Vero cytotoxin-producing strains of Escherichia coli from children with haemolytic uraemic syndrome and their detection by specific DNA probes

Faecal specimens from 66 children with haemolytic uraemic syndrome in the United Kingdom were examined for strains of Escherichia coli producing Vero cytotoxin (VT). Initially, conventional bacteriological methods were used to identify colonies of E. coli which were then tested for VT production. Subsequently, specific DNA probes for VT1 and VT2 were used in hybridisation tests to detect VT-producing E. coli (VTEC). VTEC strains were isolated from 19 cases and in 15 they belonged to serogroup O157. Fourteen of these O157 strains possessed the flagellar antigen H7 and one was non-motile. The VTEC strains from the remaining four cases belonged to serotypes O26:H11, O104:H2, O153:H25, and O163:H19 together with a rough VT+ strain with flagellar antigen H51. The O157 strains hybridised with either the VT2 probe or both VT1 and VT2 probes. The other VTEC strains hybridised with either the VT1 or VT2 probe. Confirmation of the production of VT1 and VT2 in vivo was obtained by the neutralisation of faecal VT with specific antisera raised against these two cytotoxins.     

An Investigation of Methods of Isolation of β2M1 Globulin (Syn.: Iota Protein, 19S γ Globulin, γ1 Macroglobulin, β2M Globulin) and its Association with Isoagglutinin Activity, together with Preliminary Observations on Other Macroglobulins of Slow Electrophoretic Mobility in Normal Human Serum

An investigation is described of methods of isolation and purification of the high molecular weight protein (here called β_2M1 globulin) which is often associated with the isoagglutinin activity of normal human serum. In the course of these experiments it was observed that ultracentrifugal concentration of this protein from serum fractions gives rise to the simultaneous concentration of two other macroglobulins (here called β_2M2 and β_2M3 globulins).

It was found that the concentration of β_2M1 globulin in normal serum is about 25–50 mg. per 100 ml. In serum from the blood of normal donors of groups A, B and O, isohaemagglutinin activity is associated with the β_2M1 globulin but probably accounts for 1 per cent or less of the total β_2M1-globulin concentration in serum. This activity may represent the so-called `natural' isohaemagglutinin.

The immunological relation is discussed of the normal β_2M1 globulin to certain other members of the `family' of immune globulins (γ globulin and β_2A globulin) and to the pathological macroglobulins occurring in Waldenström's syndrome.

Although rabbit antibody to β_2M1 globulin cross-reacts with γ globulin, suggesting that a portion of each molecule bears antigenic groupings in common, it was found that a considerable degree of β_2M1-globulin specificity could be demonstrated after absorbing antisera with purified γ globulin. Attention is also drawn to the evidence that deficiency of either β_2M1 globulin or γ globulin can occur independently, suggesting different cellular sources of origin.

The pathological macroglobulin demonstrable in Waldenström's syndrome is closely related immunologically to normal β_2M1 globulin but is often deficient in isoagglutinin activity. This immunological relation suggests the use of specific anti-β_2M1-globulin antiserum as a simple means of distinguishing macroglobulinaemia from myelomatosis or other conditions with raised levels of γ globulin.

The β_2M2 and β_2M3 globulins are only demonstrable in ultracentrifugal concentrates of normal serum. Evidence is presented to suggest that these proteins are nevertheless present as trace components of normal serum. The solubility and electrophoretic characteristics of these proteins resemble those of β_2M1 globulin, but they can be distinguished by immunological methods from β_2M1 globulin and each other. Attention is drawn to the evidence that β_2M2 and β_2M3 globulins may also be increased in the serum of some cases of macroglobulinaemia.

     

Centrally and peripherally induced anosmia: influences on maternal behavior in lactating female rats.

Bilateral removal of the olfactory bulbs was found to produce deficits in several components of the maternal behavior of lactating, primiparous female rats. More dead pups were found in the cages of bilaterally bulbectomized females shortly after parturition than in the cages of unilaterally bulbectomized, sham operated, or unoperated females. Futhermore, bilaterally bulbectomized females showed deficits in pup retrieval relative to females in the other surgical conditions, and pups reared by bilaterally bulbectomized females weighed less at weaning than pups reared by females in the other surgical conditions. In contrast to bilateral bulbecomy, zinc sulphate treatments had no influence on pup mortality at parturition. However, zinc sulphate treated females did exhibit deficits in pup retrieval relative to saline treated females.     

Antiphospholipid antibodies and the outcome of pregnancy after the first in-vitro fertilization and embryo transfer cycle

Increased antiphospholipid antibody prevalence has been demonstrated by a number of recent studies in in-vitro fertilization (IVF) patients but the potential effects of antiphospholipid antibodies on the different components of the reproductive process and the consideration of whether to test IVF patients for antiphospholipid antibodies are controversial. The present study was undertaken to investigate the possible association between the presence of circulating antiphospholipid antibodies (namely the lupus anticoagulant and anticardiolipin antibodies), among a series of 21 consecutive IVF patients having a clinical spontaneous abortion after their first embryo transfer. As a control group (n=42), the nearest IVF cycle resulting in an ongoing pregnancy before and after each miscarried IVF cycle (i.e. the closest cycles in temporal relationship to the index cycle) was used. One patient (4.8%) in the study group and two women (4.8%) among controls were seropositive for antiphospholipid antibodies. These low and similar seropositivity rates found in the two groups studied lead us to conclude that antiphospholipid antibodies testing in IVF patients should be considered only in those women having repeated failures of implantation/clinical abortion after embryo transfer but not in an infertile general population reaching an IVF programme.      

