Internal quality assurance in a clinical virology laboratory. I. Internal quality assessment.

AIMS--In April 1991 an internal quality assessment scheme (IQAS) was introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. The IQAS was established to identify recurring technical and procedural problems, to check the adequacy of current techniques, and to calculate the frequency of errors. METHODS--Between April 1991 and December 1993, 715 anonymous clinical serum samples were submitted to the laboratory to test 3245 individual procedures of diagnostic viral serology. RESULTS--A total of 485 (14.9%) procedural and 61 (1.9%) technical discrepancies were observed, the technical discrepancies mainly being recorded in complement fixation tests. Twenty two (0.7% of total procedures) of the technical discrepancies were diagnostically significant. CONCLUSIONS--Evaluation criteria developed with the introduction of IQAS to viral serology, and technical and procedural discrepancies are assessed. As yet, IQAS has not been introduced to other sections of the diagnostic virology laboratory (virus isolation, electron microscopy, immunofluorescence, and enzyme linked immunosorbent assays for viral and chlamydial antigens).     

Internal quality assurance in a clinical virology laboratory. II. Internal quality control.

AIMS--In April 1991 additional quality control procedures were introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. Internal quality control (IQC) samples were gradually included in the serological assays performed in the laboratory and supplemented kit controls and standard sera. METHODS--From April 1991 to December 1993, 2421 IQC procedures were carried out with reference sera. RESULTS--The IQC samples were evaluated according to the Westgard rules. Violations were recorded in 60 of 1808 (3.3%) controls and were highest in the IQC samples of complement fixation tests (25/312 (8%) of controls submitted for complement fixation tests). CONCLUSIONS--The inclusion of IQC samples in the serological assays performed in the laboratory has highlighted batch to batch variation in commercial assays. The setting of acceptable limits for the IQC samples has increased confidence in the validity of assay results.     

Immunohistochemical demonstration of altered intracellular localization of the c-Myc oncogene product in human colorectal neoplasms

The distribution of the c-myc oncogene product p62 was examined by immunohistochemistry using the monoclonal antibody Mycl-9E10 in a series of 50 colorectal resections for carcinoma. The specimens were specially handled to ensure rapid fixation in formalin, and a significant improvement was shown in the quality and localization of staining compared with routinely handled specimens. Non-neoplastic mucosa showed the presence of nuclear staining of epithelial ceiis in 93 per cent of the samples, whilst all carcinomas showed cytoplasmic staining and infrequent nuclear staining. Adenomas showed an intermediate pattern, with significantly more frequent cytoplasmic distribution than non-neoplastic mucosa, but less than carcinomas. The results show that whilst fixation conditions are important in the immunolocalization of the C-myc protein product, there may be a consistent difference between non-neoplastic mucosa and carcinoma in the manner of association of p62 with the nucleus.     

Intracellular mechanisms governing the acute phase of β-endorphin secretion from the corticotrope in vitro

It is not certain which protein kinase (A, C or both) is involved in the acute phase of β-endorphin (β-EP) release stimulated in the corticotrope by vasopressin (VP) and corticotropin-releasing factor (CRF). We have employed an isolated ovine anterior pituitary cell superfusion system to determine the dynamic effects of forskolin, a protein kinase A (PKA) stimulator, and phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator. Both secretagogues stimulated β-EP release within 5 min and therefore both PKA and PKC are potential mediators of the acute phase of hormonal stimulation of the corticotrope. Pretreatment with PMA specifically desensitized the pituitary cell columns to subsequent PMA exposure while not significantly altering sensitivity to forskolin or 50 mM KCl.     

The hermeneutics of symptoms

Medicine, Health Care and Philosophy - The clinical encounter begins with presentation of an illness experience; but throughout that encounter, something else is constructed from it – a...     

Group B Streptococcus Screening Guidelines in Pregnancy: A Critical Review of Compliance

Maternal and Child Health Journal - Colonization with Group B Streptococcus in pregnancy is a major risk factor for neonatal infection. Universal screening for maternal streptococcal colonization...     

