Sample stability of autoantibodies: A tool for laboratory quality initiatives

OBJECTIVES

Serum autoantibody measurement aids in diagnosing and monitoring various autoimmune conditions. Defining autoantibody stability limits can improve laboratory process quality. Here, we define short-term stability in a refrigerator, long-term stability in a freezer, and the effect of freeze-thaw cycles to improve autoantibody testing procedures.

DESIGN AND METHODS

Seventy-nine residual serum samples were used to assess the stability of 11 autoantibodies (anti-dsDNA, anti-Ro52, anti-Ro60, anti-SSB, anti-RNP, anti-Sm, anti-aCL-IgG, anti-tTG-IgA, anti-tTG-IgG, anti-DGP-IgA, anti-DGP-IgG) and two screening assays (CTD screen, ENA7 screen) on the BIO-FLASH (Inova Diagnostics). Three storage conditions were assessed: 8 weeks at 2-8 °C, 12 months at -30 °C, and 6 freeze (-30 °C)-thaw cycles. The maximum permissible instability (MPI) for each autoantibody was set as 2x %CV, calculated as the weighted average CV from cumulative QC data over the study period.

RESULTS

By considering both mean percent difference (MPD) and mean absolute relative difference (MARD), all autoantibodies were stable for up to 8 weeks stored at 2-8 °C, except for CTD screen and anti-dsDNA. All autoantibodies were stable for up to 12 months stored at -30 °C, except ENA screen, anti-dsDNA, anti-DGP-IgA, anti-cardiolipin, and CTD screen. Lastly, all autoantibodies were stable for up to 6 freeze(-30 °C)-thaw cycles, except anti-RNP, anti-Ro60, anti-cardiolipin and anti-dsDNA.

CONCLUSIONS

It is important to develop laboratory procedures derived from evidence-based stability limits. This study will aid laboratories in undertaking quality assurance and improvement initiatives to enhance autoantibody testing by ensuring appropriate storage conditions that consider defined sample stability limits.

AmAMP1 from Acropora millepora and damicornin define a family of coral-specific antimicrobial peptides related to the Shk toxins of sea anemones

A candidate antimicrobial peptide (AmAMP1) was identified by searching the whole genome sequence of Acropora millepora for short (<125AA) cysteine-rich predicted proteins with an N-terminal signal peptide but lacking clear homologs in the SwissProt database. It resembled but was not closely related to damicornin, the only other known AMP from a coral, and was shown to be active against both Gram-negative and Gram-positive bacteria. These proteins define a family of AMPs present in corals and their close relatives, the Corallimorpharia, and are synthesised as preproproteins in which the C-terminal mature peptide contains a conserved arrangement of six cysteine residues. Consistent with the idea of a common origin for AMPs and toxins, this Cys motif is shared between the coral AMPs and the Shk neurotoxins of sea anemones. AmAMP1 is expressed at late stages of coral development, in ectodermal cells that resemble the "ganglion neurons" of Hydra, in which it has recently been demonstrated that a distinct AMP known as NDA-1 is expressed.

Catecholamines, Renin, Aldosterone and Arterial Pressure in Patients on Chronic Hemodialysis Treatment

To assess the interaction between adrenergic activity and blood pressure regulation, plasma catecholamines (CA), plasma renin activity (PRA) and plasma aldosteron (PA) were measured in 66 normal subjects and 18 dialysis patients. Prior to dialysis, blood levels of free norepinephrine (NE), epinephrine (E) and PRA were normal, but total (free and conjugated) CA as well as PA were significantly elevated.

There was a spectrum of response during hemodialysis. On an average mean arterial blood pressure (MAP) fell during the first two hours of treatment, concomitantly followed by an increase in mean NE level. Whereas PRA and PA were highest at the end of treatment, mean free NE returned promptly to predialysis values through the late dialysis period. Severe hypotensive episodes during dialysis were associated with a baroreceptor-mediated adrenergic stimulation. These results indicate a qualitatively normal reaction of dialysis patients to volume removal and the importance of the renin-angiotensin-system in maintaining blood pressure during dialysis.