Assessment of bioequivalence after subcutaneous and intramuscular administration of urinary gonadotrophins

The objective was to demonstrate bioequivalence between s.c. and i.m. administration of Humegon (FSH/LH ratio 1:1) and Normegon (FSH/LH ratio 3:1). In two randomized, single-centre, cross-over studies, 18 healthy volunteers on each formulation were assigned to one of the two administration sequences. Subjects were given single doses of one of the above gonadotrophins after endogenous gonadotrophin production had first been suppressed using high-dose oral contraceptive. Subsequently, rate (Cmax, tmax) and extent (AUC) of absorption of follicle stimulating hormone (FSH) and luteinizing hormone (LH) were determined for 14 days. For Cmax and AUC, analysis of variance (ANOVA) was performed on log-transformed data and for tmax ANOVA was performed on ranks. Intramuscular and s.c. injections of Humegon were bioequivalent with respect to the main pharmacokinetic parameters, being AUC and Cmax of FSH absorption. Intramuscular and s.c. injections of Normegon were bioequivalent with respect to the AUC of FSH and not bioequivalent with respect to the Cmax of FSH. For tmax of FSH as well as for most LH variables of both preparations, bioequivalence could not be proven due to the high intra- and interindividual variability and/or concentrations being close to the detection limit. Thus, the main pharmacokinetic FSH variables after i.m. and s.c. administration of Humegon and Normegon were bioequivalent.      

Is the outcome of in-vitro fertilization and embryo transfer treatment improved by spontaneous or surgical drainage of a hydrosalpinx?

A pilot study was designed to examine whether the outcome of embryo transfer in women with a hydrosalpinx might be improved by surgical drainage of the hydrosalpinx at the time of oocyte collection for in- vitro fertilization treatment. A comparative, controlled but retrospective analysis of the results was performed of all women with infective tubal damage aged <40 years old, who had ovulatory cycles, a normal uterus and a partner with normal spermatozoa. A standardized treatment regimen was used. A maximum of three embryos were transferred. Hydrosalpinx was defined by prior hysterosalpingography and/or laparoscopy with transcervical dye injection. A total of 237 embryo transfer cycles in women with hydrosalpinges (tubal distension not visible in 151, visible but not drained in 30 and drained in 56) were compared with 705 embryo transfer cycles in women with tubal disease but no hydrosalpinx. Results were analysed in the first three cycles but also separately in the first cycle to check for bias. Success rates were higher in the first cycle, but did not significantly influence overall differences. Implantation rates were significantly reduced overall in the hydrosalpinx group (8.0 versus 13.2% for controls; P < 0.001), being 8.3% (P < 0.01) in the subgroup without evident tubal distension and 7.5% (not significant) in the drained hydrosalpinx group. This study shows that tubal damage with distal occlusion is associated with a marked reduction in embryo implantation, even in the absence of obvious fluid distension. Surgical drainage of distended hydrosalpinges appears to offer no benefit.      

Initial evaluation of a continuous speech recognition program for radiology

The aims of this work were to measure the accuracy of one continuous speech recognition product and dependence on the speaker's gender and status as a native or nonnative English speaker, and evaluate the product's potential for routine use in transcribing radiology reports. IBM MedSpeak/Radiology software, version 1.1 was evaluated by 6 speakers. Two were nonnative English speakers, and 3 were men. Each speaker dictated a set of 12 reports. The reports included neurologic and body imaging examinations performed with 6 different modalities. The dictated and original report texts were compared, and error rates for overall, significant, and subtle significant errors were computed. Error rate dependence on modality, native English speaker status, and gender were evaluated by performing ttests. The overall error rate was 10.3 +/- 3.3%. No difference in accuracy between men and women was found; however, significant differences were seen for overall and significant errors when comparing native and nonnative English speakers (P = .009 and P = .008, respectively). The speech recognition software is approximately 90% accurate, and while practical implementation issues (rather than accuracy) currently limit routine use of this product throughout a radiology practice, application in niche areas such as the emergency room currently is being pursued. This methodology provides a convenient way to compare the initial accuracy of different speech recognition products, and changes in accuracy over time, in a detailed and sensitive manner.     

New fimbrial antigenic type (E8775) that may represent a colonization factor in enterotoxigenic Escherichia coli in humans.

An enterotoxigenic strain of Escherichia coli O25:H42 (strain E8775), isolated from a patient in Bangladesh with diarrhea, caused mannose-resistant hemagglutination (MRHA) of human and bovine erythrocytes. The strain did not show slide agglutination or immunodiffusion precipitin lines with antiserum specific for the colonization factor antigen CFA/I or CFA/II. A variant E. coli strain, E8775-B, did not cause MRHA or produce enterotoxin. Electron microscopy revealed the presence of fimbriae on the surface of strain E8775 but not strain E8775-B. When strain E8775 was grown at 22 degrees C, it became MRHA negative and fimbriae were absent. An antiserum prepared against strain E8775 was absorbed with strain E8775-B to make an antiserum specific for the fimbrial antigen. Using this absorbed antiserum, we found the fimbrial antigen in 48 of 742 enterotoxigenic E. coli strains. The 48 strains belonged to serogroups O25, O115, and O167. It is suggested by analogy to the properties of previously described colonization factors that these fimbriae may play a part in the colonization of the intestinal epithelium.     

The Burt controversy: A comparison of Burt's data on IQ with data from other studies

A recent controversy has given reason to examine the place of Burt's data among other behavioral genetic data on IQ. Although Burt's kinship correlations are higher than the average of other studies, his results are generally consistent with other data.