The anatomy of the anterior inferior tibiofibular ligament and its relationship with the Wagstaffe fracture

BackgroundOur aim in this study was to identify the fibular footprint of the Anterior Inferior Tibiofibular Ligament (AITFL) and its relation to Wagstaffe fracture fragment size.MethodsWe examined 25 cadaveric lower limbs which were carefully dissected to identify the lateral ankle ligaments. The AITFL anatomy was compared to 40 Wagstaffe fractures identified from our ankle fracture database.ResultsThe AITFL origin was from the anterior fibular tubercle with an average length of 21.61 mm (95% CI 20.22, 22.99). The average distance of the distal aspect of the AITFL footprint to the distal fibula margin was 11.60 mm (95% CI 10.49, 12.71). In the ankle fractures analyzed, the average length of the Wagstaffe fragment was 17.88 mm (95% CI 16.21, 19.54). The average distance from the distal tip of the fibula to the Wagstaffe fracture fragment was 21.40 mm (95% CI 19.78, 23.01).In total there were 22 syndesmosis injuries. There was no statistical difference in Wagstaffe fragment size between stable and unstable groups.ConclusionThe AITFL fibular origin was both larger and more distal than the Wagstaffe fracture fragments seen in our institution. Therefore, this suggests that a ligamentous failure will also have to occur to result in syndesmotic instability. The size of fracture fragment also did not confer to syndesmotic instability on testing.Level of Evidence - 3     

Soap Gets in Your Eyes

We present a previously unreported series of five cases of acute angle closure glaucoma associated with watching the Australia soap opera "Neighbours". Two cases were bilateral and associated with watching two episodes of "Neighbours" on the same day. The pathogenesis, and possible role of watching soap operas in the causation of primary angle closure glaucoma is discussed.

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Dielectric Analysis of Phosphorylcholine Head Group Mobility in Egg Lecithin Liposomes

Purpose. A knowledge of the interfacial properties of lecithin underpins our understanding of many of the physicochemical characteristics of drug delivery systems such as liposomes and lecithin stabilized microemulsions. In order to further this understanding, a high frequency dielectric study of the interfacial properties of egg lecithin liposomes was undertaken. Methods. The effect of temperature, lecithin concentration and probe sonication on the interfacial dielectric properties of liposomal suspensions was investigated by high frequency dielectric relaxation spectroscopy between 0.2–6 GHz. Results. The frequency dependent permittivity of each suspension exhibited a dielectric dispersion centred around 100 MHz, corresponding to the relaxation of zwitterionic head groups. The activation energy for head group reorientation was estimated as H = 6.3 kJ mol^–1. There was an increase in extent of inter-head group interactions on increasing the liposome volume fraction, whereas the effect of probe sonication showed that: (i) head groups in both the outer and inner lamellae contribute to the dielectric response; (ii) the head groups may be less restricted in liposomes of high surface curvature with few lamellae; (iii) the high frequency permittivity of the suspension increased on sonication, as a result of a reduction in the amount of (depolarized) interlamellar water following a reduction in the number of lamellae per liposome. Conclusions. Dielectric analysis of the zwitterionic head groups of lecithin therefore provides a means for investigating the surface of lecithin liposomes, and may be used to investigate the effect of drugs and other solutes on membranes.     

Herbal supplements for renal patients: what do we know?

The use of complementary and adjunctive therapy has been steadily increasing in the U.S. since the 1960s. This can be attributed to several factors, particularly because over 80 million "baby boomers" are embracing alternative medicine as a way to enhance their medical care. The perceived coldness and remoteness of conventional medicine; the entanglement of managed care in red tape; continued emphasis on "natural" which supposedly connotes "better," as well as the popularity of vegetarian practices have also contributed to the general population's increasing involvement in alternative medicine. In 1999, 40% of all Americans sought alternative medical treatment, outpacing visits to conventional primary care physicians.