An evaluation of lectin-mediated magnetic bead cell sorting for the targeted separation of enteric bacteria

Lectin-labelled magnetic beads were assessed and compared with antisera as an alternative approach for the targeted separation and isolation of enteric bacteria. Of the 16 lectins tested against a range of bacterial species, concanavalin A (conA) showed the greatest potential. Agglutination of bacterial cells in suspension using conA and methods for effective labelling of the magnetic beads with the lectin were optimized. ConA-labelled magnetic beads were compared with antibody-labelled beads for recovery of bacterial cells from pure or mixed laboratory cultures and from natural populations in river water. Recovered cell populations were free from environmental impurities and a high percentage of the culturable cells was extracted. Specific cell recovery was found to be variable, but the use of lectins offers some promise as an alternative cell discriminator.

Competency-based learning for the surgical assistant

In the first of two articles about the benefits and drawbacks of occupational standards, the authors describe a competency-based programme of continuing education for surgical assistants. The structure and content of the modules offered are discussed and the authors emphasise the validation of the courses by institutions of higher education. Next week's article will examine occupational standards in relation to professional development.

Development of a bioassay employing the desert locust (Schistocerca gregaria) for the detection of saxitoxin and related compounds in cyanobacteria and shellfish

Monitoring paralytic shellfish toxins (PST) in shellfish and freshwater cyanobacteria is largely dependent on the mouse bioassay. An alternative assay was devised using the desert locust Schistocerca gregaria. The bioassay successfully identified the optimum extraction procedure for PST from cyanobacterial cells and was also suitable for screening acid extracts of shellfish flesh. These results demonstrate the potential of the locust bioassay for the routine screening of PST in a range of sample matrices.

Isolation and growth physiology of novel thermoactinomycetes

A total of 34 thermophilic isolates identified as members of the genus Thermoactinomyces by a range of chemotaxonomic, microscopic and determinative biochemical tests, were isolated from two acid soils. Growth studies in shake flask and fermenter identified the isolates to be moderately acidophilic with growth occurring between pH 4.5 and 6.0 with optima at pH 5.0. The isolates differed considerably from known Thermoactinomyces cultures in their pH profile, colony morphology and in several biochemical tests. Extracellular enzyme activities are identified and partially characterized in terms of their thermostability, pH and temperature profiles from crude supernatant fluid samples. Optimal protease, amylase and pullulanase activity was observed at pH 5.0-5.5 and 75-80 degrees C with each showing T(50) values of 10, 30 and 30 min, respectively. A highly thermotolerant extracellular esterase was also identified which retained 50% activity after 8 h at 90 degrees C. This is the first report of an acidophilic member of the genus Thermoactinomyces.

Dimethyldioxirane converts benzene oxide/oxepin into (Z,Z)-muconaldehyde and sym-oxepin oxide: modeling the metabolism of benzene and its photooxidative degradation

Oxidation of 7-oxabicyclo[4.1.0]hepta-2,4-diene (benzene oxide)/oxepin with dimethyldioxirane (DMDO) gave mainly (Z,Z)-muconaldehyde, with complete diastereoselectivity. Similarly, 2-methyl-7-oxabicyclo[4.1.0]hepta-2,4-diene (toluene 1,2-epoxide)/2-methyloxepin gave (Z,Z)-1,6-dioxohepta-2,4-diene, while 2,6-dimethyl-7-oxabicyclo[4.1.0]hepta-2,4-diene (1,2-dimethylbenzene 1,2-epoxide)/2,7-dimethyloxepin gave (Z,Z)-2,7-dioxo-3,5-octadiene. By monitoring the DMDO oxidation of benzene oxide/oxepin by 1H NMR spectroscopy, a significant byproduct was identified as 4,8-dioxabicyclo[5.1.0]octa-2,5-diene (sym-oxepin oxide). This observation supports the hypothesis that the route to (Z,Z)-muconaldehyde proceeds from oxepin via 6,8-dioxabicyclo[5.1.0]octa-2,4-diene (oxepin 2,3-oxide), with a minor pathway leading to sym-oxepin oxide. The DMDO oxidations described provide model systems for the cytochrome P450-dependent metabolism of benzene and for the atmospheric photooxidation of benzenoid hydrocarbons.