Essential role of glucose transporter GLUT3 for post-implantation embryonic development

Deletion of glucose transporter gene Slc2a3 (GLUT3) has previously been reported to result in embryonic lethality. Here, we define the exact time point of growth arrest and subsequent death of the embryo. Slc2a3(-/-) morulae and blastocysts developed normally, implanted in vivo, and formed egg-cylinder-stage embryos that appeared normal until day 6.0. At day 6.5, apoptosis was detected in the ectodermal cells of Slc2a3(-/-) embryos resulting in severe disorganization and growth retardation at day 7.5 and complete loss of embryos at day 12.5. GLUT3 was detected in placental cone, in the visceral ectoderm and in the mesoderm of 7.5-day-old wild-type embryos. Our data indicate that GLUT3 is essential for the development of early post-implanted embryos.

Deletion of glucose transporter GLUT8 in mice increases locomotor activity

Transport of glucose into neuronal cells is predominantly mediated by the glucose transporters GLUT1 and GLUT3. In addition, GLUT8 is expressed in some regions of the brain. By in situ hybridization we detected GLUT8-mRNA in hippocampus, thalamus, and cortex. However, its cellular and physiological function is still unknown. Thus, GLUT8 knockout (Slc2a8^−/−) mice were used for a screening approach in the modified hole board (mHB) behavioral test to analyze the role of GLUT8 in the central nervous system. Slc2a8^−/− mice showed increased mean velocity, total distance traveled and performed more turns in the mHB test. This hyperactivity of Slc2a8^−/− mice was confirmed by monitoring locomotor activity in the home cage and voluntary activity in a running wheel. In addition, Slc2a8^−/− mice showed increased arousal as indicated by elevated defecation, reduced latency to the first defecation and a tendency to altered grooming. Furthermore, the mHB test gave evidence that Slc2a8^−/− mice exhibit a reduced risk assessment because they performed less rearings in an unprotected area and showed significantly reduced latency to stretched body posture. Our data suggest that behavioral alterations of Slc2a8^−/− mice are due to dysfunctions in neuronal processes presumably as a consequence of defects in the glucose metabolism.

Mitogenic and anti-apoptotic activity of insulin on bovine embryos produced in vitro

Insulin improves development of mammalian preimplantation embryos and, in addition to the regulation of glucose transport, it exerts mitogenic and anti-apoptotic activities. The expression of glucose transporters (Glut) mediating the uptake of this essential energy substrate is critical for embryo survival. An impaired expression of Glut leads to an increase in apoptosis at the blastocyst stage and involves Bax. The various effects of insulin were unravelled by supplementing the in vitro culture medium with insulin (1.7 micromol l(-1)) and (i) the rates of cleavage and blastocyst development were recorded; (ii) mitogenic activity was studied by determining the total number of blastocyst cells and the ratio between trophectoderm and inner cell mass (ICM) cells; (iii) the frequency of apoptosis in blastocysts was determined by the TdT-mediated duTP nick-end labelling (TUNEL) assay and by quantification of the relative amounts of mRNA for Bax and Bcl-XL; and (iv) expression for Glut1, Glut3 and Glut8 transcripts was compared between embryos cultured in the presence or absence of insulin. Insulin increased rates of cleavage (81.2+/-2.2 (control) to 86.0+/-2.5) and blastocyst development (24.7+/-1.9 to 31.3+/-1.2), and number of blastocyst cells (123.7+/-6.0 to 146.3+/-6.6); the increase in the number of blastocyst cells was due to a significantly higher number of trophectoderm cells (82.3+/-5.0 versus 100.3+/-5.5). Blastocysts derived from cultures supplemented with insulin showed a significant decrease in apoptosis as determined by the TUNEL assay (14.8+/-0.9 to 12.2+/-0.7). No effects of insulin on the mRNA expression of Glut isoforms and Bax and Bcl-XL were found. These results demonstrate that the mitogenic and anti-apoptotic effects of insulin on bovine preimplantation embryos did not correlate with changes in the amounts of mRNA for the glucose transporter isoforms Glut1, -3 and -8, or transcripts for Bax and Bcl-XL.

