of eye fixations on each section of a figure in response to questioning in a comparison task. In addition, we investigated the validity of the currently employed discriminant function to extract a common feature of schizophrenia by applying it to the findings of the present study. The exploratory eye movements of 145 patients with schizophrenia, 116 depressed patients and 124 healthy controls at seven WHO collaborative centers in six countries were measured using eye mark recorders during viewing of stationary S-shaped figures in two sequential tasks. The RSSs of patients with schizophrenia were found to be significantly lower than those of depressed patients or healthy controls irrespective of geographical location, with no significant difference existing between the RSSs for depressed patients and those for healthy controls. By inserting the RSS and NEF data for each subject into the formula used to calculate discriminant function, patients with schizophrenia could be discriminated from depressed patients and healthy controls with a sensitivity of 89.0% and a specificity of 86.7%. The RSS is an exploratory eye movement parameter that detected schizophrenia irrespective of culture, race and various other subject variables. Furthermore, it is indicative of the stable, significant difference that exists between subjects with and without schizophrenia. The results of discriminant analysis confirm the previously reported validity of discriminant function.

Mouse popliteal lymph node assay for assessment of allergic and autoimmunity-inducing potentials of low-molecular-weight drugs.

In the present collaborative study, popliteal lymph node (PLN) responses to penicillin G (an allergenic chemical), D-penicillamine (an autoimmunity-inducing chemical), and barbital (a negative reference chemical) were investigated in three different mouse strains by ten pharmaceutical companies. Two inbred mouse strains (BALB/c and A/J) and one outbred strain (ICR) were subcutaneously injected with saline solutions containing penicillin G (1.25, 2.5 and 5 mg/mouse), D-penicillamine (0.5, 1 and 2 mg/mouse), or barbital (2 mg/mouse) into one hind footpad and saline only was injected into the contralateral footpad. PLN cellularity indices were determined on day 7. In the three strains tested, the penicillin G and D-penicillamine injections resulted in approximately dose-dependent responses. In contrast, barbital failed to generate a significant PLN reaction. In the typical data from one of the participating laboratories, the PLN responses of A/J, BALB/c, and ICR to penicillin G were high, intermediate and low, respectively, while their PLN responses to D-penicillamine were all high. Some variation in PLN cellularity indices was observed among the participating laboratories, but reproducibility of the popliteal lymph node assay (PLNA) evaluation was partly confirmed. Although the appropriate selection of mouse strains and drug dosage levels has to be considered, these results suggest that the PLNA may be an appropriate screening system for prediction of the allergic or autoimmunity-inducing potentials of low-molecular-weight drugs.

Myelofibrosis with myeloid metaplasia in young individuals: disease characteristics, prognostic factors and identification of risk groups.

Myelofibrosis with myeloid metaplasia (MMM) is an uncommon disorder in young individuals, for whom haemopoietic stem cell transplantation offers the only possibility of cure. However, although the latter procedure is associated with significant morbidity and mortality, the clinical course of MMM is variable, with some patients surviving for less than a year and others showing an indolent course. Selection of young MMM patients for transplantation or other newer therapies is currently difficult since no prognostic data exists for this subgroup. In the present collaborative study a number of initial clinical and laboratory parameters have been evaluated for prognosis in 121 MMM patients aged 55 years or less. Median survival of the series was 128 months (95% CI 90-172). In the Cox proportional hazard regression model three initial variables were independently associated with shorter survival: Hb <10 g/dl (P <0.0001), the presence of constitutional symptoms (fever, sweats, weight loss) (P=0.001), and circulating blasts >/=1% (P=0.003). Based on the above three criteria, of the 116 patients with complete data, two groups were identified: a 'low-risk' group, characterized by 88 patients with up to one adverse prognostic factor, in whom MMM had an indolent course (median survival 176 months, 95% CI 130-188), and a 'high-risk' group, including 28 patients with two or three factors, who had a more aggressive disease (median survival 33 months, 95% CI 20-42). The above prognostic scoring system showed a high positive predictive value, sensitivity and specificity to predict survival in the series, and could be of help in making treatment decisions in young patients with MMM.

Collaborative Behavioral Teratology Study of Phenytoin: A Test Battery for Neurobehavioral Developmental Toxicity in Rats.