Neutralizing IGF-1 monoclonal antibody with cross-species reactivity

We report the generation of a murine IGF-1 monoclonal antibody designated 35I17, which exhibits unique cross-species reactivity. The antibody recognizes recombinant human and rat IGF-1 in ELISA, Western blots, and in an 125I-recombinant human IGF-1 Scintillation Proximity Assay. In addition, 35I17 blocks cell proliferation induced by recombinant human and rat IGF-1, and inhibits cell proliferation induced by sera from human, rat, calf, dog, goat, or mouse. The antibody inhibits rat IGF-1 binding to IGF-1 receptors, and prevents IGF-1-stimulated receptor and IRS-1 phosphorylation in LISN C4 cells, an IGF-1 receptor-transfected cell line. The cross-species and neutralizing properties of 35I17 may be useful in in vitro and in vivo animal studies for elucidating the role of IGF-1 in cancer, rheumatoid arthritis, and other diseases.

Non-invasive in vivo techniques to differentiate photodamage and ageing in human skin

It is important to differentiate skin changes due to the intrinsic ageing process from those due to chronic photodamage in the development of therapies to assist the latter condition, and in this study we have used instrumental techniques to differentiate between changes in a range of properties of skin due to ageing and those due to photodamage, especially with regard to elasticity. We measured three sites of differing sun exposure in a group of younger and in a group of older subjects. A pulsed A-scan ultrasound system was used to measure skin thickness, and a uniaxial extensometer was employed to assess elastic properties. Skin surface roughness measurements were made using silicone rubber impressions and a stylus profilometer. We demonstrated significant differences in skin roughness between young and old subjects at every site and differences between sun-exposed and sun-protected sites only in the older group. Parameters of the elastic properties of skin differed between the groups, and also between sites of most different sun exposure. The uniaxial extensometer can demonstrate a loss of the skin's elasticity predominantly by photodamage, and the roughness of the skin surface can be shown to increase mostly by chronological ageing but to decrease modestly by photodamage. This demonstrates that differences between the two processes can be quantified, and indeed they should be.

The coagulation/fibrinolysis balance in systemic sclerosis: evidence for a haematological stress syndrome

Systemic sclerosis (SSc) is a disease characterized by progressive microvascular occlusion and fibrosis resulting in irreversible organ damage, the pathogenesis of which is felt to be of vascular origin. To gain a comprehensive view of the coagulation/fibrinolytic balance in SSc, a number of haemostatic and fibrinolytic variables were measured in 26 SSc patients (11 limited, 15 diffuse) and in 22 control subjects. Of the coagulation activation markers, the mean plasma level of prothrombin fragment 1 + 2 (F1 + 2), but not of thrombin-antithrombin complexes (TAT), was higher in SSc patients than in controls (P < 0.001). Plasma levels of fibrin split product D-dimer (DD), fibrinogen (FNG) and von Willebrand factor (vWF) were higher amongst patients than controls (P < 0.001). vWF and FNG levels were positively correlated (P < 0.001). Mean levels of DD and vWF were more elevated in patients with diffuse than limited disease (P = 0.001 and P = 0.04, respectively). On the fibrinolytic side, defective tissue plasminogen activator (tPA) release (venous occlusion test, stimulated level < basal level) was noted in 46% (12/26) of SSc patients, but only in 4% (1/22) of controls. Patients had higher mean levels of tPA inhibitor (PAI) than controls (P < 0.001), levels being more elevated amongst patients with diffuse than limited disease (P = 0.01). An abnormally high lipoprotein (a) [Lp(a)] level was found in 9% (2/20) of control subjects, but in 30% (8/26) of SSc patients (P = 0.04) where it clustered with fibrinolytic defects. Altogether, these data suggest that patients with SSc are in a hypercoagulable state characterized by elevated plasma levels of FNG and vWF, by a dual hypofibrinolytic pattern (defective tPA release and elevated PAI), and by increased thrombin generation with enhanced fibrin formation. Higher levels of vWF, DD and PAI in patients with diffuse disease are consistent with more extensive (micro)vascular involvement, although no causal relationship can be inferred. The lack of a parallel increase of TAT with F1 + 2, in the presence of normal levels of antithrombin III (ATIII), indirectly suggests an impairment of the heparan sulphate-ATIII system which would favour thrombin generation. Since thrombin may act as a mitogen for fibroblasts, may upregulate vWF, PAI and endothelin production by endothelial cells, and may promote fibrin deposition on the vessel wall leading to worsening of microvascular occlusions, limitation of thrombin generation, besides fibrinolytic enhancement, could represent a possible coadjuvant interventional strategy.