[Slot machine gambling behaviour in East Germany 1990-2000]

TARGET

To test the hypothesis that parameters of slot machine gambling behaviour and related treatment cases have been increasing heavily in the new Länder of Germany (after reunification).

METHOD

Data from the National Population Survey 2000 and from the EBIS Treatment Monitoring System (1998-2000) were compared with figures from previous analyses for 1990-1997.

RESULTS

The percentage of people with gambling experience increased, but the proportion of currently active gamblers decreased. The proportion of frequent gamblers (as an indicator of high-risk behaviour) did not change. The annual average number of new outpatient treatment cases per treatment facility increased, from a low baseline of 1.5 cases, by about 20 %. All figures are still below those for former Western Germany.

CONCLUSION

At least until 2000 A.D., the expected extreme increase in gambling behaviour and related treatment demand did not occur.

Childhood-onset schizophrenia: research update

This review is a research update of recent literature related to childhood-onset schizophrenia (onset of psychotic symptoms by age 12 years). This subgroup of patients has attracted considerable research interest because patients with a childhood onset may represent a more homogeneous patient population in which to search for risk or etiologic factors. We examine data indicating that childhood-onset schizophrenia (COS) shares the same clinical and neurobiologic features as later-onset forms of the disorder. Compared with adults with schizophrenia, however, this subgroup of patients appears to have more severe premorbid neuro-developmental abnormalities, more cytogenetic anomalies, and potentially greater family histories of schizophrenia and associated spectrum disorders. While preliminary, these data indicate that a greater genetic vulnerability may be one of the underpinnings of COS. Future studies of this subgroup may provide important clues as to the genetic basis for schizophrenia and how gene products influence certain features of the disease, such as age of onset and mode of inheritance.

[The influence of regional differences in drinking style on hazardous use, excessive drinking, abuse and dependence]

INTRODUCTION

Previous research in Germany identified a "north-south" gradient in the hazardous use of alcoholic drinks, but this had methodological limitations. The present study estimates the hazardous use of alcohol more reliably. In addition, regional differences in drinking style and their relation to indicators of problematic alcohol use are examined.

METHODS

Data are from 1995 and 1997 representative samples of the non-institutionalised German general population aged 18 to 59 years. Based on 15,017 complete observations prevalence rates for abstinence, hazardous consumption (>30 g ethanol per day for men; >20 g ethanol per day for women), two or more CAGE-symptoms, and heavy episodic drinking (5+ drinks consumed in a day) were calculated and a cluster analysis was performed with regard to the 16 German federal states.

RESULTS

Regional differences exist in the prevalence of abstinence and hazardous drinking, but a "north-south" gradient was not evident. However, cluster analysis results suggest a "north-south" difference in drinking style, i.e. the quantity-frequency pattern of beer, wine, and spirits consumption. Compared with the northern German federal states, those in the south experienced more beer and less wine and spirits consumption in combination with a lower frequency of drinking beer and spirits. No cluster difference was found for hazardous drinking, lifetime prevalence of 2+ CAGE items or consumption of 5+ drinks in a day. Yet, mean consumption of ethanol was significantly higher in the north.

CONCLUSIONS

Research suggesting more hazardous consumption in southern Germany must be tempered by these findings that found no 'north-south' gradient in several different indicators of problematic alcohol use. Different drinking styles in northern and southern states do not result in differences concerning prevalence of binge drinking nor alcohol-related problems. Drinking style only made a difference in the mean consumption of ethanol. Methodological differences between the reported studies are discussed.

Glucose transporter expression is developmentally regulated in in vitro derived bovine preimplantation embryos

Glucose is readily been taken up and utilized by preimplantation embryos from different species. However, a comprehensive analysis of the glucose transporter expression throughout preimplantation development is still missing. Here, we have investigated the expression of facilitative glucose transporters (Glut1-5 and 8) and sodium-dependent-glucose transporter (SGLT-I) in bovine oocytes and preimplantation embryos up to d16 of development, using RT-PCR and immunohistochemistry. The embryos were produced in vitro by IVM-IVF. Glut1, Glut3, Glut8, and SGLT-I were expressed in all stages studied. Glut4 transcripts were first detected at the blastocyst stage. Glut2 expression was restricted to the period of blastocyst elongation at d14 and d16. Transcription of the fructose transporter Glut5 started at the 8-/16-cell stage. Our results show a distinct expression pattern for glucose transporters during bovine embryo development in vitro indicating specialized functions for these isoforms at different developmental stages in bovine embryos. Mol. Reprod. Dev. 60:370-376,