Abstract: At the Behavioral Teratology Meeting (BTM) of the Japanese Teratology Society in 1992, a core test battery was proposed from a practical and simple point of view as an estimation of developmental neurobehavioral toxicity for use in pharmaceutical drug screening. The validity of the core test battery is being examined in a new series of collaborative studies. The present study is the first such study; phenytoin, a well‐known behavioral teratogen, was selected as the test compound, and 32 laboratories took part in a behavioral teratology study of phenytoin using the new test battery.Sprague‐Dawley strain rats from four breeds were used. Phenytoin (200 mg/kg) was administered orally to pregnant rats from days 10 to 14 of gestation (sperm detection = day 0), and in the male offspring, the survival rate, development of physical landmarks, functional developments, open field test scores, and Biel water maze test results were assessed and the brain weights were measured. The shuttle box conditioned avoidance test was also performed in some laboratories.In the present collaborative study, by taking an aggregate of the relative values converted from the measured values of each breed (providing a much larger sample size than that recommended by reproduction toxicity study guidelines), a high detectability level for phenytoin's effects was established.Under these conditions, the effects of phenytoin on eye opening, incisor eruption, the surface righting reflex, the negative geotaxis reflex, and performance of the open field test, Biel water maze test and shuttle box conditioned avoidance test were observed. It was found that present collaborative study made it possible to evaluate the detectable capacity of each of these test battery items. In addition, the critical period of abnormalities demonstrated in many test items was identified, and the results of several previous reports were confirmed. Furthermore, a breed difference in the effect of phenytoin for several test items was found.The present results established that the core test battery accurately detected the effects of phenytoin.

Comparison of Preston Agar and a Blood-Free Selective Medium for Detection of Campylobacter jejuni in Food

The present collaborative study compares recovery of Campylobacter jejuni from food in 2 agar media. Six laboratories analyzed 8 samples each of chicken liver inoculated with Campylobacter jejuni. Samples were enriched in Preston broth and isolation was carried out on Preston agar (PA) and campylobacter blood-free selective medium (CBFS), a charcoal-based medium with cefoperazone and amphoteracin as antibiotic supplements. There was no difference in the recovery rate between the 2 agar media; however, the specificity of CBFS was better than that of PA. There was a slightly better growth of campylobacters, and competing organisms were more inhibited on CBFS than on PA.

The Li-Na exchange in red cells of essential hypertensive patients with low Na-K cotransport.

Impairments of sodium-potassium (Na-K) cotransport and lithium-sodium (Li-Na) countertransport have been reported in essential hypertension. The Vmax of Li-Na countertransport was measured in Li-loaded cells (9 mmol/l cells) by determining the external Na-stimulated Li efflux. Countertransport was measured in 29 normotensive subjects without a family history of hypertension (NT -FHH), 22 normotensive subjects with a family history of hypertension (NT +FHH) and 45 essential hypertensive patients (HT) [mean +/- s.d.: 348 +/- 138 (NT -FHH), 397 +/- 133 (NT +FHH) and 456 +/- 166 (HT)]. There was no significant elevation of Li-Na countertransport in the hypertensive group with respect to NT -FHH. The outward Na-K cotransport was measured in Na-loaded cells (Na greater than 25 mmol/l cells) by determining the frusemide-sensitive Na efflux. Na-K cotransport was found to be significantly decreased in the hypertensive patients compared to the normotensive controls [mean +/- s.d.:280 +/- 136 (HT) and 424 +/- 128 (NT -FHH)]. The present collaborative study between the two laboratories revealed that the fraction of patients with an alteration in the Vmax of cotransport or countertransport was different in the two laboratories and could not be accounted for by any methodological or experimental procedure. This study shows that different patterns of transport impairments might occur in different populations, thus suggesting a heterogeneity of cation transport alterations in hypertensives.

Basic Study and Laboratory Standardization

The present four-center collaborative study was undertaken in an attempt to define the best vaccine and/or vaccination procedure for use in areas of the world that are free of smallpox. The study was designed to compare the effect of different vaccinial strains, viral concentrations, and routes of administration on the morbidity and antibody response associated with primary vaccination and standard challenge revaccination. Primary vaccinations were performed on 1,585 children; 49.6% of the children were vaccinated by the percutaneous route, and 50.4% received vaccine subcutaneously. The overall age and sex distributions of percutaneous and subcutaneous vaccinees were comparable, but there were marked differences in participants among the four study centers. Vaccines in Kentucky had a greater mean age; the greatest number of Negroid children were enrolled in St. Louis, and more of them were vaccinated by the subcutaneous route; and the dropout rate was much greater in San Diego and Colorado. An analysis of comparative interlaboratory serologic procedures with the use of 20 coded duplicate samples of serum revealed good agreement in the hemagglutination-inhibition test; results of neutralization tests had greater variability of mean titers. On duplicate samples of serum from study participants there was generally good correlation between each of the four study centers and the Center for Disease Control's reference laboratory in titers of hemagglutination-inhibiting antibody. In contrast, 38% of the neutralization titers determined at the four study centers were greater than or equal to 0.67 log10 higher than the respective titers noted at the Center for Disease Control.

Progesterone withdrawal during hypertonic saline-induced abortions

In the present collaborative study, 4 independent investigators analyzed 24 samples of plasma from 6 normal obstetric patients. Careful exchange of amniotic fluid with 20 per cent NaCl predictably provoked evolution of uterine activity and abortion. This occurrence has been explained by an induced, partial, progesterone withdrawal.