A dynamic test of lower extremity function following anterior cruciate ligament reconstruction and rehabilitation

It is essential to assess the functional status of patients with surgically reconstructed and rehabilitated anterior cruciate ligaments prior to discharge. This study established a testing paradigm for functional force production and absorption. Data were obtained from 100 healthy subjects for maximal hops, controlled leaps, and hopping and leaping symmetry. Only 10% of symptomatic patients met maximal hopping criteria, while 15% achieved controlled leaping norms. Ninety-five percent of these patients failed to reach both hopping and leaping symmetry norms. Asymptomatic patients were 63% successful in meeting hopping criteria, and 57% were successful in meeting leaping criteria. Hop symmetry and leap symmetry were achieved at rates of 70% and 60%, respectively. The performance of both groups fell significantly below that of normal subjects (p < .05). Data suggest that this protocol does accurately assess functional and dysfunctional knees, and that force absorption may be more critical than force production in the determination of functional capacity.

Sleep electroencephalographic abnormalities in adolescent depressives: effects of scopolamine

In contrast to sleep studies of adult depressives that have consistently demonstrated abnormalities of sleep continuity, slow-wave sleep, and REM sleep, existing studies of depressed children and adolescents have been conflicting. Furthermore, only one study has explored the cholinergic regulation of sleep in early-onset depressives. In the present study, the electroencephalographic sleep of 20 adolescent outpatients with major depressive episodes and 13 normal control adolescents was obtained on two separate 2-night sessions, 1 night incorporating challenge with scopolamine. Depressed adolescents showed increased baseline phasic REM sleep measures, increased arousals, a trend toward reduced slow-wave sleep, and a greater difference in the change of first REM period density on the scopolamine night versus placebo night compared to controls. These findings support the continuity of some sleep abnormalities of depression into adolescence, and suggest that adolescent depression may be associated with alterations of cholinergic neurotransmission in some patients.

Detection, distribution and probable fate of Escherichia coli O157 from asymptomatic cattle on a dairy farm

The use of commercial anti-Escherichia coli O157-labelled magnetic beads was investigated to improve detection of E. coli O157 by immunomagnetic separation (IMS) from a range of environments on a dairy farm. Immunomagnetic separation proved effective for separation of target cells from laboratory mixtures and during stress in sterile and non-sterile pond water. The IMS procedure was possible with a range of samples (water, faeces, slurry, grass and soil). Non-specific binding of non-target bacterial cells proved problematic in a number of sample types. However, indigenous E. coli O157 cells were detected from samples with a high faecal load, and only with use of IMS. Data on the probable survival and spread of the organism around the farm environment are also discussed.

Fosinopril national survey: a post-marketing surveillance study of fosinopril (Staril) in general practice in the UK

This open, non-comparative, PMS study of fosinopril (Staril) involved 12,067 hypertensive patients assessed at baseline and after two and six months of treatment; 10,791 patients provided evaluable data with 5.2 months average treatment totalling 4667 patient-years. Adverse events were reported in 24% of patients, the most common being mild-to-moderate cough (6.05%). Events considered possibly related to fosinopril were reported in 15% of patients, the frequency being lower in younger patients, males and those receiving fosinopril monotherapy. Patient well-being improved during the study. At the end of the study, most patients were taking fosinopril 10 mg once daily. Mean reductions in systolic and diastolic blood pressures were -11.0% and -11.7%, respectively; 71.3% of patients were 'responders'. No important differences were observed between subgroups. This study found fosinopril to be effective, well tolerated in a broad range of hypertensive patients, and with no previously unrecognised adverse events reported.

Anti-cytokeratin 5/6: a positive marker for epithelioid mesothelioma

AIMS

Previous studies using frozen material have suggested that cytokeratin 5 is expressed by pleural mesothelioma but not by adenocarcinoma. In the present study, reactions for cytokeratins 5 and 6 were investigated in 33 pleural mesotheliomas and 27 secondary adenocarcinomas of the pleura using formalin-fixed, paraffin-embedded material and a commercially available antibody (anti-cytokeratin 5/6).

METHODS AND RESULTS

All of the adenocarcinomas originated in the peripheral lung. The epithelioid component of the mesotheliomas gave a strongly positive reaction: the reaction in sarcomatoid or desmoplastic areas was absent or weak. Twenty-two of the adenocarcinomas were negative, in four there was a weak, equivocal reaction, and in one there was patchy positivity.

CONCLUSIONS

We conclude that this antibody is potentially a useful positive marker for the identification of the epithelioid variant of mesothelioma in formalin-fixed and paraffin-embedded material.

Early medical career choices and eventual careers

The revised structure of hospital specialist training being introduced in the United Kingdom means that a doctor wanting a career in a hospital specialty will need to be confident that his or her early career choice, made within 3 years of qualification, is realistic. Using data from a longitudinal study of the 1983 cohort of UK medical graduates, the early career choices made by over 2000 doctors were compared with their employment 11 years after qualification. At year 11 65% of the doctors were working within the first choice they had expressed towards the end of their pre-registration year, and 79% were employed in their year 3 first choice. There was, however, important variation within this general picture: lower predictive value was associated with choices made by women; choices for hospital mainstreams rather than for general practice; and choices that were less than definite. The recent drop in popularity of general practice as a career choice of new graduates in the UK, and the steady increase in the proportion of women graduates, mean that the predictive value of the career choices of recent graduates may prove to be lower than that of the 1983 cohort.