Measuring alcohol consumption and alcohol-related problems: comparison of responses from self-administered questionnaires and telephone interviews

AIMS

Compared with surveys using self-administered questionnaires, telephone interviews generally yield higher coverage rates, have a lower proportion of missing values and result in fewer inconsistencies. Meta-analyses, however, show that responses to sensitive questions by telephone tend to be biased by social expectations. The aim of the study is to examine whether responses on alcohol consumption and alcohol-related problems differ with respect to mode of administration (self-administered vs. telephone). Design and participants. Data were analysed from the 1995 self-administered survey among 6427 subjects and from telephone surveys conducted annually between 1994 and 1996 yielding a pooled sample of 6193 subjects.

MEASUREMENTS

Alcohol consumption within the last 30 days was measured using a beverage-specific quantity-frequency index. For a summary measure responses were converted into pure alcohol (ethanol) per day and categorized into no alcohol consumption (0 g), non-hazardous consumption (< or = 20 g for female and < or = 40 g for males) and hazardous consumption (> 20 g for females and > 40 g for males). Alcohol-related problems were assessed using the CAGE questionnaire with a cut-off point of at least two positive responses.

FINDINGS

Using (cumulative) logistic regression, a significant mode effect was found for both alcohol consumption and alcohol-related problems. Lower beverage-specific prevalences in the telephone mode were found to be responsible for the difference in the distribution of the summary consumption measure.

CONCLUSIONS

Results indicate that patterns of drinking and alcohol-related problems are more easily reported in self-administration questionnaires compared to telephone interviews.

Prevalence of alcohol use and the association between onset of use and alcohol-related problems in a general population sample in Germany

AIMS

This paper examines the prevalence of alcohol use, alcohol-related problems and onset of regular alcohol use, including its association with the prevalence of CAGE symptoms.

DESIGN AND PARTICIPANTS

Data come from three nationally representative samples of the non-institutionalized German general population aged 18-59 years which were conducted annually between 1994 and 1996. Subjects (n = 7501) were surveyed through telephone interviews.

FINDINGS

Overall, men were more likely to drink alcohol, to be heavier drinkers and to experience more alcohol problems than women. Prevalence of 12-month use was constant across age among males, but decreased with age among women. Prevalence of heavier drinking, however, increased with age in both sexes. While for both sexes the median age of onset decreased towards younger cohorts, the prevalence of regular use at younger ages increased more strongly among females compared to males. In all cohorts of both sexes, an association between early age of onset and negative consequences measured by the CAGE questionnaire could be observed. Odds ratios were significantly lower for life-time experience of at least two CAGE symptoms among respondents if they had started regular alcohol use later than their peers.

CONCLUSIONS

The results indicate a narrowing of the gender gap due to an increasing prevalence of regular alcohol use for females across cohorts. Gender differences with regard to heavier drinking are still prominent. The findings confirm those of related studies in which early age of onset of regular alcohol use was found to be a significant predictor for life-time alcohol-related problems.

The insulin-dependent glucose transporter isoform 4 is expressed in bovine blastocysts

We have investigated the expression of two glucose transporter isoforms, Glut1 and 4, in 14- and 16-day-old bovine blastocysts (d14, d16) using RT-PCR, competitive RT-PCR and in situ hybridization. The blastocysts were grown in vivo or had been produced in vitro. Glut1 mRNA was detected in all blastocysts studied, Glut4 in all d14 blastocysts, but only in a few d16 blastocysts. Glut4 mRNA was localized in trophoblast and endoderm cells. Glut1 mRNA increased from d14 to d16 while Glut4 transcription was down-regulated in d16 blastocysts. The mRNA amounts varied between 0.8 to 23 pg and 3.9 to 65 fg per 100 ng embryonic RNA for Glut1 and Glut4, respectively, displaying a 100- to 1500-fold lower expression of Glut4 compared with Glut1 during blastocyst elongation. This is the first report on the expression of the insulin-sensitive Glut4 isoform in mammalian preimplantation embryos.