Administration of medicines by emergency nurse practitioners according to protocols in an accident and emergency department

OBJECTIVE

To present the legal and professional issues related to nurse administration of drugs according to protocols, and describe the implementation and initial audit findings of such a scheme.

SETTING

Accident and emergency (A&E) department of a district general hospital.

METHODS

Analysis of legal and professional opinion. Protocols acceptable to the medical, nursing, and pharmacy professions were developed across a wide range of drugs appropriate for administration by accident and emergency nurse practitioners (ENPs). The first six months of the scheme were audited. Audit initially addressed general compliance with protocols and later the specific areas of tetanus immunisation and emergency contraception.

RESULTS

ENPs assessed 2925 patients in six months (10.9% of all new patients); 455 patients (15.5% of the ENP patients) were given drugs according to protocols. There were no breaches of the protocols. Subsequent audit of tetanus immunisation showed 94-100% compliance with protocol standards and 71-100% compliance for emergency contraception.

CONCLUSIONS

There are no legal or professional obstacles to the development of protocols for the administration of drugs to patients by nurses without reference to a doctor, providing the protocols meet all the requirements of the UKCC and have the support of consultant medical staff. Such a system must be subject to regular audit to promote a dynamic approach to protocols and training. The system safely enhanced the quality of care of patients treated by ENPs in A&E.

Efficiency of the polymerase chain reaction amplification of the uid gene for detection of Escherichia coli in contaminated water

Direct detection of Escherichia coli from polluted river water was achieved using polymerase chain reaction (PCR) amplification of the uid gene. Amplification using DNA from environmental samples resulted in non-specific DNA fragments. Specific amplification was achieved through use of the touch-down PCR procedure. Targeting the uidA structural region of the gene gave reproducibly better amplification than targeting the uidR regulatory region. The data demonstrate conditions for optimal specific detection.

Differential response of rapid eye movement sleep to cholinergic blockade by scopolamine in currently depressed, remitted, and normal control subjects

The degree of cholinergic dysregulation of sleep in adult depression was evaluated using scopolamine. On separate sessions, placebo and scopolamine (4.5 micrograms/kg, IM) were administered to 14 patients with unipolar major depression, 16 recovered/remitted patients, and 18 normal controls. Scopolamine increased rapid eye movement (REM) latency (RL), reduced REM activity (RA), REM density (RD), and REM duration, and increased the percentage of stage 4 sleep in all groups. There was a differential effect of scopolamine on RL, RA, and REM duration for the first REM period, and on percentage of stage 4 sleep. Whereas a primary cholinergic hyperactivity could account for the RA and RD responses, the response profile for RL was more compatible with reduced aminergic tone as the proximal cause of the cholinergic hyperactivity. Whether the sleep abnormalities observed in remitted patients reflect an underlying vulnerability for development or recurrence of depression, and/or a scar, remains to be determined.

The Tripler Army Medical Center LEAN Program: a healthy lifestyle model for the treatment of obesity

This paper provides an overview of the Tripler Army Medical Center LEAN Program for the treatment of obesity, hypercholesterolemia, and essential hypertension. The LEAN Program, a multi-disciplinary prevention program, emphasizes healthy Lifestyles, Exercise and Emotions, Attitudes, and Nutrition for active duty service members. The treatment model offers a medically healthy, emotionally safe, and reasonable, low-intensity exercise program to facilitate weight loss. We will discuss the philosophy behind the LEAN Program and the major components. Thereafter, we will briefly discuss the preliminary results.

Preeclampsia, labor duration and mode of delivery

OBJECTIVE

To determine if there is a difference in the length of labor, and method of delivery between preeclamptic and normotensive patients.

METHODS

A retrospective case control study was performed using a perinatal database. Study subjects included nulliparous patients diagnosed with preeclampsia, and were compared with normotensive nulliparous patients.

RESULTS

There were 1454 controls and 727 subjects identified. There was no difference between groups with regard to duration of total labor. There was a statistically but not clinically significant increase in the duration of the second stage in preeclamptics (35 vs. 27 min, P = 0.003). Preeclamptics had a consistently higher risk of cesarean delivery, even when controlled for confounding variables.

CONCLUSION

The clinical belief that preeclamptic patients have more rapid labors is not supported. Preeclamptics do seem to have a higher risk of cesarean delivery.