Plasma catecholamines and alpha- and beta-adrenoceptors in circulating blood cells in patients on continuous ambulatory peritoneal dialysis

Autonomic system dysfunction could be the cause of postural hypotension seen in patients on continuous ambulatory peritoneal dialysis (CAPD). To verify this hypothesis, we examined the alpha 2- and beta 2-adrenoceptors on blood cells after 1/2 h in the resting supine position with the peritoneal cavity filled for 2-3 h, as well as the response of plasma norepinephrine (NE), heart rate (HR) and mean arterial blood pressure (MAP) to 10 min of standing. Supine free and particularly conjugated NE levels were significantly higher in all uremic patients compared with controls. The postural test induced similar increases of MAP and HR in 8 diabetic, 11 nondiabetic patients and 23 controls, whereas 4 diabetic patients became hypotensive. Orthostasis caused a mean free NE increment of only 0.5 nmol/l in the latter patient group with mean NE responses of 1.45-1.65 nmol/l in the former 3 groups. The densities of platelet alpha 2-adrenoceptors (assessed by [3H] yohimbine binding) and of mononuclear leucocyte (MNL) beta 2-adrenoceptors determined by (-) (125I) iodocyanopindolol binding amounted to 160 +/- 50 and 1600 +/- 520 binding sites/cell, respectively, in controls and were unchanged in patients without postural hypotension. The 4 diabetic patients suffering from postural hypotension showed numerically higher beta 2-receptor numbers (2080 binding sites/cell), significantly increased alpha 2-receptor densities (280 binding sites/cell, p less than 0.05) and significantly increased MNL isoproterenol-stimulated adenylate cyclase activities (38 vs 24 pmol cAMP/10(6) MNL/10 min in controls, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced production of interferon alpha and interferon gamma in leukocyte cultures from patients with active rheumatoid arthritis

Tests for lymphoproliferation and interferon induction in normal blood donors and patients with rheumatoid arthritis (RA) were performed in a whole-blood assay. Patients with high inflammatory RA showed significantly reduced lymphoproliferation and interferon gamma production after stimulation with phytohemagglutinin (PHA) and concanavalin A (Con A) when compared with patients with low inflammatory activity, or with normal control individuals. Similarly, patients with high and low inflammatory RA exhibited a significantly reduced interferon alpha production after stimulation with Newcastle Disease Virus (NDV) when compared with normal blood donors. Our findings may point to an important immunodeficiency of the circulating lymphocytes of RA patients and may explain some of the in vitro immunoregulatory abnormalities reported in this disease.

Golgi and computer morphometric analysis of cortical dendrites in metabolic storage disease

Golgi and computer morphometric analysis of neuronal dendrites was done on four cases, one each of Tay-Sachs disease, infantile type 2 sialidosis, Hurler's syndrome, and Sanfilippo's syndrome. There were large meganeurites on pyramidal neurons in Tay-Sachs disease, and small ones in Hurler's and Sanfilippo's syndromes. All the meganeurites in these three diseases were predominantly distal to the soma in layer 3, but close to it in layer 5. These findings may be accounted for by different rates of ganglioside accumulation and cortical neuronal morphogenesis. Computer morphometric analysis revealed atrophic or less developed layer 5 dendritic length and branching in Tay-Sachs disease, sialidosis, and Hurler's syndrome compared with tissues from control patients. These dendritic changes may be secondary to ganglioside accumulation or due to abnormal surface membrane production during dendritic development. This study contributes to an understanding of how enzyme deficiency is translated into abnormal cell structure and, presumably, function.

Proliferation and interferon production in whole blood samples and isolated lymphocyte preparations

To establish a method for the evaluation of immunological parameters in small blood samples, a whole blood technique was developed for the estimation of mitogen induced cell proliferation and interferon (IFN) production. The results obtained were compared with data using isolated peripheral blood lymphocytes (PBL). Mixtures of heparinized whole blood and culture medium or equal numbers of PBL of healthy volunteers or of patients were cultured with the mitogens concanavalin A, phytohemagglutinin, pokeweed mitogen or the monoclonal antibodies OKT3 and anti-Leu-4. Cell proliferation as measured by 3H-thymidine incorporation and interferon production were found to be of higher magnitude in the whole blood assay. The only situation in which results were similar was pokeweed mitogen induced cell proliferation. Since in the whole blood assay the cell populations are present in their natural distribution, this test system may reflect the in vivo situation better than the test using isolated lymphocytes. Furthermore, our data indicate that whole blood samples may be used clinically for the evaluation of different immune parameters, as data on a limited number of patients with Hodgkin's disease have shown.

Catecholamines, renin, aldosterone and arterial pressure in patients on chronic hemodialysis treatment

To assess the interaction between adrenergic activity and blood pressure regulation, plasma catecholamines (CA), plasma renin activity (PRA) and plasma aldosteron (PA) were measured in 66 normal subjects and 18 dialysis patients. Prior to dialysis, blood levels of free norepinephrine (NE), epinephrine (E) and PRA were normal, but total (free and conjugated) CA as well as PA were significantly elevated. There was a spectrum of response during hemodialysis. On an average mean arterial blood pressure (MAP) fell during the first two hours of treatment, concomitantly followed by an increase in mean NE level. Whereas PRA and PA were highest at the end of treatment, mean free NE returned promptly to predialysis values through the late dialysis period. Severe hypotensive episodes during dialysis were associated with a baroreceptor-mediated adrenergic stimulation. These results indicate a qualitatively normal reaction of dialysis patients to volume removal and the importance of the renin-angiotensin-system in maintaining blood pressure during dialysis.

[Hyperparathyroidism in hemodialysis patients: studies on parathyroid regulation and classification problems (author's transl)]

In a series of 22 patients undergoing chronic intermittent hemodialysis the response in secretion of parathyroid hormone (PTH) to an acute increase in serum calcium (Ca) concentration was studied. All patients had raised levels of predialysis PTH. Ca concentrations were measured by means of atomic absorption spectrophotometry and PTH concentrations were determined by radioimmunoassay. A close, significant, linear, negative correlation was demonstrated by regression analysis when Ca concentrations were correlated to changes in PTH, expressed as a percentage of the initial predialysis PTH value (100%). This finding supports the assumption that the function of the parathyroid gland at cellular level is similar in all patients, irrespective of very different predialysis PTH concentrations in peripheral blood. The results together with findings in literature were used to describe secondary hyperparathyroidism as a disease which shows typical phases during progression. Some still obscure phenomena of secondary hyperparathyroidism can be explained by discriminating between parathyroid function at a cellular and an organ level. The classification of hyperparathyroidism in regulative and autonomous forms only seems to be applicable when referred to the cellular level.

[Bacteriological examinations using the invagination catheter]

Quantitative and qualitative bacteriological studies have been performed on bladder urines taken by two different technics. Bladder urine was first obtained by suprapubic bladder aspiration. Immediately after the puncture another sample of bladder urine was obtained by the "invagination catheter" (only usable in women) transurethrally. In 80 consecutive parallel studies no differences were found in the bacterial counts, and only one difference were found in bacterial type. From the diagnostic point of view, therefore, the two methods were found to be equivalent. In another series of 52 patients catheterization by the invagination catheter was repeated at least 6 hours later without urination in the meantime. The bacteriologic results in the two corresponding specimens were exactly the same in all patients. Contrary to other transurethral methods, no introduction of bacterial agents into the bladder appears to occur with this method.

[Quantitative and qualitative bacteriological studies on urine specimens obtained by suprapubic needle aspiration and on midstream-voided samples]

In 398 patients with suspected urinary tract infection, quantitative and qualitative bacteriological studies were conducted in urine samples obtained by suprapubic needle aspiration of the bladder (BPU) and in midstream-voided specimens (MSU) collected immediately following the aspirations. In MSU, bacteria were found in 96.5% of all cases and in BPU in only 38.2%. Of the infected MSU, 63.3% showed mixed infections, while mixed cultures were found in only 11.2% of infected BPU. In 80% of the investigated patients, the MSU contained at least one more type of bacteria than the BPU, thus indicating urethral contamination. Of the patients with bladder bacteriuria, only 74% had bacterial counts of 10(5)/ml or more in the midstream-voided urine. Accordingly, 26% of the urinary tract infections diagnosed by bladder aspiration would not have been recognized on the basis of a single bacterial count in the midstream-voided urine. On the other hand, about 4% of patients with bacterial counts of 10(5)/ml or more in the MSU had a sterile bladder aspirate. In 72.4% of the infected BPU, E. coli was found, followed in frequency by Enterococcus (14.5%). In the infected MSU, however, Enterococcus was more frequent than C. coli (65.6% and 61.7% respectively). Thus, E. coli appears to be the most important etiological species in infections of the bladder and the kidneys, while Enterococcus seems to be the most frequent contaminant during urethral passage. The most frequent bacterial combination in mixed cultures in both BPU and MSU was that of E. coli and Enterococcus.

[Acute rise in serum calcitonin concentration during haemodialysis (author's transl)]

Calcium and calcitonin concentrations were measured at the beginning, during and at the end of haemodialysis in 31 unselected patients on chronic intermittent haemodialysis. Blood samples were drawn at the end of dialysis under two different conditions: first, at the end of dialysis during which dialysate calcium concentration was always at 1.75 mmol/1 and secondly, at the end of dialysis with dialysate concentration elevated to 3.0 mmol/1 for the last third of the dialysis period. There was a highly significant increase in serum calcium concentration during haemodialysis, due to transmembranous calcium transfer in all instances. Calcitonin was detectable in free dialysis blood samples of 30 among the 31 patients. In 14 patients there was a significant increase in calcitonin concentration due to increasing calcium concentration during haemodialysis, while in 17 patients there was no change in the calcitonin concentration. Where calcitonin secretion could be stimulated there was a highly significant positive linear correlation, on a percentage basis, between calcium and calcitonin concentrations (r = 0.83, P less than 0.001).

[Parathyroid function in patients on chronic intermittent hemodialysis (author's transl)]

In three groups of hemodialysis patients the effects of an acute elevation of the serum calcium concentration on the predialysis parathyroid hormone concentration was studied. In the first group (13 patients) the predialysis parathyroid hormone (PTH) concentrations were normal, in the second group (11 patients) slightly elevated, in the third group (5 patients) highly elevated. Calcium was determined by atomic absorption-spectrophotometry, PTH by radioimmunological methods. In hemodialysis patients with normal predialysis PTH concentrations a correlation between the serum calcium concentration and the serum PTH concentration could not be detected. In hemodialysis patients with slightly as well as with highly elevated predialysis PTH concentrations a significant, linear, negative correlation was found between the calcium and the PTH concentration. This correlation, however, was only strong within groups of similar parathyroid hyperfunction. If instead of the absolute PTH concentration calcium is correlated with the changes of the PTH concentration in per cent, a strong correlation between these two parameters can be detected, it is independent of the degree of parathyroid hyperfunction.

Demonstration of reaginic antibodies on human basophils by immune adherence to allergen-coated Sepharose beads

Human basophils purified by gradient density centrifugation and differential glass bead adherence were interacted with grass pollen allergen in particulate form prepared by covalent coupling of Dactylis glomerata protein concentrate to Sepharose beads. Basophils from allergic subjects were found to interact specifically with the allergen-coated bead surface in a manner so highly characteristic that false negatives with basophils from non-allergic subjects or subjects with unrelated allergies were not encountered. Microscopic examination indicated that the specifically stained malleable basophils had adapted in a multi-point attachment to the rigid bead surface by becoming one-sidedly flattened against it. When using basophils from highly pollen sensitive subjects all the beads carried basophils and sometimes as many as thirty per bead. The percentage of beads with basophils and the number of basophils per bead roughly correlated with clinical history and skin tests. Immunocytoadherence of the basophils to the allergen-coated beads was specifically inhibited by anti-IgE and anti-allergen antibodies, including reagins.